Document:

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                                                                    Exhibit 10.6

                                    LEASE OF

                               125 HARTWELL AVENUE
                            LEXINGTON, MASSACHUSETTS

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<Caption>
Section
Number                                          Caption                                 Page
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<S>          <C>                                                                           <C>
             EXHIBIT 1
1.           REFERENCE DATA...............................................................
2.           LEASE OF PREMISES............................................................
3.           BASIC RENT...................................................................
4.           COVENANT BY LANDLORD OF TENANT'S QUIET ENJOYMENT.............................
5.           RENT COMMENCEMENT DATE.......................................................
6.           PREPARATION OF THE PREMISES..................................................
7.           USE..........................................................................
8.           IMPROVEMENTS AND ALTERATIONS.................................................
9.           ASSIGNMENT AND SUBLETTING....................................................
10.          REPAIRS AND MAINTENANCE BY LANDLORD..........................................
11.          REPAIRS AND MAINTENANCE BY TENANT............................................
12.          SERVICES, UTILITIES, SUPPLIES AND FACILITIES.................................
13.          INTERRUPTION OR CURTAILMENT OF BUILDING SERVICES.............................
14.          BUILDING EXPENSE.............................................................
15.          INSURANCE....................................................................
16.          INDEMNITIES OF TENANT AND LANDLORD...........................................
17.          TENANT'S RISK................................................................
18.          LANDLORD'S ACCESS RIGHTS.....................................................
19.          CONDEMNATION.................................................................
20.          CASUALTY.....................................................................
21.          TENANT'S DEFAULT.............................................................
22.          LANDLORD'S DEFAULT...........................................................
23.          LIMITATIONS ON LIABILITY.....................................................
24.          RULES AND REGULATIONS........................................................
25.          NOTICE.......................................................................
26.          LANDLORD'S TITLE AND CONFORMITY WITH LEGAL
             REQUIREMENTS.................................................................
27           SUBORDINATION AND NON-DISTURBANCE............................................
28.          ESTOPPEL CERTIFICATE.........................................................
29.          REMEDYING TENANT DEFAULTS....................................................
30.          REASONABLE CONSENT...........................................................
31.          HOLDING OVER.................................................................
32.          SURRENDER OF PREMISES........................................................
33.          ARBITRATION..................................................................
34.          BROKERAGE....................................................................
35.          GOVERNING LAW................................................................
36.          TENANT'S OPTION TO EXTEND THE TERM OF LEASE..................................
</Table>

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<Table>
<S>          <C>                                                                           <C>
37.          DEFINITION OF FAIR MARKET RENTAL VALUE.......................................
38.          TENANT'S RIGHT OF FIRST OFFER................................................
39.          FORCE MAJEURE................................................................
40.          ENVIRONMENTAL CONCERNS.......................................................
41.          SIGNS........................................................................
42.          NOTICE OF LEASE..............................................................
43.          CHANGE OF NAME...............................................................
44.          MISCELLANEOUS PROVISIONS.....................................................
45.          BINDING AGREEMENT............................................................
46.          ENTIRE AGREEMENT.............................................................

EXHIBIT 1       Lease Reference Data
EXHIBIT 2       Building Expense Base
EXHIBIT 3       Plans showing the Premises, the parking area, the so-called RFO Premises,
                and Tenant's Approved Floor Plan
EXHIBIT 4       Items of Tenant's Work to be paid from the Proceeds of Landlord's
                Contribution
EXHIBIT 5       125 Hartwell Avenue Fact Sheet
EXHIBIT 6       Rules and Regulations
EXHIBIT 7       Cleaning Specifications
EXHIBIT S       Certificate of Landlord's Insurance
EXHIBIT 9       Notice of Lease
EXHIBIT 10      Plans for Additional Bathrooms
</Table>

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                                      LEASE

       THIS INSTRUMENT IS A LEASE, dated as of the Execution Date stated in
Exhibit 1, in which Landlord and Tenant are the parties named in said Exhibit,
and which relates to space in the Building. The parties to this instrument
hereby agree with each other as follows:

       1.     REFERENCE DATA. All Exhibits attached to this Lease are hereby
incorporated herein and made a part hereof.

       2.     LEASE OF PREMISES. Landlord hereby demises and leases to Tenant
for the Term of the Lease and upon the terms and conditions hereinafter set
forth, and Tenant hereby accepts from Landlord, the Premises described in
Exhibit 1 and shown on Exhibit 3 (Exhibit 3 hereto shall show the Premises, the
parking area and the so-called RFO Premises, and shall include the Tenant's
Approved Floor Plan described in Section 6(b) below). Excepted and excluded from
the Premises are the ceiling, floor, perimeter walls and exterior windows,
except the inner surfaces of each thereof, but the entry doors (and related
glass and finish work) to the Premises are a part thereof; and Tenant agrees
that Landlord shall have the right to place in the premises (but in such manner
so as not to unreasonably interfere with Tenant's use of the Premises) utility
lines, pipes, equipment and the like, in, over, upon and through the Premises
provided that such items are located in the central core of the Building, above
ceiling surfaces, below floor surfaces and within perimeter walls, no material
reduction in square footage of the Premises shall result, and Landlord shall
provide Tenant with reasonable advance written notice of the foregoing. Tenant
shall have as appurtenant to the Premises the right, in common with others
entitled thereto, to use the first floor loading dock at the rear of the
Building, the elevator located at the rear of the Building, the common hallway
dividing the second floor of the Building, common walks leading to and from the
Building, parking at the parking lots serving the Building, and all other
appurtenant rights or easements available to the Property. Tenant shall also
have as appurtenant to the Premises the exclusive right to use the bathrooms and
showers located in the center of the second floor of the Building. The Landlord,
at no additional charge to Tenant, shall provide and maintain, for the use of
the Tenant's employees and invitees, a total of forty-one (41) parking spaces
(allocated at the ratio of 3.8 spaces per 1,000 square feet of leased Premises)
in a paved parking area located adjacent to the Building as shown on Exhibit 3;
provided that in the event Tenant exercises any rights arising under Section 38
hereof relating to so-called "RFO Premises" or otherwise leases additional space
within the Building, then the Tenant shall thereupon become entitled to the use
of additional parking spaces at the ratio of 3.8 spaces per 1,000 square feet of
so-called RFO Premises or other additional leased space. In the event that other
tenants in the Building or other persons utilize the parking spaces of the
Property, in a general way, which prevents Tenant from generally using the
above-referenced 41 parking spaces (as they may be increased from time to time)
allocable to Tenant, then Tenant shall have the right to require Landlord to
specifically designate that appropriate number of parking spaces allocable to
Tenant for the sole and exclusive use of Tenant.

       3.     BASIC RENT. Tenant agrees to pay to Landlord, commencing on the
Rent Commencement Date, the Basic Rent (sometimes hereinafter "rent") set forth
in Exhibit 1. Tenant's obligation to pay all charges for utilities and other
items specified in Section 12 shall commence to accrue as of the Execution Date.
Such Basic Rent shall be payable in equal monthly installments, in advance, on
the first day of each calendar month during the Term of this

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Lease, at such address as Landlord shall from time to time designate by notice.
Basic Rent for any period of less than one month shall be apportioned based on
the number of days in that month. In the event that any installment of Basic
Rent is not paid within ten (10) days after the same shall have become due,
Tenant shall pay, at Landlord's request, an administrative fee equal to 1% of
the overdue payment.

       4.     COVENANT BY LANDLORD OF TENANT'S QUIET ENJOYMENT. In consideration
for payment by the Tenant of the Basic Rent so long as the Tenant pays the Basic
Rent reserved under this Lease and fulfills its obligations hereunder, the
Tenant shall peaceably hold and quietly enjoy the leased Premises without
interruption by reason of claims asserted by the Landlord or any other person,
firm, corporation or other entity claiming under Landlord, subject always to the
terms and conditions of this Lease.

       5.     RENT COMMENCEMENT DATE. The Rent Commencement Date shall be the
earlier of (i) February 1, 1993 or (ii) the day on which Tenant shall occupy all
or any part of the Premises for the conduct of business.

       6.     PREPARATION OF THE PREMISES.

              (a)    BY TENANT. Tenant shall, at Tenant's sole cost and expense,
subject to the provisions of paragraph (e) of this Section 6, prepare the
Premises for Tenant's occupancy (except as described in Section 6(f)). Landlord
shall have no obligation to perform any construction work to prepare the
Premises for Tenant's occupancy. As of the date hereof, Landlord hereby delivers
to Tenant and Tenant hereby accepts from Landlord the Premises in the condition
in which they are in, "as is," as of the date hereof. Tenant shall have access
to the Premises from and after the date hereof in order to perform its work
("Tenant's Work") in the Premises, subject to the other terms and conditions of
this Lease, including, without limitation, Sections 15, 16 and 17. Tenant shall
use all reasonable diligence to perform Tenant's Work in a timely manner.

              (b)    PLANS. Tenant shall prepare all necessary plans and working
drawings ("Tenant's Plans") reflecting all of Tenant's Work. The cost to prepare
and revise Tenant's Plans as necessary shall be borne solely by Tenant. Tenant's
Plans shall be subject to review and approval by Landlord, which shall not be
unreasonably withheld or delayed. Tenant shall use all reasonable diligence to
prepare Tenant's Plans in a timely manner for Landlord's review. If Landlord
shall disapprove such Tenant's Plans, it shall state in reasonable detail the
grounds for its disapproval, and Tenant shall revise its Plans and resubmit same
for Landlord's review. Tenant shall make no material changes to Tenant's Plans
except upon prior written notice to Landlord setting forth such changes.
Landlord shall respond to Tenant's submission of its Plans within five (5)
business days of receiving Tenant's Plans. Landlord shall respond to any
resubmission of Tenant's Plans with revisions in response to Landlord's
disapproval of Tenant's Plans within two (2) business days of receiving Tenant's
resubmission of Plans. Landlord shall respond to any other revisions of Tenant's
Plans within three (3) business days of receiving them from Tenant. Landlord
hereby approves the floor plan of the Premises ("Tenant's Approved Floor Plan")
attached hereto as part of Exhibit 3; Tenant's Approved Floor Plan shall
constitute a part of Tenant's Plans.

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              (c)    TERMINATION. If Landlord shall fail to respond to the
submission of Tenant's Plans (or changes thereto) within the applicable time
periods specified above, then Tenant, upon a written notice of one (l) business
day to Landlord, shall have the option to proceed with the changes as if
Landlord had agreed thereto, or to terminate the Lease, provided that if
Landlord shall respond to the submission in respect of Tenant's Plans in
question by the end of such business day then Tenant's notice shall be of no
force or effect.

              (d)    CONSTRUCTION. Tenant shall diligently proceed with
construction of the Premises substantially in accordance with Tenant's Plans
(and any amendments thereto approved or deemed approved by Landlord as
hereinabove provided), utilizing Tenant's Contractor named in Exhibit 1, who has
been approved by Landlord, or such other contractors as Tenant may engage with
Landlord's prior consent, which consent shall not be unreasonably withheld or
delayed. All work shall be of a good and workmanlike quality, utilizing
materials at least equal to the materials specified in Part C of Exhibit 5 of
the Lease. Tenant shall, at its own cost and expense, obtain all permits needed
to construct the Premises for its occupancy and to occupy the Premises for the
uses specified in Exhibit 1. Prior to the commencement of Tenant's Work, all
contractors shall provide Landlord and Tenant with reasonable evidence of
insurance coverage, including policies of comprehensive general liability
insurance in a combined single limit of not less than $2,000,000.00, workers'
compensation coverage in the statutory amounts, and automobile liability
insurance. Tenant shall pay for all labor and materials supplied to it promptly
and shall permit no contractor's or material supplier's lien to be filed against
the Premises, the Building or the Property. If any such lien shall be filed,
Tenant shall promptly cause such lien to be discharged, by paying such claimed
amounts or by bonding over the lien in a manner satisfactory to Landlord. If
Tenant shall fail to discharge any such lien within ten (10) days of filing,
Landlord may, but shall not be obligated to, pay the amount of such claim and
thereby discharge the lien. Tenant shall promptly reimburse Landlord therefor
upon demand and Landlord shall have the same right to enforce collection of such
reimbursement (together with interest thereon at the rate provided for in
Section 29 below) as to enforce collection of unpaid amounts of Basic Rent,
escalations or other charges due under the Lease.

              (e)    LANDLORD'S CONTRIBUTION. Notwithstanding anything to the
contrary the foregoing contained, Landlord shall contribute an amount up to
$54,900 ("Landlord's Contribution") expressly for the purchase and installation
of the items of work set forth in Exhibit 4 of this Lease, which Tenant shall
purchase and install as part of Tenant's Work. All such items set forth in
Exhibit 4 shall be at least equal to the quality of items set forth in Part C of
Exhibit 5. Landlord's Contribution shall be used for no purpose other than for
the purchase and installation of the items listed in Exhibit 4. Landlord shall
pay amounts on account of Landlord's Contribution directly to contractors or
suppliers upon receiving from Tenant actual vendor invoices for labor and/or
materials billed to Tenant. There shall be no credit due Tenant for any unused
portion of Landlord's Contribution.

              (f)    LANDLORD'S SPRINKLER WORK. Notwithstanding the foregoing,
Landlord shall, at its own cost and expense, install the sprinkler system as
described in Exhibit 5 for the Premises and a fire protection system as required
by all applicable federal, state or local requirements for the Premises, to the
extent applicable to general office space. With respect to additional
sprinkler/fire protection requirements, if any, necessitated by Tenant's
particular use of the Premises, at Tenant's election, either (i) Tenant shall
make such installations as are

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necessary to conform to such additional requirements at Tenant's expense, or
(ii) Landlord shall make such additional installations, and Tenant shall
reimburse Landlord (as additional rent hereunder) for the costs and expenses
incurred by Landlord in performing such additional work, upon receiving from
Landlord copies of actual invoices from Landlord's contractor(s) or other
evidence of the cost thereof reasonably satisfactory to Tenant. Landlord's
sprinkler installation shall be commenced by Landlord promptly after approval of
Tenant's Plans, and shall be coordinated with Tenant's work so as not to
unreasonably interfere with or delay the completion of Tenant's Work.

              (g)    ADDITIONAL CONSTRUCTION. Notwithstanding anything to the
contrary in the Lease contained, if after the date of this Lease, Landlord shall
enter into one or more leases or occupancy agreements with third parties
demising all or part of the balance of the second (2nd) floor of the Building
(this Lease being the only lease of second floor space as of the date hereof),
then Landlord shall, at Tenant's cost and expense, construct on the second (2nd)
floor separate men's and women's bathrooms (in finishes equal to those in the
existing bathrooms) and one or more corridors as necessary for access to such
premises and to such bathrooms from such premises for the exclusive use of
Landlord and such third parties. All such work shall be performed substantially
in accordance with Exhibit 10. Such additional construction work shall be
performed by Landlord as and when required so that the same shall be completed
in conjunction with the completion of any work required to prepare such leased
premises by Landlord for occupancy by such other tenants or occupants. Tenant
shall reimburse Landlord (as additional rent hereunder) for all costs and
expenses incurred by Landlord in performing such work, upon receiving from
Landlord copies of actual invoices from contractors, suppliers and/or vendors
for labor and/or materials furnished with respect to such work or other evidence
of the cost thereof reasonably satisfactory to Tenant; provided, however, that
in no event shall Tenant's costs and expenses under this Section 6(g) exceed the
amount of $17,500.00.

              (h)    INSPECTION BY LANDLORD. Upon substantial completion of
Tenant's Work, Tenant shall give notice thereof to Landlord, and shall afford
Landlord the opportunity to participate with Tenant in the preparation of a
punchlist for Tenant's Contractor. Upon completion of such punchlist items,
Tenant shall give Landlord notice thereof and an opportunity to inspect Tenant's
Work; and thereafter, (except for latent defects) Landlord shall be deemed to
have accepted Tenant's Work as having been performed in accordance with the
requirements of this Lease applicable thereto, unless and except to the extent
that Landlord notifies Tenant of defects therein or other items requiring
correction within ten (10) days after Tenant notifies Landlord of the final
completion of Tenant's work.

       7.     USE. Tenant agrees that it shall use and occupy the Premises
during the Term only for the Permitted Uses described in Exhibit 1. Tenant
shall, in its use of the Premises, comply with the requirements of all
applicable governmental laws, rules and regulations, and shall obtain (and keep
in full force and effect) all required licenses and permits therefor. Tenant
shall not permit any use of the Premises which will make voidable any insurance
on the Property, or on the contents of the Property, or which shall be contrary
to any law or regulation from time to time established by the New England Fire
Insurance Rating Association, or any similar body succeeding to its powers.
Tenant shall within 10 days after demand reimburse Landlord for all extra
insurance premiums caused by Tenant's use of the Premises other than for
Permitted Uses. If any governmental license or permit, including, without
limitation, a certificate

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of occupancy shall be required for the proper and lawful conduct of Tenant's
business, Tenant, at its expense, shall duly procure and thereafter maintain and
comply with such license or permit and submit the same to inspection by
Landlord. To the extent reasonably necessary or expedient to obtain such license
or permit, Landlord agrees to cooperate with Tenant in procuring such license or
permit.

       8.     IMPROVEMENTS AND ALTERATIONS. Subject to the further provisions of
this Section 8, Tenant shall make no additional (i.e., in addition to the items
shown on Tenant's Plans in respect of the initial preparation of the Premises)
alterations or improvements to the Premises except in each case, (i) at Tenant's
sole cost and expense, (ii) with the prior written consent of Landlord, (iii) in
accordance with complete plans and specifications, presented to Landlord for
Landlord's prior approval, and (iv) performed by contractors approved by
Landlord and in accordance with all applicable laws, rules and ordinances and
otherwise in accordance with the other terms, provisions and conditions of the
Lease. All approvals required to be obtained from Landlord pursuant to the
foregoing by Tenant shall not be unreasonably withheld or delayed. Without
limiting Landlord's right of review, Landlord may disapprove any proposed
alteration or improvement which, in Landlord's reasonable opinion, may adversely
affect any of the Building's exterior, common areas, structure or systems.
Notwithstanding the foregoing for any alteration or improvement which Tenant may
propose and which shall not, in Landlord's reasonable opinion, affect the
Building's exterior, common areas, structure or systems, and which shall not
exceed an aggregate "completed-job" cost of $5,000.00 per alteration, Tenant
shall not be required to obtain Landlord's prior written consent, provided
Tenant shall first notify Landlord of the proposed alteration or improvement and
present complete plans and specifications therefor. All alterations or
improvements shall be performed by Tenant in accordance with the applicable
provisions of Section 6(d) of this Lease. If any alteration or improvement which
Tenant shall make shall result in any increase in the real estate taxes upon the
Property, then Tenant shall pay the entire increase in such taxes attributed to
such alteration or improvement. All fixtures (whether or not attached) and
equipment installed by or at the expense of Tenant (including, without
limitation, fixtures and equipment installed by Tenant at its expense as part of
Tenant's Work) shall remain the property of the Tenant and in case of damage or
destruction thereto by fire or other causes, the Tenant shall have the right to
recover the value thereof as its own loss from any insurance company with which
it has insured the same, or to claim an award in the event of condemnation,
notwithstanding that any of such things might be considered a part of the
Premises, subject to the provisions of Section 19. Tenant may remove all or any
of such fixtures and equipment at any time during the term, provided Tenant
repairs any damage to the Premises caused by the installation, presence or
removal thereof, or, at its option, Tenant may abandon the same, in whole or in
part, to Landlord. Tenant shall not be required to remove pipes, wires and the
like from the walls, ceilings or floors, provided the Tenant properly cuts,
disconnects and caps such pipes and wires and seals them off, if necessary, in a
safe and lawful manner.

       9.     ASSIGNMENT AND SUBLETTING.

              (a).   Upon prior written notice to Landlord, Tenant may assign
this Lease or sublet all or any part of the Premises at any time during the term
hereof (or any extension thereof) without the consent of the Landlord to a
division, department, subsidiary or corporation a majority of the stock of which
is controlled by Tenant, provided such entity remains in the

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same relationship with Tenant after such transfer, or to an entity created by
merger, split-off, reorganization or by governmental action relating to Tenant
or in the event of the acquisition of Tenant or of substantially all of its
assets by another party. (Any entity referred to in this paragraph (a) is
sometimes hereinafter called a "Fuji Successor.")

              (b)    In all other cases not involving entities described in
paragraph (a) of this Section 9, the prior written consent of Landlord shall be
required prior to any assignment of this Lease or sublease by Tenant of all or
any portion of the Premises, or other transfer of Tenant's leasehold interest.
Such consent by Landlord shall not be unreasonably withheld or delayed;
provided, however, Landlord shall not be deemed to be unreasonable in
withholding its consent to a proposed assignment, subletting or other transfer
if (i) the proposed assignee or subtenant (or a related or controlled entity) is
then a tenant in the Building, unless such proposed assignee or subtenant
requires expansion premises in addition to, rather than in substitution for, the
other premises in the Building then occupied by such proposed assignee or
subtenant (or a related or controlled entity), and/or (ii) Tenant is then in
default of its obligations under this Lease.

              (c)    Landlord agrees that if Tenant assigns or transfers this
Lease to anyone other than a Fuji Successor, Tenant shall be given a copy of any
notice of default given by Landlord to any assignee or transferee, and Tenant
shall have the right to avoid termination of this Lease by curing such default
within the applicable notice and grace periods provided under Section 21 below,
and in such event Tenant shall have the right to recover possession of the
Premises, provided that it cures such defaults within the applicable notice and
grace periods as aforesaid.

              (d)    No subletting or assignment shall relieve Tenant of its
primary obligation as party-Tenant hereunder. No subletting or assignment
pursuant to this Section 9 shall affect or vary the Permitted Uses. No consent,
once given by Landlord, shall negate the obligation to obtain Landlord's
consent, when required, to any subsequent assignment or subletting whatsoever.

              (e)    Landlord may, whether or not Landlord's Consent is
required, require such assignee, sublessee or transferee to expressly assume the
covenants, terms and conditions of the Lease.

              (f)    Tenant hereby agrees to reimburse Landlord for the
reasonable amount of any legal and other out-of-pocket expenses incurred by
Landlord in connection with any request by Tenant for Landlord's consent
required under this Section 9 or in connection with any transfer or assignment
permitted hereunder.

              (g)    In the event that Tenant assigns or transfers this Lease or
subleases all or any part of the Premises, Tenant shall pay to Landlord (as
additional rent) twenty-five percent (25%) of the Profits (as hereinafter
defined), if any, earned by Tenant in connection with such assignment or
sublease, as and when received by Tenant. "Profits" shall mean, the excess, if
any, of (a) the rent and additional rent (including, without limitation,
payments on account of escalation) and any other consideration received by
Tenant on account of or in connection with the assignment, transfer or
subletting in question over (b) the rent and additional rent (including, without
limitation, payments on account of escalation) payable by Tenant under this
Lease in

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respect of the Premises or portion thereof in question (calculated on a per
square foot basis in the case of a subletting of less than all of the Premises).
Profits shall be calculated on a gross basis as aforesaid, without regard to the
costs and expenses incurred by Tenant in connection with the assignment,
transfer or subletting in question or in connection with entering into this
Lease or preparing the Premises for occupancy by Tenant or by any assignee or
sublessee.

       10.    REPAIRS AND MAINTENANCE BY LANDLORD. Landlord represents that as
of the date hereof, the parking facility and all Building and Property service
systems (including, without limitation, plumbing and electrical lines and
equipment, heating, ventilating and air conditioning systems, boilers and
elevators) are in good repair and condition. Notwithstanding anything to the
contrary contained herein, Tenant shall pay all costs associated with the
maintenance or repair of, or any changes to, any of the foregoing, the need for
which arises from Tenant's construction to prepare the Premises for its
occupancy or subsequent alteration or improvement for Tenant's use and benefit.

              During the term of this Lease, Landlord shall maintain, repair and
replace, as necessary, and keep in good order, safe and clean condition: (1) the
plumbing, sprinkler, HVAC, electric and mechanical lines and equipment
associated therewith, and elevators and boilers, all of which are located in or
serve the Premises, common areas of the building and the parking facility;
broken glass; (2) underground utility lines and transformers and interior and
exterior structure of the Building, including the roof, exterior doors and
windows and lateral support to the Building and parking facility; (3) the
interior walls, ceilings and floors of the common areas of the Building, and
floor coverings (including carpets and tiles) of the common areas of the
Building; (4) repair and replacement of the interior walls, ceilings and floors
of the Premises due to latent defects and any negligent act or omission of
Landlord, its agents, contractors, employees and invitees; (5) the exterior
improvements to the land, including ditches, shrubbery, landscaping and fencing;
(6) the common areas located within or outside the Building, including the
common entrances, corridors, doors and windows, loading dock, stairways and
lavatory facilities and the parking facility and access ways therefor; and (7)
all lawns and landscaped areas of the Property, which shall be watered,
fertilized and trimmed. Landlord shall provide for removal of snow and ice from,
and sanding of, the sidewalks, parking lots, access driveways and walkways as
necessitated by weather conditions and shall provide for parking lot lighting
and shall repair and maintain the parking lot and the lighting serving the same
as reasonably necessary. The Landlord shall perform all repairs and restoration
required arising from the provisions of section 19, "Casualty," and Section 20,
"Condemnation," subject to the limitations set forth therein.

              Notwithstanding anything to the contrary in the foregoing
contained, Landlord shall have no obligation to repair, maintain or replace (a)
any equipment or systems installed by or at the expense of Tenant, or (b) any
damage to the Premises, the Building or the Property caused by Tenant, its
agents or employees.

              The Landlord shall comply with all rules, regulations, orders,
laws, ordinances and legal requirements and standards issued thereunder, all
insofar as any of the sane shall relate to the use of the Building for general
office purposes.

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              Landlord shall be responsible for providing those specific
cleaning, janitorial and trash removal services for the Premises as described on
Exhibit 7 hereto. If Landlord shall have failed to make or proceed with due
diligence to make any necessary or appropriate repairs or fulfill any
maintenance responsibilities set forth in this Lease within two (2) business
days after notice thereof from Tenant, Tenant shall have the right, upon a
subsequent written notice of not less than two (2) business days to Landlord, to
undertake and perform such repair(s), provided, however, that if Landlord shall
commence such repair(s) during such second two (2) business day period and
thereafter diligently pursue same to completion, Tenant shall not have the right
to continue to undertake such repair(s). Landlord shall pay all costs of such
repairs required of Landlord under this Section 10 and which may be made by
Tenant as permitted hereby upon the presentation of bona fide contractor
invoices therefor. Landlord shall have no liability to Tenant for any loss or
damage to Tenant or its property resulting from Tenant's performance of any
repair or maintenance on behalf of Landlord pursuant to its rights hereunder.

              All costs and expenses incurred by the Landlord under this
Section 10 which are incurred in, furtherance of the Landlord's repair and
maintenance responsibilities hereunder and are defined as Operating Costs
hereunder shall be included in Operating Costs under Section 14 below, subject
to the specific limitations and exclusions set forth in Section 14.

       11.    REPAIRS AND MAINTENANCE BY TENANT. Subject to the provisions
herein, Tenant shall keep and maintain all portions of the Premises, including,
without limitation, all equipment and systems installed by or at the expense of
Tenant, in good order and repair, in a clean and orderly condition, free of
accumulation of dirt, rubbish and other debris. Tenant shall be responsible (up
to the amount of Landlord's deductible in the case of an insured loss) for the
cost of repairs which may be made necessary by reason of damage to the Building
or the Property caused by any act or neglect of Tenant or its agents, employees,
contractors or invitees (including any damage by fire or any other casualty
arising therefrom). Tenant shall not be liable for such insured costs above such
deductible. Tenant shall comply with all applicable rules, regulations, orders,
laws, ordinances and legal requirements (including, without limitation, the
Occupational Safety and Health Act, as amended) and standards issued thereunder,
all insofar as any of the same shall relate to Tenant's use of the Premises
and/or the conduct of its business therein.

       12.    SERVICE, UTILITIES, SUPPLIES AND FACILITIES.

              (a)    In addition to the repair and maintenance by Landlord as
stated in Section 10 hereof, Landlord shall furnish to the Tenant the following
services, utilities, supplies and facilities:

                     (1)    Access to the Premises twenty-four (24) hours a day,
       seven (7) days a week. Access to the Premises shall be subject to a
       reasonable security system installed by Tenant as part of Tenant's
       construction o the Premises. Landlord shall, at Landlord's cost and
       expense in addition to the amount of Landlord's Contribution, purchase
       and install one (1) card key access device at the rear entrance to the
       Building for use by Tenant and all other tenants occupying space in the
       Building. Such device shall be consistent with like systems generally in
       use in similar buildings in the greater Boston area. Landlord agrees to
       hire Tenant's security contractor to install such system (at a cost

                                        8
<Page>

       to Landlord not to exceed commercially competitive rates) so as to
       reasonably coordinate the operation of such Building access system with
       Tenant's security system to be installed in the Premises by Tenant.
       Landlord acknowledges the particular security needs of Tenant and shall
       make reasonable efforts to accommodate such needs in Landlord's
       compliance with the provisions of this Lease and their application to
       Tenant.

                     (2)    Freight and passenger elevator service for the use
       of the Tenant, in common with others entitled thereto.

                     (3)    Heat in accordance with seasonal requirements on
       Mondays through Saturdays (except legal holidays) from 8:00 a.m. to 9:00
       p.m. and at such additional times as may be requested by Tenant from time
       to time upon reasonable advance notice to Landlord. Landlord's cost of
       supplying such additional service shall be paid by the Tenant or
       alternatively shall be shared proportionately between the Tenant and
       other tenants, if any, who request such service. Any such costs for
       additional heating services whether requested by Tenant or other tenants
       in the Building shall not be included in Operating costs but calculated
       as a separate charge to Tenant, and/or other tenants, by Landlord.

                     (4)    Cleaning and janitor services including removal of
       refuse and rubbish and furnishing washroom supplies, as set forth in
       Exhibit 7.

                     (5)    Hot and cold running water as supplied by the city
       or town or other supplier. If Tenant uses water for anything other than
       ordinary lavatory and drinking purposes, Landlord may assess a reasonable
       charge for the additional water so used, or install a water meter and
       thereby measure Tenant's water consumption for an purposes. In the latter
       event, Tenant shall pay the cost of the meter and the cost of the
       installation thereof and shall keep such meter and installation equipment
       in good working order and repair. Tenant agrees to pay for water
       consumed, as shown on said meter, together with the sewer charges based
       on such meter charges, as and when bills are rendered, and in default of
       making such payment, Landlord may pay such charges and collect the same
       from Tenant as an additional charge.

                     (6)    Electricity for all common areas in the Building and
       parking area lighting.

                     (7)    Provision, installation, and replacement of all
       necessary light bulbs, tubes, lighting fixtures, and ballasts.

                     (8)    Vermin extermination.

                     (9)    The existing facilities for the Tenant's loading,
       unloading, delivery and pick-up activity including access thereto in
       common with others entitled thereto. The Tenant may use such facilities
       without providing the Landlord with notice on business days (i.e.,
       Mondays through Fridays, except legal holidays) from 8:00 a.m. to 6:00
       p.m. At all other times the Tenant shall give the Landlord reasonable
       advance notice.

                                        9
<Page>

Except for items to be charged directly to Tenant as expressly provided above,
all costs and expenses incurred by the Landlord under this paragraph (a) shall
be included in Operating Costs under Section 14 below, subject to the specific
limitations and exclusions set forth in Section 14.

              (b)    Tenant shall contract directly with the electric utility
supplier to furnish electric current to the Premises through the existing
utility facilities serving the Building for lighting, outlets and the operation
of the air conditioning system serving the Premises. The consumption of such
electricity shall be measured by a separate Premises electric meter which Tenant
shall install. Tenant shall pay all charges as reflected on such meter directly
to the utility supplier. Tenant shall maintain and keep such meter in good order
and repair throughout the term.

              (c)    The parties agree and acknowledge that the air conditioning
system which serves the Premises serves the entire second floor of the Building.
Until such time as another tenant(s) occupies all or any portion of the
remainder of the second floor, Tenant shall pay for the entire cost of operating
such air conditioning system, as provided in paragraph (b) above. From and after
the date on which another tenant(s) occupy(ies) all or part of the balance of
the second floor, Landlord shall reimburse Tenant on a monthly basis for the pro
rata portion of the cost of electricity to operate such air conditioning system
fairly allocable to such other tenant(s).

       13.    INTERRUPTION OR CURTAILMENT OF BUILDING SERVICES.

              (a)    Landlord shall have the right to interrupt, curtail, stop
or suspend the operation of the Building's plumbing and electrical systems and
any other Building services or utilities in the case of emergency or accident,
or for the purpose of making any repairs, alteration, or improvement to the
Building or Premises, or in the case of Force Majeure or other event beyond
Landlord's reasonable control; provided however, that in any such case where it
is possible, Landlord shall provide to Tenant reasonable prior written notice
thereof and Tenant shall have the option to consult and meet with and accompany
Landlord and/or any of his agents or contractors during such period(s).

              (b)    Notwithstanding anything to the contrary in this Lease
contained, if the Premises shall lack any service which Landlord is required to
provide hereunder or if Tenant's use and occupancy of the Premises be adversely
affected by any of the Landlord's actions or inactions arising in connection
with the situations described in paragraph (a) above, (in either case) rendering
the Premises or a portion thereof untenantable for a period of five (5)
consecutive business days, then, provided that such condition or Landlord's
inability to cure such condition is not caused by the fault or neglect of Tenant
or Tenant's agents, employees, contractors, or invitees, nor by events arising
from Force Majeure, as defined in section 39, Basic Rent shall thereafter be
abated in proportion to such untenantability until the day such condition is
completely corrected. In the case where the cause of such interruption arises
from an event of Force Majeure (i.e., but not due to the fault or neglect of
Tenant, its agents, contractors, employees or invitees), Tenant's right to such
abatement shall commence from and after the twenty-first (21st) consecutive day
of such interruption. If such interruption continuer for thirty (30) consecutive
days (forty-five (45) consecutive days in the case of an interruption caused by
Force Majeure), for any reason other than the fault or neglect of Tenant, its
agents, contractor, employees or invitees, then Tenant shall have the right and
option, in addition to the right to

                                       10
<Page>

continue abatement of rent, from and after such date, to terminate this Lease by
giving Landlord a written thirty (30) day termination notice, and in such event,
the Lease shall terminate on the thirtieth (30th) day after the giving of the
notice without further obligation or liability on the part of either party,
provided however that if Landlord shall have corrected the condition previously
rendering the Premises or a portion thereof untenantable by such thirtieth
(30th) day, this Lease shall not terminate and Tenant's notice of such
termination shall be of no further force or effect.

       14.    BUILDING EXPENSES.

              (a)    DEFINITIONS. For the purposes of this Section 14, the
following terms shall have the following respective meanings:

                     (i)    YEAR: Each calendar year in which any part of the
       Term of this Lease shall fall.

                     (ii)   OPERATING COSTS: "Operating Costs" are defined as
       those costs and expenses incurred by Landlord to operate, repair and
       maintain the Building and the Property as required by this Lease, and in
       the manner in which similar properties in the area in which the Property
       is located are operated, and shall include the following:

                            (a)    Costs and expenses directly related to the
              Building for repairing, maintaining, operating and cleaning the
              tenant and common areas, and for removing snow, ice and debris,
              costs of property, liability and business interruption insurance,
              and associated equipment, tools and supplies.

                            (b)    Costs and expenses of repairing paving,
              curbs, walkways, landscaping (including replanting and replacing
              flowers and other plantings), common and public lighting
              facilities in the Building and the Property.

                            (c)    Electricity for lighting the common and
              public areas, and fuel used in heating, ventilating and
              air-conditioning the Building (exclusive of electricity for air
              conditioning furnished to the Premises and to the premises of
              other tenants, the cost of which shall not be included in
              Operating Costs).

                            (d)    Maintenance and repair of mechanical and
              electrical equipment, including, without limitation, heating,
              ventilating and air-conditioning equipment in the Building (not
              including supplemental HVAC units installed by or at the expense
              of Tenant).

                            (e)    Window cleaning and janitor service,
              including janitor equipment and supplies for the common and public
              areas.

                            (f)    Maintenance of elevators, rest rooms,
              lobbies, hallways and other common and public areas of the
              Building.

                            (g)    Building management fees in a sum equal to
              the amounts customarily and reasonably charged by management firms
              for similar properties in the area in which the Property is
              located.

                                       11
<Page>

                     Operating Costs shall not include: expenses for any capital
repairs, replacements or improvements (capital repairs and/or capital
expenditures shall include, without limitation, any repair which under Internal
Revenue Code regulations would be amortized or depreciated over a period of
three (3) years or greater); expenses for which the Landlord is reimbursed or
indemnified (either by an insurer, condemnor, tenant or otherwise); expenses
incurred in leasing or procuring tenants (including, without limitation, lease
commissions, brokerage fees, advertising expenses and expenses of renovating
space for current or prospective lessees or tenants), or any expenses or
payments arising in any way in connection with the preparation, negotiation,
and/or enforcement of the provisions of any lease of space in the Building or
Property, including any professional fees; interest, principal, or any other
payments or charges of any sort or nature on any mortgage or mortgages,
including any professional fees related thereto, and rental or other charges
under any ground or underlying lease or leases; depreciation, amortization,
and/or other non-cash charges; wages, salaries or other compensation paid for
clerks or attendants in concessions or newsstands operated by the Landlord; the
cost of any work or service performed for or facilities furnished to a tenant at
the tenant's cost; the cost of correcting defects (latent or otherwise) in the
construction of the Building or in the Building equipment, except that
conditions (not occasioned by construction defects) resulting from ordinary wear
and tear shall not be deemed defects; salaries and fringe benefits and other
costs of personnel above the grade of building supervisor; the cost of
installing, operating and maintaining a specialty improvement including, without
limitation, an observatory or broadcasting, cafeteria or dining facility, or
athletic, luncheon or recreational club; and any cost or expense representing an
amount paid to a related corporation or other entity which is in excess of the
amount which would be paid in the absence of such relationship; any income,
estate, franchise, succession, inheritance, use, occupancy, gross receipts,
rental or capital gains taxes, or any other taxes.

                     If Tenant shall assume responsibility for its own cleaning
of the Premises, premises cleaning costs shall be excluded from Operating Costs,
and in such event, the Building Expense Base shall be reduced by the cost of
premises cleaning included therein.

                     If less than all of the Building Rentable Area was occupied
by tenants during any Year or if Landlord did not incur Operating costs with
respect to all tenants during any Year, then each of said Costs shall be
reasonably adjusted and extrapolated by Landlord on an item-by-item basis (i.e.,
those which vary in accordance with the extent of occupancy or the provision of
services, as the case may be) to the estimated Operating Costs that would have
been incurred if the Building had been fully occupied for such Year and such
Costs had been incurred in respect of all tenants; and such extrapolated amount
shall, for the purposes hereof, be deemed to be the operating Costs for such
Year.

                     (iii)  TAXES. The real estate taxes and other taxes, levies
and assessments imposed upon the Building and the Property and upon any personal
property of Landlord used solely and exclusively in the operation thereof;
betterment assessments apportioned over the longest payment period permitted by
law (including interest thereon); charges, fees and assessments for police, fire
or other governmental services or purported benefits to the Building; service or
user payments in lieu of taxes; and any and all other taxes, levies,
betterments, assessments and charges arising from the ownership, leasing,
operating, use or occupancy of the Building or based upon rentals derived
therefrom, which are or shall be

                                       12
<Page>

imposed by National, State, Municipal or other authorities having jurisdiction.
As of the Execution Date, Taxes shall not include any income, estate, franchise,
succession, inheritance, use, occupancy, gross receipts, rental, capital gains
or profit tax, provided, however, that any tax, excise, fee, levy, charge or
assessment, however described, that may in the future be levied or assessed as a
substitute for or in addition to (in whole or in part) any tax, levy or
assessment which would otherwise constitute Taxes, whether or not now customary
or in the contemplation of the parties on the Execution Date of this Lease,
shall constitute Taxes, but only to the extent calculated as if the Building and
the Property were the only real estate owned by Landlord. Taxes shall also
include reasonable, actual out-of-pocket expenses of tax abatement or other
proceedings contesting assessments or levies, or any professional fees related
thereto. Although Taxes in Massachusetts are payable on the basis of a July 1 -
June 30 fiscal/tax year, for the purposes of this Section, Taxes shall be
computed on a calendar year basis, based upon the sum of one-half (1/2) the
Taxes payable in respect of each applicable fiscal/tax year. (For example, Taxes
for 1993 would be 1/2 the Taxes in respect of the 1993 fiscal/tax year, plus 1/2
the Taxes in respect of the 1994 fiscal/tax years.)

              If the real estate taxes are reduced after the Tenant has paid its
proportionate share thereof, and provided Tenant shall not then be in default of
any monetary obligation under this Lease, beyond any applicable grace period,
the Landlord will pay to the Tenant or the Tenant will be credited with the
Tenant's proportionate share of the reduction. Any real estate tax increase or
decrease during the term of this Lease shall be apportioned so that the Tenant
shall pay or receive its proportionate share of only that portion of the real
estate tax increase or decrease as falls within the term.

              Notwithstanding anything herein contained to the contrary,
Landlord shall bear the cost of and pay when due all special assessments and
real estate taxes resulting from assessments attributable to redesign and
expansion or renovation of the Building or Property, except for any improvements
or facilities or changes to the Building or Property as are made or requested by
Tenant.

                     (iv)   BUILDING EXPENSES: The sum of Operating Costs plus
Taxes. Provided, however, for purposes hereof, in no event shall Building
Expenses in any Year exceed the Building Expense Cap (as hereinafter defined)
for such Year.

                     (v)    BUILDING EXPENSE CAP: For 1993, the Building Expense
Cap shall be $198,720.00. Thereafter, the Building Expense Cap shall be
increased each Year so as to be equal to one hundred fifteen percent (115%) of
the Building Expense Cap for the prior Year (e.g., the Building Expense Cap for
1994 shall be $228,528.00.)

                     (vi)   BUILDING EXPENSE BASE: The amount set forth on
Exhibit 1. Landlord hereby represents that the Building Expense Base set forth
on Exhibit 2 hereto is Landlord's good faith estimate of all Operating Costs
Landlord anticipates incurring for the Building for the Year 1993 on an
annualized basis if the Building were fully occupied.

                     (vii)  TENANT'S PROPORTIONATE SHARE: The fraction or
percentage set forth on Exhibit 1, being the Premises Rentable Area divided by
the Building Rentable Area.

                                       13
<Page>

              (b)    TENANT'S PAYMENTS.

                     (i)    If in any Year of the term of this Lease, as it may
be extended, Building Expenses (subject to the Building Expense Cap as
hereinabove provided) shall exceed the Building Expense Base (the amount of such
excess being hereinafter defined as the "Excess Building Expense"), Tenant shall
pay to Landlord, as additional rent, a Building Expense Escalation Charge in an
amount equal to the product of (i) such Excess Building Expense multiplied by
(ii) Tenant's Proportionate Share, such amount to be paid by Tenant to be
apportioned for any Year in which the Rent Commencement Date occurs or the Term
of this Lease ends.

                     (ii)   Tenant's Building Expense Escalation charge, if any,
for 1993, shall be paid by Tenant to Landlord within thirty (30) days after
Tenant is billed therefor; Landlord may render such bill not earlier than
January 1, 1994. Commencing January 1, 1994, estimated payments by Tenant on
account of amounts due hereunder shall be made monthly in advance on the first
day of each month. The monthly amount so to be paid to Landlord shall be
sufficient to provide Landlord by the end of each Year a sum equal to Tenant's
required payments, as reasonably estimated by Landlord from time to time during
each year, on account of Building Expense Escalation Charges for such Year. Such
estimate shall be based on the actual Building Expenses for the prior year.
Landlord shall have the right from time to time during the course of the Year to
adjust the amount of Tenant's estimated payments based upon the most recent data
with respect to Building Expenses then available (e.g., Landlord's receipt of a
new Tax bill).

                     (iii)  Not later than four (4) months following the end of
each Year during the term of this Lease and any extensions thereof, Landlord
shall cause its actual Building Expenses to be audited by an independent
certified public accountant; such statement may be prepared by Landlord and
certified by one of the trustees of Landlord, and in any event, shall be sent by
Landlord to Tenant within thirty (30) days after the end of such four (4) month
period. In such statement, Landlord shall duly note any cost or expense
representing an amount paid to a related corporation or other entity. Landlord
shall, at Tenant's request, to be made not later than the date which is sixty
(60) days after Tenant's receipt of Landlord's statement, make available to
Tenant for inspection and examination at the office of Landlord all the books
and records that relate to such statement. Tenant shall complete such audit
within ninety (90) days after Tenant advises Landlord of its intention to do so
as aforesaid, and any Year so audited or reviewed by Tenant shall thereafter be
closed to further audit.

                     (iv)   If estimated payments previously made for any
particular Year by Tenant exceed Tenant's required payment on account thereof
for such Year, according to such statement, Landlord shall promptly refund such
overpayment, but, if the required payments on account thereof for such Year are
greater than the estimated payments (if any) previously made on account thereof
for such Year, Tenant shall make payment to Landlord within 30 days after being
so advised by Landlord. Landlord's and Tenant's obligations with respect to
adjusting Building Expense Escalation Charges for the Year in which the Term of
this Lease ends shall survive the expiration or sooner termination of this
Lease. In no event shall Tenant be entitled to receive a refund or credit (other
than in respect of payments, if any, made by Tenant on account

                                       14
<Page>

of estimated Building Expense Escalation Charges for such Year) if in any Year
Building Expenses are less than the Building Expense Base.

              (c)    TAX CONTEST. If Landlord will not be adversely affected
thereby, either through the imposition of a lien upon the Property or otherwise,
and provided that Tenant shall have paid to Landlord all amounts due in respect
of Tenant's Building Expense Escalation Charge and is not otherwise in monetary
or material non-monetary default under this Lease, Tenant shall have the right,
by appropriate proceedings, if Landlord shall fail or refuse to do so, to
protest or contest any assessment or reassessment for real estate taxes, or any
special assessment, or the validity of either, or of any change in assessments.
At Tenant's request, from time to time, Landlord shall provide to Tenant copies
of all bills for taxes and assessments, as the case may be, received by
Landlord. In the contest or proceedings, Tenant may act in its own name and/or
the name of Landlord and the Landlord will, at Tenant's request and provided
Landlord is not put to any expense thereby, cooperate with Tenant in any way
Tenant may reasonably require in connection with such contest. Any contest
conducted by Tenant hereunder shall be at Tenant's expense and, in the event any
penalties, interest or late charges become payable with respect to the real
estate taxes as the result of such contest or protest, Tenant shall reimburse
Landlord for the same. However, Landlord shall be solely responsible for any
penalties, interest or late charges imposed on the Landlord through no fault of
Tenant.

       15.    INSURANCE.

              (a)    LANDLORD'S INSURANCE. Landlord shall, from and after the
date hereof and throughout the term of this Lease, as it may be extended,
maintain a policy of comprehensive public liability insurance of at least
$2,000,000 and property damage insurance covering the Building and Property
(excluding Tenant's Work, any alterations or improvements made to the Premises
by Tenant pursuant to Section 8 and, if applicable, Tenant's RFO Work referred
to in Section 38 below [all of the foregoing being hereinafter called "Tenant's
Improvements"]) against loss, damage or destruction caused by fire with extended
coverage. (A certificate of Landlord's present insurance coverage is attached
hereto as Exhibit 8.) Fire and extended coverage shall equal at least ninety
(90%) percent of the replacement cost of the Building (exclusive of Tenant's
Improvements, as aforesaid) above foundations. Each such policy of insurance
shall be non-cancelable and non-amendable without thirty (30) days prior notice
to Tenant. Landlord shall provide to Tenant duplicate originals or certificates
of all insurance coverages required to be maintained by Landlord hereunder.

              (b)    TENANT'S INSURANCE. Tenant shall, from and after the date
hereof and throughout the term of this Lease, as it may be extended, maintain a
policy of comprehensive public liability insurance of at least $2,000,000 and
property insurance for Tenant's Improvements and for Tenant's personal property,
equipment, furnishings and fixtures in an amount equal to at least ninety (90%)
percent of the replacement cost thereof. For purposes hereof and other
applicable provisions of this Lease (including, without limitation, Sections
16(b) and 17), Tenant's property (and phrases of similar import) shall include
property leased, as well as owned, by Tenant. Landlord (and such other persons
as Landlord may designate by notice to Tenant from time to time) shall be named
as insureds on Tenant's liability insurance. Each such policy of liability
insurance shall be non-cancellable and non-amendable with respect to Landlord
and Landlord's said designees without thirty (30) days prior notice to Landlord
and

                                       15
<Page>

its designees. Tenant shall provide to Landlord and Landlord's designees
duplicate originals or certificates of all insurance coverages required to be
maintained by Tenant hereunder.

              (c)    SUBROGATION. Landlord and Tenant shall each cause all
policies of fire, extended coverage, and other physical damage insurance
covering the Premises, the Building, Tenant's Improvements, and any property in
the Building to contain a clause or endorsement denying the insurer any rights
of subrogation against the other party. Notwithstanding any provisions of this
Lease to the contrary, Landlord and Tenant respectively waive all claims and
rights to recover against the other for injury or loss due to hazards covered by
insurance, except as to Tenant's obligations with respect to Landlord's
deductible as set forth in the second sentence of Section 11.

       16.    INDEMNITIES OF TENANT AND LANDLORD.

              (a)    TENANT INDEMNITY. Subject to Section 15(c), and except to
the extent arising from a negligent or wilfull act or omission on the part of
Landlord, its agents, employees, invitees or contractors, Tenant agrees to
defend, indemnify and save harmless Landlord, Landlord's Agent (identified on
Exhibit 1) and any mortgagee or ground lessor of which Tenant is given notice
from and against all loss, liability, damage, costs, expenses and claims of
whatever nature arising (i) from any accident, injury or damage to any person or
to the property of any person in the Premises; or (ii) from any accident, injury
or damage to persons or property occurring outside of the Premises but in or
about the Building or on the Property, where such accident, damage or injury
outside of the Premises results or is claimed to have resulted from a negligent
or willful act or omission on the part of Tenant or Tenant's agents or
employees. Landlord shall notify Tenant of such loss, etc. when Landlord learns
of any such matter it understands involves Tenant and (subject to the approval
of Landlord's insurer) Tenant shall have the right to assume the defense thereof
with reputable and qualified legal counsel reasonably acceptable to Landlord.

              (b)    LANDLORD INDEMNITY. Subject to Sections 15(c) and 17, and
except to the extent arising from a negligent or wilfull act or omission on the
part of Tenant, its agents, employees, invitees or contractors, Landlord agrees
to defend, indemnify and save harmless Tenant from and against all loss,
liability, damage, costs, expenses and claims of whatever nature arising (i)
from any accident, injury or damage to any persons or to the property of any
person (other than Tenant) in the Premises, or (ii) from any accident, injury or
damage to persons or to the property of any person (other than Tenant) occurring
outside of the Premises but in or about the Building or occurring elsewhere on
the Property, where such accident, damage or injury in the Premises or outside
the Premises results or is claimed to have resulted from a negligent or wilfull
act or omission on the part of the Landlord or its agents or employees. Tenant
shall notify Landlord of such loss, etc., when Tenant learns of any such matter
it understands involves Landlord and (subject to the approval of Tenant's
insurer) Landlord shall have the right to assume the defense thereof with
reputable and qualified legal counsel reasonably acceptable to Tenant.

       17.    TENANT'S RISK. Tenant agrees to use and occupy the Premises at
Tenant's own risk. Tenant shall maintain insurance in respect of its personal
property, business fixtures and leasehold improvements and Landlord shall have
no responsibility or liability for any loss of or

                                       16
<Page>

damage to any of the same, or for any inconvenience, annoyance, interruption or
injury to business arising from Landlord's making any repairs or changes which
Landlord is permitted by this Lease, or required by law, to make in or to any
portion of the Premises or other sections of the Building or Property, except to
the extent arising from a negligent or wilfull act or omission on the part of
Landlord, its agents, employees or contractors, provided that Landlord shall
bear such responsibility only for ordinary office and research and development
property, as hereinafter defined, and provided further that Landlord's
responsibility hereunder shall also be subject to Section 15(c). For purposes
hereof, "ordinary office and research and development property" shall mean such
property as is customarily found in office/r&d facilities comparable to Tenant's
Premises in the greater Boston area and shall exclude property of a rare or
exotic nature, works of art and the like. Tenant agrees that Landlord shall not
be responsible or liable to tenant, or to those claiming by, through or under
Tenant, for any loss or damage that may be occasioned by or through the acts or
omissions of persons occupying adjoining premises or any other part of the
Building or the Property.

       18.    LANDLORD'S ACCESS RIGHTS.

              (a)    Upon reasonable prior written notice to Tenant, except
that no such notice shall be required in the case of an emergency, and subject
to all of the relevant provisions of Section 13, Landlord shall have the right
to enter the Premises at reasonable hours for the purpose of inspecting or
making repairs to the same, and to show the Premises to prospective or existing
mortgagees, purchasers or, during the last nine (9) months of the term of this
Lease, to prospective tenants. Except were not possible by reason of an
emergency, Tenant shall have the right to accompany any such parties during such
period(s).

              (b)    Tenant acknowledges that the only access to the balance of
the second floor of the Building will be through Tenant's reception area until
such time (if ever) as Landlord constructs the corridor(s) contemplated by
Section 6(g) above. Accordingly, until such corridor(s) are constructed,
Landlord reserves, and Tenant agrees that Landlord shall have, an unlimited
right of access during business hours (and without notice to Tenant, except that
Landlord shall use reasonable efforts to give Tenant prior oral notice of
Landlord's intention to enter the Premises pursuant to this paragraph (b))
through Tenant's reception area to the balance of the second floor of the
Building for the purpose of showing such space to existing or prospective
tenants, mortgagees, purchasers and others, for making inspections, repairs and
replacements, and for constructing such space for occupancy by others. Landlord
shall exercise such access rights in a manner so as to minimize interference
with the conduct of Tenant's business in the Premises.

       19.    CONDEMNATION.

              (a)    If at any time during the Term or any extension thereof the
whole of the Building and Property shall be taken for any public or quasi-public
use, under any statute, or by right of eminent domain, then except as provided
in paragraph (c), this Lease shall terminate as of the date Tenant is scheduled
to be deprived of possession by reason of such taking. If less than all of the
Building and Property shall be so taken and in the Tenant's reasonable, bona
fide business judgment, exercised in good faith, the remaining part is
insufficient for the conduct of the Tenant's business, the Tenant may, by notice
to the Landlord given within ninety (90) days

                                       17
<Page>

after notice of such taking, terminate this Lease. If the Tenant exercises its
option, this Lease and the term hereof shall end on the date Tenant is scheduled
to be deprived of possession by reason of such taking, and the rent and
additional rent shall be apportioned and paid to such date and Tenant shall have
no further liability or obligation to Landlord.

              (b)    If less than all of the Building and Property shall be
taken and Tenant does not elect to terminate this Lease pursuant to paragraph
(a) above, this Lease shall remain unaffected, except that the Tenant shall be
entitled to a pro-rata abatement of rent and additional rent based on the
proportion which the area of the Premises so taken bears to the area of the
Premises demised hereunder immediately prior to such taking.

              (c)    If the use and occupancy of the whole or any part of the
Building or Property is temporarily taken for a public or quasi-public use for a
period of more than three (3) months but less than the balance of the term, at
the Tenant's option to be exercised in writing and delivered to the Landlord not
later than ninety (90) days after the date the Tenant is notified of such
taking, this Lease and the term hereby granted shall terminate on the date
specified in the Tenant's notice or shall continue in full force and effect. If
the Lease remains in effect, the Tenant shall be entitled to a proportional
abatement of rent and additional rent in the manner and to the extent provided
in paragraph (b).

              (d)    In the event of a taking hereunder, the Tenant shall be
entitled, if allowed by law, to appear, claim, prove and receive in the
condemnation proceeding (1) the unamortized value (calculated on a straight-line
basis over the remainder of the then current term of the Lease, including any
extension terms the option for which Tenant has exercised as of the date of such
taking) of the improvements and alterations to the Premises as made by Tenant at
the Tenant's expense but regardless of whether the improvements and alterations
might be considered a part of the premises or shall be or become the property of
the Landlord under the terms of this Lease; (2) the value of the Tenant's
fixtures; (3) the cost of relocation; and (4) special awards or allowances
provided by law to tenants (other than for the value of Tenant's leasehold) in
the event their rental space is taken by eminent domain; provided, however, that
the amount of the award due Landlord as a result of such taking shall not be
reduced by Tenant's claims and that Tenant's claims shall in all events be
subject and subordinate to the rights of Landlord's mortgagee(s). Except for any
award specifically referred to in the preceding sentence which Tenant is
entitled to claim, there are expressly reserved to Landlord all rights to
compensation and damages created, accrued or accruing by reason of any such
taking, in implementation and confirmation of which Tenant does hereby
acknowledge that Landlord shall be entitled to receive all such compensation and
damages, grant to Landlord all and whatever rights (if any) Tenant may have to
such compensation and damages, and agree to execute and deliver all and whatever
further instruments of assignment as Landlord may from time to time request.

              (e)    If there is a taking hereunder and this Lease is continued,
the Landlord shall, at its expense, but limited to the amount of condemnation
proceeds made available to it by the taking authority and the holder of any
mortgage or lessor under any ground lease on the Property, proceed with
reasonable diligence to repair, alter and restore the Building (and Property, if
relevant) as a complete architectural unit of substantially the same
proportionate usefulness, design and construction existing immediately prior to
the date of taking.

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<Page>

              (f)    Taking by condemnation or eminent domain hereunder shall
include the exercise of any similar governmental power and any sale, transfer or
other disposition to the condemning authority of the Building or Property in
lieu or under threat of condemnations.

       20.    CASUALTY.

              (a)    If any portion of the Premises, the common areas of the
Building or Building equipment or systems serving the Premises or common areas
(hereinafter collectively referred to as the "damaged property") shall incur
minor damage by reason of fire or other casualty, Landlord will restore such
damaged property (excluding Tenant's Improvements, which shall be restored by
Tenant) to substantially their condition immediately prior to such damage for
Tenant's use and occupancy as speedily as possible. If, for any reason, such
restoration shall not be completed by Landlord within one hundred twenty (120)
days after such damage shall have occurred, Tenant shall have the right to
terminate this Lease by giving a thirty (30) day termination to Landlord. Upon
giving of such notice, this Lease shall cease and come to an end as of said
thirtieth (30th) day after the giving of notice without further obligation of
liability on the part of either party, unless by the said thirtieth (30th) day
Landlord shall have completed such restoration, in which event Tenant's
termination notice shall be void and of no further force or effect.
Notwithstanding anything to the contrary contained in this Section 20,
Landlord's obligation to restore any damage shall be limited to the amount of
any insurance proceeds made available to Landlord by any holder of a mortgage or
lessor under any ground lease on the Property.

              (b)    If damaged property shall be substantially damaged by fire
or other casualty ("substantial damage" meaning damage which Landlord reasonably
anticipates cannot be restored substantially to the condition they were in
immediately prior to such fire or casualty within one hundred twenty [120] days
after the occurrence thereof) Landlord shall have the right to terminate this
Lease. Landlord shall notify Tenant in writing of its determination to terminate
this Lease or restore the damaged property within thirty (30) days of such fire
or casualty. The term of this Lease may be so terminated not earlier than twenty
(20) days after delivery of Landlord's termination notice nor later than thirty
(30) days thereafter. If Landlord shall not elect to terminate this Lease but
if, in the opinion of Tenant, the operation of Tenant's business in the Premises
in the normal course is materially adversely affected, then, within fourteen
(14) days of its receipt of Landlord's notice of its election to restore the
damaged property, Tenant shall request a written engineering estimate of
Landlord as to the length of time needed to restore the damaged property. Within
fifteen (15) days of such request, Landlord shall submit to Tenant a reasonable
engineering estimate as to the estimated length of time to complete such
repairs. If such estimate shall exceed one hundred twenty (120) days from the
date of such casualty, Tenant may elect, by a notice sent within fifteen (15)
days after Tenant's receipt of such estimate, to terminate this Lease. If such
estimate shall fall within the one hundred twenty (120) day limit, Tenant shall
have no such right to terminate and Landlord shall, subject to the provisions of
this Section 20, proceed with due diligence and promptness to

                                       19
<Page>

substantially complete the repairs or restoration (excluding property to be
restored by Tenant, as provided in paragraph (a) above) within such one hundred
twenty (120) day period. If Landlord's estimate exceeds 120 days as aforesaid
but Tenant, although having the right to do so, does not elect to terminate this
Lease within 15 days after receipt of such estimate as aforesaid, then and in
such event, Landlord shall, subject to the provisions of this Section 20,
proceed with due diligence and promptness to substantially complete the repairs
or restoration (excluding property to be restored by Tenant, as provided in
paragraph (a) above) within the period set forth in Landlord's estimate. If, for
any reason, such restoration shall not be completed by Landlord within the
period set forth in Landlord's estimate (or, if longer, within one hundred
twenty (120) days after such damage shall have occurred), Tenant shall have the
right to terminate this Lease by giving a thirty (30) day termination to
Landlord. Upon giving of such notice, this Lease shall cease and come to an end
as of said thirtieth (30th) day after the giving of notice without further
obligation or liability on the part of either party, unless by the said
thirtieth (30th) day Landlord shall have completed such restoration, in which
event Tenant's termination notice shall be void and of no further force or
effect.

              (c)    Pending Landlord's restoration of the damaged property
(excluding property to be restored by Tenant, as provided in paragraph (a)
above) or termination of this Lease as aforesaid, Tenant shall be entitled to a
proportionate abatement of rent and additional rent payable during the period
commencing on the date of the damage and ending on the date the damaged property
is restored as aforesaid or this Lease is terminated, as the case may be. The
extent of rental abatement shall be based upon the portion of the Premises
rendered untenantable, unfit or inaccessible for use by Tenant during such
period. If this Lease is terminated pursuant to paragraphs (a) or (b) above,
then rent and additional rent (as the same may have been abated pursuant to the
preceding sentence) shall be apportioned as of the date of termination and all
prepaid rent and additional rent, if any, in respect of periods from and after
the effective termination date shall be repaid.

       21.    TENANT'S DEFAULT. Tenant shall be in default under this Lease
in the event that Tenant (a) shall fail to make any payment of money (including,
without limitation, Basic Rent and Building Expense Escalation Charges) when it
is due hereunder and such failure shall continue for ten (10) days after written
notice from Landlord to Tenant, or (b) shall fail or neglect to perform or
observe any other covenant or obligation under this Lease and Tenant shall fail
to remedy the same within thirty (30) days after written notice from Landlord to
Tenant specifying such failure or neglect, or if such failure is of such nature
that Tenant cannot reasonably remedy the same within such 30-day period, Tenant
shall fail to commence promptly to remedy the same and to prosecute such remedy
to completion with diligence and continuity, or (c) shall commence
reorganization, bankruptcy or insolvency proceedings or, in case any such
proceedings are brought against Tenant, if the same are not dismissed within
sixty (60) days or if any assignment shall be made of all or substantially all
of Tenant's property for the benefit of creditors.

       If Tenant shall be in default under this Lease, Landlord shall have all
rights and remedies as are available at law or in equity. Such remedies shall
include, without limitation, the right to evict Tenant, take exclusive
possession of the Premises, continue to collect Basic Rent, Building expense
Escalation Charges and other charges, terminate the Lease, obtain a judgment for
all damages that might flow from a breach or termination of this Lease, re-let
the Premises or any part thereof and make any repairs or alterations to the
Premises, but not including alterations or repairs not reasonably necessary for
Landlord to seek mitigation of damages arising in connection with Tenant's
default. In the event of termination by reason of default by Tenant, Landlord
shall be obligated to use all reasonable efforts to mitigate any and all damages
therefrom. For purposes hereof, "reasonable efforts" shall mean listing the
Premises with a

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<Page>

commercial property broker who in the ordinary course deals with similar
properties; but Landlord shall in no event be required to re-let the Premises in
lieu of leasing other space in the Building. Tenant shall pay Landlord's
reasonable actual out-of-pocket costs of enforcing this Lease, including,
without limitation, reasonable attorneys' fees and costs, as additional rent.

       At any time within one (1) year after termination of this Lease for
Tenant's default, as liquidated damages and in lieu of all other damages beyond
the date of demand hereunder, at Landlord's election, Tenant shall pay to
Landlord an amount equal to Basic Rent, Building Expense Charges and other sums
payable under this Lease which would have been payable hereunder for the period
of one (1) year from the date of Landlord's election had this Lease remained in
effect (assuming, for the purpose of this sentence, that Building Expense
Charges payable by Tenant for said one year period would be in an amount equal
to the Building Expense charges required for the year immediately preceding the
Year in which such election is made).

       22.    LANDLORD'S DEFAULT. Landlord shall be in default under this
Lease in the event that Landlord shall have failed to perform any of its
obligations hereunder within thirty (30) days of notice thereof by Tenant to
Landlord and to any mortgagee or ground lessor whose names and addresses have
been previously given by written notice to Tenant, or if such failure is of such
nature that Landlord cannot reasonably remedy the same within thirty (30) days,
Landlord shall have failed promptly to commence to remedy the same and to
prosecute such remedy with diligence and continuity.

       23.    LIMITATIONS ON LIABILITY.

              (a)    LANDLORD'S LIABILITY. With respect to the Landlord's
obligations as Landlord hereunder, Tenant agrees, in the event of breach of any
of the terms and conditions of this Lease, to look solely to the Landlord's
interest in the Property for recovery of any judgment from Landlord; it being
specifically agreed that in no event shall Landlord (original or successor), or
any of the officers, trustees, directors, partners, beneficiaries, stockholders
or other principals or representatives, and the like, disclosed or undisclosed,
thereof, ever be personally liable for any such judgment, or other liability or
for the payment of any monetary obligation to Tenant arising out of a breach of
any of the terms and conditions of this Lease with respect to the Landlord's
obligations as Landlord hereunder. In no event shall Landlord (original or
successor) or any such officers, etc., as aforesaid, ever be liable for indirect
or consequential damages arising from whatever cause.

              (b)    TENANT'S LIABILITY. Landlord agrees, in the event of breach
of any of the terms and conditions of this Lease, to look solely to the Tenant
for recovery of any judgment from Tenant; it being specifically agreed that in
no event shall any recourse under any provisions of this Lease otherwise
permitted by any statute or rule of law or decision be had against any of
Tenant's past, present, or future incorporators, subscribers, stockholders,
officers, or directors, partners, beneficiaries, trustees, representatives, or
principal(s), whether disclosed or undisclosed, and the like, either directly or
through such entity

       24.    RULES AND REGULATIONS. Tenant shall abide by rules and regulations
from time to time reasonably established by Landlord, it being agreed that such
rules and regulations will be established and applied by Landlord in a
non-discriminatory fashion. Landlord agrees to use

                                       21
<Page>

reasonable efforts to insure that any such rules and regulations are uniformly
enforced, but Landlord shall not be liable to Tenant for violation of the same
by any other tenant or occupant of the Building, or persons having business with
them. The current rules and regulations are attached to this Lease as Exhibit 6.
In the event that there shall be a conflict between such rules and regulations
and the provisions of this Lease, the provisions of this Lease shall control.
The Rules and Regulations shall not be applicable to Tenant to the extent that
any such rule or regulation unreasonably interferes with the Tenant's
contemplated use of the Premises (including Tenant's Work) or with Tenant's
particular security requirements. Without limiting the generality of the
foregoing, notwithstanding such Rules and Regulations: (i) Tenant may keep on
the Premises animals or birds, etc. necessary for the conduct of its business
therein, provided that Tenant complies with all laws and other legal
requirements applicable thereto and that Tenant shall keep such animals or
birds, etc. appropriately caged (or otherwise restricted) so as to avoid escape
or other annoyance or disturbance to other occupants of the Building; and (ii)
chemicals, combustible or otherwise, shall be permitted on the Premises as
necessary for the conduct of Tenant's business therein, subject to the
provisions of Section 40(b), which shall be applicable thereto.

       25.    NOTICE. Whenever, by the terms of this Lease, notices, requests,
consents and approvals shall or may be given either to Landlord or to Tenant,
they shall be in writing and shall be delivered in hand or sent by express,
registered or certified mail, return receipt requested, postage prepaid:

       If intended for Landlord, addressed to Landlord at Landlord's
       Original Address as stated in Exhibit 1 (or to such other address or
       addresses as may from time to time hereafter be designated by
       Landlord by like notice).

       If intended for Tenant, addressed to Tenant at Tenant's original
       Address as stated in Exhibit 1 until the Rent Commencement Date and
       thereafter to the Premises (or to such other address or addresses as
       may from time to time hereafter be designated by Tenant by like
       notice).

All such notices shall be effective (i) when hand-delivered or (ii) if mailed,
when deposited in the United States Mail within the Continental United States,
provided that the same are received in ordinary course at the address to which
the same were sent.

       26.    LANDLORD'S TITLE AND CONFORMITY WITH LEGAL REQUIREMENTS. Landlord
covenants as a condition of this Lease that it has good marketable fee title to
the Building and Property subject to the encumbrances listed as of the date
hereof on Certificate of Title No. 161435 filed with the Middlesex South
Registry District of the Land Court in Book 937, Page 85, and that Landlord has
the right to make this Lease for the term aforesaid; that the provisions of this
Lease do not conflict with or violate the provisions of existing agreements
between Landlord and third parties; that, to the best knowledge of Landlord, the
Premises and Property are in conformity with all applicable legal requirements,
including, without limitation, zoning and planning ordinances, and do not
violate applicable restrictions, if any; that as of the date of this Lease,
there are no claims, lawsuits, judgments or similar matters affecting the
Premises, Building or the Property in connection with the title, zoning and
planning ordinances or environmental matters, and that Landlord will notify
Tenant within five (5) business days of discovery of any

                                       22
<Page>

such claims, causes of action, lawsuits, controversies or judgments which would
affect this Lease or Tenant's use and occupancy of the Premises; and that
Landlord will deliver actual possession of the Premises to Tenant free of all
tenants and occupants and in accordance with all terms and conditions of this
Lease.

       27.    SUBORDINATION AND NON-DISTURBANCE. Tenant acknowledges and agrees
that this Lease shall be subordinate to any mortgage or ground lease from time
to time encumbering the Premises, whether executed and delivered prior to or
subsequent to the date of this Lease, if the holder of such mortgage or ground
lease shall so elect. If this Lease is subordinate to any mortgage or ground
lease and the holder thereof (or successor) shall succeed to the interest of
Landlord, at the election of such holder (or successor) Tenant shall attorn to
such holder and this Lease shall continue in full force and effect between such
holder (or successor) and Tenant. Tenant agrees to execute such instruments of
subordination or attornment in confirmation of the foregoing agreement as such
holder (or successor) may reasonably request.

              (b)    Notwithstanding anything to the contrary in the foregoing
contained, the above provided subordination shall be effective only if the
encumbering mortgage or ground lease documentation (as the case may be)
provides, or if the mortgagee or ground lessor (as the case may be) agrees by a
written instrument in recordable form and otherwise in the customary form of
such mortgagee or ground lessor and in form reasonably acceptable to Tenant,
that, INTER ALIA, as long as Tenant shall not be in default, beyond the
expiration of applicable grace periods, of the obligations on its part to be
kept and performed under the terms of this Lease, this Lease will not be
affected and Tenant's possession hereunder will not be disturbed by any default
in, termination and/or foreclosure of, such mortgage and/or ground lease (as the
case may be). For purposes of the preceding sentence, Tenant agrees (without
limitation) that the form of non-disturbance agreement which Tenant enters into
with the present mortgagee, Lexington Savings Bank, will be acceptable to Tenant
with respect to future mortgagees.

       28.    ESTOPPEL CERTIFICATE. Either party shall at any time and from time
to time within ten (10) days of the other party's request, execute and deliver
an estoppel certificate affirming this Lease, indicating whether there are any
defaults hereunder and addressing such other matters as the requesting party,
its lender(s) or prospective purchaser(s) or investors may reasonably require.

       29.    REMEDYING TENANT DEFAULTS. Landlord shall have the right, but not
the obligation, to pay such sums or take such action as may be necessary or
appropriate by reasons of the failure or neglect of Tenant to perform any of the
provisions of this Lease, and in such event, Tenant agrees to reimburse Landlord
within fifteen (15) days after demand for all reasonable costs and expenses so
inquired by Landlord, together with interest thereon at a rate equal to 12% per
annum. Any payment of Basic Rent, Building Expense Charges or other sums payable
hereunder not paid within ten (10) days the same shall have become due shall
bear interest at the rate as aforesaid from the date thereof and shall be
payable within fifteen (15) days after demand. by Landlord, as additional rent.

       30.    REASONABLE CONSENT. Whenever any provision of this Lease states
that the consent, approval or acceptance of either Landlord or Tenant is
required, such consent, approval or acceptance shall not be unreasonably
withheld.

                                       23
<Page>

       31.    HOLDING OVER. Any holding over by Tenant after the expiration or
sooner termination of the Term of this Lease shall be treated as a daily
tenancy at sufferance at a rate equal to two (2) times the sum of (i) Basic Rent
then in effect plus (ii) Building Expense Charges and all other charges herein
provided for (prorated on a daily basis). Tenant shall also pay to Landlord all
damages, direct and/or indirect (including, without limitation, the loss of a
tenant and of rental income) sustained by reason of any such holding over.
Otherwise, such holding over shall be on the terms and conditions set forth in
this Lease as far as applicable.

       32.    SURRENDER OF PREMISES. Upon the expiration or earlier termination
of the Term of this Lease, Tenant shall peaceably quit and surrender to Landlord
the Premises in neat and clean condition and otherwise in the same condition as
Tenant is required to surrender and return the Premises to Landlord pursuant to
Section 8 and to maintain the Premises pursuant to Section 11 above, excepting
only as to Tenant's maintenance obligations, reasonable wear and tear and damage
by fire or other casualty.

       33.    ARBITRATION. In the event that any dispute should arise between
the parties hereto as to the validity of this Lease or as to the construction,
enforcement or performance of this Lease, such dispute, subject to the
provisions of this Section 33, shall be settled by arbitration before a single
arbitrator conducted at Boston, Massachusetts, in accordance with the Commercial
Arbitration Rules of the American Arbitration Association. As to any dispute
involving the payment of money, however, no arbitration shall be permitted until
the party with the payment obligation in question shall have paid such money in
dispute, under protest (and reserving its rights), in full to the other party.
No refusal to pay any amount coupled with a call for arbitration shall be deemed
to negate any of the provisions of default set forth in the Lease. The decision
of the arbitrator shall be final and binding on all parties thereto, and
judgment upon any award entered in such proceeding may be entered in any court
having jurisdiction thereof. The unsuccessful party to such arbitration shall
pay to the successful party all costs and expenses, including, without
limitation, reasonable attorneys' fees, incurred therein by such successful
party and such costs, expenses and attorneys' fees shall be included in and as
part of such judgment or award. The determination of the arbitrator shall be
conclusive on the matter of which party is successful for purposes hereof.

       In no event, however, shall this Section 33 be deemed to preclude a party
hereto from instituting legal action seeking relief in the nature of a
restraining order, an injunction or the like in order to protect his or its
rights pending the outcome of an arbitration hereunder. With respect to matters
submitted to arbitration the parties shall continue to perform their obligations
hereunder relative to said matters pending resolution of the dispute by
arbitration. Nothing in this Section 33 shall prevent Tenant's continued
occupancy of the Premises during the term of this Lease and the pendency of any
arbitration proceedings, provided Tenant is not otherwise in default (beyond the
expiration of any applicable notice and grace periods) under this Lease.

       34.    BROKERAGE. Landlord and Tenant each represent to the other that
they nave not entered into any agreement or incurred any obligation in
connection with this transaction which might result in the obligation to pay a
brokerage commission to any broker other than the Landlord's agreement with the
broker listed in Exhibit 1. Landlord shall pay all fees and commissions due to
such broker in connection with this transaction. Each party shall indemnify and
hold the other party harmless from and against any claim or demand by any broker
or other

                                       24
<Page>

person for bringing about this Lease who claims to have dealt with such
indemnifying party, including all expenses incurred in defending any such claim
or demand (including reasonable attorneys' fees).

       35.    GOVERNING LAW. This Lease shall be governed by and construed in
accordance with the laws of the Commonwealth of Massachusetts.

       36.    TENANT'S OPTION TO EXTEND THE TERM OF LEASE.

              (a)    On the condition, which condition Landlord may waive, at
its election, by written notice to Tenant at any time, that Tenant is not in
default after the expiration of applicable notice and grace periods of its
covenants and obligations under this Lease both as of the time of option
exercise and as of the commencement of the hereinafter described additional
term, Tenant shall have the option to extend the term of this Lease for two (2)
additional successive five (5) year terms, each such additional term commencing
as of the day after the expiration of the initial term or immediately preceding
the first additional term, as the case may be. Tenant may exercise such option
to extend by giving Landlord written notice on or after the date twenty-four
(24) months prior to the expiration date of the original term of this Lease or
of the first additional term (as the case may be) and on or before the date
which is six (6) months prior to the expiration date of this original term of
this Lease or of the first additional term (as the case may be). Upon the timely
giving of such notice, the term of this Lease shall be deemed extended upon all
of the terms and conditions of this Lease, except that the Basic Rent and
Building Expense Base during such additional term shall be as hereinafter set
forth, (ii) Section 6 shall not be applicable thereto, and (iii) the Rent
Commencement Date in respect of each such additional term shall be the first day
thereof. If Tenant fails to give timely notice, as aforesaid, Tenant shall have
no further right to extend the term of this Lease, time being of the essence of
this Section 36(a). It and when Tenant exercises its first and/or second
extension option hereunder, Landlord shall, at no cost to Tenant, and prior to
the commencement of the first and, applicable, second extension term, repaint
the Premises, with two coats of paint of quality and type to match existing
paint. The options to extend described herein shall be applicable to any "RFO
Premises" leased by Tenant pursuant to Section 38 below.

              (b)    BASIC RENT. The Basic Rent during the additional term shall
be the Fair Market Rental Value, as defined in paragraph (a) of Section 37, as
of the commencement of the then applicable additional term, of the Premises then
demised to Tenant; provided, however, that in no event shall the sum of the
applicable Basic Rent and Building Expense Escalation Charges for the Premises
then demised to Tenant, to be payable during such additional term, be less than
sum of the Basic Rent and Building Expense Escalation Charges for such Premises
which were payable immediately preceding the commencement of each such
additional term.

              (c)    Tenant shall have no further option to extend the term of
this Lease other than the two (2) successive five (5) year additional terms
herein provided.

              (d)    Notwithstanding the fact that upon Tenant's exercise of
the herein options to extend the term of the Lease such extensions shall be
self-executing, as aforesaid, the parties shall promptly execute a lease
amendment reflecting each such additional term after Tenant exercises the
applicable option, except that the Basic Rent payable in respect of each such

                                       25
<Page>

additional term and the figure for the Building Expense Base need not be set
forth in the applicable amendment. Subsequently, after such Basic Rent and the
figure for the Building Expense Base are determined, the parties shall execute a
written agreement confirming the same. The execution of such lease amendment
shall not be deemed to waive any of the conditions to Tenant's exercise of its
rights under paragraph (a) of this Section 36, unless otherwise specifically
provided in such lease amendment.

       37.    DEFINITION OF FAIR MARKET RENTAL VALUE. For the purpose of this
Lease:

              (a)    "Fair Market Rental Value" shall be computed as of the date
in question at the then current annual rental charge (i.e., the sum of Basic
Rent plus escalation and other charges), including provisions for subsequent
increases and other adjustments for leases and agreements to lease then
currently being negotiated or executed in comparable general office space (but
not comparable lab space as built by Tenant hereunder at its own cost and
expense) located in 125 Hartwell Avenue, Lexington, Massachusetts, or if no new
leases or agreements to lease are then currently being negotiated or executed in
the Building, the Fair Market Rental Value shall be determined by reference to
bona fide offers being made by Landlord to prospective tenants for the lease of
comparable general office space (but not comparable lab space as built by Tenant
hereunder at its own cost and expense) in the Building; or if there are no
prospective tenants to whom Landlord may make such offers, then Fair Market
Rental Value shall be determined by reference to new leases or agreements to
lease then currently being negotiated or executed for comparable general office
space (but not comparable lab space as built by Tenant hereunder at its own cost
and expense) located elsewhere in office/research and development buildings aged
and otherwise equipped comparably with the Building located within a two (2)
mile radius of the Building. In determining Fair Market Rental Value, the
following factors, among others, shall be taken into account and given effect:
size, location of premises, lease term, condition of building and services
provided by the Landlord.

              (b)    DISPUTE AS TO FAIR MARKET RENTAL VALUE. Landlord shall
initially designate Fair Market Rental Value and Landlord shall furnish data in
support of such designation. If Tenant disagrees with Landlord's designation of
a Fair Market Rental Value, Tenant shall have the right, by written notice given
within thirty (30) days after Tenant has been notified of Landlord's
designation, to submit such Fair Market Rental Value to arbitration. Fair Market
Rental value shall be submitted to arbitration as follows: Fair Market Rental
Value shall be determined by impartial arbitrators, one to be chosen by the
Landlord, one to be chosen by Tenant and a third to be selected, if necessary,
as below provided. The unanimous written decision of the two first chosen,
without selection and participation of a third arbitrator, or otherwise, the
written decision of a majority of three arbitrators chosen and selected as
aforesaid, shall be conclusive and binding upon Landlord and Tenant. Landlord
and Tenant shall each notify the other of its chosen arbitrator within ten (10)
days following the call for arbitration and, unless such two arbitrators shall
have reached a unanimous decision within thirty (30) days after their
designation, they shall so notify the American Arbitration Association (or such
organization as may succeed to said Association) and request said Association to
select an impartial third arbitrator to determine Fair Market Rental Value as
herein defined. Such third arbitrator and the first two chosen shall, subject to
commercial arbitration rules of the American Arbitration Association, hear the
parties and their evidence and render their decision within thirty (30) days
following the conclusion of such hearing and notify Landlord and Tenant thereof.
Landlord and

                                       26
<Page>

Tenant shall bear the expense of the third arbitrator (if any) equally. The
decision of the arbitrators shall be final and binding of the parties and
judgment thereon may be entered in the Superior Court having jurisdiction over
the Premises; and the parties consent to the jurisdiction of such court and
further agree that any process or notice of motion or other application to the
court or a judge thereof may be served outside the Commonwealth of Massachusetts
by registered mail or by personal service, provided a reasonable time for
appearance is allowed. If the dispute between the parties as to a Fair Market
Rental Value has not been resolved before the commencement of Tenant's
obligation to pay rent based upon such Fair Market Rental Value, then Tenant
shall pay Basic Rent and other charges under the Lease in respect of the
premises in question based upon the Fair Market Rental Value designated by
Landlord until either the agreement of the parties as to the Fair Market Rental
Value, or the decision of the arbitrators, as the case may be, at which time
Tenant shall pay any underpayment of rent and other charges to Landlord, or
Landlord shall refund any overpayment of rent and other charges to Tenant.

       38.    TENANT'S RIGHT OF FIRST OFFER. On the conditions (which conditions
Landlord may waive, at its election, by written notice to Tenant at any time)
(i) that Tenant is not in default after the expiration of applicable notice and
grace periods of its covenants and obligations under the Lease, (ii) that Fuji
ImmunoPharmaceuticals Corp. and/or a Fuji Successor itself is occupying at least
fifty percent (50%) of the premises then demised to Tenant (in the case of (i)
and (ii), both at the time that Landlord is required to give Landlord's Notice,
as hereinafter defined, and as of the Commencement Date in respect of the RFO
Premises in question), (iii) that Fuji ImmunoPharmaceuticals Corp and/or a Fuji
Successor will itself occupy the RFO Premises in question, and (iv) that if
there are two (2) years or less remaining in the then applicable term of the
Lease, Tenant shall have previously or simultaneously with the valid exercise of
its rights hereunder exercised its next applicable extension option, Tenant
shall have the following rights to lease RFO Premises, as hereinafter defined,
when such RFO Premises become available for lease to Tenant, as hereinafter
defined. In no event shall Tenant have any rights under this Section 38 on or
after the date on which there shall be less than two (2) full years remaining in
the Term of this Lease, unless Tenant shall have validly exercised any remaining
applicable extension option, as aforesaid. It Tenant exercises its second
extension option under Section 36, Tenant's rights under this Section 38 shall
lapse as of the third (3rd) anniversary of the commencement date of such second
additional term.

              (a)    DEFINITION OF RFO PREMISES. "RFO Premises" shall be defined
as any separately demised area which is situated within the second floor of 125
Hartwell Avenue, Lexington, Massachusetts, and which becomes available for lease
to Tenant, as hereinafter defined, during the term of this Lease, as the same
may be extended. For the purposes of this paragraph (a), an area shall be deemed
to be "available for lease to Tenant" if, during the term of this Lease,
Landlord, in its sole judgment, determines that such area will become available
for leasing to Tenant (i.e., when Landlord determines that the then current
tenant of such RFO Premises will vacate such RFO Premises, or any portion
thereof, and when Landlord intends to offer such premises for lease). In no
event shall Tenant have any such rights under this Section 38 in respect of
Landlord's initial leasing (after the date hereof) of any space on the second
floor of 125 Hartwell Avenue.

              (b)    EXERCISE OF RIGHT TO LEASE RFO PREMISES. Landlord shall
give Tenant written notice ("Landlord's Notice") at the time that Landlord
determines, as aforesaid, that RFO

                                       27
<Page>

Premises will become available for lease to Tenant. Landlord's Notice shall set
forth Landlord's designation of the Fair Market Rental Value (as hereinabove
defined) applicable to such RFO Premises, the estimated date on which Landlord
expects to deliver such RFO Premises to Tenant, and the exact location of such
RFO Premises. Tenant shall have the right, exercisable upon written notice
("Tenant's Exercise Notice") given to Landlord within thirty (30) days after the
receipt of Landlord's Notice, to lease such RFO Premises. If Tenant fails timely
to give Tenant's Exercise Notice, Tenant shall have no further right of lease
such RFO Premises pursuant to this paragraph (b). Upon the timely giving of
Tenant's Exercise Notice, Landlord shall lease and demise to Tenant and Tenant
shall hire and take from Landlord, such RFO premises, upon all of the same terms
and conditions of the Lease (including the options to extend described in
Section 36 hereof) except as hereinafter set forth.

              (c)    LEASE PROVISIONS APPLYING TO RFO PREMISES. The leasing to
Tenant of any RFO Premises shall be upon all of the same terms and conditions of
the Lease, including, without limitation, Building Expense Base, except as
follows:

                     (1)    COMMENCEMENT DATE. The Commencement Date in respect
of any RFO Premises shall be the earlier of (A) ninety (90) days after the later
of (x) the estimated delivery date in respect of such RFO Premises as set forth
in Landlord's Notice, or (y) the date that Landlord actually delivers such RFO
Premises to Tenant, or (B) the date on which Tenant shall occupy all or any
portion of such RFO Premises for the conduct of its business therein.

                     (2)    RENT COMMENCEMENT DATE. The Rent Commencement Date
in respect of any RFO Premises shall be the Commencement Date in respect of such
RFO Premises.

                     (3)    TERMINATION DATE. The Termination Date in respect of
any RFO Premises shall be the Termination Date set forth on Exhibit 1 of the
Lease, as the same may be or may have been extended by Tenant pursuant to
Section 36.

                     (4)    BASIC RENT. The Basic Rent rental rate in respect of
any RFO Premises shall be based upon ninety percent (90%) of the Fair Market
Rental Value, as defined in Section 37 of this Lease, of such RFO Premises as of
the Commencement Date in respect of such RFO Premises; provided, however, that
in no event shall the sum of the applicable Basic Rent rental rate and Building
Escalation charges per square foot of rentable area of the RFO Premises be less
than the average, if any (weighted on a square foot basis) of the sum of the
applicable Basic Rent rental rate and Building Escalation Charges, per square
foot in effect, as of such Commencement Date, in respect of the remainder of the
Premises then demised to Tenant.

                     (5)    CONDITION OF RFO PREMISES; TENANT'S RFO WORK. Tenant
shall take any RFO Premises "as-is" in its then (i.e., as of the date of
premises delivery) state of construction, finish, and decoration, without any
obligation on the part of Landlord to construct or prepare any RFO Premises for
Tenant's occupancy. Accordingly, Section 6 shall not apply to the RFO Premises.
However, upon Tenant's exercise of its option to lease RFO Premises and delivery
of such RFO Premises by Landlord to Tenant, Tenant shall have the right, subject
to Landlord's approval of the plans therefor and to the other provisions of
Section 8 above, to make such alterations and improvements to the RFO Premises
as Tenant deems reasonably necessary for its use and occupancy thereof
("Tenant's RFO Work").

                                       28
<Page>

                     (d)    EXECUTION OF LEASE AMENDMENTS. Notwithstanding the
fact that Tenant's exercise of the above-described option to lease RFO Premises
shall be self-executing, as aforesaid, the parties hereby agree promptly to
execute a lease amendment reflecting the addition of any RFO Premises, except
that the Basic Rent payable in respect of any such RFO Premises may not be as
set forth in such amendment. At the time that such Basic Rent is determined, the
parties shall execute a written agreement confirming the same. The execution of
such lease amendments shall not be deemed to waive any of the conditions to
Tenant's exercise of the herein option to lease RFO Premises, unless otherwise
specifically provided in such lease amendments.

       39.    FORCE MAJEURE. As used in this Lease, "Force Majeure" shall mean,
collectively and individually, strike, lock-out or other labor trouble, fire or
other casualty, governmental preemption of priorities or other controls in
connection with a national or other public emergency or shortages of fuel,
supplies or labor; breakdown; accident; or because of war or other emergency, or
for any cause beyond the reasonable control of the party obligated to, but
prevented from performing. In no event, however, shall Force Majeure apply to
nonpayment of monetary obligations.

       40.    ENVIRONMENTAL CONCERNS.

              (a)    Landlord represents, warrants and covenants to the best of
its knowledge and belief that (i) Landlord has not caused or permitted any
activity to take place on, in, or under the Premises which has generated,
manufactured, refined, transported, treated, stored, handled, disposed,
transferred, produced, cleaned up or processed any oil, hazardous or toxic
substances or materials, except in compliance with all applicable federal, state
and local laws, regulations, ordinances and orders, and has not caused or
permitted and has no knowledge of any discharge, release, storage, or disposal
of any oil, hazardous or toxic substances or materials, on, in or under the
Premises in violation of any such laws, etc; (ii) Landlord is in compliance with
all federal, state and local requirements relating to protection of health or
the environment in connection with its ownership or use of the Premises; (iii)
there is no action, suit, lien or other proceeding brought by or threatened by
any governmental agency against Landlord or the Premises to enforce any law,
regulation, ordinance or order relating to protection of health or the
environment or any lien, litigation or other proceeding brought or threatened
against the Landlord or the Premises, or any settlements reached by any
person(s) or group(s) alleging the presence, disposal, release, or threatened
release of any oil, hazardous or toxic substance or material, or on arising from
any activity conducted on the Premises; (iv) there are no underground tanks
located on or under the Premises; and (v) there are no PCBs or PCB contaminated
material or asbestos contained in or otherwise present on, in or under the
Premises.

              (b)    Tenant shall not (either with or without negligence) cause
or permit the illegal escape, disposal or release of any biologically or
chemically active or other hazardous substances or materials. Tenant shall not
allow the storage or use of such substances or materials in any manner not
sanctioned by law or by the highest reasonable standards prevailing in the
industry for the storage and use of such substances or materials, nor allow to
be brought onto the Property and into the Building and such materials or
substances except to use in the ordinary course of Tenant's business, and then
only after written notice is given to Landlord of the identity of such
substances or materials, except that no such notice need be given with respect
to

                                       29
<Page>

ordinary cleaning fluids and other materials ordinarily used incident to routine
business office purposes. If and to the extent that, in such notice, Tenant
advises Landlord that the information contained therein constitutes Tenant's
trade secrets, Landlord shall keep such information confidential; provided,
however, the foregoing confidentiality provisions shall not prevent or restrict
Landlord from disclosing such information to Landlord's environmental
consultants, Landlord's existing or prospective mortgagee(s), or to any
governmental authority having jurisdiction with respect to environmental
matters, or as may be otherwise required by any applicable law, rule or
regulation. Without limitation, hazardous substances and materials shall include
those described in the Comprehensive Environmental Response, Compensation and
Liability Act of 1980, as amended, 42 U.S.C., Section 9601 et seq., the Resource
Conservation and Recovery Act, as amended, 42 U.S.C., Section 6901 et seq., any
applicable state or local laws and the regulations adopted under these acts. If
any governmental agency shall ever require testing to ascertain whether or not
there has been any release or that there exists the threat of any release of
hazardous materials as a result of the act or omission of Tenant (or anyone
claiming by, through or under Tenant), its (or their) agents, employees or
contractors, then the reasonable costs thereof shall be paid by Tenant. In
addition, Tenant shall execute affidavits, representations and the like from
time to time at Landlord's reasonable request concerning Tenant's best knowledge
and belief regarding the presence of hazardous substances or materials on the
Premises. In all events, Tenant shall indemnify Landlord in the manner elsewhere
provided in this Lease from any release of hazardous materials on the Premises
occurring while Tenant is in possession, or elsewhere if caused by Tenant or
persons acting under Tenant. The within covenants shall survive the expiration
or earlier termination of the lease term.

       41.    SIGNS.

              (a)    Subject to Landlord's prior approval, not to be
unreasonably withheld or delayed, Tenant may place (i) Tenant-identification
signs on the entrance doors to the Premises, and (ii) a Tenant-identification
sign on the existing small brick wall located by the driveway entry to the
Property. The Tenant's name, and the name of each division, subsidiary or
affiliate thereof occupying space in the Building, shall be affixed to a
directory board in the Building to be provided by the Landlord at the Landlord'
s expense.

              (b)    If Tenant shall occupy the entire second (2nd) floor of
the Building, or otherwise occupy fifty percent (50%) of the Building Rentable
Area, Tenant shall be permitted either to place a Tenant-identification sign on
the exterior of the Building or to construct a free-standing
Tenant-identification sign on the Property, provided that Tenant shall obtain
and maintain in full force and effect all governmental approvals, licenses,
permits and the like required with respect to the installation and/or
maintenance of such sign. Provided further, however, Landlord shall have the
right to pre-approve the location, size and other design features of any such
sign to be installed by Tenant pursuant to this paragraph (b).

              (c)    At the expiration or earlier termination of the Term of
this Lease, Tenant shall, at its sole cost and expense, remove any signs
installed by Tenant in or upon the Premises, the Building and/or the Property,
and repair any damage thereto caused by the installation, presence and/or
removal of such sign(s).

                                       30
<Page>

       42.    NOTICE OF LEASE. The parties hereto shall in the form attached
hereto as Exhibit 9 execute a notice of this Lease (including any options or
extensions thereof) for recording purposes. The Tenant shall pay all costs of
recording.

       43.    CHANGE OF NAME. If at any time after the execution of this Lease
the Landlord desire to change the existing name of the Building or the
exterior signs now affixed to the Building or the Property, the Landlord shall
notify the Tenant at least sixty (60) days prior to the date of such a change.
If the proposed new name or sign identifies, or in the Tenant's reasonable
judgment may be associated with, a competitor of the Tenant, the Tenant may
require Landlord to refrain from changing the existing name of the Building or
the affixation to the Building or the Property of a new sign.

       44.    MISCELLANEOUS PROVISIONS. The Section and paragraph headings
throughout this instrument, and the Table of Contents, are for convenience and
reference only, and shall not be used to construe this Lease; the provisions of
this Lease shall be construed against both parties in accordance with the
language hereof and no prior statements, representations or agreements not
expressly incorporated herein shall be given effect for this purpose; no remedy
or election given by any provision in this Lease shall be deemed exclusive
unless so indicated, but each shall, wherever possible, be cumulative in
addition to all other remedies in law or equity which either party may have
arising out of the default of the other party and failure to cure such default
within the applicable grace period; each provision hereof shall be deemed both a
covenant and a condition running with the land; failure of either party to cure
a default of the other under this Lease shall not render such non-defaulting
party in any way liable therefor, or relieve the defaulting party from any of
its obligations hereunder; the acceptance of possession of the Premises by the
Tenant shall not be deemed a waiver of any of the obligations under this Lease
to be performed by the Landlord; the Landlord hereby covenants that the Tenant
may deal with any person, firm or corporation for services, supplies, materials,
labor, equipment, transportation, tools, machinery and any other similar or
dissimilar services or items in connection with the use and occupation of the
Premises and any work performed therein, subject to express right of Landlord,
under other provisions of this Lease, to review and approve the selection of any
of the foregoing.

       45.    BINDING AGREEMENT. This Lease shall bind and inure to the benefit
of the parties hereto and their respective executors, distributees, heirs,
representatives, successors and assigns.

       46.    ENTIRE AGREEMENT. This Lease contains the entire agreement of the
parties and may not be modified except by an instrument in writing which is
signed by both parties. No prior statements, representations or agreements not
expressly incorporated therein or herein shall be given effect for this purpose.

                                       31
<Page>

       IN WITNESS WHEREOF, Landlord and Tenant have caused this Lease to be duly
executed, under seal, by persons hereunto duly authorized, in multiple copies,
each to be considered an original hereof, as of the Execution Date state in
Exhibit 1.

LANDLORD:                                 TENANT:

125 HARTWELL TRUST                        FUJI IMMUNOPHARMACEUTICALS
                                          CORP.

By: /S/ MICHAEL L. COLANGELO              By: /S/ STEPHEN D. GILLIES
   --------------------------------          ------------------------------
   Michael L. Colangelo,                     Stephen D. Gillies,
   As Trustee and Not Individually           President
                                             Hereunto Duly Authorized

                                       32
<Page>

                               EXHIBIT 1, SHEET 1

                               125 Hartwell Avenue
                            Lexington, Massachusetts
                                (the "Building")

                                BASIC PROVISIONS
                                       AND
                              LEASE REFERENCE DATA

Execution Date:     October 26, 1992

TENANT              Fuji ImmunoPharmaceuticals Corp.
and Original
Address:            a Delaware corporation
                    (description of business organization

                    400 Brookline Avenue, Suite 8F
                    Boston, Massachusetts  02115
                    (principal place of business-original address)

LANDLORD            125 Hartwell Trust, under a declaration of trust dated
and Original        February 20, 1980 and filed with the Middlesex South
Address:            Registry District of the Land Court as Document No. 600788,
                    as amended. Mailing Address-- c/o Lexington Management
                    Incorporated, 62 Massachusetts Avenue, Lexington, MA 02173,
                    Attention: President

BUILDING:           The building in the town of Lexington, Middlesex County,
                    Massachusetts, known as and numbered 125 Hartwell Avenue,
                    and shown as Lot 2 on Land Court Plan No. 23467C, a copy of
                    which is filed in the Registry of Deeds for the South
                    Registry District of Middlesex County in Registration Book
                    852, Page 189, with Certificate of Title No. 144539.

PROPERTY:           The Building and the Land Parcel on which it is located
                    (including adjacent sidewalks and parking areas).

<Page>

                               EXHIBIT 1, SHEET 2

                               125 Hartwell Avenue
                            Lexington, Massachusetts
                                (the "Building")

                                BASIC PROVISIONS
                                       AND
                              LEASE REFERENCE DATA

ESTIMATED RENT
COMMENCEMENT        February 1, 1993
DATE:

TERM:               The period commencing (the 'Commencement Date") on the Rent
                    Commencement Date and expiring on the date immediately
                    preceding the fifth (5th) anniversary of the Rent
                    Commencement Date, provided that it the Rent Commencement
                    Date occurs on any day other than the first day of a
                    calendar month, the expiration date ("Termination Date")
                    shall be the last day of the calendar month in which the
                    fifth (5th) anniversary of the Rent Commencement Date shall
                    fall, subject to the terms and conditions hereof, including
                    options to extend.

PREMISES            10,980 (+/-50) square feet of Premises Rentable Area in the
DESCRIPTION AND     Building, substantially as shown on Exhibit 3. The Premises
AREA:               are subject to expansion as provided in Article 38 below.

BUILDING            38,400 square feet.
RENTABLE AREA:

BASIC RENT:         $104,310.00 per year ($8,692.50 per month).

SECURITY DEPOSIT:   N/A

PERMITTED USES:     To be used and occupied by the Tenant for office, research
                    and development; engineering, education and training of the
                    Tenant's customers and employees; light assembly and
                    manufacturing; processing, packaging, marketing, sales and
                    all other uses or activities incidental or related thereto.

                                       34
<Page>

                               EXHIBIT 1, SHEET 3

                               125 Hartwell Avenue
                            Lexington, Massachusetts
                                (the "Building")

                                BASIC PROVISIONS
                                       AND
                              LEASE REFERENCE DATA

TENANT'S            10,980 S/F divided by 38,400 S/F or 28.59%
PROPORTIONATE
SHARE:

BUILDING EXPENSE    $172,800.00
BASE:

BROKER:             Ian Grant, Spaulding & Slye Colliers
                    High Street Tower
                    125 High Street
                    16th Floor
                    Boston, MA  02110

LANDLORD'S          Lexington Management Incorporated
AGENT:              62 Massachusetts Avenue, Lexington, MA  02173

TENANT'S            H. Randolph Lewis
CONSTRUCTION        Olson Lewis
REPRESENTATIVE:     17 Elm Street
                    Manchester, MA  01944

TENANT'S            Kaplan Corporation, Contractors and Builders
CONTRACTOR:         116 Harvard Street
                    Brookline, MA  02146

LANDLORD:                                 TENANT:

125 HARTWELL TRUST                        FUJI IMMUNOPHARMACEUTICALS
                                          CORP.

By: /S/ MICHAEL L. COLANGELO              By: /S/ STEPHEN D. GILLIES
   --------------------------------          ---------------------------
   Michael L. Colangelo, As Trustee          Dr. Stephen D. Gillies,
   and Not Individually                      President

                                       35
<Page>

                                    EXHIBIT 2

                               125 HARTWELL AVENUE

                            LEXINGTON, MASSACHUSETTS

                              BUILDING EXPENSE BASE

BUILDING SIZE - 38,400 RSF

<Table>
<Caption>
                                             ESTIMATED
                                               COST            PSF
                                            ------------   -----------
<S>     <C>                                   <C>              <C>
1.      Property Taxes                        $   75,000       $  1.96
2.      Boston Gas (Heat & Hot Water)         $    7,890           .21
3.      Electricity (House Panel)             $    3,800           .10
4.      Ground Maintenance                    $    8,210           .21
5.      HVAC Maintenance                      $    6,750           .18
6.      Janitorial & Trash Removal            $   38,500       $  1.00
7.      Insurance                             $    6,080           .16
8.      Maintenance & Repairs                 $    4,068           .10
9.      Sewer & Water                         $    3,072           .08
10.     Property Management                   $   19,200           .50
                                            -----------    -----------
TOTAL BUILDING (TAX & OPERATING) EXPENSES     $  172,800       $  4.50
</Table>

<Page>

                                    EXHIBIT 3

                                   FLOOR PLANS

<Page>

                                    EXHIBIT 4

                            ITEMS OF TENANT'S WORK TO
                            BE PAID FROM THE PROCEEDS
                           OF LANDLORD'S CONTRIBUTION

     The following items shall be performed, purchased and/or installed, as the
case may be, in the Premises by Tenant and paid for utilizing Landlord's
Contribution, all as set forth in Section 6(e) of the Lease:

     1.   new carpet or vinyl composition tile, as Tenant may elect, throughout
the Premises;

     2.   repaint all existing walls;

     3.   replace broken or damaged acoustical ceiling titles; and

     4.   repair or adjust, as appropriate, the existing Building mechanical
systems, consistent with Tenant's requirements contained in Tenant's Plans.

<Page>

                                    EXHIBIT 5

                               125 HARTWELL AVENUE
                            LEXINGTON, MASSACHUSETTS
                                   FACT SHEET

<Table>
<S>  <C>  <C>                                       <C>
A.   GENERAL

     1.   Site                                      4.1 Acres, . 5 Acres
                                                    Conservation Land

     2.   Building Area                             38,400 rentable square feet/2
                                                    floors

     3.   Parking                                   140 spaces or 3.8:1 ratio
                                                    including 11 visitor spaces and
                                                    4 handicapped

     4.   Developer Owner                           125 Hartwell Trust

     5.   Management                                Lexington Management
                                                    Incorporated

B.   CONSTRUCTION MATERIALS INFORMATION

     1.   Floor Loading Capacity                    Floor 1 - Slab on grade-150 psf
                                                    Floor 2 - 50 psf - Partitions

     2.   Glass                                     PPG 1" Solar Cool reflective
                                                    insulated glass set in
                                                    individual black anodized
                                                    frames.

     3.   Brick                                     Glen Gery "Dark Ironspot"
                                                    4" X 8" utility.

     4.   Roof                                      Carlisle .060 EPDM elastomeric
                                                    sheet roofing fully adhered
                                                    non-ballasted to 2" ISG
                                                    insulation.

     5.   HVAC System                               Heat is provided through
                                                    perimeter baseboard radiation
                                                    supplied by a gas fired forced
                                                    hot water boiler. Ventilation
                                                    and cooling is supplied by two
                                                    45 ton roof top variable air
                                                    volume units with economizer
                                                    cycles. The air distribution
                                                    system is medium pressure
                                                    through overhead insulated duct
                                                    work with variable air.
</Table>

                                  -Exhibit 5-1-
<Page>

<Table>
<S>  <C>  <C>                                       <C>
     6.   Sprinklers                                A light service (office/R&D)
                                                    wet sprinkler system is
                                                    provided throughout.

     7.   Electrical Service                        1200 AMP 480/277 Volt - 3 phase
                                                    4 wire.

     8.   Lobby                                     Features atrium with natural
                                                    plant boxes and bench seating,
                                                    brick paver flooring, and brick
                                                    walls.

     9.   Service Core                              Stairs, rest rooms, showers,
                                                    freight elevator, boiler and
                                                    maintenance rooms are located
                                                    in the central service core.

     10.  Loading                                   One truck height loading dock
                                                    at rear of building.

     11.  Drinking Fountain                         One handicapped accessible
                                                    drinking fountain per floor.

C.   STANDARDS FOR MATERIALS FOR
     NEW TENANT FIT-UP (to be provided by Tenant)

     1.   Lighting                                  Columbia "Parabolume" low
                                                    brightness 2X4 fixtures with
                                                    energy saving ballasts.

     2.   Doors                                     Interior doors will be solid
                                                    core birch paint grade wood
                                                    paneled in welded metal door
                                                    frames. Size - 3' X 7'0".

    3.    Hardware                                  Entrance Door: Sargent lever
                                                    handled mortise handset.
                                                    Interior Doors: Sargent 7 line
                                                    lever handled, latchsets or
                                                    equivalent. Hinges: Stanley 4
                                                    Knuckle Butts, 1 1/2 pair per
                                                    frame. Finish: Brushed
                                                    Chrome.

     4.   Ceiling                                   Exposed 'T' 24" X 48" X 5/8"
                                                    thick lay in acoustical panel
                                                    system. Armstrong "Shasta".
                                                    Ceiling heights to be finished
                                                    at 8'6". Volume units to
                                                    control space temperature.

     5.   Flooring                                  Philadelphia "Evolution" 32 oz.
                                                    Commercial continuous filament
                                                    nylon carpet, or Armstrong
</Table>

                                  -Exhibit 5-2-
<Page>

<Table>
     <S>  <C>                                       <C>
                                                    "Excellon" vinyl composition
                                                    tile.

     6.   Paint                                     Benjamin Moore latex "eggshell"
                                                    wall paint. Benjamin Moore
                                                    "semi gloss" oil paint on all
                                                    doors and frames.

     7.   Sun Control                               1" Levelor Horizontal Blinds at
                                                    all Exterior Glass.
</Table>

                                 -Exhibit 5-3-
<Page>

                                    EXHIBIT 6

                              RULES AND REGULATIONS

     Tenant shall comply with the following Rules and Regulations and with such
other reasonable Rules and Regulations as Landlord may promulgate for the
Building and the Park:

     (1)  The sidewalks, entrances, driveways, stairways and halls shall not be
obstructed or encumbered by any tenant or used for any purpose other than for
ingress to and egress from the leased Premises and for delivery of merchandise
and equipment in a prompt and efficient manner using loading docks and
passageways designated for such delivery by Landlord. There shall not be used in
any space, either by any tenant or by jobbers or others in the delivery or
receipt of merchandise, any hand trucks, except those equipped with rubber tires
and sideguards.

     (2)  The water and wash closets and plumbing fixtures shall not be used for
any purposes other than those for which they were designed or constructed and no
sweepings, rubbish, rags, or acids or other substances shall be deposited
therein, and the expense of any breakage, stoppage or damage resulting from the
violation of this rule shall be borne by the tenant who, or whose agents,
employees or visitors, shall have caused it.

     (3)  No carpet, rug or other article shall be hung or shaken out of any
window of the Building; and no tenant shall sweep or throw or permit to be
swept or thrown from the leased Premises any dirt or other substances out of
the doors or windows or stairways of the Building and no tenant shall use,
keep or permit to be used or kept any foul or noxious gas or substance in its
leased Premises or permit or suffer its leased Premises to be occupied or
used in a manner offensive or objectionable to Landlord or other occupants of
the Building by reason of noise, odors and/or vibrations, or interfere in any
way with other tenants or those having business therein, nor shall any
animals or birds be kept in or about the Building, except that Tenant may
keep animals or birds, etc. on the Premises necessary for the conduct of its
business therein, subject to the conditions set forth in clause (i) of the
last sentence of Section 24 of the Lease to which these Rules and Regulations
are attached.

     (4)  No awnings or other projections shall be attached to the outside walls
of the Building without the prior written consent of the Landlord.

     (5)  No sign, advertisement, notice or other lettering shall be exhibited,
inscribed, painted or affixed by any tenant on any part of the outside of the
lease Premises or the Building or the inside of the leased Premises if the same
is visible from the outside of the leased Premises without prior written consent
of the Landlord. In the event of the violation of the foregoing by

                                  -Exhibit 6-1-
<Page>

any tenant, Landlord may remove same without any liability, and may charge the
expense incurred by such removal to the tenant(s) violating this rule.

     (6)  No tenant shall mark, paint, drill into, or in any way deface any part
of the leased Premises or the Building of which they form a part. No boring,
cutting or stringing of wires shall be permitted, except with the prior written
consent of Landlord, and as Landlord may direct. No tenant shall lay linoleum,
or other similar floor covering, so that the same shall come in direct contact
with the floor of the leased Premises, and, if linoleum or other similar floor
covering is desired to be used, an interlining of builder's deadening felt shall
be first affixed to the floor, by a paste or other material, soluble in water,
the use of cement or other similar adhesive material being expressly prohibited.

     (7)  No additional locks or bolts of any kind shall be placed upon any of
the doors or windows by any tenant, nor shall any changes be made in existing
locks or mechanism thereof. Each tenant must, upon the termination of its
tenancy, restore to Landlord all keys of stores, offices and electrical rooms,
either furnished to, or otherwise procured by, such tenant, and in the event of
the loss of any keys so furnished, such tenant shall pay to Landlord the cost
thereof.

     (8)  Freight, furniture, business equipment, merchandise and bulky matter
of any description shall be delivered to and removed from the leased Premises
only on loading dock(s) in the rear of the leased Premises.

     (9)  Canvassing, soliciting and peddling in the Building and the Park is
prohibited and each tenant shall cooperate to prevent the same.

     (10) Landlord shall have the right to prohibit any advertising by any
tenant which, in Landlord's opinion, tends to impair the reputation of the
Building or its desirability as a Building for offices, research and development
and light assembly, and upon written notice from Landlord, such tenant shall
refrain from or discontinue such advertising.

     (11) No tenant shall bring or permit to be brought or kept in or on the
leased Premises, any inflammable, combustible or explosive fluid, material,
chemical or substance, without the prior written consent of Landlord, which
consent will not be unreasonably withheld or delayed (except that chemicals,
combustible or otherwise, shall be permitted on the Premises, without Landlord's
consent, as necessary for the conduct of Tenant's business therein, subject to
the provisions of Section 40(b) of the Lease to which these Rules and
Regulations are attached), or cause or permit any odors of cooking or other
processes, or any unusual or other objectionable odors to permeate in or emanate
from the leased Premises.

                                  -Exhibit 6-2-
<Page>

                                    EXHIBIT 7

                             CLEANING SPECIFICATIONS

1.   CLEANING: Cleaning and janitor services as provided below:

     A:   OFFICE AREAS.

Daily (Monday through Friday, inclusive, holiday excepted):

1.   Empty and clean all waste receptacles and ash trays and remove waste
     material from the Premises; wash receptacles as necessary.

2.   Sweep and dust mop all uncarpeted areas using a dust treated mop.

3.   Vacuum all rugs and carpeted areas.

4.   Hand dust and wipe clean with treated cloths all horizontal surfaces,
     including furniture, office equipment, window sills, chair rails, convector
     tops, door ledges, base boards, and grill work, within normal reach.

5.   Wash clean all water fountains and adjacent floor areas.

6.   Upon completion of cleaning, all lights will be turned off and all doors
     locked, leaving the Premises in an orderly condition.

Weekly:

1.   Brush and hand dust all carpet edges or other areas non-accessible to
     vacuum attachments.

2.   Remove all finger marks from private entrance doors, light switches and
     doorways.

3.   Dust all ventilating, air conditioning, louvers and grills.

Every Month or When Needed:

1.   All resilient tile floors to be washed or cleaned with dry system cleaner.

Quarterly:

1.   Dusting of accessible surfaces not reached by daily cleaning.

2.   Move and vacuum clean underneath all furniture that can reasonably be
     moved.

                                  -Exhibit 7-1-
<Page>

3.   Clean inside of all windows as needed. Clean outside of all windows weather
     permitting.

B.   LAVATORIES.

Daily (Monday through Friday, inclusive, holiday excepted):

1.   Sweep and wash floors.

2.   Wash and polish all mirrors, powder shelves, bright work, flushometers,
     piping and toilet seat hinges.

3.   Wash both sides of all toilet seats.

4.   Wash all basins, bowls and urinals.

5.   Dust all partitions, tile walls, dispensers and receptacles.

6.   Dust and clean all powder room fixtures.

7.   Empty and clean paper towel and sanitary disposal receptacles.

8.   Remove waste paper and refuse from the Premises.

9.   Refill tissue holders, soap dispensers, towel dispenser, sanitary
     dispensers, materials to be furnished by Lessor.

Monthly:

1.   Machine scrub lavatory floors.

2.   Wash all partitions and tile walls in lavatories.

C.   MAIN LOBBIES, ELEVATORS, STAIR WELLS AND COMMON CORRIDORS

Daily (Monday through Friday, inclusive, holidays excepted):

1.   Sweep and wash all floors, empty and clean waste receptacles, dispose of
     waste.

2.   Wash all rubber mats.

3.   Clean elevators, wash or vacuum floors, wipe down walls and doors.

4.   Clean any metal work inside lobbies.

5.   Clean any metal work surrounding Building entrance doors.

6.   Clean glass in the common areas, including interior of elevator cabs and
     entrance vestibules, but excluding glass in atriums.

                                  -Exhibit 7-2-
<Page>

Monthly:

1.   All resilient tile floors in public areas to be washed and waxed or cleaned
     with dry system cleaner.

                                  -Exhibit 7-3-
<Page>

                                    EXHIBIT 8

<Table>
<S>                                       <C>
[ILLEGIBLE] ORD. CERTIFICATE OF INSURANCE                                                                  ISSUE DATE (MM/DD/YY)
                                                                                                                        10/14/92
------------------------------------------------------------------------------------------------------------------------------------
                                          THIS CERTIFICATE IS ISSUED AS A MATTER OF INFORMATION ONLY AND CONFERS NO RIGHTS UPON THE
                                          CERTIFICATE HOLDER. THIS CERTIFICATE DOES NOT AMEND, EXTEND OR ALTER THE COVERAGE AFFORDED
                                          BY THE POLICIES BELOW.
[ILLEGIBLE] E A STEVENS CO INC            ------------------------------------------------------------------------------------------
[ILLEGIBLE] 389 MAIN ST BOX 188                                              COMPANIES AFFORDING COVERAGE
[ILLEGIBLE] MALDEN       MA 02148-5076    ------------------------------------------------------------------------------------------
                                          COMPANY A       CONTINENTAL INS COS
                                          LETTER
                                          ------------------------------------------------------------------------------------------
----------------------------------------- COMPANY B
                                          LETTER
                                          ------------------------------------------------------------------------------------------
[ILLEGIBLE] LEXINGTON MANAGEMENT          COMPANY C       CONTINENTAL INS COS
[ILLEGIBLE] 62 MASSACHUSETTS AV           LETTER
[ILLEGIBLE] LEXINGTON    MA 02173         ------------------------------------------------------------------------------------------
                                          COMPANY D
                                          LETTER
                                          ------------------------------------------------------------------------------------------
                                          COMPANY E       CONTINENTAL INS COS
                                          LETTER
------------------------------------------------------------------------------------------------------------------------------------
[ILLEGIBLE]
------------------------------------------------------------------------------------------------------------------------------------
</Table>

[ILLEGIBLE] IS TO CERTIFY THAT THE POLICIES OF INSURANCE LISTED BELOW HAVE BEEN
ISSUED TO THE INSURED NAMED ABOVE FOR THE POLICY PERIOD [ILLEGIBLE] DATED,
NOTWITHSTANDING ANY REQUIREMENT, TERM OR CONDITION OF ANY CONTRACT OR OTHER
DOCUMENT WITH RESPECT TO WHICH THIS CERTIFICATE MAY BE ISSUED OR MAY PERTAIN,
THE INSURANCE AFFORDED BY THE POLICIES DESCRIBED HEREIN IS SUBJECT TO ALL THE
TERMS, [ILLEGIBLE] AND CONDITIONS OF SUCH POLICIES. LIMITS SHOWN MAY HAVE BEEN
REDUCED BY PAID CLAIMS.

<Table>
<Caption>
                                                     POLICY EFFECTIVE  POLICY EXPIRATION
TYPE OF INSURANCE                     POLICY NUMBER   DATE (MM/DD/YY)   DATE (MM/DD/YY)                 LIMITS
------------------------------------------------------------------------------------------------------------------------------------
<S>                                      <C>                  <C>                <C>       <C>                           <C>
[ILLEGIBLE] LIABILITY                    0610096893           7/15/92            7/15/93   GENERAL AGGREGATE             $ 2,000,000
                                                                                           -----------------------------------------
[ILLEGIBLE] COMMERCIAL GENERAL                                                             PRODUCTS COMP/OF AGG.         $ 2,000,000
LIABILITY
                                                                                           -----------------------------------------
[ILLEGIBLE] / / CLAIMS MADE /X/ OCCUR.                                                     PERSONAL & ADV. INJURY        $ 1,000,000
                                                                                           -----------------------------------------
[ILLEGIBLE] OWNER'S & CONTRACTOR'S                                                         EACH OCCURENCE                $ 1,000,000
[ILLEGIBLE]
                                                                                           -----------------------------------------
                                                                                           FIRE DAMAGE (Any one          $    50,000
                                                                                           [ILLEGIBLE])
                                                                                           -----------------------------------------
                                                                                           MED. EXPENSE (Any             $     5,000
                                                                                           [ILLEGIBLE])
------------------------------------------------------------------------------------------------------------------------------------
[ILLEGIBLE] LIABILITY                                                                      COMBINED SINGLE               $
                                                                                           LIMIT
[ILLEGIBLE] AUTO                                                                           -----------------------------------------

[ILLEGIBLE] ALL OWNED AUTOS                                                                BODILY INJURY                 $
                                                                                           ([ILLEGIBLE])
[ILLEGIBLE] SCHEDULED AUTOS                                                                -----------------------------------------

[ILLEGIBLE] HIRED AUTOS                                                                    BODILY INJURY                 $
                                                                                           PER ACCIDENT
[ILLEGIBLE] NON-OWNED AUTOS                                                                -----------------------------------------

[ILLEGIBLE] GARAGE LIABILITY                                                               PROPERTY DAMAGE               $
------------------------------------------------------------------------------------------------------------------------------------
[ILLEGIBLE] LIABILITY                    0610096893           7/15/92            7/15/93   EACH OCCURRENCE               $ 2,000,000
                                                                                           -----------------------------------------
UMBRELLA FORM                                                                              AGGREGATE                     $ 2,000,000
                                                                                           -----------------------------------------
[ILLEGIBLE] OTHER THAN UMBRELLA FORM                                                       [ILLEGIBLE]
------------------------------------------------------------------------------------------------------------------------------------
                                                                                             STATUTORY LIMITS
[ILLEGIBLE] WORKER'S COMPENSATION                                                          -----------------------------------------
                                                                                           EACH ACCIDENT                 $
         AND                                                                               -----------------------------------------
                                                                                           DISEASE--POLICY LIMIT         $
[ILLEGIBLE] EMPLOYERS' LIABILITY                                                           -----------------------------------------
                                                                                           DISEASE--EACH EMPLOYEE        $
------------------------------------------------------------------------------------------------------------------------------------
                                         0610096893           7/15/92            7/15/93
[ILLEGIBLE] PROPERTY
------------------------------------------------------------------------------------------------------------------------------------
[ILLEGIBLE] OF OPERATIONS/LOCATIONS/VEHICLES/SPECIAL ITEMS
[ILLEGIBLE] 125 HARTWELL AVE LEXINGTON MA BLANKET BLDG LIMIT @ $13391000 DED $1000 [ILLEGIBLE] REPLACEMENT COST COVERAGE AGREED
AMOUNT CLAUSE LOSS OF RENT COVERAGE @ [ILLEGIBLE] 000 BLDG LIMIT FOR LOCATION @ $2671000
------------------------------------------------------------------------------------------------------------------------------------
[ILLEGIBLE] HOLDER                                      CANCELLATION
------------------------------------------------------------------------------------------------------------------------------------
                                                         SHOULD ANY OF THE ABOVE DESCRIBED POLICIES BE CANCELLED BEFORE THE
[ILLEGIBLE] FUJI - IMMUNO - PHARMACEUTICAL               EXPIRATION DATE THEREOF, THE ISSUING COMPANY WILL ENDEAVOR TO MAIL 30 DAYS
[ILLEGIBLE] 125 HARTWELL AVE                             WRITTEN NOTICE TO THE CERTIFICATE HOLDER NAMED TO THE LEFT, BUT FAILURE TO
[ILLEGIBLE] LEXINGTON MA01940                            MAIL SUCH NOTICE SHALL IMPOSE NO OBLIGATION OR LIABILITY OF ANY KIND UPON
                                                         THE COMPANY, ITS AGENTS OR REPRESENTATIVES.
                                                         ---------------------------------------------------------------------------
                                                         AUTHORIZED [ILLEGIBLE]
                                                         /s/ [ILLEGIBLE]
</Table>

<Page>

                                    EXHIBIT 9

                                 NOTICE OF LEASE

                  In accordance with Massachusetts General Laws
                                Chapter 185, Section 71

Date of Execution:         October 23, 1992

Description of
Premises Leased:           10, 980 (+/- 50) square feet of Premises in the
                           building in the Town of Lexington, Middlesex County,
                           Massachusetts, known as and numbered 125 Hartwell
                           Avenue. Said building is located on land shown as Lot
                           2 on Land Court Plan No. 23467C, a copy of which is
                           filed in the Registry of Deeds for the South Registry
                           District of Middlesex County in Registration Book
                           852, Page 189, with Certificate of Title No. 144539.

Term:                      The period commencing on the Rent Commencement Date
                           (as defined in the Lease) and expiring on the date
                           immediately preceding the fifth (5th) anniversary of
                           the Rent Commencement Date, provided that if the Rent
                           Commencement Date occurs on any day other than the
                           first day of a calendar month, the expiration date
                           ("Termination Date") shall be the last day of the
                           calender month in which the fifth (5th) anniversary
                           of the Rent Commencement Date shall fall, subject to
                           rights of extension as described herein.

                           Estimated Rent Commencement Date is February 1, 1993.

Rights of Extension and
Expansion:                 Two consecutive five (5) year options to extend the
                           Lease term. Rights of first refusal to lease
                           additional promises on the 2nd floor of the Building
                           after the initial leasing thereof.

This Notice of Lease has been executed for recording purposes only, and shall
not be deemed to amend or supplement the Lease. In the event of any conflict
between the provisions of this Notice of Lease and the provisions of the Lease,
the provisions of the Lease shall control.

                                  -Exhibit 9-1-
<Page>

     Signed, sealed and delivered this 23rd day of October, 1992.

                                       LESSOR

                                       125 HARTWELL TRUST*

                                       By:
                                       -----------------------------------------
                                           Michael L. Colangelo, as Trustee
                                       of 125 Hartwell Trust and not
                                       individually

                                       LESSEE

                                       FUJI IMMUNOPHARMACEUTICALS CORP.

                                       By:
                                       -----------------------------------------
                                           Stephen D. Gillies, President

*125 Hartwell Trust, under a declaration of trust dated February 20, 1980 and
filed with the Middlesex South Registry District of the Land Court as Document
No. 600788, as amended; Mailing Address - c/o, Lexington Management
Incorporated, 62 Massachusetts Avenue, Lexington, NA 02173, Attention:
President.

                         COMMONWEALTH OF MASSACHUSETTS

______________, SS.                                         October ____, 1992

     Then personally appeared before me the above-named Michael L. Colangelo,
Trustee of the 125 Hartwell Trust and acknowledged the foregoing to be his free
act and deed as Trustee, as of the date first above written.

                                       -----------------------------------------
                                       Notary Public
(Seal)                                 My Commission Expires:

                                  -Exhibit 9-2-
<Page>

                          COMMONWEALTH OF MASSACHUSETTS

_____________, SS.                                           October ___, 1992

     Then personally appeared before me the above-named Stephen D. Gillies,
President of Fuji ImmunoPharmaceuticals Corp., and acknowledged the foregoing to
be his free act and deed and the duly authorized free act and deed of Fuji
ImmunoPharmaceuticals Corp., as of the date first above written.

                                   -------------------------------------------
                                   Notary Public
(Seal)                             My Commission Expires:

                                  -Exhibit 9-3-
<Page>

                                   EXHIBIT 10

                                   FLOOR PLAN

<Page>

                               125 Hartwell Avenue

                            Lexington, Massachusetts
                                (the "Building")

                                 FIRST AMENDMENT
                             As of January 31, 1993

<Table>
<S>                                  <C>
          LANDLORD:                  125 Hartwell Trust

          TENANT:                    Fuji ImmunoPharmaceuticals Corp.

          EXISTING PREMISES:         An area containing 1.0,980 (+/-50) square
                                     feet of Premises Rentable Area located on
                                     the second (2nd) floor of the Building,
                                     substantially as shown on Exhibit 3 to the
                                     Lease.

ORIGINAL  LEASE EXECUTION DATE:      October 26, 1992
LEASE
DATA:     PREVIOUS LEASE             None
          AMENDMENTS:

          ADDITIONALPREMISES:        An area containing 8,830 square feet of
                                     Premises Rentable Area located on the
                                     second (2nd) floor of the Building,
                                     substantially as shown as the "RFO
                                     Premises" on Exhibit 3 to the Lease.
</Table>

       WHEREAS, Tenant desires to lease additional premises in the Building, to
wit, the Additional Premises; and

       WHEREAS, Landlord is willing to lease the Additional Premises to Tenant
on the terms and conditions hereinafter set forth.

       NOW THEREFORE, the above-described lease (the "Lease") is hereby amended
as follows:

       1.     MATTERS PERTAINING TO THE EXISTING PREMISES.

              Landlord and Tenant wish to confirm certain understandings with
respect to the Existing Premises.

Accordingly, Landlord and Tenant hereby acknowledge and agree that:

              A.     The Commencement Pate in respect of the Existing Premises
shall be February 1, 1993.

<Page>

              B.     The Rent Commencement Date in respect of the Existing
Premises shall be February 1, 1993.

              C.     The Termination Date in respect of the Existing Premises
shall be January 31, 1998, subject to the options to extend set forth in Section
36 of the Lease.

              D.     The Basic Rent in respect of the Existing Premises shall be
increased to $115,290.00 per year (i.e., $9,607.50 per month).

              E.     Section 6(g) of the Lease is hereby deleted in its
entirety.

              F.     The following clause (10) is hereby added to Section 12(a)
of the Lease before the last sentence thereof:

                     (10) Air conditioning in accordance with seasonal
                     requirements on Mondays' through Fridays (except legal
                     holidays) from 8:00 am. to 6:00 p.m. and at such additional
                     times as may be requested by Tenant from tine to time upon
                     reasonable advance notice to Landlord. Landlord's cost of
                     supplying such additional service shall be paid by Tenant
                     or alternatively shall be shared proportionately between
                     Tenant and other tenants, if any who request such service.
                     Any such costs for additional air conditioning services
                     whether requested by Tenant or other tenants in the
                     Building shall not be included in Operating Costs but
                     calculated as a separate charge to Tenant, and/or other
                     tenants, by Landlord.

              G.     The first sentence of section 12(b) of the Lease is hereby
deleted and replaced by the following:

                     Tenant shall contract directly with the electric utility
                     supplier to furnish electric current to the Premises
                     through the existing utility facilities serving the
                     Building for lighting, outlets and equipment installed by
                     Tenant.

              H.     Section 12(c) of the Lease is hereby deleted in its
entirety.

              I.     The parenthetical at the end of clause (a) of Section 14(a)
(ii) of the Lease is hereby deleted in its entirety.

              J.     The Building Expense Base in respect of the Existing
premises shall be increased to $211,200.00. In furtherance thereof:

                     (i)    Exhibit 2 to the Lease is hereby deleted and
replaced by Exhibit 2 attached hereto and made a part hereof; and

                     (ii)   The figures "$198,720.00" and "$228,528.00" as they
appear in Section 14(a) (v) of the Lease are hereby deleted and the figures
"$242,880.00" and "$279,312.00", respectively, are inserted, in place thereof.

                                        2
<Page>

              K.     Tenant has installed supplemental roof-top HVAC units to
provide additional heat and air conditioning to the Existing Premises. Such
units have been separately metered by Tenant for gas and electricity. Tenant
shall pay all charges as reflected on such meters directly to the applicable
utility suppliers. Tenant shall maintain and keep such meters in good condition
and repair throughout the Text of the Leans. Landlord and Tenant further
acknowledge and agree that any supplemental roof-top HVAC units which Tenant
intends to install to provide additional heat end air conditioning to the
Additional Premises (which installation shall be subject to the terms and
conditions of the Lease, as hereby amended) shall be connected by Tenant to the
meters measuring the consumption of gas and electricity with respect to the
roof-top HVAC units serving the Existing Premises, and Tenant shall pay all
charges as reflected on such meters directly to the applicable utility
suppliers, as aforesaid.

              L.     Section 18(b) of the Lease is hereby deleted in its
entirety.

       2.     DEMISE OF ADDITIONAL PREMISES

              Landlord hereby demises and leases to Tenant, and Tenant hereby
hires and takes from Landlord, the Additional Premises. Said demise of the
Additional Premises shall be upon all of the same tens and conditions of the
Lease (as hereby amended) applicable to the Existing Premises (including,
without limitation, the Commencement Pate of February 1, 1993, the Rent
Commencement Date of February 1, 1993, the Termination Date of January 11, 1998
(which shall be subject to the options to extend set forth in Section 36 of the
Lease), and the Building Expense Base of $211,200.00), except as follows:

              A.     The Basic Rent payable in respect of the Additional
Premises shall be as follows:

                     (i)    For the period commencing on the Rent Commencement
Date (i.e., February 1, 1993) and ending on January 31, 1994, an amount (the
"Base Additional Premises Rental Amount") equal to $39,735.00 per year (i.e.,
$3,311.25 per month). Notwithstanding anything to the contrary herein contained,
if Tenant shall occupy any portion of the Additional Premises for the conduct of
its business prior to February 1, 1994, then the Base Additional Premises Rental
Amount for the period from the date that Tenant first occupies such portion of
the Additional Premises for the conduct of its business through January 31, 1994
shall be increased by the product of (I) Seven Dollars ($7.00) per square foot
of Premises Rentable Area per year, multiplied by (II) the number of square feet
of Premises Rentable Area of such portion of the Additional Premises occupied by
Tenant for the conduct of its business (e.g., if Tenant occupies 4,415 square
feet of Premises Rentable Area of the Additional Premises on August 1, 1993,
then the Base Additional Premises Rental Amount as of August 1, 1993 shall be
increased from $39,735.00 per year to $70,640.00 per year); and

                     (ii)   For the period commencing on February 1, 1994 and
ending on the Termination Date (i.e., January 31, 1998), $101,545.00 per year
(i.e., $8,462.08 per month).

Accordingly, the Basic Rent payable in respect of all premises demised by Tenant
under the Lease (i.e., the Existing Premises and the Additional Premises) shall
be as follows:

                                        3
<Page>

                            (x)    For the period commencing on the Rent -
Commencement Date and ending on January 31, 1994, an annual amount equal to the
sum of (A) $115,290.00, plus (B) the Base Additional Premises Rental Amount (as
and to the extent the same may be increased in accordance with clause (i)
above); and

                            (y)    For the period commencing on February 1, 1994
and ending on the Termination Pate, $216,835.00 per year (i.e., $18,069.58 per
month).

              B      Tenant's Proportionate Share in respect of the Additional
Premises shall be 8,830 S/F divided-by 36,400 S/F, or 23.00%. Accordingly,
Tenant's Proportionate Share in respect of all premises demised by Tenant under
the Lease (i.e., the Existing Premises and the Additional Premises) shall be
51.59%.

              C.     In accordance with section 2 of the Lease, Tenant shall, by
reason of the demise of the Additional Premises, be entitled to an additional
thirty-four (34) parking spaces in the paved parking area located adjacent to
the Building as shown cm Exhibit 3 to the Lease, the use of which spaces shall
be subject to the same tens and conditions of the Lease applicable to the
original forty-one (41) spaces provided to Tenant incident to its lease of the
Existing Premises. Accordingly, the total number of parking spaces which
Landlord shall provide and maintain for the use of Tenant's employees and
invitees pursuant to Section 2 of the Lease shall be seventy-five (75).

              D.     Section 6 at the Lease shall not apply to the Additional
Premises, except to the extent otherwise provided in Paragraph 3 of this First
Amendment.

              E.     Any other provisions of the Lease inconsistent with this
First Amendment or the state of facts contemplated hereby.

       3.     CONDITION OF ADDITIONAL PREMISES

              A.     Tenant hereby accepts the Additional Premises in their
"as-is" condition (i.e., in the condition which they are in as of the
Commencement Date in respect of the Additional Premises) without any obligation
on the part of Landlord to prepare or construct the Additional Premises for
Tenant's occupancy. Tenant shall, at Tenant's sole cost and expense, subject to
the provisions of subparagraph C below, prepare the Additional Premises for
Tenant's occupancy (except as described in subparagraph D below). Tenant shall
use all reasonable diligence to perform its work ("Tenant's Additional Premises
Work") in the Additional Premises in a timely manner.

              B.     Tenant's Additional Premises Work shall be performed by
Tenant subject to, in accordance with and upon the same terms and conditions of
sections 6(b), (c), (d) and (h) of the Lease applicable to the performance of
Tenant's Work in the Existing Premises, except as follows:

                     (i)    The last sentence of Section 6(b) of the Lease shall
have no force or effect upon, nor applicability to, the Additional Premises or
Tenant's Additional Premises Work. Tenant shall have the right, subject to the
terms and conditions of Sections 6(b), (c), (d)

                                        4
<Page>

and (h) end the other relevant provisions of the Lease (as hereby amended), to
install supplemental roof-top HVAC units to provide additional beat and air
conditioning to the Additional Premises.

                     (ii)   Tenant's termination right set forth in Section 6(c)
of the Lease, as it relates to Tenant's Additional Premises Work, shall apply
only to the Additional Premises and not the Existing Premises (i.e., in the
event that such right of termination arises in connection with the performance
of Tenant's Additional Premises Work, Tenant shall have the right to terminate
the Tern of the Lease only in respect of the Additional Premises)

                     (iii)  Tenant's general contractor and all so-called "major
trade" subcontractors (which shall include, but-not be limited to, electrical,
HVAC, plumbing, drywall and acoustical ceiling subcontractors) and such other
contractors as Tenant intends to engage in connection with the performance of
Tenant's Additional Premises Work shall be subject to Landlord's prior consent,
which consent shall not be unreasonably withheld or delayed For purposes hereof,
the term "Tenant's Contractor" as used in sections 6(d) and (h) of the Lease
shall mean the general contractor (to be approved by Landlord, as aforesaid)
which Tenant shall engage in connection with the performance of Tenant's
Additional Premises Work.

                     (iv)   Tenant hereby acknowledges that, unlike the
situation with respect to the performance of Tenant's Work for the Existing
Premises, the portion of the first (1st) floor of the Building over which the
Additional Premises are located is, and during the construction of Tenant's
Additional Premises Work will be, occupied by another tenant (the "First Floor
Tenant"). Accordingly, and without limiting anything contained in Section 6(d)
of the Lease, Tenant agrees to perform Tenant's Additional Premises Work, and to
cause its contractors to perform Tenant's Additional Premises Work, in a manner
which will not materially interfere with the use and occupancy of such portion
of the first (1st) floor of the Building by the First Floor Tenant. If any
portion of Tenant's Additional Premises Work will, in Landlord's reasonable
judgment, materially interfere with the business operations of the First Floor
Tenant (such as, but not limited to, penetrations into the floor of the
Additional Premises), Landlord shall have the right to require such portion of
Tenant's Additional Premises Work to be performed during non-business hours. To
assist Landlord in determining whether any portion of Tenant's Additional
Premises Work will materially interfere with the business operations of the
First Floor Tenant, Tenant shall provide Landlord with a reasonably detailed
construction schedule setting forth the date(s) and times on and during which it
is anticipated that each portion of Tenant's Additional Premises Work will be
performed. Such construction schedule shall be given to Landlord prior to the
commencement of Tenant's Additional Premises Work, and Tenant shall promptly
advise Landlord of any change in or deviation from such schedule and submit to
Landlord a revised construction schedule reflecting any such change or
deviation. Tenant agrees that the second and third sentences of Section 11 of
the Lease shall, without limitation, apply to any damage to the premises or the
property of the First Floor Tenant caused by or attributable to the performance
of Tenant's Additional Premises Work, and that the provisions of clause (ii) of
the first sentence of Section 16(a) of the Lease, as well as the provisions of
the last sentence of Section 16(a) of the Lease, shall, without limitation,
apply to any liability to the First Floor Tenant with respect thereto.

                                        5
<Page>

              C.     Landlord shall contribute an amount up to $44,150.00
("Landlord's Additional Praises Contribution") expressly for the purchase and
installation of the items of work set forth in Exhibit 4 to the Lease, which
Tenant shall purchase and install as part of Tenant's Additional Premises Work.
An such items set forth in said Exhibit 4 shall be at least equal to the quality
of items set forth in Part C of Exhibit 5 to the Lease. Landlord's Additional
Premises contribution shall be used for no purpose other than for the purchase
and installation of the items listed in said Exhibit 4. Landlord shall pay
amounts on account of Landlord's Additional Premises Contribution directly to
contractors or suppliers upon receiving from Tenant actual vendor invoices for
labor and/or materials billed to Tenant. There shall be no credit due Tenant for
any unused portion of Landlord's Additional Premises Contribution. Section 6(e)
of the Lease shall not apply to the Additional Premises; but nothing herein
shall relieve Landlord of its obligation to contribute Landlord's Contribution
as provided in said Section 6(e) with respect to the performance of Tenant's
Work in the Existing Premises.

              D.     Notwithstanding the foregoing, Landlord shall, at its own
cost and expense, install a sprinkler system as described in Exhibit 5 to the
Lease for the Additional Premises and a firs protection system as required by
all applicable federal, state or local requirements for the Additional Premises,
to the extent applicable to general office space. The last two sentences of
Section 6(f) of the Lease shall apply to the Additional Premises and Tenant's
Additional Premises Work, MUTATIS MUTANDIS.

       4.     TENANT'S RIGHT OF FIRST OFFER

              As Tenant's lease Of the Additional Premises constitutes the
remaining space on the second (2nd) floor of the Building, Section 38 at the
Lease is hereby deleted from the Lease in its entirety.

       5.     PREMISES

              Unless the context otherwise requires (e.g., in Section 6 of the
Lease), the term "Premises" as used in the Lease (as hereby amended) shall refer
to both the Existing Premises and the Additional Premises.

       6.     HEADINGS

              Titles and paragraph headings are for reference purposes and for
convenience of the parties only and shall have no bearing upon, nor force or
effect in respect of, the interpretation and application of the substantive
provisions in this First Amendment contained.

                                        6
<Page>

       As hereby amended, the Lease is ratified, approved and confirmed in all
respects.

       EXECUTED under seal as of the date first written above.

LANDLORD:                                 TENTANT:

125 HARTWELL TRUST                        FUJI IMMUNOPHARMACEUTICALS
                                          CORP.

By:  /S/ MICHAEL L. COLANGELO             By:  /S/ DR. STEPHEN D. GILLIES
   --------------------------------          ------------------------------
   Michael L. Colangelo, As Trustee          Dr. Stephen D. Gillies,
   and Not Individually                      President

                                        7
<Page>

                                    EXHIBIT 2

                               125 HARTWELL AVENUE

                            LEXINGTON, MASSACHUSETTS

                              BUILDING EXPENSE BASE

BUILDING SIZE - 38,400 RSF

<Table>
<Caption>
                                                       ESTIMATED
                                                         COST         PSF
                                                       ---------   --------
<S>     <C>                                            <C>         <C>
1.      Property Taxes                                 $  75,200   $   1.96
2.      Boston Gas (Heat & Hot Water)                      7,890        .21
3.      Boston Edison (Cooling)                           38,400       1.00
4.      Electricity (House Panel)                          3,800        .10
5.      Grounds Maintenance                                8,240        .21
6.      HVAC Maintenance                                   6,750        .18
7.      Janitorial & Trash Removal                        38,500       1.00
8.      Insurance                                          6,080        .16
9.      Maintenance & Repairs                              4,068        .10
10.     Sewer & Water                                      3,072        .08
11.     Property Management                               19,200        .50
                                                        --------   --------
TOTAL BUILDING (TAX & OPERATING) EXPENSES              $ 211,200   $   5.50
</Table>

<Page>

                               125 Hartwell Avenue
                            Lexington, Massachusetts
                                (the "Building")

                                SECOND AMENDMENT
                                 October 1, 1997

<Table>
<S>                                  <C>
          LANDLORD:                  125 Hartwell Trust, under a declaration of
                                     trust dated February 20, 1980 and filed
                                     with the Middlesex South Registry District
                                     of the Land Court as Document No. 600788,
                                     as amended

          TENANT:                    Fuji ImmunoPharmaceuticals Corp., a
                                     Delaware corporation

          PREMISES:                  Approximately 19,810 square feet of
                                     Premises Rentable Area on the second (2nd)
                                     floor of the Building, consisting of
                                     approximately 10,980 square feet of
                                     Premises Rentable Area under the original
                                     Lease shown as the leased premises on
EXISTING                             Exhibit 3 thereto, plus approximately 8,830
LEASE                                square feet of Premises Rentable Area added
DATA:                                by the First Amendment referred to below
                                     shown as the "RFO Premises" on said Exhibit
                                     3.

          LEASE EXECUTION DATE:      October 26, 1992

          TERMINATION DATE:          January 31, 1998

          PREVIOUS LEASE             First Amendment dated as of January
          AMENDMENTS:                31, 1993

          EXTENDED TERMINATION       January 31, 2003 (subject to Tenant's
          DATE:                      option to further extend the Term pursuant
                                     to Section 36 of the lease)
</Table>

       WHEREAS, Tenant has, by notice dated July 28, 1997, a copy of which is
attached hereto as Exhibit A, exercised its option to extend the Term of the
lease for the first five-(5)-year additional term provided for in Section 36 of
the lease;

       WHEREAS, the parties have agreed upon the Basic Rent and the Building
Expense Base for such additional term pursuant to Sections 36 and 37 of the
Lease; and

<Page>

       WHEREAS, the parties wish to confirm such lease extension, Basic Rent and
Building Expense Base and the other terms and conditions to apply during such
additional term.

       NOW THEREFORE, the parties hereby agree that the above referenced lease,
as amended by the aforesaid First Amendment (collectively, the "Lease"), is
hereby further amended as follows (capitalized terms used herein without
definition shall have the meanings ascribed to them in the Lease):

       1.     EXTENSION OF TERM OF LEASE

       The Term of the Lease is hereby extended for an additional term
commencing as of February 1, 1998 and expiring as of January 31, 2003. The
demise of the Premises for such additional term shall be upon all of the same
terms and conditions of the Lease in effect immediately preceding the
commencement of such additional term, except as fol1ows:

       A.     The Basic Rent payable in respect of the Premises during the
additional term shall be $495,250.00 per annum (i.e., $41,270.83 per month).
Tenant's obligation to pay Basic Rent at such new rate and to pay all other
charges under the Lease with respect to the additional term shall commence on
February 1, 1998. The current Basic Rent and charges under the Lease shall
remain in effect prior to said date.

       B.     The Building Expense Base during the additional term shall be the
actual amount of Building Expenses for calendar year 1997. Further in such
regard, the Building Expense Cap for calendar year 1998 shall be one hundred
fifteen percent (115%) of the Building Expenses for calendar year 1997.
Thereafter, the Building Expense Cap shall be increased each Year so as to equal
one hundred fifteen percent (115%) of the Building Expense Cap for the prior
Year. Building Expense Escalation Charges payable by Tenant in respect of the
additional term shall be calculated using such revised Building Expense Base,
and Building Expenses during such additional term shall be subject to the
applicable Building Expense Cap as set forth above.

       C.     Landlord shall have no obligation to renovate or construct any new
improvements in the Premises (or to provide any construction allowance or
contribution or the like) for or with respect to Tenant's occupancy during the
additional term.

       D.     In the event any of the provisions of the Lease are Inconsistent
with this Second Amendment or the state of facts contemplated hereby, the
provisions of this Second Amendment shall control.

Without limiting the foregoing, Tenant shall have its remaining option to
further extend the Term of the Lease for one (1) additional five (5) year period
(i.e., February 1, 2003 through January 31, 2008) subject to and in accordance
with Section 36 of the Lease.

       2.     BROKER

       If any commission, fee or other compensation shall be due, with respect
to this Second Amendment and the extension of the Term effected hereby, to the
original brokers who were paid a commission by Landlord at the time of the
execution and delivery of the original Lease

<Page>

(the "Original Brokers"), Landlord shall pay the Original Broker such
commission, fee or compensation. Tenant shall indemnify and hold Landlord (and
its trustees, beneficiaries, agents and employees) harmless of and from all
claims that may be made by any person (other than the Original Brokers) against
Landlord (or its trustees, beneficiaries, agents or employees) for brokerage or
other compensation in the nature of brokerage with respect to this Second
Amendment on account or arising out of Tenant's dealings with such person.

       As amended by this Second Amendment, the Lease is hereby ratified,
approved and confirmed in all respects.

       WHEREFORE, the parties have hereunto set their hands and seals as of the
date first above written.

LANDLORD:                                         TENTANT:

                                                  FUJI IMMUNOPHARMACEUTICALS
                                                  CORP.

    /S/ MICHAEL L. COLANGELO                     /S/ DR. STEPHEN D. GILLIES
------------------------------------------   -----------------------------------
Michael L. Colangelo, signing as Trustee     Name:  Stephen D. Gillies
of 125 Hartwell Trust and not individually   Title: President
and without recourse against the Trustee     Hereunto Duly Authorized
personally or his assets

<Page>

                                    EXHIBIT A

     FIP

     FUJI IMMUNOPHARMACEUTICALS CORP.

     July 28, 1997

     Mr.Steven Colangelo
     Lexington Management Incorporated
     125 Hartwell Ave.
     Lexington, MA 02173

     Dear Steve:

     As you know, the first term of Fuji ImmunoPharmaceuticals Corp.'s(FIP's)
     lease with you at 125 Hartwell Ave. will expire on January 31, 1998.

     I am writing to inform you of FIP's formal intention to extend it's lease
     with the 125 Hartwell Trust for another five year term, pursuant to Section
     36 of the Lease. It is my understanding that the terms contained in the
     original lease document will all stay the same with the expectation of the
     lease rate and base building expenses. I would like to arrange a meeting
     with you in the near future to discuss FIP'S extension and to get some idea
     of the current market rents in the Lexington area.

     I would like to thank you for all your support during FIP's first five
     years. We look forward to our continued relationship with you.

     Sincerely,

     /s/ Bryan G.Keaney
     Bryan G.Keaney
     Director of Finance and Administration

                    125 Hartwell Avenue - Lexington, MA 02173
                      Tel: 617-861-5300 - Fax: 617-861-5301

<Page>

                               125 Hartwell Avenue
                            Lexington, Massachusetts
                                (the "Building")

                                 THIRD AMENDMENT
                                November 1, 2002

<Table>
<S>                                  <C>
          LANDLORD:                  125 Hartwell Trust, under a declaration of
                                     trust dated February 20, 1980 and filed
                                     with the Middlesex South Registry District
                                     of the Land Court as Document No. 600788,
                                     as amended

          ASSIGNOR:                  EMD Lexigen Research Center Corp. (formerly
                                     known as Lexigen Pharmaceuticals Corp. and
                                     before that Fuji ImmunoPharmaceuticals
                                     Corp.), a Delaware corporation

          TENANT OR                  EMD Pharmaceuticals, Inc., a Delaware
          ASSIGNEE:                  corporation

          PREMISES:                  Approximately 19,810 square feet of
                                     Premises Rentable Area on the second (2nd)
                                     floor of the Building, consisting of
                                     approximately 10,980 square feet of
                                     Premises Rentable Area under the original
                                     Lease shown as the leased premises on
EXISTING                             Exhibit 3 thereto, plus approximately 8,830
LEASE                                square feet of Premises Rentable Area added
DATA:                                by the First Amendment referred to below
                                     shown as the "RFO Premises" on said
                                     Exhibit 3

          LEASE EXECUTION DATE:      October 26, 1992

          TERMINATION DATE:          January 31, 2003

          PREVIOUS LEASE             First Amendment dated as of January 31,
          AMENDMENTS:                1993 Second Amendment dated October 1, 1997

          EXTENDED TERMINATION       January 31, 2008
          DATE:
</Table>

<Page>

       WHEREAS, Assignor has, by notice dated July 29, 2002, a copy of which is
attached hereto as EXHIBIT A, exercised its option to extend the Term of the
above-referenced lease, as amended by the aforesaid First Amendment and Second
Amendment (collectively, the "Lease"), for the second five-(5)-year additional
term provided for in Section 36 of the Lease;

       WHEREAS, Assignor desires to assign its interest in the Lease to Assignee
arid Assignee desires to accept such assignment;

       WHEREAS, the parties have agreed upon the Basic Rent and the Building
Expense Base for such additional term pursuant to Sections 36 and 37 of the
Lease and Landlord is willing to consent to Assignor's assignment of its
interest in the Lease to Assignee; and

       WHEREAS, the parties wish to confirm such assignment of the Lease and to
confirm such lease extension, Basic Rent and Building Expense Base and the other
terms and conditions to apply during such additional term

       NOW TEEREFORE, the parties hereby agree that the Lease is hereby amended
as follows (capitalized terms used herein without definition shall have the
meanings ascribed to them in the Lease):

       1.     ASSIGNMENT AND ASSUMPTION OF LEASE

       A.     Effective as of November 1, 2002, Assignor hereby assigns all of
its right, title and interest in and to the Lease (as hereby amended) to
Assignee.

       B.     For the express benefit of Landlord, Assignee hereby assumes all
of the obligations of Assignor under the Lease (as hereby amended) and agrees to
perform and keep all covenants, conditions and agreements of Assignor under the
Lease (as hereby amended). Without limiting the foregoing, Assignee agrees that
the provisions of Section 9 of the Lease shall apply to all future proposed
assignments of Assignee's interest in the Lease and to all future proposed
subleases of the Premises.

       C.     In consideration of the foregoing agreements by Assignee, and
without in any way diminishing the primary liability of Assignor as party-tenant
under the Lease (as hereby amended), Landlord hereby consents and agrees to the
foregoing assignment by Assignor to Assignee. Said consent by Landlord shall not
constitute a waiver of the obligation of the tenant under the Lease to obtain
Landlord's consent to any subsequent assignment or sublease of or under the
Lease, if and to the extent that such consent is required by the Lease.

       2.     EXTENSION OF TERM OF LEASE

       The Term of the Lease is hereby extended for an additional term
commencing as of February 1, 2003 and expiring as of January 31, 2008. The
demise of the Premises for such additional term shall be upon all of the same
terms and conditions of the Lease in effect immediately preceding the
commencement of such additional term (including, without limitation, the Basic
Rent payable in the amount of $495,250.00 per annum (i.e., $41,270.83 per month)
and the Building Expense Base equal to the actual amount of Building Expenses
for

<Page>

calendar year 1997, subject to the provisions of Paragraph 1B of the Second
Amendment to the Lease), except as follows:

       A.     Tenant shall have no right to extend the Term of the Lease beyond
January 31, 2008.

       B.     Except for Landlord's obligation to repaint the Premises as
required by Section 36(a) of the Lease, which obligation Tenant acknowledges has
been satisfied by Landlord, Landlord shall have no obligation to renovate or
construct any new improvements in the Premises (or to provide any construction
allowance or contribution or the like) for or with respect to Tenant's occupancy
during the additional term.

       C.     In the event any of the provisions of the Lease are inconsistent
with this Third Amendment or the state of facts contemplated hereby, the
provisions of this Third Amendment shall control.

Tenant acknowledges that (i) its current monthly payment of Basic Rent and
Building Expense Escalation Charges under the Lease is based upon an annual rate
of $26.70 per square foot of Premises Rentable Area, (ii) such annual rate is
comprised of $25.00 per square foot of Premises Rentable Area on account of
Basic Rent and $1.70 per square foot of Premises Rentable Area on account of
Building Expense Escalation Charges, and (iii) Tenant's payments on account of
Building Expense Escalation Charges are subject to adjustment and year-end
reconciliation pursuant to Section 14(b) of the Lease.

       3.     BROKER

       Tenant represents and warrants to Landlord that it has not dealt with any
broker or agent in connection with this Third Amendment or the extension of the
Term effected hereby. Tenant shall indemnify and hold Landlord (and its
trustees, beneficiaries, agents and employees) harmless of and from all claims
that may be made by any person against Landlord (or its trustees, beneficiaries,
agents or employees) for brokerage or other compensation in the nature of
brokerage with respect to this Third Amendment on account or arising out of
Tenant's dealings with such person.

       As amended by this Third Amendment, the Lease is hereby ratified,
approved and confirmed in all respects.

<Page>

       WHEREFORE, the parties have hereunto set their hands and seals as of the
date first above written.

LANDLORD:                                    ASSIGNOR:

                                             EMD LEXIGEN RESEARCH CENTER
                                             CORP.

     /S/ STEVEN COLANGELO                    By: /S/  STEPHEN D. GILLIES
----------------------------------------         -----------------------------
Steven Colangelo, signing as Trustee of          Name:  Stephen D. Gillies
125 Hartwell Trust and not individually          Title: President
and without recourse against the Trustee         Hereunto Duly Authorized
personally or his assets

                                             ASSIGNEE:

                                             By:   /S/ ILLEGIBLE
                                                 -----------------------------
                                                 Name:
                                                 Title:
                                                 Hereunto Duly Authorized

<Page>

                                    EXHIBIT A

[LEXIGEN PHARMACEUTICALS CORP. LOGO]

     July 29, 2002

     Mr.Steven Colangelo
     125 Hartwell Trust
     125 Hartwell Ave
     Lexington, MA 02421
                                        CERTIFIED MAIL, RETURN RECEIPT REQUESTED

     RE:  Extension of Lease at 125 Hartwell Avenue

     Dear Steve:

     As you know, EMD-Lexigen Research Center Corp.'s, formerly Lexigen
     Pharmaceuticals Corp.'s ("Lexigen's") Lease with 125 Hartwell Trust for
     space at 125 Hartwell Avenue-Second Floor, will expire on January 31, 2003.
     As previously communicated verbally, it is Lexigen's intention to extend
     for an additional term, as provided in Section 36 of the Lease. This letter
     is intended as formal notification of Lexigen's intention to extend.

     I would also like to inform you that Lexigen, pursuant to Section 9(a) of
     the Lease, intends to assign its right in the Lease to EMD Pharmaceuticals,
     Inc., a directly affiliated company with Lexigen. I wanted to inform you of
     this now, as it may be easier to take care of the Assignment in conjunction
     with the Lease Extension.

     I will be in touch within the next couple of weeks to begin discussions to
     determine the appropriate terms of the Lease Extension. I look forward to
     working with you on this matter and look forward to a continued mutually
     beneficial relationship between our companies.

     Sincerely yours,

     /s/ Jason M. Walsh
     Jason M. Walsh
     Director of Operations and Administration

     CC:  Dr. Richard Schoenfeld, VP Supply Chain, EMD Pharmaceuticals, Inc.
           Ms. Gilda Thomas, Esq., General Counsel, EMD Pharmaceuticals, Inc.

              LEXIGEN PHARMACEUTICALS CORP.        TEL: [ILLEGIBLE]

<Page>

                       ASSIGNMENT AND ASSUMPTION OF LEASE
                     AND CONSENT OF AND RELEASE BY LANDLORD
                          AND FOURTH AMENDMENT TO LEASE

       THIS ASSIGNMENT AND ASSUMPTION OF LEASE AND CONSENT OF AND RELEASE BY
LANDLORD AND FOURTH AMENDMENT TO LEASE (this "Agreement") is made and entered as
of July 9, 2004. the ("Effective Date") by and among EMD Pharmaceuticals, Inc.,
a Delaware corporation ("Assignor"), Synta Pharmaceuticals Corp., a Delaware
corporation ("Assignee"), and 125 Hartwell Trust, under Declaration of Trust
dated February 20, 1980 and filed with the Middlesex South Registry District of
the Land Court as Document No. 600788, as amended ("Landlord"). Assignor,
Assignee and Landlord are sometimes referred to herein individually as a "Party"
and collectively as the "Parties".

                                    RECITALS

       A.     Assignor, as successor by assignment to EMD Lexigen Research
Center Corp. (formerly known as Lexigen Pharmaceuticals Corp. and before that
Fuji ImmunoPharmaceuticals Corp.), as tenant, and Landlord, as landlord, are
parties to that certain Lease dated as of October 26, 1992, as amended by First
Amendment dated as of January 31, 1993, Second Amendment dated October 1, 1997,
and Third Amendment dated November 1, 2002 (as so amended and collectively, the
"Lease").

       B.     Assignor desires to assign to Assignee all of Assignor's right,
title, and interest in and to the Lease on and after the Effective Date (as
hereinafter defined) and to delegate to Assignee all of Assignor's obligations
under the Lease from and after the Effective Date pursuant to the terms of this
Agreement, and Assignee has agreed to accept the foregoing assignment and to
assume all of Assignor's obligations under the Lease pursuant to the terms of
this Agreement on and after the Effective Date.

       C.     Landlord has agreed to consent to the assignment and assumption
set forth herein pursuant to the terms of this Agreement and to release Assignor
from any continuing liability under the Lease except as hereinafter provided.

       D.     Landlord has agreed to lease to Assignee during the Assignment
Period (as hereinafter defined) certain equipment and other personal property
presently located in the Premises and sold to Landlord by Assignor as of the
Effective Date, and, in consideration thereof, Assignee has agreed to pay to
Landlord monthly rent for the lease of such equipment and other personal
property.

       E.     Landlord has agreed to lease to Assignee during the Assignment
Period as part of the Premises certain tenant improvements made to the Premises
by Assignor and sold to Landlord by Assignor as of the Effective Date, and, in
consideration thereof, Assignee has agreed to pay to Landlord monthly rent for
the lease of such tenant improvements.

       NOW, THEREFORE, in consideration of the recitals (which, by this
reference, are incorporated into the operative provisions of this Agreement),
the mutual agreements set forth

<Page>

herein, and other good and valuable consideration, the receipt and legal
sufficiency of which are hereby acknowledged, the Parties, intending to be
legally bound, agree as follows:

       1.     ASSIGNMENT OF LEASE. Subject to the provisions of this Agreement,
Assignor, as of the Effective Date, hereby sells, assigns, grants, and conveys
to Assignee all of Assignor's right, title, and interest in and to the Lease
(including, without limitation, all of Assignor's rights regarding parking and
signage) and the estate created thereby, and delegates to Assignee all of the
obligations of Assignor as tenant under the Lease arising on and after the
Effective Date.

       2.     ASSUMPTION OF OBLIGATIONS. Subject to the provisions of this
Agreement, Assignee, as of the Effective Date, hereby accepts the assignment of
Assignor's right, title, and interest in and to the Lease and the estate created
thereby and assumes and agrees to be bound by the Lease and all of the
obligations of the tenant thereunder arising on and after the Effective Date.

       3.     EFFECTIVE DATE. The assignment, delegation, acceptance, and
assumption set forth in Paragraphs 1 and 2 hereof shall be effective on the
Effective Date; provided, however, Assignee's obligation to pay Basic Rent (as
defined in the Lease) required to be paid under the Lease and additional rent
required to be paid under Section 14 of the Lease shall not begin until the Rent
Commencement Date (as hereinafter defined), Assignor remaining liable for
payment of Basic Rent required to be. paid under the Lease and additional rent
required to be paid under Section 14. of the Lease through the day prior to the
Rent Commencement Date. Assignee is expressly liable as of the Effective Date
for payment and performance of all obligations of the tenant under the Lease
arising on and after the Effective Date other than payment of Basic Rent
required to be paid under the Lease and additional rent required to be paid
under Section 14 of the Lease as provided in the preceding proviso. In
furtherance of the foregoing, Assignee acknowledges that Assignor shall
terminate the insurance it is required to carry under, the Lease as of 11:59
p.m. of the day before the Effective Date, and Assignee shall have in effect not
later than midnight of the Effective Date the insurance coverages required to be
carried by the tenant under the Lease. Assignor has delivered the Premises to
the Assignee as of the Effective Date broom clean, free of all tenants or other
occupants, free of all equipment and other personal property (except for the
Included Property (as hereinafter defined)) and with the Included Property and
all laboratory space within the Premises decommissioned in accordance with all
applicable laws, rules, and regulations and with the standards set forth on
EXHIBIT A attached hereto and incorporated herein by reference (the
"Decommissioning Standards"). Assignee has examined the Premises and, subject to
Paragraph 4.5 below, accepts the Premises in its condition as of the Effective
Date. As used herein, the phrase "Rent Commencement Date" shall mean August 8,
2004. Basic Rent required to be paid under the Lease and additional rent
required to be paid under Section 14 of the Lease shall be prorated between
Assignor and Assignee as of the Rent Commencement Date.

       4.     REPRESENTATIONS OF ASSIGNOR AND INDEMNIFICATION BY ASSIGNOR. To
induce Assignee to assume the obligations of Assignor under the Lease on and
after the Effective Date as provided herein, Assignor represents and warrants to
Assignee the following matters, all of which are true and correct as of the date
hereof and all of which will be true and correct on the Effective Date and
further indemnifies Assignee as set forth below:

<Page>

              4.1.   AUTHORITY. Assignor has the authority to enter into this
              Agreement and to assign the rights and to delegate the obligations
              of Assignor under the Lease to Assignee. The officers of Assignor
              who have executed this Agreement are duly authorized to do so and
              to bind Assignor to the covenants, representations, warranties,
              and agreements of Assignor set forth in this Agreement. There are
              no provisions contained in any law, rule, or regulation of any
              federal, state, or local governmental authority having
              jurisdiction over Assignor, or in any instrument or agreement to
              which Assignor is a party or by which it is bound, which would
              prohibit, limit, or adversely affect the actions or obligations of
              Assignor set forth in this Agreement. No consent of any party
              other than the Parties to this Agreement is required for the
              assignment and delegation set forth in Paragraph 1 hereof.

              4.2.   COMPLIANCE WITH LEASE. Through the day before the Effective
              Date; (i) Assignor has observed and faithfully performed all of
              its obligations as tenant under, or set forth in, the Lease; (ii)
              Assignor is not in default under the Lease; (iii) Landlord is not
              in default under the Lease; and (iv) Assignor has not exercised
              any right to terminate the Lease reserved unto Assignor under the
              Lease as the result of an uncured default by Landlord.

              4.3.   NO OTHER ASSIGNMENTS. Except as set forth herein, Assignor
              has not assigned, sold, pledged, hypothecated, mortgaged, or
              otherwise transferred its interest in and to the Premises or in or
              to its rights under the Lease to any person.

              4.4.   LEASE. Attached hereto as EXHIBIT B, and by this reference
              made a part hereof, is a true, correct, and complete copy of the
              Lease and all amendments thereto, which Lease is in full force and
              effect on the date hereof. There are no material oral agreements
              or understandings between Assignor and Landlord which relate to
              the Lease or the obligations of the parties thereunder that would
              be binding upon Assignee. The current term of the Lease is
              scheduled to expire on January 31, 2008. The Basic Rent and
              additional rent (to the extent additional rent is determinable and
              currently due) required to be paid by the tenant under the Lease
              has been paid through July 31, 2004.

              4.5.   INDEMNIFICATION OF ASSIGNEE. Assignor shall and does
              indemnify and hold Assignee harmless from and against any and all
              loss, liability, charge, cost, damages, fees, and expenses in
              connection with: (i) any and all liability of Assignor which
              arises under or pursuant to the obligations of Assignor set forth
              in the Lease and which relates specifically to those obligations
              which have accrued and have become due and payable in or for the
              period prior to the Effective Date; (ii) any injury to any person
              or damage to any property which occurs in the Premises prior to
              the Effective Date and which results from the negligence or
              willful misconduct of Assignor or its agents, guests, invitees, or
              employees; and (iii) any failure of Assignor to have
              decommissioned the Included Property and the Premises in
              accordance with all applicable laws, rules, and regulations.

<Page>

              4.6    PREMISES. Assignor represents and warrants to Assignee that
              the Premises are presently in good and clean order and condition.
              Except for the foregoing representation and warranty and except as
              otherwise provided in this Paragraph 4 or in Paragraph 3 above,
              Assignor makes no warranty or representation as to the condition
              of the Premises nor its compliance with applicable laws, rules,
              and regulations, and the Premises shall be delivered to Assignee
              "as is, where is, with all defects." Assignee agrees that in
              entering into this Agreement, it has relied upon its own
              investigation of the condition of the Premises and the suitability
              of the Premises for Assignee's intended uses and not upon any
              warranty or representation of Assignor except for the warranties
              or representations set forth in this Agreement.

       5.     REPRESENTATIONS OF ASSIGNEE AND INDEMNIFICATION BY ASSIGNEE. To
induce Assignor to assign to Assignee Assignor's rights under the Lease on and
after the Effective Date as provided herein, Assignee represents and warrants to
Assignor the following matters, all of which are true and correct as of the date
hereof and all of which will be true and correct on the Effective Date and
further indemnifies Assignor as set forth below:

              5.1.   AUTHORITY. Assignee has the authority to enter into this
              Agreement and to accept the assignment of Assignor's interest in
              the Lease arising on and after the Effective Date and to assume
              the obligations of Assignor set forth therein arising on and after
              the Effective Date. The officers of Assignee who have executed
              this Agreement are duly authorized to do so and to bind Assignee
              to the covenants, representations, warranties, and agreements of
              Assignee set forth in this Agreement. There are no provisions
              contained in any law, rule, or regulation of any federal, state,
              or local governmental authority having jurisdiction over Assignee,
              or in any instrument or agreement to which Assignee is a party or
              by which it is bound, which would prohibit, limit, or adversely
              affect the actions or obligations of Assignee set forth in this
              Agreement. No consent of any party other than the Parties to this
              Agreement is required for the acceptance and assumption set forth
              in Paragraph 2 hereof.

              5.2.   COMPLIANCE WITH LEASE. From and after the Effective Date,
              Assignee shall observe and faithfully perform all of the
              obligations of tenant under, or set forth in, the Lease arising on
              or after the Effective Date.

              5.3    INDEMNIFICATION OF ASSIGNOR. Assignee shall and does
              indemnify and hold Assignor harmless from and against all loss,
              liability, charge, cost, damages, fees, and expense in connection
              with: (i) any and all liability of Assignee which arises under or
              pursuant to the obligations of Assignee set forth in the Lease and
              which is applicable to the period from and after the Effective
              Date; and (ii) any injury to any person or damage to any property
              which occurs in or about the Premises from and after the Effective
              Date.

       6.     ADJUSTMENT OF CHARGES. Upon receipt from Landlord of supporting
documentation therefor, Assignor and Assignee agree, promptly and upon demand
made by either Assignor or Assignee, to prorate as appropriate any payments or
expenses made or to be

<Page>

made, or received or to be received, in connection with the Lease so
that Assignor shall incur all expenses and receive the benefit of all payments
and reimbursements to Landlord to be made under the Lease attributable to the
period prior to the Rent Commencement Date and so that Assignee shall be
responsible for all such expenses and entitled to the benefit of all such
payments and reimbursements to the extent attributable to the period on and
after the Rent Commencement date.

       7.     REPRESENTATIONS OF ASSIGNOR AND ASSIGNEE WITH RESPECT TO THE
INCLUDED PROPERTY AND ASSIGNOR'S IMPROVEMENTS. Assignor and Assignee represent
and warrant to Landlord that neither of them has encumbered or granted a lien or
security interest in any of the Included Property or the Assignor's Improvements
(as hereinafter defined) nor shall either of them grant a lien or security
interest in the Included Property or the Assignor's Improvements.

       8.     CONSENT OF AND RELEASE BY LANDLORD; LANDLORD'S REPRESENTATIONS. By
its execution of this Agreement, Landlord consents to the assignment and
assumption contained in Paragraphs 1 and 2 of this Agreement and as of the
Effective Date releases Assignor of any liability under the Lease accruing or
arising on and after the Effective Date, it being understood and agreed that
Assignor shall remain liable for any obligations under the Lease accruing or
arising prior to the Effective Date, including (without limitation) any
liability for underpayments on account of Building Expense Escalation Charges
(as defined in the Lease) for the period prior to the Effective Date, as well as
the obligation to pay Basic Rent and Building Expense Escalation Charges (and
any underpayments on account thereof) through the day prior to the Rent
Commencement Date. Landlord does not release Assignor, and Assignor acknowledges
its continuing liability, for any liability for breach of this Agreement by
Assignor or any other agreement to which Landlord and Assignor are parties.
Assignor shall and does indemnify and hold Landlord harmless from and against
any and all loss, liability, charge, cost, damages, fees, and expenses in
connection with any failure by Assignor to have decommissioned the Included
Property and the Premises in accordance with the Decommissioning Standards and
all applicable laws, rules, and regulations. Landlord agrees that, from and
after the Effective Date, the address for any notice to the tenant required
under the Lease shall be Synta Pharmaceuticals Corp., 45 Hartwell Avenue,
Lexington, Massachusetts 02421, Attention: Chief Financial Officer.

       Landlord represents and warrants to Assignee and Assignor that:

       (a)    attached hereto as EXHIBIT B is a true, correct and complete copy
              of the Lease and all amendments thereto, which Lease is in full
              force and effect on the date hereof;

       (b)    there are no oral agreements or understandings between Assignor
              and Landlord which relate to the Lease or the obligations of the
              parties thereunder;

       (c)    to the knowledge of Landlord without investigation or inquiry,
              there are no defaults of Assignor under the Lease;

       (d)    the current term of the Lease is scheduled to expire on January
              31, 2008;

<Page>

       (e)    the Basic Rent and the Building Expense Escalation Charge required
              to be paid by the tenant under the Lease have been paid through
              July 31, 2004, subject to reconciliation of the Building Expense
              Escalation Charge for calendar year 2004;

       (f)    no broker or agent or other person has represented Landlord in
              connection with this Agreement and the transactions contemplated
              hereby; and

       (g)    there are no mortgages encumbering the Property (as defined in the
              Lease) or any portion thereof other than that granted to
              Mortgagee.

       9.     MISCELLANEOUS PROVISIONS.

              9.1.   GOVERNING LAW. This Agreement shall be governed by, and
              enforced, construed, and interpreted under, the laws and judicial
              decisions of the Commonwealth of Massachusetts.

              9.2.   BINDING EFFECT. This Agreement shall be binding upon, and
              shall inure to the benefit of, the Parties, and their respective
              heirs, executors, successors, and permitted assigns.

              9.3.   BROKERS. Assignee and Assignor each represents and warrants
              to the other that no broker or agent or other person other than
              Spaulding and Slye/Colliers International as to Assignor and
              Richards Barry Joyce & Partners LLC as to Assignee (the "Brokers")
              has represented Assignor or Assignee in connection with this
              Agreement and the transactions contemplated hereby, and that no
              commissions, fees, or compensation of any kind are due or payable
              in connection herewith to any such person or entity except for the
              Brokers. Each party agrees to indemnify and hold the other
              harmless from and against any claim for any such commission, fee
              or other form of compensation by any such party or entity except
              for the Brokers claiming through the indemnifying party. Assignor
              shall pay the commissions payable to the Brokers in connection
              with this Agreement.

              9.4.   ENTIRE AGREEMENT; AMENDMENT. Except with respect to the
              agreements set forth in the Lease, this Agreement contains the
              entire agreement among the Parties, and there are no oral
              agreements or understandings among the Parties, with respect to
              the subject matter hereof. This Agreement may not be amended
              except by a writing signed by the Party against whom such
              amendment is to be enforced.

              9.5.   FURTHER ASSURANCES. Assignor and Assignee agree to
              cooperate with each other with respect to the subject matter
              hereof, and each agrees to execute such other instruments and
              agreements as may reasonably be required by the other to evidence
              further the intent of Assignor and Assignee with respect to the
              subject matter hereof.

       10.    NON-DISTURBANCE AGREEMENT. Assignor shall exercise reasonable
efforts to deliver to Assignee before the Rent Commencement Date a letter or
other memorandum from

<Page>

The Manufacturers Life Insurance Company (USA), Landlord's mortgagee
("Mortgagee"), stating that Assignee is entitled to the benefits of the
Subordination, Non-Disturbance and Attornment Agreement dated as of May 5, 1998
among Landlord, Assignor's predecessor in interest, and Mortgagee. Such letter
or other memorandum shall be in form and content reasonably acceptable to
Assignee. If Assignor is unable to obtain such letter or memorandum in form and
content reasonably acceptable to Assignee, then Assignor shall defend,
indemnify, and hold harmless Assignee from and against any and all liability,
charge, or expense, including reasonable attorneys' fees, actually incurred by
Assignee as a result of the exercise by Mortgagee (or any successor-in-interest
to Mortgagee) of any rights or remedies it may have as a result of default or
non-performance by Landlord (or any successor-in-interest to Landlord) under any
agreement it has with Mortgagee.

       11.    INCLUDED PROPERTY. During the period from the Effective Date
through and including the expiration or earlier termination of the term of the
Lease (the "Assignment Period"), Landlord hereby leases to Assignee (and its
permitted successors and assigns), and Assignee leases from Landlord, the
equipment and other personal property owned by Landlord and described on EXHIBIT
C attached hereto and incorporated herein by this reference (collectively, the
"Included Property"). During the Assignment Period, Assignee shall maintain the
Included Property in a reasonably clean and working condition. If any of the
Included Property shall be damaged or destroyed as a result of the act or
omission of Assignee or its agents, employees, contractors, or permitted
subtenants or other occupants, then Assignee shall reimburse Landlord for the
cost incurred by Landlord to repair or replace such Included Property except to
the extent that such cost would be recoverable under a commercially reasonable
insurance policy covering the full replacement cost of the Included Property,
although Assignee shall be liable for the amount of any commercially reasonable
deductible. Assignee shall pay Landlord the cost of insurance coverage obtained
by Landlord with respect to the Included Property within thirty, (30) days of
receipt from time to time of Landlord's invoice therefor. Assignee is not
required to replace any of the Included Property that becomes worn out or
obsolete. Landlord and Assignee agree that Assignee shall deliver to Landlord
the Included Property at the end of the Assignment Period in the same condition
it was in on the Effective Date, ordinary wear and tear and damage due to fire
or other casualty excepted, and upon expiration or earlier termination of the
term of the Lease, the Included Property shall no longer be leased to Assignee
pursuant to the terms of this Agreement. Notwithstanding the foregoing, to the
extent that any of the Included Property or the Premises has been used after the
Effective Date for chemical, biological, or radioactive substances, such
Included Property and/or the Premises, as applicable, shall be decommissioned by
Assignee in accordance with all applicable laws, rules, and regulations and with
the Decommissioning Standards upon its delivery to Landlord, and Section 40 of
the Lease is accordingly amended to require such decommissioning upon expiration
or earlier termination of the term of the Lease.

       12.    ASSIGNOR'S IMPROVEMENTS. During the Assignment Period, Landlord
shall lease to Assignee (and its permitted successors and assigns), and Assignee
shall lease from Landlord, the Assignor's Improvements. As of the Rent
Commencement Date (but not prior thereto), Assignee shall pay to Landlord as
additional rent for the right to use the Assignor's Improvements and the
Included Property during the Assignment Period the sum of $11,555.83 per month
(the "Monthly Improvements Rent"). Assignee shall pay the Monthly Improvements
Rent by separate check

<Page>

payable to Landlord, Monthly Improvements Rent being additional rent and not a
component of Basic Rent. The Monthly Improvements Rent shall be paid by Assignee
to Landlord commencing on the Rent Commencement Date (rent for any partial month
to be prorated) and continuing thereafter through January 31, 2008 at the same
time and in the same manner as payments of Basic Rent and shall be subject to
the overdue payment charge in Section 3 of the Lease and the interest charge in
Section 29 of the Lease. Failure by Assignee to pay any installment of Monthly
Improvements Rent when due and payable shall be a default under this Agreement
and the Lease, and if Assignee defaults in the payment of Monthly Improvements
Rent after passage of the notice and cure period provided in Section 21 of the
Lease, then Landlord shall be entitled to exercise any and all rights or
remedies Landlord may have under the Lease or applicable law as a result of such
default, including, without limitation, the right to collect from Assignee the
Monthly Improvements Rent payable through January 31, 2008. Notwithstanding
anything in this Agreement, for purposes of Sections 13(b), 19, and 20 of the
Lease, Monthly Improvements Rent shall be considered part of Basic Rent. As used
herein, the phrase "Assignor's Improvements" shall mean any and all alterations,
additions, and improvements to the Premises performed by or on behalf of the
tenant under the Lease before the Effective Date.

<Page>

       IN WITNESS WHEREOF, the Parties, upon authority duly given, have executed
this Agreement as a sealed instrument as of the date first written above.

                              ASSIGNOR:

                              EMD Pharmaceuticals, Inc.,
                              a Delaware corporation

                              By: /S/ GILDA M. THOMAS
                                  ---------------------------------------
                              Name: Gilda M. Thomas
                              Title: Vice President and General Counsel

                              ASSIGNEE:

                              SYNTA Pharmaceuticals Corp.,
                              a Delaware corporation

                              By: /S/ KEITH EHRLICH
                                  ---------------------------------------
                              Name: Keith Ehrlich
                              Title: Vice President, Finance and Administration

                              LANDLORD:

                              125 Hartwell Trust

                              By: /S/ STEVEN COLANGELO
                                  ---------------------------------------
                              Name: Steven Colangelo
                              Title: As Trustee and not individually

<Page>

                                    EXHIBIT A

                            DECOMMISSIONING STANDARDS

          STANDARDS FOR DECOMMISSIONING OF SPACE AT 125 HARTWELL AVENUE

Section 1 - Purpose

The purpose of decommissioning of space is to make safe the decommissioned space
and to provide assurances of proper cleaning and decontamination of said space
for the next occupant. The purpose of setting forth actions taken with respect
to decontamination of space is to document the actions taken and to allow the
owner or the next occupant to make their own judgment with respect to the
sufficiency of such actions.

Section 2 - Activities & Schedule

The following are the specific actions to be taken with respect to the
decommissioning of said space.

Chemicals - (Removal & Disposal)

     -  All hazardous or toxic chemicals are to be removed from the space before
        the expiration or earlier termination of the Lease or other mutually
        agreed deadline except for any cleaning materials under the control of
        the landlord's or tenant's cleaning contractor.
     -  The decommissioner shall hire a licensed contractor to pack, remove, and
        transport to a new location all usable chemicals. PROCESS AND/OR RESULTS
        ARE TO BE DOCUMENTED.
     -  The decommissioner shall hire a licensed contractor to pack, remove, and
        transport for proper disposal all unusable chemicals. PROCESS AND/OR
        RESULTS ARE TO BE DOCUMENTED.
     -  The decommissioner shall hire a licensed contractor to remove and
        dispose properly all limestone chips in the Wastewater Neutralization
        Tank. The contractor will clean the tank and replace with fresh
        limestone. PROCESS AND/OR RESULTS ARE TO BE DOCUMENTED.

Biological Materials - (Removal & Disposal)

     -  All biological materials will be removed from the space before the
        expiration or earlier termination of the Lease or other mutually agreed
        deadline.
     -  The decommissioner shall hire a licensed contractor to pack, remove, and
        transport to a new location all usable biological materials. PROCESS
        AND/OR RESULTS ARE TO BE DOCUMENTED.
     -  The decommissioner shall hire a licensed contractor to pack, remove, and
        transport for proper disposal all unusable biological materials. PROCESS
        AND/OR RESULTS ARE TO BE DOCUMENTED.
     -  Decontamination of Storage Equipment and Work Surfaces detailed below.

                                       10
<Page>

Radioactive Materials - Disposition

     -  The decommissioner shall hire a licensed contractor to perform wipe
        tests and provide count results to the extent required by applicable
        law.
     -  Wipe tests will be performed prior to the expiration or earlier
        termination of the Lease or other mutually agreed deadline. PROCESS
        AND/OR RESULTS ARE TO BE DOCUMENTED.

Equipment -

     -  All Equipment listed on Exhibit C will be decontaminated prior to the
        expiration or earlier termination of the Lease or other mutually agreed
        deadline.
     -  Chemical Fume Hoods will be steam cleaned using an organic peroxide
        vapor on the outside and inside of the cabinet by a licensed contractor.
        NOTE: STEAM CLEANING WILL BE PERFORMED TO ALL EXPOSED SURFACES. NO
        DUCTWORK OR ELEMENTS ABOVE THE SUSPENDED CEILING WILL BE TREATED. Each
        Fume Hood will have attached a decontamination sheet signed by the
        contractor. PROCESS AND/OR RESULTS ARE TO BE DOCUMENTED.
     -  Biological Safety Cabinets will be decontaminated by a licensed
        contractor using paraformaldehyde gas and post-treatment cleaning. NO
        DUCTWORK OR ELEMENTS ABOVE THE SUSPENDED CEILING WILL BE TREATED.
        PROCESS AND/OR RESULTS ARE TO BE DOCUMENTED.
     -  Warm and Cold Room Interiors and Door Fronts will be steam cleaned using
        an organic peroxide vapor. PROCESS AND/OR RESULTS ARE TO BE DOCUMENTED.

General Laboratory Space

     -  The decommissioner shall hire a licensed contractor to wipe down all
        Laboratory Floors and Countertops will a 10% bleach solution or
        equivalent. PROCESS AND/OR RESULTS ARE TO BE DOCUMENTED.
     -  All Laboratory space to be wiped down prior to the expiration or earlier
        termination of the Lease or other mutually agreed deadline.

                                       11
<Page>

                                    EXHIBIT B

                   TRUE CORRECT AND COMPLETE COPY OF THE LEASE

                                       12
<Page>

[MANULIFE FINANCIAL LOGO]

July 9, 2004

VIA TELECOPIER AND FIRST CLASS MAIL

Steven Colangelo, Trustee of 125 Hartwell Trust
125 Hartwell Avenue
Lexington, MA 02173

Synta Pharmaceuticals Corp.
45 Hartwell Avenue
Lexington, Massachusetts 02421
Attention: Chief Financial Officer

Re:  Assignment and Assumption of Lease
     125 Hartwell Avenue
     Lexington, Massachusetts
     MORTGAGE ACCOUNT NO. 826501

Dear Sirs:

The Manufacturers Life Insurance Company (U.S.A.) ("Manulife") is the mortgagee
under the Mortgage, Security Agreement and Fixture Filing from Steven Colangelo,
trustee of 125 Hartwell Trust (the "Mortgagor"), encumbering property generally
known as 125 Hartwell Avenue, Lexington, Massachusetts and filed with the
Middlesex South Registry District of the Land Court as Document No. 1064641 (the
"Mortgage"). Lexigen Pharmaceuticals Corp. (f/k/a Fuji ImmunoPharmaceuticals
Corp.), Mortgagor, and Manulife are parties to that certain Subordination,
Non-Disturbance and Attornment Agreement dated as of May 5, 1998 (the "SNDA").
We understand that EMD Pharmaceuticals Inc. ("EMD"), as the successor tenant
under that certain Lease dated as of October 26, 1992, as amended by First
Amendment dated as of January 31, 1993, Second Amendment dated October 1, 1997,
and Third Amendment dated November 1, 2002 (as so amended and collectively, the
"Lease" and being the lease referenced in the SNDA), will assign its interest as
tenant under the Lease to Synta Pharmaceuticals Corp. ("Synta") pursuant to the
attached Assignment and Assumption of Lease and Consent of and Release by
Mortgagor and Fourth Amendment to Lease (the "Assignment").

Manulife hereby approves the form and substance of the Assignment, expressly
including the Mortgagor's consent to the assignment of the Lease to Synta, the
release of EMD from liability under the Lease as and to the extent provided in
the Assignment, and the assumption by Synta of the tenant's obligations under
the Lease arising on and after the Effective Date (as defined in the Assignment)
as and to the extent provided in the Assignment.

Manulife also hereby agrees that Synta shall to entitled to the benefits of the
SNDA as if Synta were the Tenant named therein.

Manulife's approval and agreement pursuant to this letter are expressly
conditioned upon receipt, no later than July 16, 2004, of a $1,000.00 Lease
Approval Fee, together with fully executed copies of this letter, the
Assignment, and all other documentation pertaining to the assignment, assumption
and release.

The Manufacturers Life Insurance Company
Boston Mortgage Branch
118 Huntington Avenue, Suite 6900, Boston, MA 02116
Phone: (617) 238-0880 Fax: (617) 238-0585                       www.manulife.com

Manulife Financial and the block design are registered services marks and
trademarks of The Manufacturers Life Insurance Company and are used by it and
its affiliates including Manulife Financial Corporation.

<Page>

125 Hartwell Ave.
Mortgage Account No. 826501
Page 2

Time is of the essence hereof.

Very truly yours,

THE MANUFACTURERS LIFE INSURANCE COMPANY (U.S.A.)

/s/ IAN S. [ILLEGIBLE]
Ian S. [ILLEGIBLE]
Regional Manager

Cc:      John Van [ILLEGIBLE]
         Robert Mack, Esq.
         Delia Williams

Attachment

Agreed and accepted by:

                              ASSIGNOR:

                              EMD Pharmaceuticals, Inc.,
                              a Delaware corporation

                              By:    /s/ Gilda M. Thomas
                                     --------------------------
                              Name:  Gilda M. Thomas
                              Title: Vice President and General Counsel

                              ASSIGNEE:

                              SYNTA Pharmaceuticals Corp.,
                              a Delaware corporation

                              By:    /s/ Keith Ehrlich
                                     ----------------------------
                              Name:  Keith Ehrlich
                              Title: Vice President, Finance and Administration

                              MORTGAGOR:

                              125 Hartwell Trust

                              By:    /s/ Steven Colangelo
                                     ----------------------------
                              Name:  Steven Colangelo
                              Title: As Trustee and not individually

<Page>

                               125 Hartwell Avenue
                         Lexington, Massachusetts 02421
                                (the "Building")

                                 FIFTH AMENDMENT
                                October 22, 2002

<Table>
<S>                                  <C>
          LANDLORD:                  125 Hartwell Trust, under a declaration of
                                     trust dated February 20, 1980 and filed
                                     with the Middlesex South Registry District
                                     of the Land Court as Document No. 600788,
                                     as amended

          TENANT:                    Synta Pharmaceuticals Corp., a Delaware
                                     corporation, successor-by-assignment to EMD
                                     Pharmaceuticals, Inc.

          PREMISES:                  Approximately 19,810 square feet of
                                     Premises Rentable Area on the second (2nd)
                                     floor of the Building, consisting of
                                     approximately 10,980 square feet of
                                     Premises Rentable Area under the original
EXISTING                             Lease shown as the leased premises on
LEASE                                Exhibit 3 thereto, plus approximately 8,830
DATA:                                square feet of Premises Rentable Area added
                                     by the First Amendment referred to below
                                     shown as the "RFO Premises" on said
                                     Exhibit 3

          LEASE EXECUTION DATE:      October 26, 1992

          TERMINATION DATE:          January 31, 2003

          PREVIOUS LEASE             First Amendment dated as of January 31,
          AMENDMENTS:                1993 Second Amendment dated October 1, 1997
                                     Third Amendment dated November 1, 2002
                                     Assignment and Assumption of Lease and
                                     Consent of Release by Landlord and Fourth
                                     Amendment to Lease dated as of July 9, 2004

          ADDITIONAL PREMISES:       Approximately 2,670 square feet of Premises
                                     Rentable Area on the first (1st) floor of
                                     the Building, substantially as shown
                                     cross-hatched on EXHIBIT A attached hereto
                                     and mace a part hereof
</Table>

<Page>

       WHEREAS, Tenant desires to lease additional space in the Building; and

       WHEREAS, Landlord is willing to lease additional space in the Building to
Tenant upon the terms and conditions hereinafter set forth.

       NOW THEREFORE, the parties hereby agree that the above-described lease,
as previously amended (the "Lease"), is hereby further amended as follows
(capitalized terms used herein without definition shall have the meanings
ascribed to them in the Lease):

       1.     DEMISE OF ADDITIONAL PREMISES

       Landlord hereby demises and leases to Tenant, and Tenant hereby accepts
and leases from Landlord, the Additional Premises for a Term commencing as of
the Commencement Date in respect of the Additional Premises (as hereinafter
defined) and expiring on January 31, 2008. The demise of the Additional Premises
shall otherwise be upon and governed by the terms and conditions of the Lease
(as hereby amended), except as follows or as otherwise provided in this
Amendment:

       A.     The Commencement Date in respect of the Additional Premises shall
be the earlier of (i) the first date on which Tenant occupies all or any part of
the Additional Premises for the conduct of business, or (ii) the date on which
Landlord's Work (as hereinafter defined) shall be (or be deemed to be)
substantially (i.e., complete except for so-called "punch list" items and other
work to be undertaken by Landlord which does not materially impair Tenant's use
of the Additional Premises for the Permitted Uses (collectively, the "Punchlist
Work")), as reasonably determined by Landlord. Landlord shall complete all
Punchlist Work within thirty (30) days after the substantial completion of
Landlord's Work. If Tenant (or any agent, employee or contractor of Tenant)
causes any delay in the preparation of any drawings, plans or specifications or
the performance or substantial completion of Landlord's Work, then Landlord's
Work shall be deemed to have been substantially completed on the date that
Landlord's Work would have been substantially completed but for such delay.
Landlord shall notify Tenant of any such delay promptly after Landlord becomes
aware of the same. Landlord shall use reasonable efforts to cause Landlord's
Work to be substantially completed on or before the date (the "Estimated
Substantial Completion Date") which is sixty (60) days after the execution and
delivery of this Amendment, but Tenant shall not have any claim against
Landlord, and Landlord shall have no liability to Tenant, if Landlord's Work
shall not be substantially completed by the Estimated Substantial Completion
Date. The parties shall confirm in writing the Commencement Date in respect of
the Additional Premises as soon as it is known.

       B.     Basic Rent payable in respect of the Additional Premises shall be
$60,075.00 per year (i.e., $5,006.25 per month).

       C.     The Building Expense Base applicable to the Additional Premises
shall be the actual amount of Building Expenses for calendar year 2004.

<Page>

       D.     Tenant shall have no obligation to pay for electricity for lights
and plugs in the Additional Premises.

       E.     Tenant's Proportionate Share in respect of the Additional Premises
shall be 6.95%.

       F.     Tenant shall, by reason of the demise of the Additional Premises,
be entitled to an additional ten (10) parking spaces in the paved parking area
located adjacent to the Building. The use of such spaces shall be subject to the
same terms and conditions of the Lease as are applicable to Tenant's use of the
other parking spaces provided to Tenant under the Lease. Accordingly, the total
number of parking spaces which Landlord shall provide and maintain for the use
of Tenant's employees and invitees pursuant to Section 2 of the Lease shall be
eighty-five (85).

       2.     LANDLORD'S WORK IN RESPECT OF ADDITIONAL RREMISES

       Landlord agrees to perform, at Landlord's expense (except as otherwise
provided herein), the work within the Additional Premises described in or shown
on, and substantially in accordance with, the space plan attached hereto as
EXHIBIT B and made a part hereof (the "Space Plan") using Building standard
materials, finishes and mechanical and electrical improvements ("Landlord's
Work"). Landlord's Work shall also include the installation of one (1) teledata
outlet device per office in the Additional Premises and the wiring associated
therewith. Except for Landlord's Work, Tenant shall accept the Additional
Premises "as is" and Tenant acknowledges that it has had an opportunity to
inspect the Additional Premises and that Landlord has made no representation or
warranty as to the condition of the Additional Premises.

       Landlord agrees to undertake construction of the Additional Premises in
accordance with the provisions hereof in a good and workmanlike fashion and in
compliance with applicable laws, rules and regulations.

       In the event that Tenant shall request in writing and Landlord shall
approve work not presently described on or contemplated by the Space Plan, then
Landlord shall render to Tenant an estimate of the additional cost of such work
(and any cost associated with new or revised plans and/or specifications
required to be prepared by reason of such work), and Tenant shall pay such
amount to Landlord prior to Landlord having any obligation to undertake any such
work; provided, however, that Tenant shall be responsible for any delays in the
performance or substantial completion of Landlord's Work on account of any such
work requested by Tenant in writing.

       3.     MODIFICATION TO LEASE

       Effective as of the date hereof the following language is hereby inserted
at the end of the first sentence of Section 22 of the Lease:

                     ; and in no event shall Tenant have the right to terminate
                     or cancel this Lease or to withhold or abate rent or to
                     set-off any claim or damages against rent as a result of
                     any default or breach by Landlord of its

<Page>

                     covenants or obligations or any representations, warranties
                     or promises hereunder, except as may otherwise be expressly
                     set forth, herein.

       4.     BROKER

       Each party (the "indemnifying party") represents and warrants to the
other party that it has not dealt with any broker or agent in connection with
this Amendment or the leasing of the Additional Premises. The indemnifying party
shall indemnify and hold the other party (and such other party's trustees,
beneficiaries, agents and employees) harmless of and from, all claims that may
be made by any person against such other party (or its trustees, beneficiaries,
agents or employees) for brokerage or other compensation in the nature of
brokerage with respect to Amendment on account or arising out of the
indemnifying party's dealings with such person.

       As amended by this Fifth Amendment, the Lease is hereby ratified,
approved and confirmed in all respects.

       WHEREFORE, the parties have hereunto set their hands and seals as of the
date first above written.

LANDLORD:                                       TENANT:

                                                SYNTA PHARMACEUTICALS CORP.

    /S/ STEVEN COLANGELO                        By:   /S/ KEITH EHRLICH
-----------------------------------------           ----------------------------
Steven Colangelo, signing as                        Name:  Keith Ehrlich
Trustee of 125 Hartwell Trust and not               Title:  V.P. Finance
individually and without recourse                   Hereunto Duly Authorized
against and Trustee personally or his assets

<Page>

                                    EXHIBIT A

                                   FLOOR PLAN

<Page>

                                    EXHIBIT B

                                   FLOOR PLAN

<Page>

                              125 Hartwell Avenue
                         Lexington, Massachusetts 02421
                                (the "Building")

                                 SIXTH AMENDMENT
                                 --------------
                                 August 1, 2005

LANDLORD:           125 Hartwell Trust, under a declaration of trust dated
                    February 20, 1980 and filed with the Middlesex South
                    Registry District of the Land Court as Document No. 600788,
                    as amended

TENANT:             Synta Pharmaceuticals Corp., a Delaware corporation,
                    successor-by-assignment to EMD Pharmaceuticals, Inc.

PREMISES:           Collectively, (i) approximately, 19,810 square feet of
                    Premises Rentable Area on the second (2nd) floor of the
                    Building, consisting of approximately 10,980 square feet of
                    Premises Rentable Area under the original Lease shown as the
                    "Premises" on Exhibit 3 thereto, plus approximately 8,830
                    square feet of Premises Rentable Area added by the First
                    Amendment referred to below shown as the "RFO Premises" on
                    said Exhibit 3, and (ii) approximately 2,670 square feet of
                    Premises Rentable Area on the first (1st) floor of the
                    Building, substantially as shown cross-hatched on Exhibit A
                    attached to the Fifth Amendment referred to below

LEASE
EXECUTION
DATE:               October 26, 1992

TERMINATION
DATE:               January 31, 2008

PREVIOUS
LEASE
AMENDMENTS:         First Amendment dated as of January 31, 1993 Second
                    Amendment dated October 1, 1997 Third Amendment dated
                    November 1, 2002 Assignment and Assumption of Lease and
                    Consent of and Release by Landlord and Fourth Amendment to
                    Lease dated as of July 9, 2004 (the "Assignment/Fourth
                    Amendment") Fifth Amendment dated October 22, 2004

<Page>

     WHEREAS, Tenant desires to obtain from Landlord (i) three (3) consecutive
options to extend the Term of the above-described lease, as previously amended
(the "Lease"), and (ii) Landlord's consent to the Tenant Improvements (as
hereinafter defined); and

     WHEREAS, Landlord is willing to grant such options to Tenant and to grant
its consent to the Tenant Improvements, all upon the terms and conditions
hereinafter set forth.

     NOW THEREFORE, the parties hereby agree that the Lease is hereby amended by
this Sixth Amendment (this "Amendment") as follows (capitalized terms used
herein without definition shall have the meanings ascribed to them in the
Lease):

     1.   OPTION TO EXTEND
          ----------------

     A. On the condition, which condition Landlord may waive, at its election,
by written notice to Tenant at any time, that Tenant is not in default after the
expiration of applicable notice and grace periods of its covenants and
obligations under the Lease (as hereby amended) both as of the time of option
exercise and as of the commencement of the applicable additional (extension)
term described below, Tenant shall have the option to extend the Term of the
Lease as to all of the premises demised thereunder for three (3) successive
additional terms, the first such additional term commencing as of February 1,
2008 and expiring as of November 30, 2011, the second such additional term
commencing as of December 1, 2011 and expiring as of November 30, 2014, and the
third such additional term commencing as of December 1, 2014 and expiring as of
November 30, 2017. Tenant may exercise each such option to extend by giving
Landlord written notice on or before the date that is nine (9) months prior to
the expiration date of the then current term of the Lease. Upon the timely
giving of such notice, the Term of the Lease shall be deemed to be automatically
extended upon all of the terms and conditions of the Lease (as hereby amended)
applicable to Premises and in effect immediately prior to the commencement of
the then applicable additional term, except that:

     (i)  the Basic Rent payable by Tenant during the first such additional term
          shall be the sum of (x) the Basic Rent payable by Tenant in respect of
          the Premises as of January 31, 2008, PLUS (y) the aggregate amounts
          payable by Tenant under the Lease on account of Building Expenses
          (i.e., the Building Expense Escalation Charge) in respect of calendar
          years 2005, 2006 and 2007, less the portion(s), if any, of any such
          amounts that have been previously included in the Basic Rent set
          forth in the foregoing clause (x) [by way of clarification, and
          notwithstanding anything to the contrary contained in the Lease, the
          aggregate Building Expense Escalation Charges payable in respect of
          each calendar year (once finally determined) are included in the Basic
          Rent payable for the subsequent calendar year and the Building Expense
          Base, for purposes of determining the Building Expense Escalation
          Charges payable in respect of such subsequent calendar year, is
          changed to the prior calendar year's Building Expenses]; and the Basic
          Rent payable by Tenant during each of the second and third such
          additional terms shall be the Fair Market Rental Value, as defined in
          Paragraph 2A below, as of the commencement of the then applicable
          (i.e., second or third) additional term, of the Premises, provided,
          however, that in no event shall the sum of the Basic Rent and Building
          Expense Escalation Charges to be payable during each of the second and

                                       2
<Page>

          third such additional terms be less than the sum of the Basic Rent and
          Building Expense Escalation Charges which were payable immediately
          preceding the commencement of the then applicable additional term;

     (ii) the Building Expense Base in respect of the fist such additional term
          shall be the amount of Building Expenses for calendar year 2007
          (accordingly, Tenant's obligation to pay Building Expense Escalation
          Charges in respect of the first such additional term shall commence to
          accrue as of February 1, 2008), and the Building Expense Base in
          respect of each of the second and third such additional terms shall be
          established as part of the determination of Basic Rent for the then
          applicable additional term in accordance with clause (i) above and
          Paragraph 2 below;

    (iii) there shall be no Building Expense Cap during or in respect of any
          additional term;

     (iv) Tenant shall have the right to continue to use the Included Property
          and the Assignor's Improvements during each additional term in
          accordance with and subject to the terms and provisions of Paragraphs
          11 and 12 of the Assignment/Fourth Amendment, except that (even if
          Tenant shall use such Included Property and Assignor's Improvements)
          Tenant shall have no obligation to pay the Monthly Improvements Rent
          in respect of any additional term; and

     (v)  Landlord shall have no obligation to reconstruct or renovate the
          Premises for Tenant's occupancy during any additional term or to
          provide any allowance or contribution with respect thereto.

If Tenant fails to give timely notice, as aforesaid, Tenant shall have no
further right to extend the Term of the Lease, time being of the essence of this
Paragraph 1.

     B. Tenant shall have no further option to extend the Term of the Lease
other than the additional terms herein provided.

     C. Notwithstanding the fact that, upon Tenant's exercise of any of the
options to extend the Term of the Lease for the additional term(s) as set forth
herein, such extension(s) shall be self-executing, as aforesaid, the parties
shall promptly execute a mutually acceptable lease amendment reflecting the
applicable additional term after Tenant exercises the option for such additional
term, except that, in the case of the exercise of the option for the second and
third additional terms, the Basic Rent payable in respect of such additional
term and the Building Expense Base for such additional term need not be set
forth in the applicable amendment. Subsequently, after such Basic Rent and
Building Expense Base for such additional term are determined, the parties shall
execute a written agreement confirming the same. The execution of such lease
amendment shall not be deemed to waive any of the conditions to Tenant's
exercise of its rights under Paragraph 1 A above, unless otherwise specifically
provided in such lease amendment.

                                       3

<Page>

     2.   DEFINITION OF FAIR MARKET RENTAL VALUE
          --------------------------------------

     A. For purposes of Paragraph 1 above, "Fair Market Rental Value" shall mean
the then current annual rental charge (i.e., the sum of Basic Rent plus
escalation and other charges), including provisions for subsequent increases and
other adjustments, computed as of the commencement of the then applicable (i.e.,
second or third) additional term, for leases and agreements to lease then
currently being executed for comparable office space located within a two (2)
mile radius of the Building. In determining Fair Market Rental Value, the
following factors, among others, shall be taken into account and given effect:
size, location and condition of premises, lease term, condition of building and
services provided by the landlord. Landlord and Tenant understand and agree
that, although a portion of the Premises is used as laboratory space by Tenant,
the Fair Market Rental Value shall be determined as if the entire Premises were
being used as office space and no part of the Premises were being used as
laboratory space; provided, however, that in evaluating whether the condition of
office space located within a two (2) mile radius of the Building is comparable
to the condition of the Premises, any damage to the Premises caused by Tenant or
its agents, employees or contractors and not attributable to normal wear and
tear for an office use shall be ignored in determining Fair Market Rental Value
(i.e., the condition of the Premises shall be evaluated as office space as if
such damage did not exist).

     B. No later than seven (7) months prior to the expiration of the then
current term of the Lease (provided that Tenant shall have timely exercised the
applicable (i.e., second or third) option), Landlord shall (acting in good
faith) designate Fair Market Rental Value (including the Building Expense Base)
with respect to the additional term in question and notify Tenant thereof in
writing. Tenant shall have ten (10) days from and after receipt of Landlord's
notice of the Fair Market Rental Value for the applicable additional term to
either (a) notify Landlord in writing of Tenant's election to accept such
designation, or (b) submit a written good faith counterproposal to Landlord of
Fair Market Rental Value for the applicable additional term, which
counterproposal shall include fair market escalations for each year during the
applicable additional term. If Tenant fails to respond within such ten (10) day
period, Tenant shall be deemed to have made the election set forth in clause (a)
of the preceding sentence. If Tenant submits a counterproposal of Fair Market
Rental Value for the applicable additional term, and Landlord and Tenant fail to
reach agreement upon the Fair Market Rental Value for the applicable additional
term within sixty (60) days after Tenant submits its written counterproposal to
Landlord, the Basic Rent for the applicable additional term shall be determined
by arbitration by the American Arbitration Association in Boston, Massachusetts,
and the decision of the arbitrator shall be binding upon Landlord and Tenant. In
any such arbitration, the arbitrator shall be a commercial real estate broker or
appraiser unaffiliated with either party and having at least ten (10) years'
experience in the leasing of comparable office space within a two (2) mile
radius of the Building, who, after hearing the presentations of the parties,
shall select, in its entirety and without modification, the Fair Market Rental
Value proposal submitted (including fair market escalations for each year during
the additional term) to such arbitrator by either Landlord or Tenant as the
Basic Rent for the Premises for the applicable. additional term, whichever such
arbitrator believes most accurately reflects the then current Fair Market Rental
Value for the Premises (it being understood that Landlord's and Tenant's
respective proposal to the arbitrator may differ from Landlord's and Tenant's
initial designations of Fair Market Rental Value given to the other party in
accordance with the first two sentences of this Paragraph 2B and, in such event,
the arbitrator shall not take into account any designations of such Fair Market
Rental

                                       4
<Page>

Value previously given by Landlord or Tenant, as the case may be, to the
other party). The party whose Fair Market Rental Value proposal is not selected
by the arbitrator shall pay for the fees, costs and expenses of the arbitrator
and the arbitration proceeding. Promptly after the determination of the Fair
Market Rental Value for the applicable additional term as provided herein,
Landlord and Tenant shall execute a suitable instrument confirming the same and
the new lease expiration date, but failure to do so shall have no effect on the
validity of the extension. The decision of the arbitrator shall be final and
binding on the parties and judgment thereon may be entered in the Superior Court
having jurisdiction over the Premises; and the parties consent to the
jurisdiction of such court and further agree that any process or notice of
motion or other application to the court or a judge thereof may be served
outside the Commonwealth of Massachusetts by registered mail or by personal
service, provided a reasonable time for appearance is allowed. If the dispute
between the parties as to Fair Market Rental Value has not been resolved before
the commencement of Tenant's obligation to pay rent based upon Fair Market
Rental Value, then Tenant shall pay Basic Rent and other charges under the Lease
in respect of the Premises based upon the Fair Market Rental Value designated by
Landlord until either the agreement of the parties as to the Fair Market Rental
Value or the decision of the arbitrator, as the case may be, at which time
Tenant shall pay any underpayment of rent and other charges to Landlord, or
Landlord shall refund any overpayment of rent and other charges to Tenant.

     3.   HOLDOVER

     The word and number "two (2)" appearing in Section 31 of the Lease is
hereby deleted and replaced by the word and number "one and one-half (1 1/2)".

     4.   BROKER.

     Each party (the "indemnifying party") represents and warrants to the other
party that it has not dealt with any broker or agent in connection with this
Amendment other than Richards Barry Joyce & Partners (the "Broker"). The
indemnifying party shall indemnify and hold the other party (and such other
party's trustees, beneficiaries, agents and employees) harmless of and from all
claims that may be made by any person against such other party (or its trustees,
beneficiaries, agents or employees) for brokerage or other compensation in the
nature of brokerage with respect to this Amendment on account or arising out of
the indemnifying party's dealings with such person. Landlord shall pay the
commission owed to the Broker in connection with this Amendment (if any) and in
connection with Tenant's exercise of the above-described extension option (if
Tenant shall timely and properly exercise such option), in each case pursuant to
a separate agreement between Landlord and the Broker.

     5.   SURRENDER

     A. Notwithstanding anything to the contrary contained in this Amendment or
the Lease, upon the expiration or sooner termination of the Term of the Lease,
Tenant shall deliver the Premises to Landlord with all of the Tenant
Improvements (as well as the Included Property and the Assignor's Improvements,
as defined in Paragraphs 11 and 12, respectively, of the Assignment/Fourth
Amendment) remaining therein, it being understood and agreed that Tenant's
personal property and equipment, if not permanently affixed to the Premises or
the Building,

                                       5
<Page>

shall be removed by Tenant from the Premises upon the expiration or sooner
termination of the Term of the Lease and any damage caused by such removal sha4
be repaired by Tenant at its expense.

     B. Landlord and Tenant acknowledge and agree that, as part of the Tenant
Improvements, Tenant removed lab benches from so-called Labs 252, 254 and 256 in
the Premises, which lab benches were part of the Included Property. Landlord
hereby consents to such removal on and subject to the condition (which condition
Tenant hereby confirms and agrees to) that there shall be no reduction (or
increase) in the Monthly Improvements Rent by reason of such removal.

     6.   NOTICE OF LEASE

     At Tenant's option, Landlord shall, within thirty (30) days of receipt
thereof, execute a notice of lease in a form provided by Tenant and reasonably
acceptable to Landlord (which form may, at Tenant's option, include a reference
to the extension options set forth herein) (the "Notice of Lease"); provided,
however, that such Notice of Lease shall state that it amends and restates any
previously recorded notice of lease with respect to the Lease. Tenant shall have
the right to record the Notice of Lease in the applicable registry of deeds at
its expense.

     7. TENANT IMPROVEMENTS

     Notwithstanding anything to the contrary contained in the Lease or this
Amendment, Tenant shall have the right to redecorate the Premises and to make
any or all such other installations, modifications and alterations (including,
but not limited to, installing a vivarium and any new or updated HVAC, plumbing,
and electrical systems or components) in, on or to the Premises, in each case to
the extent such work is described or depicted in the construction plans for the
Premises submitted to and approved by the Town of Lexington, Massachusetts, on
or around April 19, 2005, as such plans may be reasonably altered or amended
from time to time in an immaterial way (collectively, the "Tenant
Improvements"). Landlord hereby approves the Tenant Improvements and no further
approval from Landlord for the Tenant Improvements shall be required under the
Lease or this Amendment. Tenant agrees to pay promptly when due the entire cost
of the Tenant Improvements (Tenant reserving the right, however, in good faith
to contest its liability for those costs that are in dispute); to secure the
discharge of record (by bonding or otherwise) of any lien imposed with respect
to such work; to `procure and pay for all necessary insurance (including
builder's risk, so-called) and permits before undertaking such work (Landlord
hereby agreeing to execute promptly any instrument of approval which may be
required in connection with any such permit, so long as the same is without cost
or liability to Landlord, unless Tenant reimburses Landlord for such cost and/or
Landlord is indemnified by Tenant for such liability pursuant to an
indemnification agreement reasonably acceptable to Landlord, as applicable); and
to do all of such work in a good and workmanlike manner, employing materials of
good quality and complying with all applicable governmental requirements. The
Tenant Improvements shall otherwise be performed in accordance with and subject
to the terms and provisions of the Lease. Landlord also hereby approves Linbeck
Group LP to be the construction manager responsible for the installation and
performance of the Tenant Improvements.

                                       6
<Page>

     8.   MISCELLANEOUS

     As amended by this Amendment, the Lease is hereby ratified, approved and
confirmed in all respects and Landlord and Tenant each hereby acknowledge and
confirm that, to the best of its respective knowledge, neither the Landlord nor
the Tenant is in default of any term or condition of the Lease. In the event of
a conflict between the Lease and this Amendment, the terms of this Amendment
shall govern.

     WHEREFORE, the parties have hereunto set their hands and seals as of the
date first above written.

<Table>

<S>                                        <C>

LANDLORD:                                  TENANT:

                                           SYNTA PHARMACEUTICALS CORP.

/S/ STEVEN COLANGELO                       By: /s/ KEITH EHRLICH
--------------------                              -----------------
Steven Colangelo, signing                  Name: Keith Ehrlich
Trustee of 125 Hartwell Trust and not      Title: Vice President, Finance & Administration
individually and without recourse          Hereunto Duly Authorized
against the Trustee personally or his
assets

</Table><Page>

                                                                    Exhibit 10.7

                               91 HARTWELL AVENUE
                            LEXINGTON, MASSACHUSETTS

                          Lease Dated January 13, 2005

         THIS INSTRUMENT IS AN INDENTURE OF LEASE in which the Landlord and the
Tenant are the parties hereinafter named, and which relates to space in a
certain building (the "Building") known as, and with an address at, 91 Hartwell
Avenue, Lexington, Massachusetts.

         The parties to this Indenture of Lease hereby agree with each other as
follows:

                                    ARTICLE I
                                    ---------

                                 REFERENCE DATA
                                 --------------

1.1      SUBJECTS REFERRED TO.
         ---------------------

         Each reference in this Lease to any of the following subjects shall be
         construed to incorporate the data stated for that subject in this
         Article:

<Table>
<S>                                                       <C>
         Landlord:                                        Mortimer B. Zuckerman and Edward H. Linde, Trustees
                                                          of 91 Hartwell Avenue Trust under Declaration of
                                                          Trust dated September 28, 1981 filed with the
                                                          Middlesex South Registry as Document No. 616455 as
                                                          amended by instruments dated December 10, 1984 and
                                                          April 17, 1991 respectively filed with said Registry
                                                          District as Document Nos. 675674 and 844541 but not
                                                          individually.

         Landlord's Original Address:                     c/o Boston Properties Limited Partnership
                                                          111 Huntington Avenue, Suite 300
                                                          Boston, Massachusetts 02199-7610

         Landlord's Construction Representative:          Michael Schumacher

         Tenant:                                          Synta Pharmaceuticals, Inc., a Delaware corporation.

         Tenant's Original Address:                       45 Hartwell Avenue
                                                          Lexington, Massachusetts 02421

<Page>

         Tenant's Construction Representative:
                                                          ------------------------------------

         Commencement Date:                               January 15, 2005

         Second Floor Premises Rent                       February 15, 2005
         Commencement Date:

         Third Floor Premises Rent                        July 1, 2005
         Commencement Date:

         Original Term:                                   Twenty-five (25) calendar months (plus
                                                          the partial month, if any, immediately
                                                          following the Commencement Date),
                                                          unless extended or sooner terminated as
                                                          provided in this Lease.

         Extension Option:                                One (1) period of one (1) year as provided in and on
                                                          the terms set forth in Section 2.4.1 hereof.

         Term or Lease Term:                              All references in this Lease or to the Term
                                                          or Lease Term shall mean the Original Term
                                                          and if extended pursuant to Section 2.4.1, the Original
                                                          Term as extended by the exercise of the extension option
                                                          unless otherwise specifically provided in this Lease.

         The Site:                                        That certain parcel of land known as and numbered 91
                                                          Hartwell Avenue, Lexington, Middlesex Count, Massachusetts,
                                                          being more particularly described in Exhibit A attached
                                                          hereto. The Building (as defined below) is the only structure
                                                          located on the Site.

         The Building:                                    The Building known as and numbered 91 Hartwell
                                                          Avenue, Lexington, Massachusetts.

         The Complex:                                     The Building together with all surface parking areas,
                                                          the Site and all improvements (including landscaping)
                                                          thereon and thereto.

         Tenant's Space:                                  A portion of the second (2nd) floor of the Building
                                                          (the "Second Floor Premises") and a portion of the
                                                          third (3rd) floor of the Building (the "Third Floor
                                                          Premises"), in

                                      -2-

<Page>

                                                          accordance with the floor plan annexed
                                                          hereto as Exhibit D and incorporated herein by
                                                          reference.

         Number of Parking Spaces:                        Seventy-six (76) spaces.

         Annual Fixed Rent:                               (a)  With respect to the Second Floor Premises, for
                                                          the period commencing on the Second Floor Premises
                                                          Rent Commencement Date and ending on the last day of
                                                          the Original Term of this Lease at the annual rate of
                                                          $268,398.00, being the product of (i) $19.50 and (ii)
                                                          the "Rentable Floor Area of the Second Floor
                                                          Premises" (hereinafter defined in this Section 1.1).

                                                          (b) With respect to the Third Floor Premises, for the
                                                          period commencing on the Third Floor Premises Rent
                                                          Commencement Date and ending on the last day
                                                          of the Original Term of this Lease at the annual rate of
                                                          $157,326.00, being the product of (i) $19.50
                                                          and (ii) the "Rentable Floor Area of the Third Floor
                                                          Premises" (hereinafter defined in this Section 1.1).

                                                          (c)  During the extension option period (if
                                                          exercised), as determined pursuant to Section 2.4.1).

         Operating Expenses:                              As provided in Section 2.6 hereof.

         Real Estate Taxes:                               As provided in Section 2.7 hereof.

         Tenant Electricity:                              Initially as provided in Section 2.5 subject to
                                                          adjustment as provided in Section 2.8 hereof.

         Additional Rent:                                 All charges and other sums payable by Tenant as set
                                                          forth in this Lease, in addition to Annual Fixed Rent.

         Rentable Floor Area of Tenant's Space            21,832 rentable square feet, consisting of 13,764
         (sometimes also called "Rentable Floor           square feet of rentable floor area in the Second
         Area of the Premises"):                          Floor Premises (the "Rentable Floor Area of the
                                                          Second Floor Premises") and 8,068 square feet of
                                                          rentable floor area in the Third Floor Premises (the
                                                          "Rentable Floor Area of the Third Floor Premises").

                                      -3-

<Page>

         Total Rentable Floor Area of the Building:       122,328 rentable square feet.

         Permitted Use:                                   General office purposes.

         Initial Minimum Limits of Tenant's               $5,000,000.00 combined single limit per occurrence on
         Commercial General Liability Insurance:          a per location basis.

         Broker:                                          Richards Barry Joyce & Partners
                                                          53 State Street, 29th Floor
                                                          Boston, Massachusetts 02110

         Security Deposit:                                $35,477.00
</Table>

1.2      EXHIBITS.
         ---------

         There are incorporated as part of this Lease:

         Exhibit A         --       Description of Site

         Exhibit B         --       Intentionally Omitted

         Exhibit C         --       Landlord's Services

         Exhibit D         --       Floor Plan

         Exhibit E         --       Intentionally Omitted

         Exhibit F         --       Form of Lien Waivers

1.3      TABLE OF ARTICLES AND SECTIONS.
         -------------------------------

<Table>
<S>                                                                                                    <C>     <C>
         ARTICLE I.......................................................................................1
                  REFERENCE DATA..................................................................................1
                           1.1      SUBJECTS REFERRED TO..........................................................1
                           1.2      EXHIBITS......................................................................4
                           1.3      TABLE OF ARTICLES AND SECTIONS................................................4

         ARTICLE II......................................................................................6
                  BUILDING, PREMISES, TERM AND RENT...............................................................6
                           2.1      THE PREMISES..................................................................6

                                      -4-

<Page>

                           2.2      RIGHTS TO USE COMMON FACILITIES...............................................6
                           2.3      LANDLORD'S RESERVATIONS.......................................................7
                           2.4      HABENDUM......................................................................8
                           2.5      FIXED RENT PAYMENTS...........................................................8
                           2.6      OPERATING EXPENSES............................................................9
                           2.7      REAL ESTATE TAXES............................................................11
                           2.8      TENANT ELECTRICITY...........................................................14

         ARTICLE III....................................................................................15
                  CONDITION OF PREMISES; ALTERATIONS.............................................................15
                           3.1      CONDITION OF PREMISES........................................................15
                           3.2      QUALITY AND PERFORMANCE OF WORK..............................................15
                           3.3      SPECIAL ALLOWANCE............................................................15

         ARTICLE IV.....................................................................................16
                  LANDLORD'S COVENANTS; INTERRUPTIONS AND DELAYS.................................................16
                           4.1      LANDLORD COVENANTS:..........................................................16
                           4.2      INTERRUPTIONS AND DELAYS IN SERVICES AND REPAIRS, ETC........................17

         ARTICLE V......................................................................................18
                  TENANT'S COVENANTS.............................................................................18
                           5.1      PAYMENTS.....................................................................18
                           5.2      REPAIR AND YIELD UP..........................................................18
                           5.3      USE..........................................................................18
                           5.4      OBSTRUCTIONS; ITEMS VISIBLE FROM EXTERIOR; RULES AND REGULATIONS.............19
                           5.5      SAFETY APPLIANCES............................................................19
                           5.6      ASSIGNMENT; SUBLEASE.........................................................19
                           5.7      INDEMNITY; INSURANCE.........................................................25
                           5.8      PERSONAL PROPERTY AT TENANT'S RISK...........................................26
                           5.9      RIGHT OF ENTRY...............................................................26
                           5.10     FLOOR LOAD; PREVENTION OF VIBRATION AND NOISE................................27
                           5.11     PERSONAL PROPERTY TAXES......................................................27
                           5.12     COMPLIANCE WITH LAWS.........................................................27
                           5.13     PAYMENT OF LITIGATION EXPENSES...............................................27
                           5.14     ALTERATIONS..................................................................28
                           5.15     VENDORS......................................................................29

         ARTICLE VI.....................................................................................30
                  CASUALTY AND TAKING............................................................................30
                           6.1      DAMAGE RESULTING FROM CASUALTY...............................................30
                           6.2      UNINSURED CASUALTY...........................................................31
                           6.3      RIGHTS OF TERMINATION FOR TAKING.............................................31
                           6.4      AWARD........................................................................32

                                      -5-

<Page>

         ARTICLE VII....................................................................................32
                  DEFAULT  32
                           7.1      TENANT'S DEFAULT.............................................................32
                           7.2      LANDLORD'S DEFAULT...........................................................36

         ARTICLE VIII...................................................................................37
                  MISCELLANEOUS PROVISIONS.......................................................................37
                           8.1      EXTRA HAZARDOUS USE..........................................................37
                           8.2      WAIVER.......................................................................37
                           8.3      CUMULATIVE REMEDIES..........................................................37
                           8.4      QUIET ENJOYMENT..............................................................38
                           8.5      NOTICE TO MORTGAGEE AND GROUND LESSOR........................................39
                           8.6      ASSIGNMENT OF RENTS..........................................................39
                           8.7      SURRENDER....................................................................40
                           8.8      BROKERAGE....................................................................40
                           8.9      INVALIDITY OF PARTICULAR PROVISIONS..........................................40
                           8.10     PROVISIONS BINDING, ETC......................................................40
                           8.11     RECORDING....................................................................41
                           8.12     NOTICES......................................................................41
                           8.13     WHEN LEASE BECOMES BINDING...................................................42
                           8.14     SECTION HEADINGS.............................................................42
                           8.15     RIGHTS OF MORTGAGEE..........................................................42
                           8.16     STATUS REPORTS AND FINANCIAL STATEMENTS......................................43
                           8.17     SELF-HELP....................................................................43
                           8.18     HOLDING OVER.................................................................44
                           8.19     NON-SUBROGATION..............................................................44
                           8.20     SECURITY DEPOSIT.............................................................44
                           8.21     LATE PAYMENT.................................................................45
                           8.22     TENANT'S PAYMENTS............................................................45
                           8.23     WAIVER OF TRIAL BY JURY......................................................46
                           8.24     GOVERNING LAW................................................................46
</Table>

                                   ARTICLE II
                                   ----------

                        BUILDING, PREMISES, TERM AND RENT
                        ---------------------------------

2.1      THE PREMISES.

         Landlord hereby demises and leases to Tenant, and Tenant hereby hires
         and accepts from Landlord, Tenant's Space in the Building excluding
         exterior faces of exterior walls, the common stairways and stairwells,
         elevators and elevator wells, fan rooms, electric and telephone
         closets, janitor closets, and pipes, ducts, conduits, wires and
         appurtenant fixtures serving exclusively, or in common, other parts of
         the Building, and if Tenant's Space includes less than the entire
         rentable area of any floor, excluding the common corridors, elevator
         lobbies and toilets located on such floor.

                                      -6-

<Page>

         Tenant's Space with such exclusions is hereinafter referred to as the
         "Premises." The term "Building" means the Building identified on the
         first page, and which is the subject of this Lease; the term "Site"
         means all, and also any part of the Land described in Exhibit A, plus
         any additions or reductions thereto resulting from the change of any
         abutting street line and all parking areas and structures. The term
         "Property" means the Building and the Site.

2.2      RIGHTS TO USE COMMON FACILITIES.
         -------------------------------

         Subject to Landlord's right to change or alter any of the following in
         Landlord's discretion as herein provided, Tenant shall have, as
         appurtenant to the Premises, the non-exclusive right to use in common
         with others, subject to reasonable rules of general applicability to
         tenants of the Building from time to time made by Landlord of which
         Tenant is given notice (a) the common lobbies, corridors, stairways,
         elevators and loading area of the Building, and the pipes, ducts,
         conduits, wires and appurtenant meters and equipment serving the
         Premises in common with others, (b) common walkways and driveways
         necessary for access to the Building, and (c) if the Premises include
         less than the entire rentable floor area of any floor, the common
         toilets, corridors and elevator lobby of such floor. Notwithstanding
         anything to the contrary herein, Landlord has no obligation to allow
         any particular telecommunication service provider to have access to the
         Building or to the Premises except as may be required by applicable
         law. If Landlord permits such access, Landlord may condition such
         access upon the payment to Landlord by the service provider of fees
         assessed by Landlord in its sole discretion.

         2.2.1    TENANT'S PARKING.
                  ----------------

                  In addition, Tenant shall have the right to use the Number of
                  Parking Spaces (referred to in Section 1.1) of the parking
                  area, in common with use by other tenants from time to time of
                  the Complex; provided, however, Landlord shall not be
                  obligated to furnish stalls or spaces in any parking area
                  specifically designated for Tenant's use. Tenant covenants and
                  agrees that it and all persons claiming by, through and under
                  it, shall at all times abide by all reasonable rules and
                  regulations promulgated by Landlord with respect to the use of
                  the parking areas on the Site. The parking privileges granted
                  herein are non-transferable except to a permitted assignee or
                  subtenant as provided in Section 5.6 through Section 5.6.6.
                  Further, Landlord assumes no responsibility whatsoever for
                  loss or damage due to fire, theft or otherwise to any
                  automobile(s) parked on the Site or to any personal property
                  therein, however caused, and Tenant covenants and agrees, upon
                  request from Landlord from time to time, to notify its
                  officers, employees, agents and invitees of such limitation of
                  liability. Tenant acknowledges and agrees that a license only
                  is hereby granted, and no bailment is intended or shall be
                  created.

2.3      LANDLORD'S RESERVATIONS.
         -----------------------

         Landlord reserves the right from time to time, without unreasonable
         interference with Tenant's use: (a) to install, use, maintain, repair,
         replace and relocate for service to the Premises and other parts of the
         Building, or either, pipes, ducts, conduits, wires and

                                      -7-

<Page>

         appurtenant fixtures, wherever located in the Premises or Building,
         and (b) to alter or relocate any other common facility, provided that
         substitutions are substantially equivalent or better. Installations,
         replacements and relocations referred to in clause (a) above shall be
         located so far as practicable in the central core area of the
         Building, above ceiling surfaces, below floor surfaces or within
         perimeter walls of the Premises. Except in the event of an emergency,
         Landlord shall provide Tenant with forty-eight (48) hours advance
         notice of the above-referenced work if such work shall adversely
         affect Tenant's use of or access to the Premises, the common areas of
         the Site and/or the parking area.

2.4      HABENDUM.
         --------

         Tenant shall have and hold the Premises for a period commencing on the
         Commencement Date, and continuing for the Term unless sooner terminated
         as provided in Article VI or Article VII or unless extended as provided
         in Section 2.4.1.

         2.4.1    EXTENSION OPTION.
                  ----------------

                  (A) On the conditions (which conditions Landlord may waive by
                  written notice to Tenant) that both at the time of exercise of
                  the option to extend and at the commencement date of the
                  extension option period (i) there exists no Event of Default
                  (defined in Section 7.1), (ii) this Lease is still in full
                  force and effect, and (iii) Tenant has not assigned this
                  (except for an assignment permitted without Landlord's consent
                  under Section 5.6.1 hereof), Tenant shall have the right to
                  extend the Term hereof upon all the same Annual Fixed Rent,
                  terms, conditions, covenants and agreements herein contained
                  (except that the only extension option shall be as set forth
                  in this Section 2.4.1) for one (1) period of one (1) year as
                  hereinafter set forth. Such option period is sometimes herein
                  referred to as an "Extended Term." Notwithstanding any
                  implication to the contrary Landlord has no obligation to make
                  any additional payment to Tenant in respect of any
                  construction allowance or the like or to perform any work to
                  the Premises as a result of the exercise by Tenant of such
                  option.

                  (B) If Tenant desires to exercise the option to extend the
                  Term, then Tenant shall give notice to Landlord, not earlier
                  than twelve (12) months nor later than six (6) months prior to
                  the expiration of the Original Term. Upon the giving of such
                  notice, this Lease and the Term hereof shall be extended for
                  the option period, without the necessity for the execution of
                  any additional documents (except that Landlord and Tenant
                  agree to enter into an instrument in writing setting forth the
                  fixed rent); and in such event all references herein to the
                  Term or the term of this Lease shall be construed as referring
                  to the Term, as so extended, unless the context clearly
                  otherwise requires.

2.5      FIXED RENT PAYMENTS.
         -------------------

         Tenant agrees to pay to Landlord, or as directed by Landlord, at
         Landlord's Original Address specified in Section 1.1 hereof, or at such
         other place as Landlord shall from time to time designate by notice,
         (1)(a) on the Second Floor Premises Rent

                                      -8-

<Page>

         Commencement Date with respect to the Second Floor Premises and on the
         Third Floor Premises Rent Commencement Date with respect to the Third
         Floor Premises, respectively, and thereafter monthly, in advance, on
         the first day of each and every calendar month during the Original
         Term, a sum equal to one twelfth (1/12th) of the applicable Annual
         Fixed Rent (sometimes hereinafter referred to as "fixed rent") and (b)
         on the Commencement Date and thereafter monthly, in advance, on the
         first day of each and every calendar month during the Original Term, a
         sum equal to one twelfth (1/12th) of $1.00 per annum for each square
         foot of Rentable Floor Area of Tenant's Space for tenant electricity
         subject to escalation as provided in Section 2.8 and (2) on the first
         day of each and every calendar month during the extension option
         period (if exercised), a sum equal to (a) one twelfth (1/12th) of the
         Annual Fixed Rent as determined in Section 2.4.1 for the extension
         option period plus (b) then applicable monthly electricity charges
         (subject to escalation for electricity as provided in Section 2.8
         hereof). Until notice of some other designation is given, fixed rent
         and all other charges for which provision is herein made shall be paid
         by remittance to or for the order of Boston Properties Limited
         Partnership, Agents at P.O. Box 3557, Boston, Massachusetts
         02241-3557, and all remittances received by Boston Properties Limited
         Partnership, as Agents as aforesaid, or by any subsequently designated
         recipient, shall be treated as payment to Landlord.

         Annual Fixed Rent for any partial month shall be paid by Tenant to
         Landlord at such rate on a pro rata basis, and, if the Second Floor
         Premises Rent Commencement Date and/or the Third Floor Premises Rent
         Commencement Date are a day other than the first day of a calendar
         month, the first payment of Annual Fixed Rent which Tenant shall make
         to Landlord shall be a payment equal to a proportionate part of such
         monthly Annual Fixed Rent for the partial month from the Second Floor
         Premises Rent Commencement Date and/or the Third Floor Premises Rent
         Commencement Date, as applicable, to the first day of the succeeding
         calendar month.

         Additional Rent payable by Tenant on a monthly basis, as hereinafter
         provided, likewise shall be prorated, and the first payment on account
         thereof shall be determined in similar fashion but shall commence on
         the Commencement Date; and other provisions of this Lease calling for
         monthly payments shall be read as incorporating this undertaking by
         Tenant.

         Notwithstanding that the payment of Annual Fixed Rent payable by Tenant
         to Landlord with respect to the Second Floor Premises shall not
         commence until the Second Floor Premises Rent Commencement Date and
         with respect to the Third Floor Premises shall not commence until the
         Third Floor Premises Rent Commencement Date, respectively, Tenant shall
         be subject to, and shall comply with, all other provisions of this
         Lease as and at the times provided in this Lease.

         The Annual Fixed Rent and all other charges for which provision is
         herein made shall be paid by Tenant to Landlord, without offset,
         deduction or abatement except as otherwise specifically set forth in
         this Lease.

                                      -9-

<Page>

2.6      OPERATING EXPENSES.
         ------------------

         "Landlord's Operating Expenses" means the cost of operation of the
         Building and the Site which shall exclude costs of special services
         rendered to tenants (including Tenant) for which a separate charge is
         made, but shall include, without limitation, the following: premiums
         for insurance carried with respect to the Building and the Site
         (including, without limitation, liability insurance, insurance against
         loss in case of fire or casualty and insurance of monthly installments
         of fixed rent and any Additional Rent which may be due under this Lease
         and other leases of space in the Building for not more than 12 months
         in the case of both fixed rent and Additional Rent and if there be any
         first mortgage of the Property, including such insurance as may be
         required by the holder of such first mortgage); compensation and all
         fringe benefits, worker's compensation insurance premiums and payroll
         taxes paid to, for or with respect to all persons engaged in the
         operating, maintaining or cleaning of the Building or Site, water,
         sewer, electric, gas, oil and telephone charges (excluding utility
         charges separately chargeable to tenants for additional or special
         services); cost of building and cleaning supplies and equipment; cost
         of maintenance, cleaning and repairs (other than repairs directly
         chargeable to other tenants or not properly chargeable against income
         or reimbursed from contractors under guarantees); cost of snow removal
         and care of landscaping; payments under service contracts with
         independent contractors; management fees at reasonable rates consistent
         with the type of occupancy and the service rendered; and all other
         reasonable and necessary expenses paid in connection with the
         operation, cleaning and maintenance of the Building and the Site and
         properly chargeable against income, provided, however, there shall be
         included (a) depreciation for capital expenditures made by Landlord (i)
         to reduce Landlord's Operating Expenses if Landlord shall have
         reasonably determined that the annual reduction in Landlord's Operating
         Expenses shall exceed depreciation therefor or (ii) to comply with
         applicable laws, rules, regulations, requirements, statutes,
         ordinances, by-laws and court decisions of all public authorities which
         are now or hereafter in force; plus (b) in the case of both (i) and
         (ii) an interest factor, reasonably determined by Landlord, as being
         the interest rate then charged for long term mortgages by institutional
         lenders on like properties within the locality in which the Building is
         located; depreciation in the case of both (i) and (ii) shall be
         determined by dividing the original cost of such capital expenditure by
         the number of years of useful life of the capital item acquired and the
         useful life shall be reasonably determined by Landlord in accordance
         with generally accepted accounting principles and practices in effect
         at the time of acquisition of the capital item.

         "Tenant's Share" shall mean 17.85%.

         "Operating Expenses Allocable to the Premises" shall mean Tenant's
         Share of Landlord's Operating Expenses for and pertaining to the
         Building and the Site.

         "Base Operating Expenses" shall mean Landlord's Operating Expenses for
         calendar year 2005 (that is, the period beginning January 1, 2005 and
         ending December 31, 2005). Base Operating Expenses shall not include
         market-wide cost increases due to extraordinary circumstances, included
         but not limited to Force Majeure (as defined in Section 6.1),
         conservation surcharges, boycotts, strikes, embargoes or shortages.

                                      -10-

<Page>

         "Base Operating Expenses Allocable to the Premises" shall mean Tenant's
         Share of Base Operating Expenses.

         If with respect to any calendar year falling within the Term, or
         fraction of a calendar year falling within the Term at the beginning or
         end thereof, the Operating Expenses Allocable to the Premises for a
         full calendar year exceed Base Operating Expenses Allocable to the
         Premises or for any such fraction of a calendar year exceed the
         corresponding fraction of Base Operating Expenses Allocable to the
         Premises (such amount being hereinafter sometimes referred to as the
         "Operating Cost Excess") then, Tenant shall pay to Landlord, as
         Additional Rent, the amount of such excess. Such payments shall be made
         at the times and in the manner hereinafter provided in this Section
         2.6. (The Base Operating Expenses Allocable to the Premises do not
         include the $1.00 for tenant electricity to be paid by Tenant together
         with Annual Fixed Rent and for which provision is made in Section 2.5
         hereof, separate provision being made in Section 2.8 of this Lease for
         Tenant's share of increases in electricity costs.)

         Not later than one hundred and twenty (120) days after the end of the
         first calendar year or fraction thereof ending December 31 and of each
         succeeding calendar year during the Term or fraction thereof at the end
         of the Term, Landlord shall render Tenant a statement in reasonable
         detail and according to generally accepted accounting practices
         certified by a representative of Landlord, showing for the preceding
         calendar year or fraction thereof, as the case may be, Base Operating
         Expenses, Landlord's Operating Expenses and Operating Expenses
         Allocable to the Premises. Said statement to be rendered to Tenant
         shall also show for the preceding year or fraction thereof as the case
         may be the amounts of operating expenses already paid by Tenant as
         Additional Rent on account of the operating expenses and the amount of
         the Operating Cost Excess remaining due from, or overpaid by, Tenant
         for the year or other period covered by the statement. Within thirty
         (30) days after the date of delivery of such statement, Tenant shall
         pay to Landlord the balance of the amounts, if any, required to be paid
         pursuant to the above provisions of this Section 2.6 with respect to
         the preceding year or fraction thereof, or Landlord shall credit any
         amounts overpaid by Tenant against (i) monthly installments of fixed
         rent next thereafter coming due or (ii) any sums then due from Tenant
         to Landlord under this Lease (or refund such portion of the overpayment
         as aforesaid if the Term has ended and Tenant has no further obligation
         to Landlord).

         In addition, Tenant shall make payments monthly on account of Tenant's
         share of increases in Landlord's Operating Expenses anticipated for the
         then current year at the time and in the fashion herein provided for
         the payment of fixed rent. The amount to be paid to Landlord shall be
         an amount reasonably estimated annually by Landlord to be sufficient to
         cover, in the aggregate, a sum equal to the Operating Cost Excess for
         each calendar year during the Term.

         Notwithstanding the foregoing provisions, no decrease in Landlord's
         Operating Expenses shall result in a reduction of the amount otherwise
         payable by Tenant if and to the extent said decrease is attributable to
         vacancies in the Building rather than to any other causes.

                                      -11-

<Page>

2.7      REAL ESTATE TAXES.
         -----------------

         If with respect to any full Tax Year or fraction of a Tax Year falling
         within the Term, Landlord's Tax Expenses Allocable to the Premises (as
         hereinafter defined) for a full Tax Year exceed Base Taxes Allocable to
         the Premises or for any such fraction of a Tax Year exceed the
         corresponding fraction of Base Taxes Allocable to the Premises (such
         amount being hereinafter sometimes referred to as the "Tax Excess")
         then, on or before the thirtieth (30th) day following receipt by Tenant
         of the certified statement referred to below in this Section 2.7, then
         Tenant shall pay to Landlord, as Additional Rent, the amount of the Tax
         Excess. Not later than ninety (90) days after Landlord's Tax Expenses
         Allocable to the Premises are determined for the first such Tax Year or
         fraction thereof and for each succeeding Tax Year or fraction thereof
         during the Term, Landlord shall render Tenant a statement in reasonable
         detail certified by a representative of Landlord showing for the
         preceding year or fraction thereof, as the case may be, real estate
         taxes on the Building and the Site and abatements and refunds of any
         taxes and assessments. Expenditures for legal fees and for other
         expenses incurred in seeking the tax refund or abatement may be charged
         against the tax refund or abatement before the adjustments are made for
         the Tax Year. Said statement to be rendered to Tenant shall also show
         for the preceding Tax Year or fraction thereof as the case may be the
         amounts of real estate taxes already paid by Tenant as Additional Rent,
         and the amount of real estate taxes remaining due from, or overpaid by,
         Tenant for the year or other period covered by the statement. Within
         thirty (30) days after the date of delivery of the foregoing statement,
         Tenant shall pay to Landlord the balance of the amounts, if any,
         required to be paid pursuant to the above provisions of this Section
         2.7 with respect to the preceding Tax Year or fraction thereof, or
         Landlord shall credit any amounts due from it to Tenant pursuant to the
         provisions of this Section 2.7 against (i) monthly installments of
         fixed rent next thereafter coming due or (ii) any sums then due from
         Tenant to Landlord under this Lease (or refund such portion of the
         over-payment as aforesaid if the Term has ended and Tenant has no
         further obligation to Landlord).

         In addition, payments by Tenant on account of increases in real estate
         taxes anticipated for the then current year shall be made monthly at
         the time and in the fashion herein provided for the payment of fixed
         rent. The amount so to be paid to Landlord shall be an amount
         reasonably estimated by Landlord to be sufficient to provide Landlord,
         in the aggregate, a sum equal to Tenant's share of such increases, at
         least ten (10) days before the day on which such payments by Landlord
         would become delinquent.

         To the extent that real estate taxes shall be payable to the taxing
         authority in installments with respect to periods less than a Tax Year,
         the foregoing statement shall be rendered and payments made on account
         of such installments. Notwithstanding the foregoing provisions, no
         decrease in Landlord's Tax Expenses with respect to any Tax Year shall
         result in a reduction of the amount otherwise payable by Tenant if and
         to the extent said decrease is attributable to vacancies in the
         Building or partial completion of the Building rather than to any other
         causes.

                                      -12-

<Page>

         Terms used herein are defined as follows:

         (i)   "Tax Year" means the twelve-month period beginning July 1 each
               year during the Term or if the appropriate governmental tax
               fiscal period shall begin on any date other than July 1, such
               other date.

         (ii)  "Tenant's Tax Share" means 18.79%.

         (iii) "Landlord's Tax Expenses Allocable to the Premises" shall mean
               Tenant's Tax Share of Landlord's Tax Expenses.

         (iv)  "Landlord's Tax Expenses" with respect to any Tax Year means the
               aggregate real estate taxes on the Building and Site with respect
               to that Tax Year, reduced by any abatement receipts with respect
               to that Tax Year.

         (v)   "Base Taxes" means Landlord's Tax Expenses (hereinbefore defined)
               for fiscal tax year 2006 (that is, the period beginning July 1,
               2005 and ending June 30, 2006).

         (vi)  "Base Taxes Allocable to the Premises" means Tenant's Tax Share
               of Base Taxes.

         (vii) "Real estate taxes" means all taxes and special assessments of
               every kind and nature and user fees and other like fees assessed
               by any governmental authority on the Building or Site which the
               Landlord shall become obligated to pay because of or in
               connection with the ownership, leasing or operation of the Site,
               the Building and the Property (including, without limitation, if
               applicable the excise prescribed by Mass Gen Laws Chapter 121A,
               Section 10 and amounts in excess thereof paid to the Town of
               Lexington pursuant to agreement between Landlord and the Town)
               and reasonable expenses of and fees for any formal or informal
               proceedings for negotiation or abatement of taxes (collectively,
               "Abatement Expenses"), which Abatement Expenses shall be excluded
               from Base Taxes. The amount of special taxes or special
               assessments to be included shall be limited to the amount of the
               installment (plus any interest, other than penalty interest,
               payable thereon) of such special tax or special assessment
               required to be paid during the year in respect of which such
               taxes are being determined. There shall be excluded from such
               taxes all late fees or penalties, and income, estate, succession,
               inheritance and transfer taxes; provided, however, that if at any
               time during the Term the present system of ad valorem taxation of
               real property shall be changed so that in lieu of, or in addition
               to, the whole or any part of the ad valorem tax on real property
               there shall be assessed on Landlord a capital levy or other tax
               on the gross rents received with respect to the Site or Building
               or Property, or a federal, state, county, municipal, or other
               local income, franchise, excise or similar tax, assessment, levy
               or charge (distinct from any now in effect in the jurisdiction in
               which the Property is located) measured by or based, in whole or
               in part, upon any such gross rents, then any and all of such
               taxes, assessments, levies or charges, to the extent so measured
               or based, shall be

                                      -13-

<Page>

               deemed to be included within the term "real estate taxes" but
               only to the extent that the same would be payable if the Site and
               Building were the only property of Landlord.

        (viii) If during the Lease Term the Tax Year is changed by applicable
               law to less than a full 12-month period, the Base Taxes and Base
               Taxes Allocable to the Premises shall each be proportionately
               reduced.

2.8      TENANT ELECTRICITY.
         ------------------

         The current cost of furnishing electricity to the base building
         components of the Building and the Site is approximately $1.36 per
         square foot of the Total Rentable Floor Area of the Building and the
         current cost of furnishing electricity to the tenant spaces in the
         Building is approximately $1.15 per square foot of the Total Rentable
         Floor Area of the Building. The costs of electricity consumption
         chargeable to the tenants of the Building are based on the costs
         charged to Landlord by the local utility company providing service to
         the Building and the Site and are passed through to the tenants without
         mark-up. If with respect to any calendar year falling within the Term
         or fraction of a calendar year falling within the Term at the beginning
         or end thereof, the cost of furnishing electricity to the Building and
         the Site, including common areas and facilities and space occupied by
         tenants, (but expressly excluding utility charges separately chargeable
         to tenants for additional or special services) for a full calendar year
         exceeds $1.00 per square foot of Rentable Floor Area of the Building,
         or for any such fraction of a calendar year exceeds the corresponding
         fraction of $1.00 per square foot of Rentable Floor Area of the
         Building, then Tenant shall pay to Landlord, as Additional Rent, on or
         before the thirtieth (30th) day following receipt by Tenant of the
         statement referred to below in this Section 2.8, its proportionate
         share of the amount of such excess (i.e. the same proportion of such
         excess as the Rentable Floor Area of Tenant's Space bears to the Total
         Rentable Floor Area of the Building). In no event shall Tenant be
         responsible for any increases in the cost of electricity caused by
         another tenant's excessive use. Payments by Tenant on account of such
         excess shall be made monthly at the time and in the fashion herein
         provided for the payment of Annual Fixed Rent. The amount so to be paid
         to Landlord shall be an amount from time to time reasonably estimated
         by Landlord to be sufficient to cover, in the aggregate, a sum equal to
         such excess for each calendar year during the Term. If the Landlord
         shall reasonably determine that the cost of electricity furnished to
         the Tenant at the Premises exceeds the amount being paid under Sections
         2.5 and 2.8, then the Landlord may charge the Tenant for such excess
         and the Tenant shall promptly pay the same upon billing therefor.

         Not later than ninety (90) days after the end of the first calendar
         year or fraction thereof ending December 31 and of each succeeding
         calendar year during the Term or fraction thereof at the end of the
         Term, Landlord shall render Tenant a reasonably detailed accounting
         certified by a representative of Landlord showing for the preceding
         calendar year, or fraction thereof, as the case may be, the costs of
         furnishing electricity to the Building. Said statement to be rendered
         to Tenant also shall show for the preceding year or fraction thereof,
         as the case may be, the amount already paid by Tenant on account of
         electricity, and the amount remaining due from, or overpaid by, Tenant
         for the year or

                                      -14-

<Page>

         other period covered by the statement. Within thirty (30) days after
         the date of the delivery of such statement, Tenant shall pay to
         Landlord the balance of the amounts, if any required to be paid
         pursuant to the above provisions of this Section 2.8 with respect to
         the preceding year, or fraction thereof, or Landlord shall credit any
         amounts due from it to Tenant pursuant to the above provisions of this
         Section 2.8 against monthly installments of Annual Fixed Rent or
         Additional Rent next thereafter coming due unless the Lease Term has
         expired and Tenant has no other or further obligations to Landlord, in
         which case Landlord shall promptly refund such amount to Tenant.

                                   ARTICLE III
                                   -----------

                       CONDITION OF PREMISES; ALTERATIONS
                       ----------------------------------

3.1      CONDITION OF PREMISES.
         ---------------------

         Tenant shall accept the Premises in their As-Is condition without any
         obligation on the Landlord's part to perform any additions,
         alterations, improvements, demolition or other work therein or
         pertaining thereto.

3.2      QUALITY AND PERFORMANCE OF WORK.
         -------------------------------

         All construction work required or permitted by this Lease shall be done
         in a good and workmanlike manner and in compliance with all applicable
         laws, ordinances, rules, regulations, statutes, by-laws, court
         decisions, and orders and requirements of all public authorities
         ("Legal Requirements") and all Insurance Requirements (as defined in
         Section 5.14 hereof). All of Tenant's work shall be coordinated with
         any work being performed by or for Landlord and in such manner as to
         maintain harmonious labor relations. Each party may inspect the work of
         the other at reasonable times and shall promptly give notice of
         observed defects. Each party authorizes the other to rely in connection
         with design and construction upon approval and other actions on the
         party's behalf by any Construction Representative of the party named in
         Section 1.1 or any person hereafter designated in substitution or
         addition by notice to the party relying. Except to the extent to which
         Tenant shall have given Landlord notice of respects in which Landlord
         has not performed Landlord's construction obligations under this
         Article III (if any) (i) not later than the end of the sixth (6th) full
         calendar month next beginning after the Commencement Date with respect
         to the heating, ventilating and air conditioning systems servicing the
         Premises, and (ii) not later than the third (3rd) full calendar month
         next beginning after the Commencement Date with respect to Landlord's
         construction obligations under this Article III not referenced in (i)
         above, Tenant shall be deemed conclusively to have approved Landlord's
         construction and shall have no claim that Landlord has failed to
         perform any of Landlord's obligations under this Article III (if any).
         Landlord agrees to correct or repair at its expense items which are
         then incomplete or do not conform to the work contemplated under the
         Plans and as to which, in either case, Tenant shall have given notice
         to Landlord, as aforesaid.

                                      -15-

<Page>

3.3      SPECIAL ALLOWANCE.
         -----------------

         Landlord shall provide to Tenant a special allowance equal to the
         product of (i) $6.00 and (ii) the Rentable Floor Area of the Premises
         (the "Tenant Allowance"). The Tenant Allowance shall be used and
         applied by Tenant solely on account of the cost of work performed by or
         on behalf of Tenant ("Tenant's Work"), which such Tenant's Work shall
         be performed in accordance with the terms of this Lease. Provided that
         the Tenant (i) has opened for business in the Premises, (ii) has
         completed all of such Tenant's Work in accordance with the terms of
         this Lease, has paid for all of such Tenant's Work in full and has
         delivered to Landlord lien waivers from all persons who might have a
         lien as a result of such work, in the recordable forms attached hereto
         as Exhibit F, (iii) has delivered to Landlord its certificate
         specifying the cost of such Tenant's Work and all contractors,
         subcontractors and supplies involved with Tenant's Work, together with
         evidence of such cost in the form of paid invoices, receipts and the
         like, (iv) has satisfied the requirements of (i) through (iii) above
         and made request for such payment on or before May 1, 2006, (v) is not
         otherwise in default under this Lease, and (vi) there are no liens
         (unless bonded to the reasonable satisfaction of Landlord) against
         Tenant's interest in the Lease or against the Building or the Site
         arising out of Tenant's Work or any litigation in which Tenant is a
         party, then within thirty (30) days after the satisfaction of the
         foregoing conditions, the Landlord shall pay to the Tenant the lesser
         of the amount of such costs so certified or the amount of the Tenant
         Allowance. Notwithstanding the foregoing, Tenant shall have the option
         to request Landlord to make two separate disbursements of the Tenant
         Allowance (one prior to final completion of the Tenant's Work and one
         upon completion of the same), provided that in the case of the request
         made prior to final completion (1) Tenant has satisfied the
         requirements of items (ii) through (vi) above with respect to that
         portion of the Tenant's Work completed prior to the date of the request
         and (2) the disbursement requested by Tenant equals $21,832.00 or more.
         For the purposes hereof, the cost to be so reimbursed by Landlord shall
         include (x) the cost of leasehold improvements, engineering fees,
         architectural fees and third-party supervision or management fees and
         (y) up to $21,832.00 towards the cost of Tenant's voice and data
         cabling, personal property, trade fixtures or trade equipment, moving
         expenses or any so-called soft costs.

         Notwithstanding the foregoing, Landlord shall be under no obligation to
         apply any portion of the Tenant Allowance for any purposes other than
         as provided in this Section 3.4, nor shall Landlord be deemed to have
         assumed any obligations, in whole or in part, of Tenant to any
         contractors, subcontractors, suppliers, workers or materialmen.
         Further, in no event shall Landlord be required to make application of
         any portion of the Tenant Allowance on account of any supervisory fees,
         overhead, management fees or other payments to Tenant, or any partner
         or affiliate of Tenant. In the event that such cost of Tenant's Work is
         less than the Tenant Allowance, Tenant shall not be entitled to any
         payment or credit nor shall there be any application of the same toward
         Annual Fixed Rent or Additional Rent owed by Tenant under this Lease.

                                      -16-

<Page>

                                   ARTICLE IV
                                   ----------

                 LANDLORD'S COVENANTS; INTERRUPTIONS AND DELAYS
                 ----------------------------------------------

4.1      LANDLORD COVENANTS:
         ------------------

         4.1.1    SERVICES FURNISHED BY LANDLORD.
                  ------------------------------

                  To furnish services, utilities, facilities and supplies set
                  forth in Exhibit C equal to those customarily provided by
                  landlords in high quality buildings in the Boston West
                  Suburban Market subject to escalation reimbursement in
                  accordance with Section 2.6.

         4.1.2    ADDITIONAL SERVICES AVAILABLE TO TENANT.
                  ---------------------------------------

                  To furnish, at Tenant's expense, reasonable additional
                  Building operation services which are usual and customary in
                  similar office buildings in the Boston West Suburban Market
                  upon reasonable advance request of Tenant at reasonable and
                  equitable rates from time to time established by Landlord.
                  Tenant agrees to pay to Landlord, as Additional Rent, the
                  reasonable cost of any such additional Building services
                  requested by Tenant and for the reasonable cost of any
                  additions, alterations, improvements or other work performed
                  by Landlord in the Premises at the request of Tenant within
                  thirty (30) days after being billed therefor.

         4.1.3    ROOF, EXTERIOR WALL, FLOOR SLAB AND COMMON FACILITY REPAIRS.
                  -----------------------------------------------------------

                  Except for (a) normal and reasonable wear and use and (b)
                  damage caused by fire and casualty and by eminent domain, and
                  except as otherwise provided in Article VI and subject to the
                  escalation provisions of Section 2.6, (i) to make such repairs
                  to the structural portions of the Building (including but not
                  limited to the roof, exterior walls and floor slabs) and to
                  the common areas and facilities as may be necessary to keep
                  them in serviceable condition and (ii) to maintain the
                  Building (exclusive of Tenant's responsibilities under this
                  Lease) in a first class manner comparable to the maintenance
                  of similar properties in the Boston West Suburban Market.

         4.1.4    DOOR SIGNS.
                  ----------

                  To provide and install, at Landlord's expense, letters or
                  numerals on the exterior doors to the Premises to identify
                  Tenant's official name and Building address; all such letters
                  and numerals shall be in the building standard graphics and no
                  others shall be used or permitted on the Premises.

                                      -17-

<Page>

4.2      INTERRUPTIONS AND DELAYS IN SERVICES AND REPAIRS, ETC.
         -----------------------------------------------------

         Landlord shall not be liable to Tenant for any compensation or
         reduction of rent by reason of inconvenience or annoyance or for loss
         of business arising from the necessity of Landlord or its agents
         entering the Premises for any of the purposes in this Lease authorized,
         or for repairing the Premises or any portion of the Building however
         the necessity may occur. In case Landlord is prevented or delayed from
         making any repairs, alterations or improvements, or furnishing any
         services or performing any other covenant or duty to be performed on
         Landlord's part, by reason of any cause reasonably beyond Landlord's
         control, including without limitation the causes set forth in Section
         3.2 hereof as being reasonably beyond Landlord's control, Landlord
         shall not be liable to Tenant therefor, nor, except as expressly
         otherwise provided in Article VI, shall Tenant be entitled to any
         abatement or reduction of rent by reason thereof, or right to terminate
         this Lease, nor shall the same give rise to a claim in Tenant's favor
         that such failure constitutes actual or constructive, total or partial,
         eviction from the Premises.

         Landlord reserves the right to stop any service or utility system, when
         necessary by reason of accident or emergency, or until necessary
         repairs have been completed; provided, however, that in each instance
         of stoppage, Landlord shall exercise reasonable diligence to eliminate
         the cause thereof. Except in case of emergency repairs, Landlord will
         give Tenant reasonable advance notice of any contemplated stoppage and
         will use reasonable efforts to avoid unnecessary inconvenience to
         Tenant by reason thereof.

         In the event that the electrical, heating, ventilating, air
         conditioning, or all elevator service to the Premises shall be shut
         down for more than five (5) full and consecutive business days, but
         only as a result of causes which are covered by Landlord's loss of
         rentals insurance, then, Tenant shall be entitled to an abatement of
         Annual Fixed Rent equal to the "Insurance Amount" (hereinafter
         defined). The "Insurance Amount" shall be an amount equal to the
         payment actually received by Landlord (but only allocable to and on
         account of the Premises) for such shut down of electricity service to
         the Premises from Landlord's insurance carrier providing such loss of
         rents insurance less the amount of any deductible contained in such
         loss of rents insurance coverage. Notwithstanding anything herein
         contained to the contrary, in no event shall any of the events referred
         to in this Section give rise to a claim in Tenant's favor that such
         failure constitutes actual or constructive, total or partial, eviction
         from the Premises.

                                      -18-

<Page>

                                    ARTICLE V
                                    ---------

                               TENANT'S COVENANTS
                               ------------------

         Tenant covenants during the Term and such further time as Tenant
         occupies any part of the Premises:

5.1      PAYMENTS.
         --------

         To pay when due all fixed rent and Additional Rent and all charges for
         utility services rendered to the Premises (except as otherwise provided
         in Exhibit C) and, further, as Additional Rent, all charges for
         additional services rendered pursuant to Section 4.1.2.

5.2      REPAIR AND YIELD UP.
         -------------------

         Except as otherwise provided in Article VI and Section 4.1.3, to keep
         the Premises in good order, repair and condition, damage by casualty
         and reasonable wear and tear only excepted, and all glass in windows
         (except glass in exterior walls unless the damage thereto is
         attributable to Tenant's negligence or misuse) and doors of the
         Premises whole and in good condition with glass of similar type and
         quality as that injured or broken, damage by fire or taking under the
         power of eminent domain only excepted, and at the expiration or
         termination of this Lease peaceably to yield up the Premises all
         construction, work, improvements, and all alterations and additions
         thereto in good order, repair and condition, reasonable wear and tear
         only excepted, first removing all goods and effects of Tenant and, to
         the extent specified by Landlord by notice to Tenant given at the time
         Landlord approves Tenant's plans for the installation of the same that
         removal will be required upon the expiration or earlier termination of
         the Lease Term, the wiring for Tenant's computer, telephone and other
         communication systems and equipment whether located in the Premises or
         in any other portion of the Building, including all risers and all
         alterations and additions made by Tenant and all partitions. Tenant
         shall repair any damage caused by such removal and shall restore the
         Premises and leave them clean and neat. Tenant shall not permit or
         commit any waste, and Tenant shall be responsible for the cost of
         repairs which may be made necessary by reason of damage to common areas
         in the Building or to the Site caused by Tenant, Tenant's agents,
         contractors, employees, sublessees, licensees, concessionaires or
         invitees.

5.3      USE.
         ---

         Continuously from the commencement of the Term, to use and occupy the
         Premises for the Permitted Use only, and not to injure or deface the
         Premises, Building, the Site or any other part of the Complex nor to
         permit in the Premises or on the Site any auction sale, vending machine
         (except for two (2) vending machines exclusively for use by Tenant's
         employees, one per on each floor occupied by Tenant; provided, however,
         that (i) Landlord shall have the right to approve the location of each
         such vending machine and (ii) Tenant shall be required to remove the
         vending machines upon the expiration or earlier termination of this
         Lease and repair any damage to the Premises caused by their
         installation and removal), or inflammable fluids or chemicals, or
         nuisance, or the emission from the Premises of any objectionable noise
         or odor, nor to permit in the Premises anything which will in any way
         result in the leakage of fluid or the growth of mold, and not to use or
         devote the Premises or any part thereof for any purpose other than the
         Permitted Uses, nor for any use thereof which is inconsistent with
         maintaining the Building as a first class office building in the
         quality of its maintenance, use and occupancy, or which is improper,
         offensive, contrary to law or ordinance or liable to render necessary
         any alteration or addition to the Building. Further, (i) Tenant shall
         not,

                                      -19-

<Page>

         nor shall Tenant permit its employees, invitees, agents, independent
         contractors, contractors, assignees or subtenants to, keep, maintain,
         store or dispose of (into the sewage or waste disposal system or
         otherwise) or engage in any activity which might produce or generate
         any substance which is or may hereafter be classified as a hazardous
         material, waste or substance (collectively "Hazardous Materials"),
         under federal, state or local laws, rules and regulations, including,
         without limitation, 42 U.S.C. Section 6901 et seq., 42 U.S.C. Section
         9601 et seq., 42 U.S.C. Section 2601 et seq., 49 U.S.C. Section 1802
         et seq. and Massachusetts General Laws, Chapter 21E and the rules and
         regulations promulgated under any of the foregoing, as such laws,
         rules and regulations may be amended from time to time (collectively
         "Hazardous Materials Laws"), (ii) Tenant shall immediately notify
         Landlord of any incident in, on or about the Premises, the Building or
         the Site that would require the filing of a notice under any Hazardous
         Materials Laws, (iii) Tenant shall comply and shall cause its
         employees, invitees, agents, independent contractors, contractors,
         assignees and subtenants to comply with each of the foregoing and (iv)
         Landlord shall have the right upon forty-eight (48) hours notice
         (except in the event of an emergency) to make such inspections
         (including testing) as Landlord shall reasonably determine are
         necessary from time to time to determine that Tenant is complying with
         the foregoing.

5.4      OBSTRUCTIONS; ITEMS VISIBLE FROM EXTERIOR; RULES AND REGULATIONS.
         ----------------------------------------------------------------

         Not to obstruct in any manner any portion of the Building not hereby
         leased or any portion thereof or of the Site used by Tenant in common
         with others; not without prior consent of Landlord to permit the
         painting or placing of any signs, curtains, blinds, shades, awnings,
         aerials or flagpoles, or the like, visible from outside the Premises;
         and to comply with all reasonable rules and regulations now or
         hereafter made by Landlord, of which Tenant has been given notice, for
         the care and use of the Building and Site and their facilities and
         approaches; Landlord shall not be liable to Tenant for the failure of
         other occupants of the Building to conform to such rules and
         regulations.

5.5      SAFETY APPLIANCES.
         -----------------

         To keep the Premises equipped with all safety appliances required by
         any public authority because of any use made by Tenant other than for
         Tenant's Permitted Use, and to procure all licenses and permits so
         required because of such use and, if requested by Landlord, to do any
         work so required because of such use, it being understood that the
         foregoing provisions shall not be construed to broaden in any way
         Tenant's Permitted Use.

5.6      ASSIGNMENT; SUBLEASE.
         --------------------

         Except as otherwise expressly provided herein, Tenant covenants and
         agrees that it shall not assign, mortgage, pledge, hypothecate or
         otherwise transfer this Lease and/or Tenant's interest in this Lease or
         sublet (which term, without limitation, shall include granting of
         concessions, licenses or the like) the whole or any part of the
         Premises. Any assignment, mortgage, pledge, hypothecation, transfer or
         subletting not expressly

                                      -20-

<Page>

         permitted in or consented to by Landlord under Sections 5.6.1-5.6.6
         shall be void, ab initio; shall be of no force and effect; and shall
         confer no rights on or in favor of third parties. In addition,
         Landlord shall be entitled to seek specific performance of or other
         equitable relief with respect to the provisions hereof.

         5.6.1 Notwithstanding the provisions of Section 5.6 above and the
               provisions of Section 5.6.2, 5.6.3 and 5.6.5 below, Tenant shall
               have the right to assign this Lease or to sublet the Premises (in
               whole or in part) to any parent or subsidiary corporation of
               Tenant or to any corporation into which Tenant may be converted
               or with which it may merge, provided that the entity to which
               this Lease is so assigned or which so sublets the Premises has a
               credit worthiness (e.g. assets on a pro forma basis using
               generally accepted accounting principles consistently applied and
               using the most recent financial statements) which is the same or
               better than Tenant as of the date of this Lease. If any parent or
               subsidiary corporation of Tenant to which this Lease is assigned
               or the Premises sublet (in whole or in part) shall cease to be
               such a parent or subsidiary corporation, such cessation shall be
               considered an assignment or subletting requiring Landlord's
               consent, which consent shall not be unreasonably withheld,
               delayed or conditioned. Any such assignment or subletting shall
               be subject to the provisions of Section 5.6.4 and Section 5.6.6
               below.

         5.6.2 Notwithstanding the provisions of Section 5.6 above, in the
               event Tenant desires to assign this Lease or to sublet the
               Premises (in whole or in part), Tenant shall give Landlord a
               Proposed Transfer Notice (as defined in Section 5.6.4 hereof) and
               Landlord shall have the right at its sole option, to be exercised
               within fifteen (15) days after receipt of Tenant's Proposed
               Transfer Notice (the "Acceptance Period"), to terminate this
               Lease as of a date specified in a notice to Tenant, which date
               shall not be earlier than sixty (60) days nor later than one
               hundred and twenty (120) days after Landlord's notice to Tenant;
               provided, however, that upon the termination date as set forth in
               Landlord's notice, all obligations relating to the period after
               such termination date (but not those relating to the period
               before such termination date) shall cease and promptly upon being
               billed therefor by Landlord, Tenant shall make final payment of
               all rent and Additional Rent due from Tenant through the
               termination date. Notwithstanding the foregoing, in the event
               that Tenant shall propose to sublease a portion of the Premises,
               Landlord shall only have the right to so terminate this Lease
               with respect to the portion of the Premises which Tenant proposes
               to sublease (the "Terminated Portion of the Premises") and from
               and after the termination date the Rentable Floor Area of the
               Premises shall be reduced to the rentable floor area of the
               remainder of the Premises and the definition of Rentable Floor
               Area of the Premises shall be so amended and after such
               termination all references in this Lease to the "Premises" or the
               "Rentable Floor Area of the Premises" shall be deemed to be
               references to the remainder of the Premises and accordingly
               Tenant's payments for Annual Fixed Rent, operating costs, real
               estate taxes and electricity shall be reduced on a pro rata basis
               to reflect the size of the remainder of the Premises.

                                      -21-

<Page>

               In the event that Landlord elects to terminate this Lease as
               aforesaid, Tenant shall have the right upon written notice
               delivered to Landlord within fifteen (15) days from receipt of
               Landlord's termination notice, to rescind its Proposed Transfer
               Notice, at which point Landlord's termination notice shall be
               deemed null and void and this Lease shall continue in full force
               and effect.

               In the event that Landlord shall not exercise its termination
               rights as aforesaid, or shall fail to give any or timely notice
               pursuant to this Section the provisions of Sections 5.6.3-5.6.6
               shall be applicable. This Section 5.6.2 shall not be applicable
               to an assignment or sublease pursuant to Section 5.6.1.

         5.6.3 Notwithstanding the provisions of Section 5.6 above, but subject
               to the provisions of this Section 5.6.3 and the provisions of
               Sections 5.6.4, 5.6.5 and 5.6.6 below, in the event that Landlord
               shall not have exercised the termination right as set forth in
               Section 5.6.2, or shall have failed to give any or timely notice
               under Section 5.6.2, then for a period of ninety (90) days (i)
               after the receipt of Landlord's notice stating that Landlord does
               not elect the termination right, or (ii) after the expiration of
               the Acceptance Period in the event Landlord shall not give any or
               timely notice pursuant to Section 5.6.2, as the case may be,
               Tenant shall have the right to assign this Lease or sublet the
               Premises in accordance with the Proposed Transfer Notice given as
               provided in Section 5.6.4 provided that, in each instance, Tenant
               first obtains the express prior written consent of Landlord,
               which consent shall not be unreasonably withheld or delayed.
               Without limiting the foregoing standard, Landlord shall not be
               deemed to be unreasonably withholding its consent to such a
               proposed assignment or subleasing if:

               (a)  if Landlord has comparable space available for lease in the
                    Building, the proposed assignee or subtenant is a tenant in
                    the Building or is in active negotiation with Landlord for
                    premises in the Building, or

               (b)  the proposed assignee or subtenant is not of good character
                    and reputation or is not of a character consistent with the
                    operation of a first class office building (by way of
                    example Landlord shall not be deemed to be unreasonably
                    withholding its consent to an assignment or subleasing to
                    any governmental or quasi-governmental agency which is open
                    to the public), or

               (c)  the proposed assignee does not possess adequate financial
                    capability to perform the Tenant obligations as and when due
                    or required or the proposed subtenant does not possess
                    adequate financial capability to perform the subtenant
                    obligations under the sublease as and when due or required,
                    or

               (d)  the assignee or subtenant proposes to use the Premises (or
                    part thereof) for a purpose other than the purpose for which
                    the Premises may be used as stated in Section 1.1 hereof, or

                                      -22-

<Page>

               (e)  the character of the business to be conducted or the
                    proposed use of the Premises by the proposed subtenant or
                    assignee shall (i) be likely to increase Landlord's
                    Operating Expenses beyond that which Landlord now incurs for
                    use by Tenant; (ii) be likely to increase the burden on
                    elevators or other Building systems or equipment over the
                    burden prior to such proposed subletting or assignment; or
                    (iii) violate or be likely to violate any provisions or
                    restrictions contained herein relating to the use or
                    occupancy of the Premises, or

               (f)  there shall be existing an Event of Default (defined in
                    Section 7.1), or

               (g)  any part of the rent payable under the proposed assignment
                    or sublease shall be based in whole or in part on the income
                    or profits derived from the Premises or if any proposed
                    assignment or sublease shall potentially have any adverse
                    effect on the real estate investment trust qualification
                    requirements applicable to Landlord and its affiliates, or

               (h)  the holder of any mortgage or ground lease on property which
                    includes the Premises does not approve of the proposed
                    assignment or sublease, or

               (i)  due to the identity or business of a proposed assignee or
                    subtenant, such approval would cause Landlord to be in
                    violation of any covenant or restriction contained in
                    another lease or other agreement affecting space in the
                    Building or elsewhere in the Property.

         5.6.4 Tenant shall give Landlord notice (the "Proposed Transfer
               Notice") of any proposed sublease or assignment, and said notice
               shall specify the provisions of the proposed assignment or
               subletting, including (a) the name and address of the proposed
               assignee or subtenant, (b) in the case of a proposed assignment
               or subletting pursuant to Section 5.6.2, such information as to
               the proposed assignee's or proposed subtenant's net worth and
               financial capability and standing as may reasonably be required
               for Landlord to make the determination referred to in Section
               5.6.3 above (provided, however, that Landlord shall hold such
               information confidential having the right to release same to its
               officers, accountants, attorneys and mortgage lenders on a
               confidential basis), (c) all of the terms and provisions upon
               which the proposed assignment or subletting is to be made, (d) in
               the case of a proposed assignment or subletting pursuant to
               Section 5.6.2, all other information necessary to make the
               determination referred to in Section 5.6.3 above and (e) in the
               case of a proposed assignment or subletting pursuant to Section
               5.6.1 above, such information as may be reasonably required by
               Landlord to determine that such proposed assignment or subletting
               complies with the requirements of said Section 5.6.1.

               If Landlord shall consent to the proposed assignment or
               subletting, as the case may be, then, in such event, Tenant may
               thereafter sublease or assign pursuant to

                                      -23-

<Page>

               Tenant's notice, as given hereunder; provided, however, that if
               such assignment or sublease shall not be executed and delivered
               to Landlord within ninety (90) days after the date of Landlord's
               consent, the consent shall be deemed null and void and the
               provisions of Section 5.6.2 shall be applicable.

         5.6.5 In addition, in the case of any assignment or subleasing as to
               which Landlord may consent (other than an assignment or
               subletting permitted under Section 5.6.1 hereof) such consent
               shall be upon the express and further condition, covenant and
               agreement, and Tenant hereby covenants and agrees that, in
               addition to the Annual Fixed Rent, Additional Rent and other
               charges to be paid pursuant to this Lease, fifty percent (50%) of
               the "Assignment/Sublease Profits" (hereinafter defined), if any,
               shall be paid to Landlord.

               The "Assignment/Sublease Profits" shall be the excess, if any, of
               (a) the "Assignment/Sublease Net Revenues" as hereinafter defined
               over (b) the Annual Fixed Rent and Additional Rent and other
               charges provided in this Lease. The "Assignment/Sublease Net
               Revenues" shall be the fixed rent, Additional Rent and all other
               charges and sums paid either initially or over the term of the
               sublease or assignment plus all other profits and increases to be
               derived by Tenant as a result of such subletting or assignment,
               less the reasonable costs of Tenant incurred in such subleasing
               or assignment (the definition of which shall be limited to rent
               concessions, brokerage commissions, legal fees and alteration
               allowances, in each case actually paid), as set forth in a
               statement certified by an appropriate officer of Tenant and
               delivered to Landlord within thirty (30) days of the full
               execution of the sublease or assignment document, amortized over
               the term of the sublease or assignment (it being understood and
               agreed that said statement may set forth costs that are not
               required to be paid within said thirty-day period, so long as the
               obligation to pay the same has been incurred such that the costs
               are known at the time the statement is prepared).

               All payments of the Assignment/Sublease Profits due Landlord
               shall be made within ten (10) days of receipt of same by Tenant.

         5.6.6 (A) It shall be a condition of the validity of any assignment or
               subletting of right under Section 5.6.1 above, or consented to
               under Section 5.6.3 above, that the assignee or sublessee enter
               into a separate written instrument directly with Landlord in a
               form and containing terms and provisions reasonably satisfactory
               to Landlord to be bound directly to Landlord for all the
               obligations of the tenant hereunder, including, without
               limitation, the obligation (a) to pay the rent and other amounts
               provided for under this Lease (but in the case of a partial
               subletting pursuant to Section 5.6.1, such subtenant shall agree
               on a pro rata basis to be so bound) and (b) to comply with the
               provisions of Sections 5.6 through 5.6.6 hereof. Such assignment
               or subletting shall not relieve the tenant named herein of any of
               the obligations of the tenant hereunder and Tenant shall remain
               fully and primarily liable therefor and the liability of Tenant
               and such assignee (or subtenant, as the case may be) shall be
               joint and several. Further, and

                                      -24-

<Page>

               notwithstanding the foregoing, the provisions hereof shall not
               constitute a recognition of the assignment or the assignee
               thereunder or the sublease or the subtenant thereunder, as the
               case may be, and at Landlord's option, upon the termination or
               expiration of the Lease (whether such termination is based upon a
               cause beyond Tenant's control, a default of Tenant, the agreement
               of Tenant and Landlord or any other reason), the assignment or
               sublease shall be terminated.

               (B) As Additional Rent Tenant shall pay to Landlord as a fee for
               Landlord's review of any proposed assignment or sublease
               requested by Tenant and the preparation of any associated
               documentation in connection therewith, within thirty (30) days
               after receipt of an invoice from Landlord, an amount equal to the
               sum of (i) $150.00 per hour for in-house staff and/or (ii)
               reasonable out of pocket legal fees or other expenses incurred by
               Landlord in connection with such request. In no event shall the
               total amount of such fee exceed $2,000.00 in connection with any
               single request for consent.

               (C) If this Lease be assigned, or if the Premises or any part
               thereof be sublet or occupied by anyone other than Tenant,
               Landlord may upon prior notice to Tenant, at any time and from
               time to time, collect rent and other charges from the assignee,
               sublessee or occupant and apply the net amount collected to the
               rent and other charges herein reserved, but no such assignment,
               subletting, occupancy or collection shall be deemed a waiver of
               this covenant, or a waiver of the provisions of Sections 5.6
               through 5.6.6 hereof, or the acceptance of the assignee,
               sublessee or occupant as a tenant or a release of Tenant from the
               further performance by Tenant of covenants on the part of Tenant
               herein contained, the Tenant herein named to remain primarily
               liable under this Lease.

               (D) The consent by Landlord to an assignment or subletting under
               any of the provisions of Sections 5.6.1 or 5.6.3 shall in no way
               be construed to relieve Tenant from obtaining the express consent
               in writing of Landlord to any further assignment or subletting.

               (E) On or after the occurrence of an "Event of Default" (defined
               in Section 7.1), Landlord shall be entitled to one hundred
               percent (100%) of any Assignment/Sublease Profits.

               (F) Without limiting Tenant's obligations under Section 5.14,
               Tenant shall be responsible, at Tenant's sole cost and expense,
               for performing all work necessary to comply with Legal
               Requirements and Insurance Requirements in connection with any
               assignment or subletting hereunder including, without limitation,
               any work in connection with such assignment or subletting.

               (G) In addition to the other requirements set forth in this Lease
               and notwithstanding any other provision of this Lease, partial
               sublettings of the Premises shall only be permitted under the
               following terms and conditions: (i) the layout of both the
               subleased premises and the remainder of the Premises must

                                      -25-

<Page>

               comply with applicable laws, ordinances, rules and/or regulations
               and be approved by Landlord (which such approval shall not be
               unreasonably withheld, conditioned or delayed), including,
               without limitation, all requirements concerning access and
               egress; (ii) in the event the subleased premises are separately
               physically demised from the remainder of the Premises, Tenant
               shall pay all reasonable costs of separately physically demising
               the subleased premises; and (iii) there shall be no more than two
               (2) subleases in effect for the Second Floor Premises and two (2)
               subleases in effect for the Third Floor Premises at any given
               time

5.7      INDEMNITY; INSURANCE.
         --------------------

         (A) INDEMNITY. To defend with counsel first approved by Landlord (which
         approval shall not be unreasonably withheld or delayed), save harmless,
         and indemnify Landlord from any liability for injury, loss, accident or
         damage to any person or property, and from any claims, actions,
         proceedings and expenses and costs in connection therewith (including
         without limitation reasonable counsel fees) (i) arising from or claimed
         to have arisen from (a) the omission, fault, willful act, negligence or
         other misconduct of Tenant or Tenant's contractors, licensees,
         invitees, agents, servants, independent contractors or employees or (b)
         any use made or thing done or occurring on the Premises not due to the
         omission, fault, willful act, negligence or other misconduct of
         Landlord or Landlord's contractors, licensees, agents, servants,
         independent contractors or employees, or (ii) resulting from the
         failure of Tenant to perform and discharge its covenants and
         obligations under this Lease.

         (B) INSURANCE. To maintain in full force from the date upon which
         Tenant first enters the Premises for any reason, throughout the Term of
         this Lease, and thereafter, so long as Tenant is in occupancy of any
         part of the Premises, commercial general liability insurance or
         comprehensive general liability insurance written on an occurrence
         basis with a broad form comprehensive liability endorsement under which
         Tenant is the named insured and Landlord and Landlord's managing agent
         (and such persons as are in privity of estate with Landlord and
         Landlord's managing agent as may be set out in notice from time to
         time) are named as additional insureds with limits which shall, at the
         commencement of the Term, be at least equal to those stated in Section
         1.1 and from time to time during the Term shall be for such higher
         limits, if any, as are customarily carried in the Boston West Suburban
         Market with respect to similar properties or which may reasonably be
         required by Landlord, and worker's compensation insurance with
         statutory limits covering all of Tenant's employees working in the
         Premises, and to deposit with Landlord on or before the earlier of the
         date Tenant enters the Premises or the Commencement Date and concurrent
         with all renewals thereof, certificates for such insurance bearing the
         endorsement that the policies will not be canceled until after thirty
         (30) days' written notice to Landlord. In addition, in the event Tenant
         hosts a function in the Premises, Tenant agrees to obtain and maintain,
         and cause any persons or parties providing services for such function
         to obtain, the appropriate insurance coverages as reasonably determined
         by Landlord (including liquor liability, if applicable) and provide
         Landlord with evidence of the same. All insurance required to be
         maintained by Tenant pursuant to this Lease shall be maintained with
         responsible companies qualified to do

                                      -26-

<Page>

         business, and in good standing, in the Commonwealth of Massachusetts
         and which have a rating of at least "A-" and are within a financial
         size category of not less than "Class VIII" in the most current Best's
         Key Rating Guide or such similar rating as may be reasonably selected
         by Landlord if such Guide is no longer published.

5.8      PERSONAL PROPERTY AT TENANT'S RISK.
         ----------------------------------

         That all of the furnishings, fixtures, equipment, effects and property
         of every kind, nature and description of Tenant and of all persons
         claiming by, through or under Tenant which, during the continuance of
         this Lease or any occupancy of the Premises by Tenant or anyone
         claiming under Tenant, may be on the Premises or elsewhere in the
         Building or on the Site, shall be at the sole risk and hazard of
         Tenant, and if the whole or any part thereof shall be destroyed or
         damaged by fire, water or otherwise, or by the leakage or bursting of
         water pipes, or other pipes, by theft or from any other cause, no part
         of said loss or damage is to be charged to or be borne by Landlord,
         except that Landlord shall in no event be indemnified or held harmless
         or exonerated from any liability to Tenant or to any other person, for
         any injury, loss, damage or liability to the extent such indemnity,
         hold harmless or exoneration is prohibited by law. Further, Tenant, at
         Tenant's expense, shall maintain at all times during the Term of this
         Lease business interruption insurance and insurance against loss or
         damage covered by so-called "all risk" type insurance coverage with
         respect to Tenant's fixtures, equipment, goods, wares and merchandise,
         tenant improvements made by or paid for by Tenant, and other property
         of Tenant (collectively "Tenant's Property"). Such insurance shall be
         in an amount at least equal to the full replacement cost of Tenant's
         Property. Tenant shall maintain all of its equipment, furniture and
         furnishings in good order and repair. In addition, during such time as
         Tenant is performing work in or to the Premises, Tenant, at Tenant's
         expense, shall also maintain builder's risk insurance for the full
         insurable value of such work.

5.9      RIGHT OF ENTRY.
         --------------

         To permit Landlord and its agents to examine the Premises at reasonable
         times and upon at least forty-eight (48) hours prior notice (except in
         the event of an emergency) and, if Landlord shall so elect, to make any
         repairs or replacements Landlord may deem necessary; to remove, at
         Tenant's expense, any alterations, addition, signs, curtains, blinds,
         shades, awnings, aerials, flagpoles, or the like not consented to in
         writing; and to show the Premises to prospective tenants during the six
         (6) months preceding expiration of the Term and to prospective
         purchasers and mortgagees at all reasonable times. Landlord and its
         agents shall use commercially reasonable efforts to minimize any
         unreasonable interference with Tenant's business operations and use of
         the Premises in the exercise of the foregoing rights, consistent with
         the reason for entry.

5.10     FLOOR LOAD; PREVENTION OF VIBRATION AND NOISE.
         ---------------------------------------------

         Not to place a load upon the Premises exceeding an average rate of 100
         pounds of live load per square foot of floor area (partitions shall be
         considered as part of the live load); and not to move any safe, vault
         or other heavy equipment in, about or out of the Premises except in
         such manner and at such time as Landlord shall in each instance
         authorize;

                                      -27-

<Page>

         Tenant's business machines and mechanical equipment which cause
         vibration or noise that may be transmitted to the Building structure
         or to any other space in the Building shall be so installed,
         maintained and used by Tenant so as to eliminate such vibration or
         noise.

5.11     PERSONAL PROPERTY TAXES.
         -----------------------

         To pay promptly when due all taxes which may be imposed upon Tenant's
         Property in the Premises to whomever assessed.

5.12     COMPLIANCE WITH LAWS.
         --------------------

         To comply with all applicable Legal Requirements now or hereafter in
         force which shall impose a duty on Landlord or Tenant relating to or as
         a result of the use or occupancy of the Premises; provided that Tenant
         shall not be required to make any alterations or additions to the
         structure, roof, exterior and load bearing walls, foundation,
         structural floor slabs and other structural elements of the Building
         unless the same are required by such Legal Requirements as a result of
         or in connection with Tenant's use or occupancy of the Premises beyond
         Tenant's Permitted Use. Tenant shall promptly pay all fines, penalties
         and damages that may arise out of or be imposed because of its failure
         to comply with the provisions of this Section 5.12.

         Landlord at Landlord's expense, shall be responsible for the Premises
         complying on the Commencement Date with the requirements of the Federal
         Americans With Disabilities Act (the "ADA") in effect on the
         Commencement Date; provided, however, that notwithstanding the
         foregoing, Tenant at Tenant's expense, shall be responsible for (i) any
         additions, alterations or improvements performed by or for Tenant or
         any assignee of subtenant of Tenant ("Tenant Improvements") complying
         with the ADA and (ii) compliance with the ADA required because of
         "Tenant's Specific Use of the Premises" (as defined below) or Tenant
         Improvements. The term "Tenant's Specific Use of the Premises" as used
         in this Lease shall not refer to the general office use of the
         Premises, but shall refer to the specific products and operations
         Tenant and any assignee and subtenant of Tenant use in the Premises and
         the manner in which Tenant and any assignee and subtenant of Tenant use
         such products and conduct such operations.

5.13     PAYMENT OF LITIGATION EXPENSES.
         ------------------------------

         To pay as Additional Rent all reasonable costs, counsel and other fees
         incurred by Landlord in connection with the successful enforcement by
         Landlord of any obligations of Tenant under this Lease or in connection
         with any bankruptcy case involving Tenant or any guarantor.

5.14     ALTERATIONS.
         -----------

         Tenant shall not make alterations and additions to Tenant's space
         except in accordance with plans and specifications therefor first
         approved by Landlord, which approval shall not be unreasonably
         withheld. However, Landlord's determination of matters relating to

                                      -28-

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         aesthetic issues relating to alterations, additions or improvements
         which are visible outside the Premises shall be in Landlord's sole
         discretion. Without limiting such standard Landlord shall not be deemed
         unreasonable for withholding approval of any alterations or additions
         (including, without limitation, any alterations or additions to be
         performed by Tenant under Article III) which (a) in Landlord's opinion
         might adversely affect any structural or exterior element of the
         Building, any area or element outside of the Premises, or any facility
         or base building mechanical system serving any area of the Building
         outside of the Premises, or (b) involve or affect the exterior design,
         size, height, or other exterior dimensions of the Building or (c) will
         require unusual expense to readapt the Premises to normal office use on
         Lease termination or expiration or increase the cost of construction or
         of insurance or taxes on the Building or of the services called for by
         Section 4.1 unless Tenant first gives assurance acceptable to Landlord
         for payment of such increased cost and that such readaptation will be
         made prior to such termination or expiration without expense to
         Landlord, (d) enlarge the Rentable Floor Area of the Premises, or (e)
         are inconsistent, in Landlord's judgment, with alterations satisfying
         Landlord's standards for new alterations in the Building. Landlord's
         review and approval of any such plans and specifications and consent to
         perform work described therein shall not be deemed an agreement by
         Landlord that such plans, specifications and work conform with
         applicable Legal Requirements and requirements of insurers of the
         Building and the other requirements of this Lease with respect to
         Tenant's insurance obligations (herein called "Insurance Requirements")
         nor deemed a waiver of Tenant's obligations under this Lease with
         respect to applicable Legal Requirements and Insurance Requirements nor
         impose any liability or obligation upon Landlord with respect to the
         completeness, design sufficiency or compliance of such plans,
         specifications and work with applicable Legal Requirements and
         Insurance Requirements nor give right to any other parties. Further,
         Tenant acknowledges that Tenant is acting for its own benefit and
         account, and that Tenant shall not be acting as Landlord's agent in
         performing any work in the Premises. Within thirty (30) days after
         receipt of an invoice from Landlord, Tenant shall pay to Landlord as a
         fee for Landlord's review of any work or plans (excluding any review
         respecting initial improvements performed pursuant to Article III
         hereof for which a fee, if any, has previously been paid but including
         any review of plans or work relating to any assignment or subletting),
         as Additional Rent, an amount equal to the sum of: (i) $150.00 per
         hour, plus (ii) third party expenses incurred by Landlord to review
         Tenant's plans and Tenant's work. All alterations and additions shall
         be part of the Building unless and until Landlord shall specify the
         same for removal pursuant to Section 5.2. All of Tenant's alterations
         and additions and installation of furnishings shall be coordinated with
         any work being performed by Landlord and in such manner as to maintain
         harmonious labor relations and not to damage the Buildings or Site or
         interfere with construction or operation of the Buildings and other
         improvements to the Site and, except for installation of furnishings,
         shall be performed by Landlord's general contractor or by contractors
         or workers first approved by Landlord. Except for work by Landlord's
         general contractor, Tenant, before its work is started, shall secure
         all licenses and permits necessary therefor; deliver to Landlord a
         statement of the names of all its contractors and subcontractors and
         the estimated cost of all labor and material to be furnished by them
         and security satisfactory to Landlord protecting Landlord against liens
         arising out of the furnishing of such labor and material; and cause
         each contractor to carry workmen's

                                      -29-

<Page>

         compensation insurance in statutory amounts covering all the
         contractor's and subcontractor's employees and commercial general
         liability insurance or comprehensive general liability insurance with
         a broad form comprehensive liability endorsement with such limits as
         Landlord may reasonably require, but in no event less than
         $2,000,000.00 combined single limit per occurrence on a per location
         basis (all such insurance to be written in companies approved by
         Landlord and naming and insuring Landlord and Landlord's managing
         agent as additional insureds and insuring Tenant as well as the
         contractors), and to deliver to Landlord certificates of all such
         insurance. Tenant shall also prepare and submit to Landlord a set of
         as-built plans (or, in cases where the alterations, additions or
         improvements at issue are not of such a nature that as-built plans
         would customarily be prepared or otherwise be reasonably practicable
         to obtain, detailed drawings and specifications), in both print and
         electronic forms, showing such work performed by Tenant to the
         Premises promptly after any such alterations, improvements or
         installations are substantially complete and promptly after any wiring
         or cabling for Tenant's computer, telephone and other communications
         systems is installed by Tenant or Tenant's contractor. Without
         limiting any of Tenant's obligations hereunder, Tenant shall be
         responsible, as Additional Rent, for the costs of any alterations,
         additions or improvements in or to the Building that are required in
         order to comply with Legal Requirements as a result of any work
         performed by Tenant. Landlord shall have the right to provide such
         rules and regulations relative to the performance of any alterations,
         additions, improvements and installations by Tenant hereunder and
         Tenant shall abide by all such reasonable rules and regulations and
         shall cause all of its contractors to so abide including, without
         limitation, payment for the costs of using Building services. Tenant
         agrees to pay promptly when due the entire cost of any work done on
         the Premises by Tenant, its agents, employees, or independent
         contractors, and not to cause or permit any liens for labor or
         materials performed or furnished in connection therewith to attach to
         the Premises or the Buildings or the Site and immediately to discharge
         any such liens which may so attach. Tenant shall pay, as Additional
         Rent, 100% of any real estate taxes on the Complex which shall, at any
         time after commencement of the Term, result from any alteration,
         addition or improvement to the Premises made by Tenant.

5.15     VENDORS.
         --------

         Any vendors engaged by Tenant to perform services in or to the Premises
         including, without limitation, janitorial contractors and moving
         contractors shall be coordinated with any work being performed by or
         for Landlord and in such manner as to maintain harmonious labor
         relations and not to damage the Building or the Property or interfere
         with Building construction or operation and shall be performed by
         vendors first approved by Landlord.

                                      -30-

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                                   ARTICLE VI
                                   ----------

                               CASUALTY AND TAKING
                               -------------------

6.1      DAMAGE RESULTING FROM CASUALTY.
         ------------------------------

         In case during the Lease Term, the Premises and/or the Building are
         damaged by fire or casualty and such fire or casualty damage cannot, in
         the ordinary course, reasonably be expected to be repaired within one
         hundred eighty (180) days (and/or as to special work or work which
         requires long lead time then if such work cannot reasonably be expected
         to be repaired within such additional time as is reasonable under the
         circumstances given the nature of the work) from the time that repair
         work would commence, either party may, at its election, terminate this
         Lease by notice given to the other party within sixty (60) days after
         the date of such fire or other casualty, specifying the effective date
         of termination. The effective date of termination specified by the
         terminating party shall be not less than thirty (30) days nor more than
         forty-five (45) days after the date of notice of such termination.

         Unless terminated pursuant to the foregoing provisions, this Lease
         shall remain in full force and effect following any such damage
         subject, however, to the following provisions.

         If the Building or the Site or any part thereof are damaged by fire or
         other casualty and this Lease is not so terminated, or Landlord or
         Tenant have no right to terminate this Lease, and in any such case the
         holder of any mortgage which includes the Building as a part of the
         mortgaged premises or any ground lessor of any ground lease which
         includes the Site as part of the demised premises allows the net
         insurance proceeds to be applied to the restoration of the Building
         (and/or the Site), Landlord shall, promptly after such damage and the
         determination of the net amount of insurance proceeds available, use
         due diligence to restore the Premises and the Building in the event of
         damage thereto (excluding Tenant's Property) into substantially the
         same condition as they were in prior to the fire or casualty and a just
         proportion of the Annual Fixed Rent, Tenant's share of Operating Costs
         and Tenant's share of real estate taxes shall be abated according to
         the nature and extent of the injury to the Premises, until the Premises
         shall have been restored by Landlord substantially into such condition
         except for punch list items and long lead items. Notwithstanding
         anything herein contained to the contrary, Landlord shall not be
         obligated to expend for such repair and restoration any amount in
         excess of the net insurance proceeds.

         If such restoration is not completed within six (6) months from the
         time that repair work commences, such period to be subject, however, to
         extension where the delay in completion of such work is due to Force
         Majeure, as defined hereinbelow, (but in no event beyond ten (10)
         months from the date of the fire or casualty), Tenant, as its sole and
         exclusive remedy, shall have the right to terminate this Lease at any
         time after the expiration of such six-month period (as extended), which
         right shall continue until the restoration is substantially completed.
         Such termination shall be effective as of the thirtieth (30th) day
         after the date of receipt by Landlord of Tenant's notice, with the same

                                      -31-

<Page>

         force and effect as if such date were the date originally established
         as the expiration date hereof unless, within thirty (30) days after
         Landlord's receipt of Tenant's notice, such restoration is
         substantially completed, in which case Tenant's notice of termination
         shall be of no force and effect and this Lease and the Lease Term shall
         continue in full force and effect. When used herein, "Force Majeure"
         shall mean any prevention, delay or stoppage due to governmental
         regulation, strikes, lockouts, acts of God, acts of war, terrorists
         acts, civil commotions, unusual scarcity of or inability to obtain
         labor or materials, labor difficulties, casualty or other causes
         reasonably beyond Landlord's control or attributable to Tenant's action
         or inaction.

6.2      UNINSURED CASUALTY.
         ------------------

         Notwithstanding anything to the contrary contained in this Lease, if
         the Building or the Premises shall be substantially damaged by fire or
         casualty as the result of a risk not covered by the forms of casualty
         insurance at the time maintained by Landlord and such fire or casualty
         damage cannot, in the ordinary course, reasonably be expected to be
         repaired within ninety (90) days from the time that repair work would
         commence, Landlord may, at its election, terminate the Term of this
         Lease by notice to the Tenant given within sixty (60) days after such
         loss. If Landlord shall give such notice, then this Lease shall
         terminate as of the date of such notice with the same force and effect
         as if such date were the date originally established as the expiration
         date hereof.

6.3      RIGHTS OF TERMINATION FOR TAKING.
         --------------------------------

         If the entire Building, or such portion of the Premises as to render
         the balance (if reconstructed to the maximum extent practicable in the
         circumstances) unsuitable for Tenant's purposes, shall be taken by
         condemnation or right of eminent domain, Landlord or Tenant shall have
         the right to terminate this Lease by notice to the other of its desire
         to do so, provided that such notice is given not later than thirty (30)
         days after Tenant has been deprived of possession. If either party
         shall give such notice, then this Lease shall terminate as of the date
         of such notice with the same force and effect as if such date were the
         date originally established as the expiration date hereof.

         Further, if so much of the Building shall be so taken that continued
         operation of the Building would be uneconomic as a result of the
         taking, Landlord shall have the right to terminate this Lease by giving
         notice to Tenant of Landlord's desire to do so not later than thirty
         (30) days after Tenant has been deprived of possession of the Premises
         (or such portion thereof as may be taken). If Landlord shall give such
         notice, then this Lease shall terminate as of the date of such notice
         with the same force and effect as if such date were the date originally
         established as the expiration date hereof.

         Should any part of the Premises be so taken or condemned during the
         Lease Term hereof, and should this Lease not be terminated in
         accordance with the foregoing provisions, and the holder of any
         mortgage which includes the Premises as part of the mortgaged premises
         or any ground lessor of any ground lease which includes the Site as
         part of the demised premises allows the net condemnation proceeds to be
         applied to the restoration of the Building, Landlord agrees, after the
         determination of the net amount of

                                      -32-

<Page>

         condemnation proceeds available to Landlord, to use due diligence to
         put what may remain of the Premises into proper condition for use and
         occupation as nearly like the condition of the Premises prior to such
         taking as shall be practicable (excluding Tenant's Property).
         Notwithstanding the foregoing, Landlord shall not be obligated to
         expend for such repair and restoration any amount in excess of the net
         condemnation proceeds made available to it.

         If the Premises shall be affected by any exercise of the power of
         eminent domain, then the Annual Fixed Rent, Tenant's share of operating
         costs and Tenant's share of real estate taxes shall be justly and
         equitably abated and reduced according to the nature and extent of the
         loss of use thereof suffered by Tenant; and in case of a taking which
         permanently reduces the Rentable Floor Area of the Premises, a just
         proportion of the Annual Fixed Rent, Tenant's share of operating costs
         and Tenant's share of real estate taxes shall be abated for the
         remainder of the Lease Term.

6.4      AWARD.
         -----

         Landlord shall have and hereby reserves to itself any and all rights to
         receive awards made for damages to the Premises, the Building, the
         Complex and the Site and the leasehold hereby created, or any one or
         more of them, accruing by reason of exercise of eminent domain or by
         reason of anything lawfully done in pursuance of public or other
         authority. Tenant hereby grants, releases and assigns to Landlord all
         Tenant's rights to such awards, and covenants to execute and deliver
         such further assignments and assurances thereof as Landlord may from
         time to time request, and if Tenant shall fail to execute and deliver
         the same within fifteen (15) days after notice from Landlord, Tenant
         hereby covenants and agrees that Landlord shall be irrevocably
         designated and appointed as its attorney-in-fact to execute and deliver
         in Tenant's name and behalf all such further assignments thereof which
         conform with the provisions hereof.

         Nothing contained herein shall be construed to prevent Tenant from
         prosecuting in any condemnation proceeding a claim for the value of any
         of Tenant's usual trade fixtures installed in the Premises by Tenant at
         Tenant's expense and for relocation and moving expenses, provided that
         such action and any resulting award shall not affect or diminish the
         amount of compensation otherwise recoverable by Landlord from the
         taking authority.

                                   ARTICLE VII
                                   -----------

                                     DEFAULT
                                     -------

7.1      TENANT'S DEFAULT.
         ----------------

          (a)  If at any time subsequent to the date of this Lease any one or
               more of the following events (herein sometimes called an "Event
               of Default") shall occur:

                    (i)  Tenant shall fail to pay the fixed rent, Additional
                         Rent or other charges for which provision is made
                         herein on or before the date

                                      -33-

<Page>

                         on which the same become due and payable, and the same
                         continues for seven (7) days after notice from Landlord
                         thereof; or

                    (ii) Landlord having rightfully given the notice specified
                         in subdivision (i) above twice in any calendar year,
                         Tenant shall thereafter in the same calendar year fail
                         to pay the fixed rent, Additional Rent or other charges
                         on or before the date on which the same become due and
                         payable; or

                   (iii) Tenant shall assign its interest in this Lease or
                         sublet any portion of the Premises in violation of the
                         requirements of Section 5.6 through 5.6.5 of this
                         Lease; or

                    (iv) Tenant shall neglect or fail to perform or observe any
                         other covenant herein contained on Tenant's part to be
                         performed or observed and Tenant shall fail to remedy
                         the same within thirty (30) days after notice to Tenant
                         specifying such neglect or failure, or if such failure
                         is of such a nature that Tenant cannot reasonably
                         remedy the same within such thirty (30) day period,
                         Tenant shall fail to commence promptly to remedy the
                         same and to prosecute such remedy to completion with
                         diligence and continuity; or

                    (v)  Tenant's leasehold interest in the Premises shall be
                         taken on execution or by other process of law directed
                         against Tenant; or

                    (vi) Tenant shall make an assignment for the benefit of
                         creditors or shall file a voluntary petition in
                         bankruptcy or shall be adjudicated bankrupt or
                         insolvent, or shall file any petition or answer seeking
                         any reorganization, arrangement, composition,
                         readjustment, liquidation, dissolution or similar
                         relief for itself under any present or future Federal,
                         State or other statute, law or regulation for the
                         relief of debtors, or shall seek or consent to or
                         acquiesce in the appointment of any trustee, receiver
                         or liquidator of Tenant or of all or any substantial
                         part of its properties, or shall admit in writing its
                         inability to pay its debts generally as they become
                         due; or

                   (vii) A petition shall be filed against Tenant in bankruptcy
                         or under any other law seeking any reorganization,
                         arrangement, composition, readjustment, liquidation,
                         dissolution, or similar relief under any present or
                         future Federal, State or other statute, law or
                         regulation and shall remain undismissed or unstayed for
                         an aggregate of ninety (90) days (whether or not
                         consecutive), or if any debtor in possession (whether
                         or not Tenant) trustee, receiver or liquidator of
                         Tenant or of all or any substantial part of its
                         properties or of the Premises shall be appointed
                         without the consent or acquiescence of

                                      -34-

<Page>

                         Tenant and such appointment shall remain unvacated or
                         unstayed for an aggregate of ninety (90) days (whether
                         or not consecutive)--

               then, and in any of said cases (notwithstanding any license of a
               former breach of covenant or waiver of the benefit hereof or
               consent in a former instance), Landlord lawfully may, immediately
               or at any time thereafter, and without demand or further notice
               terminate this Lease by written notice to Tenant, specifying a
               date not less than ten (10) days after the giving of such notice
               on which this Lease shall terminate, and this Lease shall come to
               an end on the date specified therein as fully and completely as
               if such date were the date herein originally fixed for the
               expiration of the Lease Term (Tenant hereby waiving any rights of
               redemption), and Tenant will then quit and surrender the Premises
               to Landlord, but Tenant shall remain liable as hereinafter
               provided.

         (b)   If this Lease shall have been terminated as provided in this
               Article, then Landlord may re- enter the Premises, either by
               force, summary proceedings, ejectment or otherwise, and remove
               and dispossess Tenant and all other persons and any and all
               property from the same, as if this Lease had not been made.

         (c)   In the event that this Lease is terminated under any of the
               provisions contained in Section 7.1 (a) or shall be otherwise
               terminated by breach of any obligation of Tenant, Tenant
               covenants and agrees forthwith to pay and be liable for, on the
               days originally fixed herein for the payment thereof, amounts
               equal to the several installments of rent and other charges
               reserved as they would, under the terms of this Lease, become due
               if this Lease had not been terminated or if Landlord had not
               entered or re-entered, as aforesaid, and whether the Premises be
               relet or remain vacant, in whole or in part, or relet for a
               period less than the remainder of the Term, and for the whole
               thereof, but in the event the Premises be relet by Landlord,
               Tenant shall be entitled to a credit in the net amount of rent
               and other charges received by Landlord in reletting, after
               deduction of all reasonable expenses incurred in reletting the
               Premises (including, without limitation, remodeling costs,
               brokerage fees and the like), and in collecting the rent in
               connection therewith, in the following manner:

                         Landlord agrees to use reasonable efforts to relet
                         the Premises after Tenant vacates the same in the
                         event that this Lease is terminated based upon a
                         default by Tenant hereunder. The marketing of the
                         Premises in a manner similar to the manner in which
                         Landlord markets other premises within Landlord's
                         control in the Building shall be deemed to have
                         satisfied Landlord's obligation to use "reasonable
                         efforts." In no event shall Landlord be required to
                         (i) solicit or entertain negotiations with any other
                         prospective tenants for the Premises until Landlord
                         obtains full and unappealable legal right to relet
                         the Premises free of any claim of Tenant, (ii) relet
                         the Premises before leasing other vacant space in the
                         Building, (iii) lease the Premises for a rental less
                         than the current fair market rental then prevailing
                         for similar office space in the Building, or (iv)
                         enter into a

                                      -35-

<Page>

                         lease with any proposed tenant that does
                         not have, in Landlord's reasonable opinion,
                         sufficient financial resources or operating
                         experience to operate the Premises in a first class
                         manner

                         Amounts received by Landlord after reletting shall
                         first be applied against such Landlord's expenses,
                         until the same are recovered, and until such
                         recovery, Tenant shall pay, as of each day when a
                         payment would fall due under this Lease, the amount
                         which Tenant is obligated to pay under the terms of
                         this Lease (Tenant's liability prior to any such
                         reletting and such recovery not in any way to be
                         diminished as a result of the fact that such
                         reletting might be for a rent higher than the rent
                         provided for in this Lease); when and if such
                         expenses have been completely recovered, the amounts
                         received from reletting by Landlord as have not
                         previously been applied shall be credited against
                         Tenant's obligations as of each day when a payment
                         would fall due under this Lease, and only the net
                         amount thereof shall be payable by Tenant. Further,
                         amounts received by Landlord from such reletting for
                         any period shall be credited only against obligations
                         of Tenant allocable to such period, and shall not be
                         credited against obligations of Tenant hereunder
                         accruing subsequent or prior to such period; nor
                         shall any credit of any kind be due for any period
                         after the date when the term of this Lease is
                         scheduled to expire according to its terms.

        (d)(i) At any time after such termination and whether or not Landlord
               shall have collected any damages as aforesaid, Tenant shall pay
               to Landlord as liquidated final damages and in lieu of all other
               damages beyond the date of notice from Landlord to Tenant, at
               Landlord's election, such a sum as at the time of the giving of
               such notice represents the amount of the excess, if any, of the
               total rent and other benefits which would have accrued to
               Landlord under this Lease from the date of such notice for what
               would be the then unexpired Lease Term if the Lease terms had
               been fully complied with by Tenant over and above the then cash
               rental value (in advance) of the Premises for the balance of the
               Lease Term.

       (d)(ii) For the purposes of this Article, if Landlord elects to
               require Tenant to pay damages in accordance with the immediately
               preceding paragraph, the total rent shall be computed by assuming
               that Tenant's share of excess taxes, Tenant's share of excess
               operating costs and Tenant's share of excess electrical costs
               would be, for the balance of the unexpired Term from the date of
               such notice, the amount thereof (if any) for the immediately
               preceding annual period payable by Tenant to Landlord.

          (e)  In case of any Event of Default, re-entry, dispossession by
               summary proceedings or otherwise, Landlord may (i) re-let the
               Premises or any part or parts thereof, either in the name of
               Landlord or otherwise, for a term or terms which may at
               Landlord's option be equal to or less than or exceed the period
               which would otherwise have constituted the balance of the Term of
               this Lease and may grant

                                      -36-

<Page>

               concessions or free rent to the extent that Landlord considers
               advisable or necessary to re-let the same and (ii) may make such
               alterations, repairs and decorations in the Premises as Landlord
               in its sole judgment considers advisable or necessary for the
               purpose of reletting the Premises; and the making of such
               alterations, repairs and decorations shall not operate or be
               construed to release Tenant from liability hereunder as
               aforesaid. Landlord shall in no event be liable in any way
               whatsoever for failure to re-let the Premises, or, in the event
               that the Premises are re-let, for failure to collect the rent
               under re-letting.

          (f)  The specified remedies to which Landlord may resort hereunder are
               not intended to be exclusive of any remedies or means of redress
               to which Landlord may at any time be entitled lawfully, and
               Landlord may invoke any remedy (including the remedy of specific
               performance) allowed at law or in equity as if specific remedies
               were not herein provided for. Further, nothing contained in this
               Lease shall limit or prejudice the right of Landlord to prove and
               obtain in proceedings for bankruptcy or insolvency by reason of
               the termination of this Lease, an amount equal to the maximum
               allowed by any statute or rule of law in effect at the time when,
               and governing the proceedings in which, the damages are to be
               proved, whether or not the amount be greater, equal to, or less
               than the amount of the loss or damages referred to above.

          (g)  In lieu of any other damages or indemnity and in lieu of the
               recovery by Landlord of all sums payable under all the foregoing
               provisions of this Section 7.1, Landlord may elect to collect
               from tenant, by notice to Tenant, at any time after this Lease is
               terminated under any of the provisions contained in this Article
               VII or otherwise terminated by breach of any obligation of Tenant
               and before such full recovery, and Tenant shall thereupon pay, as
               liquidated damages, an amount equal to the sum of the Annual
               Fixed Rent and all Additional Rent payable for the twelve (12)
               months ended next prior to the such termination plus the amount
               of Annual Fixed Rent and Additional Rent of any kind accrued and
               unpaid at the time of such election plus any and all expenses
               which the Landlord may have incurred for and with respect of the
               collection to any of such rent.

7.2      LANDLORD'S DEFAULT.
         ------------------

         Landlord shall in no event be in default in the performance of any of
         Landlord's obligations hereunder unless and until Landlord shall have
         failed to perform such obligations within thirty (30) days, or such
         additional time as is reasonably required to correct any such default,
         after notice by Tenant to Landlord properly specifying wherein Landlord
         has failed to perform any such obligation. The Tenant shall not assert
         any right to deduct the cost of repairs or any monetary claim against
         the Landlord from rent thereafter due and payable, but shall look
         solely to the Landlord for satisfaction of such claim.

                                      -37-

<Page>

                                  ARTICLE VIII
                                  ------------

                            MISCELLANEOUS PROVISIONS
                            ------------------------

8.1      EXTRA HAZARDOUS USE.
         -------------------

         Tenant covenants and agrees that Tenant will not do or permit anything
         to be done in or upon the Premises, or bring in anything or keep
         anything therein, which shall invalidate or increase the rate of
         insurance on the Premises or on the Building above the standard rate
         applicable to premises being occupied for the use to which Tenant has
         agreed to devote the Premises; and Tenant further agrees that, in the
         event that Tenant shall do any of the foregoing, Tenant will promptly
         pay to Landlord, on demand, any such increase resulting therefrom,
         which shall be due and payable as Additional Rent thereunder.

8.2      WAIVER.
         ------

         Failure on the part of Landlord or Tenant to complain of any action or
         non-action on the part of the other, no matter how long the same may
         continue, shall never be a waiver by Tenant or Landlord, respectively,
         of any of its rights hereunder. Further, no waiver at any time of any
         of the provisions hereof by Landlord or Tenant shall be construed as a
         waiver of any of the other provisions hereof, and a waiver at any time
         of any of the provisions hereof shall not be construed as a waiver at
         any subsequent time of the same provisions. The consent or approval of
         Landlord or Tenant to or of any action by the other requiring such
         consent or approval shall not be construed to waive or render
         unnecessary Landlord's or Tenant's consent or approval to or of
         subsequent similar act by the other.

         No payment by Tenant, or acceptance by Landlord, of a lesser amount
         than shall be due from Tenant to Landlord shall be treated otherwise
         than as a payment on account. The acceptance by Landlord of a check for
         a lesser amount with an endorsement or statement thereon, or upon any
         letter accompanying such check, that such lesser amount is payment in
         full, shall be given no effect, and Landlord may accept such check
         without prejudice to any other rights or remedies which Landlord may
         have against Tenant.

8.3      CUMULATIVE REMEDIES.
         -------------------

         Except as expressly provided in this Lease, the specific remedies to
         which Landlord may resort under the terms of this Lease are cumulative
         and are not intended to be exclusive of any other remedies or means of
         redress to which such party may be lawfully entitled in case of any
         breach or threatened breach by Tenant of any provisions of this Lease.
         In addition to the other remedies provided in this Lease, Landlord
         shall be entitled to the restraint by injunction of the violation or
         attempted or threatened violation of any of the covenants, conditions
         or provisions of this Lease or to a decree compelling specific
         performance of any such covenants, conditions or provisions.

                                      -38-

<Page>

8.4      QUIET ENJOYMENT.
         ---------------

         Tenant, subject to the terms and provisions of this Lease on payment of
         the rent and observing, keeping and performing all of the terms and
         provisions of this Lease on Tenant's part to be observed, kept and
         performed, shall lawfully, peaceably and quietly have, hold, occupy and
         enjoy the Premises during the Term (exclusive of any period during
         which Tenant is holding over after the termination or expiration of
         this Lease without the consent of Landlord), without hindrance or
         ejection by any persons lawfully claiming under Landlord to have title
         to the Premises superior to Tenant; the foregoing covenant of quiet
         enjoyment is in lieu of any other covenant, express or implied; and it
         is understood and agreed that this covenant and any and all other
         covenants of Landlord contained in this Lease shall be binding upon
         Landlord and Landlord's successors, including ground or master lessees,
         only with respect to breaches occurring during Landlord's or Landlord's
         successors' respective ownership of Landlord's interest hereunder, as
         the case may be.

         Further, Tenant specifically agrees to look solely to Landlord's then
         equity interest in the Building at the time owned, or in which Landlord
         holds an interest as ground lessee, for recovery of any judgment from
         Landlord; it being specifically agreed that neither Landlord (original
         or successor), nor any partner in or of Landlord, nor any beneficiary
         of any Trust of which any person holding Landlord's interest is
         trustee, nor any member, manager, partner, director or stockholder, nor
         Landlord's managing agent, shall ever be personally liable for any such
         judgment, or for the payment of any monetary obligation to Tenant. The
         provision contained in the foregoing sentence is not intended to, and
         shall not, limit any right that Tenant might otherwise have to obtain
         injunctive relief against Landlord or Landlord's successors in
         interest, or any action not involving the personal liability of
         Landlord (original or successor), any partner in or of Landlord, any
         successor trustee to the persons named herein as Landlord, or any
         beneficiary of any trust of which any person holding Landlord's
         interest is trustee, or of any manager, member, partner, director or
         stockholder of Landlord or of Landlord's managing agent to respond in
         monetary damages from Landlord's assets other than Landlord's equity
         interest aforesaid in the Building, but in no event shall Tenant have
         the right to terminate or cancel this Lease or to withhold rent or to
         set-off any claim or damages against rent as a result of any default by
         Landlord or breach by Landlord of its covenants or any warranties or
         promises hereunder, except in the case of a wrongful eviction of Tenant
         from the demised premises (constructive or actual) by Landlord
         continuing after notice to Landlord thereof and a reasonable
         opportunity for Landlord to cure the same. In no event shall Landlord
         ever be liable to Tenant for any indirect or consequential damages or
         loss of profits or the like. In the event that Landlord shall be
         determined to have acted unreasonably in withholding any consent or
         approval under this Lease, the sole recourse and remedy of Tenant in
         respect thereof shall be to specifically enforce Landlord's obligation
         to grant such consent or approval, and in no event shall the Landlord
         be responsible for any damages of whatever nature in respect of its
         failure to give such consent or approval nor shall the same otherwise
         affect the obligations of Tenant under this Lease or act as any
         termination of this Lease.

                                      -39-

<Page>

8.5      NOTICE TO MORTGAGEE AND GROUND LESSOR.
         -------------------------------------

         After receiving notice from any person, firm or other entity that it
         holds a mortgage which includes the Premises as part of the mortgaged
         premises, or that it is the ground lessor under a lease with Landlord,
         as ground lessee, which includes the Premises as a part of the demised
         premises, no notice from Tenant to Landlord shall be effective unless
         and until a copy of the same is given to such holder or ground lessor
         (provided Tenant has received written notice of such holder or ground
         lessor, including correct addresses, prior to the date Tenant sends its
         notice), and the curing of any of Landlord's defaults by such holder or
         ground lessor within a reasonable time thereafter (including a
         reasonable time to obtain possession of the premises if the mortgagee
         or ground lessor elects to do so) shall be treated as performance by
         Landlord. For the purposes of this Section 8.5 or Section 8.15, the
         term "mortgage" includes a mortgage on a leasehold interest of Landlord
         (but not one on Tenant's leasehold interest).

8.6      ASSIGNMENT OF RENTS.
         -------------------

         With reference to any assignment by Landlord or Landlord's interest in
         this Lease, or the rents payable hereunder, conditional in nature or
         otherwise, which assignment is made to the holder of a mortgage or
         ground lease on property which includes the Premises, Tenant agrees:

               (a)  That the execution thereof by Landlord, and the acceptance
                    thereof by the holder of such mortgage or the ground lessor,
                    shall never be treated as an assumption by such holder or
                    ground lessor of any of the obligations of Landlord
                    hereunder, unless such holder, or ground lessor, shall, by
                    notice sent to Tenant, specifically otherwise elect; and

               (b)  That, except as aforesaid, such holder or ground lessor
                    shall be treated as having assumed Landlord's obligations
                    hereunder only upon foreclosure of such holder's mortgage
                    and the taking of possession of the Premises, or, in the
                    case of a ground lessor, the assumption of Landlord's
                    position hereunder by such ground lessor.

         In no event shall the acquisition of title to the Building and the land
         on which the same is located by a purchaser which, simultaneously
         therewith, leases the entire Building or such land back to the seller
         thereof be treated as an assumption by such purchaser-lessor, by
         operation of law or otherwise, of Landlord's obligations hereunder, but
         Tenant shall look solely to such seller-lessee, and its successors from
         time to time in title, for performance of Landlord's obligations
         hereunder subject to the provisions of Section 8.4 hereof. In any such
         event, this Lease shall be subject and subordinate to the lease to such
         purchaser provided that such purchaser agrees to recognize the right of
         Tenant to use and occupy the Premises upon the payment of rent and
         other charges payable by Tenant under this Lease and the performance by
         Tenant of Tenant's obligations under this Lease and provided that
         Tenant agrees to attorn to such purchaser. For all purposes, such
         seller-lessee, and its successors in title, shall be the landlord
         hereunder unless and until Landlord's position shall have been assumed
         by such purchaser-lessor.

                                      -40-

<Page>

8.7      SURRENDER.
         ---------

         No act or thing done by Landlord during the Lease Term shall be deemed
         an acceptance of a surrender of the Premises, and no agreement to
         accept such surrender shall be valid, unless in writing signed by
         Landlord. No employee of Landlord or of Landlord's agents shall have
         any power to accept the keys of the Premises prior to the termination
         of this Lease. The delivery of keys to any employee of Landlord or of
         Landlord's agents shall not operate as a termination of the Lease or a
         surrender of the Premises.

8.8      BROKERAGE.
         ---------

         (A) Tenant warrants and represents that Tenant has not dealt with any
         broker, finder or other agent in connection with the consummation of
         this Lease other than the Recognized Broker, if any, designated in
         Section 1.1 hereof; and in the event any claim is made against the
         Landlord relative to dealings by Tenant with brokers, finders or other
         agents other than the Recognized Broker, if any, designated in Section
         1.1 hereof, Tenant shall defend the claim against Landlord with counsel
         of Tenant's selection first approved by Landlord (which approval will
         not be unreasonably withheld) and save harmless and indemnify Landlord
         on account of loss, cost or damage which may arise by reason of such
         claim.

         (B) Landlord warrants and represents that Landlord has not dealt with
         any broker, finder or other agent in connection with the consummation
         of this Lease other than the Recognized Broker, if any, designated in
         Section 1.1 hereof; and in the event any claim is made against the
         Tenant relative to dealings by Landlord with brokers, finders or other
         agents other than the Recognized Broker, if any, designated in Section
         1.1 hereof, Landlord shall defend the claim against Tenant with counsel
         of Landlord's selection and save harmless and indemnify Tenant on
         account of loss, cost or damage which may arise by reason of such
         claim. Landlord agrees that it shall be solely responsible for the
         payment of brokerage commissions to the Recognized Broker for the
         Original Term of this Lease, if any, designated in Section 1.1 hereof.

8.9      INVALIDITY OF PARTICULAR PROVISIONS.
         -----------------------------------

         If any term or provision of this Lease, or the application thereof to
         any person or circumstance shall, to any extent, be invalid or
         unenforceable, the remainder of this Lease, or the application of such
         term or provision to persons or circumstances other than those as to
         which it is held invalid or unenforceable, shall not be affected
         thereby, and each term and provision of this Lease shall be valid and
         be enforced to the fullest extent permitted by law.

8.10     PROVISIONS BINDING, ETC.
         -----------------------

         The obligations of this Lease shall run with the land, and except as
         herein otherwise provided, the terms hereof shall be binding upon and
         shall inure to the benefit of the successors and assigns, respectively,
         of Landlord and Tenant and, if Tenant shall be an

                                      -41-

<Page>

         individual, upon and to his heirs, executors, administrators,
         successors and assigns. Each term and each provision of this Lease to
         be performed by Tenant shall be construed to be both a covenant and a
         condition. The reference contained to successors and assigns of Tenant
         is not intended to constitute a consent to subletting or assignment by
         Tenant.

8.11     RECORDING.
         ---------

         Tenant agrees not to record the within Lease, but each party hereto
         agrees, on the request of the other, to execute a so-called Notice of
         Lease or short form lease in form recordable and complying with
         applicable law and reasonably satisfactory to both Landlord's and
         Tenant's attorneys. In no event shall such document set forth rent or
         other charges payable by Tenant under this Lease; and any such document
         shall expressly state that it is executed pursuant to the provisions
         contained in this Lease, and is not intended to vary the terms and
         conditions of this Lease.

8.12     NOTICES.
         -------

         Whenever, by the terms of this Lease, notice shall or may be given
         either to Landlord or to Tenant, such notice shall be in writing and
         shall be sent by overnight commercial courier or by registered or
         certified mail postage or delivery charges prepaid, as the case may be:

                  If intended for Landlord, addressed to Landlord at the address
                  set forth in Article I of this Lease (or to such other address
                  or addresses as may from time to time hereafter be designated
                  by Landlord by like notice) with a copy to Landlord,
                  Attention: General Counsel.

                  If intended for Tenant, addressed to Tenant at the address set
                  forth in Article I of this Lease except that from and after
                  the Commencement Date the address of Tenant shall be the
                  Premises (or to such other address or addresses as may from
                  time to time hereafter be designated by Tenant by like
                  notice).

         Except as otherwise provided herein, all such notices shall be
         effective when received; provided, that (i) if receipt is refused,
         notice shall be effective upon the first occasion that such receipt is
         refused, (ii) if the notice is unable to be delivered due to a change
         of address of which no notice was given, notice shall be effective upon
         the date such delivery was attempted or (iii) if the notice address is
         a post office box number, notice shall be effective the day after such
         notice is sent as provided hereinabove.

         Where provision is made for the attention of an individual or
         department, the notice shall be effective only if the wrapper in which
         such notice is sent is addressed to the attention of such individual or
         department.

         Any notice given by an attorney on behalf of Landlord or by Landlord's
         managing agent shall be considered as given by Landlord and shall be
         fully effective.

                                      -42-

<Page>

         Time is of the essence with respect to any and all notices and periods
         for giving notice or taking any action thereto under this Lease.

8.13     WHEN LEASE BECOMES BINDING.
         --------------------------

         Employees or agents of Landlord have no authority to make or agree to
         make a lease or any other agreement or undertaking in connection
         herewith. The submission of this document for examination and
         negotiation does not constitute an offer to lease, or a reservation of,
         or option for, the Premises, and this document shall become effective
         and binding only upon the execution and delivery hereof by both
         Landlord and Tenant. All negotiations, considerations, representations
         and understandings between Landlord and Tenant are incorporated herein
         and may be modified or altered only by written agreement between
         Landlord and Tenant, and no act or omission of any employee or agent of
         Landlord shall alter, change or modify any of the provisions hereof.

8.14     SECTION HEADINGS.
         ----------------

         The titles of the Articles throughout this Lease are for convenience
         and reference only, and the words contained therein shall in no way be
         held to explain, modify, amplify or aid in the interpretation,
         construction or meaning of the provisions of this Lease.

8.15     RIGHTS OF MORTGAGEE.
         -------------------

         This Lease shall be subject and subordinate to any mortgage now or
         hereafter on the Site or the Building, or both, and to each advance
         made or hereafter to be made under any mortgage, and to all renewals,
         modifications, consolidations, replacements and extensions thereof and
         all substitutions therefor provided that the holder of such mortgage
         agrees to recognize the rights of Tenant under this Lease (including
         the right to use and occupy the Premises) upon the payment of rent and
         other charges payable by Tenant under this Lease and the performance by
         Tenant of Tenant's obligations hereunder in which event Tenant shall
         agree to attorn to such holder and its successors as landlord. In
         confirmation of such subordination and recognition, Tenant shall
         execute and deliver promptly such instruments of subordination and
         recognition as such mortgagee may reasonably request. Tenant hereby
         appoints such mortgagee (from time to time) as Tenant's
         attorney-in-fact to execute such subordination upon default of Tenant
         in complying with such mortgagee's (from time to time) request. In the
         event that any mortgagee or its respective successor in title shall
         succeed to the interest of Landlord, then, this Lease shall
         nevertheless continue in full force and effect and Tenant shall and
         does hereby agree to attorn to such mortgagee or successor and to
         recognize such mortgagee or successor as its landlord. If any holder of
         a mortgage which includes the Premises, executed and recorded prior to
         the date of this Lease, shall so elect, this Lease and the rights of
         Tenant hereunder, shall be superior in right to the rights of such
         holder, with the same force and effect as if this Lease had been
         executed, delivered and recorded, or a statutory Notice hereof
         recorded, prior to the execution, delivery and recording of any such
         mortgage. The election of any such holder shall become effective upon
         either notice from such holder to Tenant in the same fashion as notices
         from Landlord to Tenant are to be given hereunder or by the recording
         in the appropriate registry or recorder's

                                      -43-

<Page>

         office of an instrument in which such holder subordinates its rights
         under such mortgage to this Lease.

         If in connection with obtaining financing a bank, insurance company,
         pension trust or other institutional lender shall request reasonable
         modifications in this Lease as a condition to such financing, Tenant
         will not unreasonably withhold, delay or condition its consent thereto,
         provided that such modifications do not increase the monetary or other
         obligations of Tenant hereunder or materially adversely affect the
         leasehold interest hereby created, or materially decrease the
         obligations of Landlord hereunder.

8.16     STATUS REPORTS AND FINANCIAL STATEMENTS.
         ---------------------------------------

         Recognizing that Landlord may find it necessary to establish to third
         parties, such as accountants, banks, potential or existing mortgagees,
         potential purchasers or the like, the then current status of
         performance hereunder, Tenant, on the request of Landlord made from
         time to time (but no more often than once during any twelve (12) month
         period), will promptly furnish to Landlord, or any existing or
         potential holder of any mortgage encumbering the Premises, the
         Building, the Site and/or the Complex or any potential purchaser of the
         Premises, the Building, the Site and/or the Complex, (each an
         "Interested Party"), a statement of the status of any matter pertaining
         to this Lease, including, without limitation, acknowledgments that (or
         the extent to which) each party is in compliance with its obligations
         under the terms of this Lease. In addition, Tenant shall deliver to
         Landlord, or any Interested Party designated by Landlord, financial
         statements of Tenant and any guarantor of Tenant's obligations under
         this Lease, as reasonably requested by Landlord, including, but not
         limited to financial statements for the past three (3) years. Any such
         status statement or financial statement delivered by Tenant pursuant to
         this Section 8.16 may be relied upon by any Interested Party.

8.17     SELF-HELP.
         ---------

         If Tenant shall at any time default in the performance of any
         obligation under this Lease, Landlord shall have the right, but shall
         not be obligated, to enter upon the Premises and to perform such
         obligation notwithstanding the fact that no specific provision for such
         substituted performance by Landlord is made in this Lease with respect
         to such default. In performing such obligation, Landlord may make any
         payment of money or perform any other act. All sums so paid by Landlord
         (together with interest at the rate of one and one-half percentage
         points over the then prevailing prime rate in Boston as set by Bank of
         America, N.A., or its successor (but in no event greater than the
         maximum rate permitted by applicable law) and all costs and expenses in
         connection with the performance of any such act by Landlord, shall be
         deemed to be Additional Rent under this Lease and shall be payable to
         Landlord immediately on demand. Landlord may exercise the foregoing
         rights without waiving any other of its rights or releasing Tenant from
         any of its obligations under this Lease.

                                      -44-

<Page>

8.18     HOLDING OVER.
         ------------

         Any holding over by Tenant after the expiration of the term of this
         Lease shall be treated as a tenancy at sufferance and shall be on the
         terms and conditions as set forth in this Lease, as far as applicable
         except that Tenant shall pay as a use and occupancy charge an amount
         equal to the greater of (x) 150% of the Annual Fixed Rent and
         Additional Rent calculated (on a daily basis) at the highest rate
         payable under the terms of this Lease, or (y) the fair market rental
         value of the Premises, in each case for the period measured from the
         day on which Tenant's hold-over commences and terminating on the day on
         which Tenant vacates the Premises. In addition, Tenant shall save
         Landlord, its agents and employees harmless and will exonerate, defend
         and indemnify Landlord, its agents and employees from and against any
         and all damages which Landlord may suffer on account of Tenant's
         hold-over in the Premises after the expiration or prior termination of
         the term of this Lease. Nothing in the foregoing nor any other term or
         provision of this Lease shall be deemed to permit Tenant to retain
         possession of the Premises or hold over in the Premises after the
         expiration or earlier termination of the Lease Term. All property which
         remains in the Building or the Premises after the expiration or
         termination of this Lease shall be conclusively deemed to be abandoned
         and may either be retained by Landlord as its property or sold or
         otherwise disposed of in such manner as Landlord may see fit. If any
         part thereof shall be sold, then Landlord may receive the proceeds of
         such sale and apply the same, at its option against the expenses of the
         sale, the cost of moving and storage, any arrears of rent or other
         charges payable hereunder by Tenant to Landlord and any damages to
         which Landlord may be entitled under this Lease and at law and in
         equity.

8.19     NON-SUBROGATION.
         ---------------

         Any insurance carried by either party with respect to the Premises or
         property therein or occurrences thereon shall, if it can be so written
         without additional premium or with an additional premium which the
         other party agrees to pay, include a clause or endorsement denying to
         the insurer rights of subrogation against the other party to the extent
         rights have been waived by the insured prior to occurrence of injury or
         loss. Each party, notwithstanding any provisions of this Lease to the
         contrary, hereby waives any rights of recovery against the other for
         injury or loss due to hazards covered by such insurance (or which would
         have been covered had such party carried the insurance required to be
         carried by it under the Lease) to the extent of the indemnification
         received under such insurance policy. This waiver of rights by Tenant
         shall apply to, and be for the benefit of, Landlord's managing agent.

8.20     SECURITY DEPOSIT.
         ----------------

         If, in Section 1.1 hereof, a security deposit is specified, Tenant
         agrees that the same will be paid upon execution and delivery of this
         Lease, and that Landlord shall hold the same, throughout the term of
         this Lease (including any extension thereof), as security for the
         performance by Tenant of all obligations on the part of Tenant to be
         kept and performed. Landlord shall have the right from time to time
         without prejudice to any other remedy Landlord may have on account
         thereof, to apply such deposit, or any part thereof, to

                                      -45-

<Page>

         Landlord's damages arising from any default on the part of Tenant. If
         Landlord so applies all or any portion of such deposit, Tenant shall
         within seven (7) days after notice from Landlord deliver cash to
         Landlord in an amount sufficient to restore such deposit to the full
         amount stated in Section 1.1. Tenant not then being in default and
         having performed all of its obligations under this Lease, including
         the payment of all Annual Fixed Rent, Landlord shall return the
         deposit, or so much thereof as shall not have theretofore been applied
         in accordance with the terms of this Section 8.20, to Tenant on the
         expiration or earlier termination of the term of this Lease and
         surrender possession of the Premises by Tenant to Landlord in the
         condition required in the Lease at such time. While Landlord holds
         such deposit, Landlord shall have no obligation to pay interest on the
         same and shall have the right to commingle the same with Landlord's
         other funds. If Landlord conveys Landlord's interest under this Lease,
         the deposit, or any part thereof not previously applied, may be turned
         over by Landlord to Landlord's grantee, and, if so turned over, Tenant
         agrees to look solely to such grantee for proper application of the
         deposit in accordance with the terms of this Section 8.20, and the
         return thereof in accordance herewith.

         Neither the holder of any mortgage nor the lessor in any ground lease
         on property which includes the Premises shall ever be responsible to
         Tenant for the return or application of any such deposit, whether or
         not it succeeds to the position of Landlord hereunder, unless such
         deposit shall have been received in hand by such holder or ground
         lessor.

8.21     LATE PAYMENT.
         ------------

         If Landlord shall not have received any payment or installment of
         Annual Fixed Rent or Additional Rent (the "Outstanding Amount") on or
         before the date on which the same first becomes payable under this
         Lease (the "Due Date"), the amount of such payment or installment shall
         incur a late charge equal to the sum of: (a) five percent (5%) of the
         Outstanding Amount for administration and bookkeeping costs associated
         with the late payment and (b) interest on the Outstanding Amount from
         the Due Date through and including the date such payment or installment
         is received by Landlord, at a rate equal to the lesser of (i) the rate
         announced by Bank of America, N.A., (or its successor) from time to
         time as its prime or base rate (or if such rate is no longer available,
         a comparable rate reasonably selected by Landlord), plus two percent
         (2%), or (ii) the maximum applicable legal rate, if any. Such interest
         shall be deemed Additional Rent and shall be paid by Tenant to Landlord
         upon demand.

         Notwithstanding the foregoing, Landlord agrees that such late charge
         will not be imposed upon the first late payment under this Lease until
         five (5) days after the date on which such payment first became due and
         payable.

8.22     TENANT'S PAYMENTS.
         -----------------

         Each and every payment and expenditure, other than Annual Fixed Rent,
         shall be deemed to be Additional Rent hereunder, whether or not the
         provisions requiring payment of such amounts specifically so state, and
         shall be payable, unless otherwise provided in this Lease, within
         twenty (20) days after written demand by Landlord, and in the case of
         the

                                      -46-

<Page>

         non-payment of any such amount, Landlord shall have, in addition to
         all of its other rights and remedies, all the rights and remedies
         available to Landlord hereunder or by law in the case of non-payment of
         Annual Fixed Rent. Unless expressly otherwise provided in this Lease,
         the performance and observance by Tenant of all the terms, covenants
         and conditions of this Lease to be performed and observed by Tenant
         shall be at Tenant's sole cost and expense. If Tenant has not objected
         to any statement of Additional Rent which is rendered by Landlord to
         Tenant within ninety (90) days after Landlord has rendered the same to
         Tenant, then the same shall be deemed to be a final account between
         Landlord and Tenant not subject to any further dispute. In the event
         that Tenant shall seek Landlord's consent or approval under this Lease,
         then Tenant shall reimburse Landlord, upon demand, as Additional Rent,
         for all reasonable costs and expenses, including legal and
         architectural costs and expenses, incurred by Landlord in processing
         such request, whether or not such consent or approval shall be given.

8.23     WAIVER OF TRIAL BY JURY.
         -----------------------

         To induce Landlord to enter into this Lease, Tenant hereby waives any
         right to trial by jury in any action, proceeding or counterclaim
         brought by either Landlord or Tenant on any matters whatsoever arising
         out of or any way connected with this Lease, the relationship of the
         Landlord and the Tenant, the Tenant's use or occupancy of the Premises
         and/or any claim of injury or damage, including but not limited to, any
         summary process eviction action.

8.24     GOVERNING LAW.
         ----------------

         This Lease shall be governed exclusively by the provisions hereof and
         by the law of the Commonwealth of Massachusetts, as the same may from
         time to time exist.

                                      -47-

<Page>

     EXECUTED as a sealed instrument in two or more counterparts each of which
shall be deemed to be an original.

<Table>
<S>                                                          <C>
WITNESS:                                                     LANDLORD:

    /s/ Illegible                                                   By:   /s/ David C. Provost
-------------------------------------------------------             ----------------------------------------------
                                                                    DAVID C. PROVOST, FOR THE TRUSTEES OF 91
                                                                    HARTWELL AVENUE TRUST PURSUANT TO WRITTEN
                                                                    DELEGATION BUT NOT INDIVIDUALLY

                                                             TENANT:

ATTEST:                                                      SYNTA PHARMACEUTICALS, INC.

By:              /s/ Wendy E. Rieder                         By:           /s/ John A. McCarthy, Jr.
             ------------------------------------------                 ------------------------------------------

Name:                Wendy E. Rieder                         Name:             John A. McCarthy, Jr.
             ------------------------------------------                 ------------------------------------------

Title:          (Secretary or Assistant Secretary)           Title:           (President or Vice President)
             ------------------------------------------                 ------------------------------------------
                                                                                 Hereto duly authorized

                                       By:                                 /s/ Keith Ehrlich
                                                                        ------------------------------------------

                                                             Name:             Keith Ehrlich
                                                                        ------------------------------------------

                                                             Title:     (Treasurer or Assistant Treasurer)
                                                                        ------------------------------------------
                                                                                 Hereto duly authorized

                                                                                                   CORPORATE SEAL
</Table>

                                      -48-

<Page>

                                    EXHIBIT A
                                    ---------

                               DESCRIPTION OF SITE

That certain parcel of land situate in Lexington in the County of Middlesex and
Commonwealth of Massachusetts, described as follows:

SOUTHEASTERLY             by Hartwell Avenue, two hundred thirty-seven and
                          47/100 feet;

SOUTHEASTERLY             by a curving line forming the junction of said
                          Hartwell Avenue and Hartwell Place, as shown on
                          plan hereinafter mentioned, thirty-nine and 27/100
                          feet;

SOUTHWESTERLY             five hundred thirty-two and 23/100 feet, and

SOUTHWESTERLY, SOUTHERLY and SOUTHEASTERLY one hundred ninety and 25/100 feet,
                          by said Hartwell Place;

SOUTHERLY                 by lot 9 on said plan, three hundred seventy-four and
                          57/100 feet;

SOUTHWESTERLY             three hundred sixty-seven and 65/100 feet;

NORTHWESTERLY             thirty-one and 12/100 feet, and

NORTHWESTERLY             again, eight hundred ninety and 63/100 feet, by land
                          now or formerly of The United States of America;

NORTHEASTERLY             by said United States of America land and by land
                          now or formerly of John W. O(`Connor et al, nine
                          hundred thirty-three and 87/100 feet.

         Said parcel is shown as lot 10 on said plan, (Plan No.31330D).

         All of said boundaries are determined by the Court to be located as
shown on a subdivision plan, as approved by the Court, filed in the Land
Registration Office, a copy of which is filed in the Registry of Deeds for the
South Registry District of Middlesex County in Registration Book 835, Page 146,
with Certificate 141096.

         The above described land is subject to and has the benefit of the
ditches as approximately shown on said plan at date of original decree, (May 17,
1963).

                                    Exhibit A
                                   Page 1 of 3

<Page>

     So much of the above described land as is included within the area marked
"Tennessee Gas Transmission Company Easement 30' wide" is subject to the
easements set forth in a taking by the Northeastern Gas Transmission Company,
dated July 13, 1951 and duly recorded in Book 7772, Page 162.

     The above described land is subject to an Avigation Easement set forth in a
Declaration of Taking by the United States of America dated February 12, 1954
recorded with the Middlesex South District Registry of Deeds in Book 8219, Page
421 and more particularly shown as "Avigation Easement A-130E-1" on Plan No.
31330-D (referred to above).

     The above described land is subject to an Order by the Town of Lexington
for construction of water main in Hartwell Avenue, Document No. 461902 as
affected by Certificate for Dissolving Betterments filed as Document No. 499500.

     The above described land is subject to a Grant of Easement from Wilbur C.
Nylander et al Trs. to the Town of Lexington to construct and maintain sewer in
Hartwell Place, Document No. 508567.

     The above described land is subject to a grant of Easement over 20 feet
wide drain easement (i) for the benefit of lot 9 in common with others entitled
thereto, set forth in Document 511666 and (ii) set forth in Document No. 479843
for the benefit of lot 7 shown on plan recorded with said Document No. 479843.

     The above described land is subject to a Taking of easement by the Town of
Lexington in Hartwell Place, Document No. 544200.

     The above described land is subject to and has the benefit of a Grant of
Easement and Reservation from Wilbur C. Nylander et al Trs. to the Town of
Lexington for conservation purposes, Document No. 616453.

     The above described land is subject to and has the benefit of the
following:

     A.   Order of Conditions issued by the Town of Lexington Conservation
          Commission filed as Document No. 616456 as extended by Extension
          Permits issued by said Conservation Commission filed as Document Nos.
          627154, 635069, 655552 and 669180.

     B.   Decision of the Town of Lexington Board of Appeals filed as Document
          No. 616457.

     C.   Decision of the Town of Lexington Board of Appeals filed as Document
          No. 616458.

                                    Exhibit A
                                   Page 2 of 3

<Page>

     D.   Decision of the Town of Lexington Board of Appeals filed as Document
          No. 616459.

     E.   Decision of the Town of Lexington Board of Appeals filed as Document
          No. 634489.

     F.   Decision of the Town of Lexington Board of Appeals filed as Document
          No. 646344.

     G.   Decision of the Town of Lexington Board of Appeals filed as Document
          No. 646345.

     H.   Decision of the Town of Lexington Board of Appeals filed as Document
          No. 646346.

     The above described land is subject to an Easement granted to Boston Edison
Company filed as Document No. 672152.

     The above described land is subject to such other easements, agreements and
matters of record, if any, insofar as in force and applicable.

                                    Exhibit A
                                   Page 3 of 3

<Page>

                                    EXHIBIT C
                                    ---------

                                LANDLORD SERVICES

I.   CLEANING
     --------

     Cleaning and janitorial services shall be provided as needed Monday through
     Friday, exclusive of holidays, Saturdays and Sundays.

     A.   OFFICE AREAS
          ------------

          Cleaning and janitorial services to be provided in the office areas
          shall include:

               1.   Vacuuming, damp mopping of resilient floors and trash
                    removal.

               2.   Dusting of horizontal surfaces within normal reach (tenant
                    equipment to remain in place).

               3.   High dusting and dusting of vertical blinds to be rendered
                    as needed.

     B.   LAVATORIES
          ----------

          Cleaning and janitorial services to be provided in the common area
          lavatories of the building shall include:

               1.   Dusting, damp mopping of resilient floors, trash removal,
                    sanitizing of basins, bowls and urinals as well as cleaning
                    of mirrors and bright work.

               2.   Refilling of soap, towel, tissue and sanitary dispensers to
                    be rendered as necessary.

               3.   High dusting to be rendered as needed.

     C.   MAIN LOBBIES, ELEVATORS, STAIRWELLS AND COMMON CORRIDORS
          --------------------------------------------------------

          Cleaning and janitorial services to be provided in the common areas of
          the building shall include:

                                    Exhibit C
                                   Page 1 of 3

<Page>

               1.   Trash removal, vacuuming, dusting and damp mopping of
                    resilient floors and cleaning and sanitizing of water
                    fountains.

               2.   High dusting to be rendered as needed.

     D.   WINDOW CLEANING
          ---------------

          All exterior windows shall be washed on the inside and outside
          surfaces at frequency necessary to maintain a first class appearance.

II.  HVAC
     ----

     A.   Heating, ventilating and air conditioning equipment will be provided
          with sufficient capacity to accommodate a maximum population density
          of one (1) person per one hundred fifty (150) square feet of useable
          floor area served, and a combined lighting and standard electrical
          load of 3.0 watts per square foot of useable floor area. In the event
          Tenant introduces into the Premises personnel or equipment which
          overloads the system's ability to adequately perform its proper
          functions, Landlord shall so notify Tenant in writing and
          supplementary system(s) may be required and installed by Landlord at
          Tenant's expense, if within fifteen (15) days Tenant has not modified
          its use so as not to cause such overload.

          Operating criteria of the basic system are in accordance with the
          Massachusetts Energy Code and shall not be less than the following:

               (i)  Cooling season indoor conditions of not in excess of 78
                    degrees Fahrenheit when outdoor conditions are 91 degrees
                    Fahrenheit drybulb and 73 degrees Fahrenheit wetbulb.

               (ii) Heating season minimum room temperature of 72 degrees
                    Fahrenheit when outdoor conditions are 6 degrees Fahrenheit
                    drybulb.

     B.   Landlord shall provide heating, ventilating and air conditioning as
          normal seasonal charges may require during the hours of 8:00 a.m. to
          6:00 p.m., Monday through Friday, and 8:00 a.m. to 12:00 p.m. on
          Saturdays (legal holidays in all cases excepted).

          If Tenant shall require air conditioning (during the air conditioning
          season) or heating or ventilating during any other time period,
          Landlord shall use landlord's best efforts to furnish such services
          for the area or areas specified by written request of Tenant delivered
          to the Building Superintendent or the Landlord before 3:00 p.m. of the
          business day

                                    Exhibit C
                                   Page 2 of 3

<Page>

          preceding the extra usage. Landlord shall charge Tenant for such
          extra-hours usage at reasonable rates customary for first-class office
          buildings in the Boston Suburban market, and Tenant shall pay
          Landlord, as additional rent, upon receipt of billing therefor.

III. ELECTRICAL SERVICES
     -------------------

     A.   Landlord shall provide electric power for a combined load of 3.0 watts
          per square foot of useable area for lighting and for office machines
          through standard receptacles for the typical office space.

     B.   In the event that Tenant has special equipment (such as computers and
          reproduction equipment) that requires either 3-phase electric power or
          any voltage other than 120 amps, or for any other usage in excess of
          3.0 watts per square foot, Landlord may at its option require the
          installation of separate metering (Tenant being solely responsible for
          the costs of any such separate meter and the installation thereof) and
          direct billing to Tenant for the electric power required for any such
          special equipment.

     C.   Landlord will furnish and install, at Tenant's expense, all
          replacement lighting tubes, lamps and ballasts required by Tenant.
          Landlord will clean lighting fixtures on a regularly scheduled basis
          at Tenant's expense.

IV.  ELEVATORS
     ---------

     Provide passenger elevator service.

V.   WATER
     -----

     Provide hot water for lavatory purposes and cold water for drinking,
     lavatory and toilet purposes.

VI.  CARD ACCESS SYSTEM
     ------------------

     Landlord will provide a card access system at one entry door of the
     building.

                                    Exhibit C
                                   Page 3 of 3

<Page>

                                    EXHIBIT D
                                    ---------

                                   FLOOR PLAN

                                    Exhibit D
                                   Page 1 of 1

<Page>

                                    EXHIBIT F
                                    ---------

                              FORMS OF LIEN WAIVERS

              CONTRACTOR'S PARTIAL WAIVER AND SUBORDINATION OF LIEN

STATE OF                                          Date:
       ------------------------------                  -------------------------

                            COUNTY       Application for Payment No.:
---------------------------                                           ----------

OWNER:
                     -----------------------------------------------------------

CONTRACTOR:
                     -----------------------------------------------------------

LENDER / MORTGAGEE:  None
                     -----------------------------------------------------------

1.       Original Contract Amount:        $
                                             -----------------------------------

2.       Approved Change Orders:          $
                                             -----------------------------------

3.       Adjusted Contract Amount:        $
         (line 1 plus line 2)                -----------------------------------

4.       Completed to Date:               $
                                             -----------------------------------

5.       Less Retainage:                  $
                                             -----------------------------------

6.       Total Payable to Date:           $
         (line 4 less line 5)                -----------------------------------

7.       Less Previous Payments:          $
                                             -----------------------------------

8.       Current Amount Due:              $
         (line 6 less line 7)                -----------------------------------

9.       Pending Change Orders:           $
                                             -----------------------------------

10.      Disputed Claims:                 $
                                             -----------------------------------

The undersigned who has a contract with _________________________ for furnishing
labor or materials or both labor and materials or rental equipment, appliances
or tools for the erection, alteration, repair or removal of a building or
structure or other improvement of real property known and identified as located
in ____________ (city or town),

                                    Exhibit F
                                   Page 1 of 7

<Page>

_________County, _________________________ and owned by _________________, upon
receipt of __________ ($__________) in payment of an
invoice/requisition/application for payment dated __________________ does
hereby:

         (a)      waive any and all liens and right of lien on such real
                  property for labor or materials, or both labor and materials,
                  or rental equipment, appliances or tools, performed or
                  furnished through the following date ________________ (payment
                  period), except for retainage, unpaid agreed or pending change
                  orders, and disputed claims as stated above;

         (b)      subordinate any and all liens and right of lien to secure
                  payment for such unpaid, agreed or pending change orders and
                  disputed claims, and such further labor or materials, or both
                  labor and materials, or rental equipment, appliances or tools,
                  except for retainage, performed or furnished at any time
                  through the twenty-fifth day after the end of the above
                  payment period, to the extent of the amount actually advanced
                  by the above lender/mortgagee through such twenty-fifth day.

         Signed under the penalties of perjury this _________ day of _________,
20__.

WITNESS:                                CONTRACTOR:

--------------------------------------  ----------------------------------------

Name:                                   Name:
      --------------------------------         ---------------------------------
Title:                                  Title:
       -------------------------------         ---------------------------------

                                    Exhibit F
                                   Page 2 of 7

<Page>

                           SUBCONTRACTOR'S LIEN WAIVER

General Contractor:
                     -----------------------------------------------------------

Subcontractor:
                     -----------------------------------------------------------

Owner:
                     -----------------------------------------------------------
Project:
                     -----------------------------------------------------------
Total Amount Previously Paid:                     $
                                                   ----------
Amount Paid This Date:                            $
                                                   ----------
Retainage (Including This Payment) Held to Date:  $
                                                   ----------

In consideration of the receipt of the amount of payment set forth above and any
and all past payments received from the Contractor in connection with the
Project, the undersigned acknowledges and agrees that it has been paid all sums
due for all labor, materials and/or equipment furnished by the undersigned to or
in connection with the Project and the undersigned hereby releases, discharges,
relinquishes and waives any and all claims, suits, liens and rights under any
Notice of Identification, Notice of Contract or statement of account with
respect to the Owner, the Project and/or against the Contractor on account of
any labor, materials and/or equipment furnished through the date hereof.

The undersigned individual represents and warrants that he is the duly
authorized representative of the undersigned, empowered and authorized to
execute and deliver this document on behalf of the undersigned and that this
document binds the undersigned to the extent that the payment referred to herein
is received.

The undersigned represents and warrants that it has paid in full each and every
sub-subcontractor, laborer and labor and/or material supplier with whom
undersigned has dealt in connection with the Project and the undersigned agrees
at its sole cost and expense to defend, indemnify and hold harmless the
Contractor against any claims, demands, suits, disputes, damages, costs,
expenses (including attorneys' fees), liens and/or claims of lien made by such
sub-subcontractors, laborers and labor and/or material suppliers arising out of
or in any way related to the Project. This document is to take effect as a
sealed instrument.

                                    Exhibit F
                                   Page 3 of 7

<Page>

Signed under the penalties of perjury as of this ______
day of ______________, 20__.

SUBCONTRACTOR:                                     Signature and Printed Name of
                                                   Individual
                                                   Signing this Lien Waiver

----------------------------------------------     -----------------------------

WITNESS:

----------------------------------------------

Name:
      ----------------------------------------

Title:
       ---------------------------------------

Dated:
      ----------------------------------------

                                    Exhibit F
                                   Page 4 of 7

<Page>

                 CONTRACTOR'S WAIVER OF CLAIMS AGAINST OWNER AND
                         ACKNOWLEDGMENT OF FINAL PAYMENT

Commonwealth of Massachusetts                    Date:
                                                       -------------------------

COUNTY OF                                 Invoice No.:
          -------------------------------              -------------------------

OWNER:
                ----------------------------------------------------------------

CONTRACTOR:
                ----------------------------------------------------------------
PROJECT:
                ----------------------------------------------------------------

1.       Original Contract Amount:                $
                                                    ---------

2.       Approved Change Orders:                  $
                                                    ---------

3.       Adjusted Contract Amount:                $
                                                    ---------

4.       Sums Paid on Account of Contract Amount: $
                                                    ---------

5.       Less Final Payment Due:                  $
                                                    ---------

The undersigned being duly sworn hereby attests that when the Final Payment
Due as set forth above is paid in full by Owner, such payment shall constitute
payment in full for all labor, materials, equipment and work in place furnished
by the undersigned in connection with the aforesaid contract and that no further
payment is or will be due to the undersigned.

The undersigned hereby attests that it has satisfied all claims against it for
items, including by way of illustration but not by way of limitation, items of:
labor, materials, insurance, taxes, union benefits, equipment, etc. employed in
the prosecution of the work of said contract, and acknowledges that satisfaction
of such claims serves as an inducement for the Owner to release the Final
Payment Due.

The undersigned hereby agrees to indemnify and hold harmless the Owner from and
against all claims arising in connection with its Contract with respect to
claims for the furnishing of labor, materials and equipment by others. Said
indemnification and hold harmless shall include the reimbursement of all actual
attorney's fees and all costs and expenses of every nature, and shall be to the
fullest extent permitted by law.

                                    Exhibit F
                                   Page 5 of 7

<Page>

The undersigned hereby irrevocably waives and releases any and all liens and
right of lien on such real property and other property of the Owner for labor or
materials, or both labor and materials, or rental equipment, appliances or
tools, performed or furnished by the undersigned, and anyone claiming by,
through, or under the undersigned, in connection with the Project.

The undersigned hereby releases, remises and discharges the Owner, any agent of
the Owner and their respective predecessors, successors, assigns, employees,
officers, shareholders, directors, and principals, whether disclosed or
undisclosed (collectively "Releasees") from and against any and all claims,
losses, damages, actions and causes of action (collectively "Claims") which the
undersigned and anyone claiming by, through or under the undersigned has or may
have against the Releasees, including, without limitation, any claims arising in
connection with the Contract and the work performed thereunder.

Notwithstanding anything to the contrary herein, payment to the undersigned of
the Final Payment Due sum as set forth above, shall not constitute a waiver by
the Owner of any of its rights under the contract including by way of
illustration but not by way of limitation guarantees and/or warranties. Payment
will not be made until a signed waiver is returned to Owner.

The undersigned individual represents and warrants that he/she is the duly
authorized representative of the undersigned, empowered and authorized to
execute and deliver this document on behalf of the undersigned.

Signed under the penalties of perjury as a sealed instrument as of this ___ day
of ________________, _____.

                                                                     Corporation
                                  ----------------------------------

                           By:
                                   ---------------------------------------------
                           Name:
                                   ---------------------------------------------
                           Title:
                                   ---------------------------------------------
                                            Hereunto duly authorized

                                    Exhibit F
                                   Page 6 of 7

<Page>

                          COMMONWEALTH OF MASSACHUSETTS

COUNTY OF SUFOLK

         On this ___ day of __________, 20___, before me, the undersigned notary
public, personally appeared _____________________________, proved to me through
satisfactory evidence of identification, to be the person whose name is signed
on the preceding or attached document, and acknowledged to me that he/she signed
it as ______________ for ______________, a corporation/partnership voluntarily
for its stated purpose.

------------------------------------------------
NOTARY PUBLIC
My Commission Expires:

                                    Exhibit F
                                   Page 7 of 7
<Page>

SYNTA                                              Synta Pharmaceuticals Corp.
PHARMACEUTICALS                                    45 Hartwell Avenue
                                                   Lexington, MA  02421

                                                   TEL:  781 274 8200
                                                   FAX:  781 274 8228

                                                   www.syntapharma.com

August 1, 2006

Ms. Stacey Baker
Vice President
Boston Properties, Inc.
Prudential Center
111 Huntington Avenue
Boston, MA 02199-8001

Dear Stacey:

Pursuant to Section 2.4.1 of the lease (the "Lease") dated January 13, 2005
between Mortimer B. Zuckerman and Edward H. Linde, Trustees of 91 Hartwell
Avenue Trust ("Lessor") and Synta Pharmaceuticals Inc. ("Lessee"), relating to
21,832 rentable square feet of space (the "Leased Premises") at 91 Hartwell
Avenue, Lexington, MA, Lessee hereby exercises its option to extend the term of
the Lease for a one year term at Lessee's current Annual Fixed Rent, Terms and
Conditions per the Lease

Sincerely,

/s/ Keith S. Ehrlich

Keith S. Ehrlich
Vice President, Finance and Administration

<Page>

August 14, 2006

VIA FEDERAL EXPRESS

Mr. Keith S. Ehrlich
Vice President, Finance and Administration
Synta Pharmaceuticals
45 Hartwell Avenue
Lexington, MA 02421

Dear Keith:

Thank you for your letter of August 1st regarding Synta's lease extension at 91
Hartwell Avenue in Lexington.

The existing premises of 21,832 RSF shall be renewed for one (1) year on all the
same terms and conditions as is your right under Section 2.4.1 of your Lease.

We look forward to Synta's continued occupancy at 91 Hartwell Avenue.

Please feel free to contact me directly if I may be of any assistance.

Very truly yours,

/s/ STACEY BAKER

Stacey Baker
Vice President

CC:  Mr. Jon Varholack

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