Document:

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                                                                 EXHIBIT 10.29

                             BASIC LEASE INFORMATION

                       LEASE DATED AS OF FEBRUARY 8, 2001

LANDLORD:                              TRINET PROPERTY PARTNERS, L.P.

TENANT:                                TRANSKARYOTIC THERAPIES, INC.

PROPERTY:                              76 Pacella Park Drive, Randolph,
                                       Massachusetts (entire Building)

RENTABLE SPACE:                        47,586 square feet

COMMENCEMENT DATE:                     February 8, 2001

LEASE EXPIRATION DATE:                 11:59 p.m. Boston time on the last day of
                                       the tenth (10th) Lease Year, unless
                                       extended pursuant to Section 3(b) of the
                                       Lease.

PRIMARY TERM FIXED RENT:               The annual Fixed Rent during the Primary
                                       Term of the Lease shall be in the
                                       following amounts:

-------------------------------------------------------------------------------
     DATES                 ANNUAL FIXED RENT           PER RENTABLE SQUARE FOOT
-------------------------------------------------------------------------------
Lease Years 1-4              $537,245.94                      $11.29
-------------------------------------------------------------------------------
Lease Years 5-7              $591,018.12                      $12.42
-------------------------------------------------------------------------------
Lease Years 8-10             $650,024.76                      $13.66
-------------------------------------------------------------------------------

     Fixed Rent shall be payable in advance in equal monthly installments on the
Commencement Date and on the first day of each month thereafter during the Term.
If the Commencement Date is other than the first day of a calendar month, then
the rent for the remainder of such calendar month shall be in proportion to the
number of days remaining in such calendar month.

EXTENSION TERMS: Two (2) options of five (5) years each, to be exercised not
less than eighteen (18) months prior to expiration of the Primary Term or first
Extension Term, as applicable.

RENT DURING EXTENSION TERMS:

(a) The annual Fixed Rent during the first Extension Term, if any, shall be
$743,769.18, which is equivalent to a per-square-foot amount of $15.63.

(b) The annual Fixed Rent during the second Extension Term, if any, shall be
$855,120.42, which is equivalent to a per-square-foot amount of $17.97.

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LANDLORD ADDRESS:                       TriNet Property Partners, L.P.
                                        c/o IStar Financial Inc.
                                        3480 Preston Ridge Road, Suite 575
                                        Alpharetta, GA  30005-8891
                                        Attn: Vice President, Asset Management

                                        with a copy to:

                                        TriNet Property Partners, L.P.
                                        c/o Keller/Davis Company, LLC
                                        101 Derby Street
                                        Hingham, MA  02043

TENANT ADDRESS:                         Transkaryotic Therapies, Inc.
                                        195 Albany Street
                                        Cambridge, MA  02139
                                        Attn: Chief Financial Officer

                                        with a copy to:

                                        Katharine E. Bachman, Esq.
                                        Hale and Dorr LLP
                                        60 State Street
                                        Boston, MA  02109

<PAGE>

                                 LEASE AGREEMENT

                                     Between

                         TRINET PROPERTY PARTNERS, L.P.
                                   as Landlord

                                       and

                          TRANSKARYOTIC THERAPIES, INC.
                                    as Tenant

                         Dated as of February ___, 2001

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                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                            Page
<S>                                                                        <C>
1.  DEMISE OF PREMISES; CONDITION OF PREMISES; QUIET ENJOYMENT:.........      4
2.  USE:................................................................      4
3.  TERM:...............................................................      5
4.  RENTAL:.............................................................      6
5.  PROPERTY TAXES:.....................................................      7
6.  OPERATING EXPENSES:.................................................      8
7.  NET LEASE; NON-TERMINABILITY:.......................................      8
8.  REPAIRS, MAINTENANCE AND REPLACEMENTS:..............................      9
9.  DESTRUCTION, DAMAGE OR CONDEMNATION:...............................      11
10. INSURANCE, HOLD HARMLESS AND INDEMNIFICATION:......................      12
11. COMPLIANCE WITH LAWS, COVENANTS:...................................      14
12. [INTENTIONALLY OMITTED]............................................      16
13. ARBITRATION:.......................................................      16
14. EVENTS OF DEFAULT:.................................................      17
15. REMEDIES:..........................................................      18
16. SUBORDINATION; NON-DISTURBANCE; MORTGAGEE PROTECTION:..............      20
17. LANDLORD'S RIGHT OF ENTRY:.........................................      21
18. NOTICES:...........................................................      22
19. ESTOPPEL CERTIFICATE...............................................      23
20. MECHANICS' LIENS:..................................................      23
21. END OF TERM:.......................................................      24
22. ALTERATIONS:.......................................................      25
23. MEMORANDUM OF LEASE:...............................................      28
24. SUBLETTING/ASSIGNMENT:.............................................      28
25. HAZARDOUS MATERIAL:................................................      30
26. [INTENTIONALLY OMITTED]............................................      33
27. GRANTING OF EASEMENTS:.............................................      33
28. LETTER OF CREDIT:..................................................      33
29. [INTENTIONALLY OMITTED]............................................      35
30. BROKERS:...........................................................      35
31. FINANCIAL REPORTING:...............................................      36
32. MISCELLANEOUS PROVISIONS:..........................................      37
</TABLE>

EXHIBIT A. LEGAL DESCRIPTION - REAL ESTATE
EXHIBIT B. FORM OF LETTER OF CREDIT
EXHIBIT C. TENANT'S PERSONAL PROPERTY

<PAGE>

     LEASE AGREEMENT ("LEASE") made and entered into as of February _, 2001, by
and between TRINET PROPERTY PARTNERS, L.P., a Delaware limited partnership d/b/a
TriNet Property Partners Limited Partnership, having an address c/o IStar
Financial Inc., 3480 Preston Ridge Road, Suite 575, Alpharetta, GA 30005-8891
("LANDLORD"), and TRANSKARYOTIC THERAPIES, INC., a Delaware corporation having
an address at 195 Albany Street, Cambridge, Massachusetts 02139 ("TENANT").

                                  DEFINITIONS

     The following terms shall have the following meanings for all purposes of
this Lease and shall be equally applicable to both the singular and plural forms
of the terms herein defined.

     "ADDITIONAL RENT" means all amounts, liabilities and obligations other than
Fixed Rent which Tenant assumes or agrees to pay under this Lease to Landlord or
others.

     "AFFILIATE" means, with respect to any Person, a Person who, directly or
indirectly, through one or more intermediaries, controls, or is controlled by or
is under common control with, such Person. The term "control" means the
possession, directly or indirectly, of the power to direct or cause the
direction of the management and policies of a Person, whether through the
ownership of voting securities, by contract or otherwise.

     "ANTENNAE" is defined in Section 12(a) of this Lease.

     "APPRAISAL REQUEST" is defined in Section 26(b) of this Lease.

     "BASIC LEASE INFORMATION" means the pages preceding this Lease which are
hereby incorporated by reference.

     "BUILDING" means the existing building located on the Land containing
approximately 47,586 square feet of floor area and commonly known as 76 Pacella
Road, Randolph, Massachusetts.

     "COMMENCEMENT DATE" is defined in the Basic Lease Information.

     "ENVIRONMENTAL LAWS" means the Resource Conservation and Recovery Act of
1976, as amended, 42 U.S.C. ss.ss.6901, ET SEQ. (RCRA), the Comprehensive
Environmental Response, Compensation and Liability Act of 1980, as amended by
the Superfund Amendments and Reauthorization Act of 1986, 42 U.S.C. ss.ss.9601
ET SEQ. (CERCLA), the Toxic Substance Control Act, as amended, 15 U.S.C.
ss.ss.2601 ET seq., the Federal Insecticide, Fungicide and Rodenticide Act, as
amended, 7 U.S.C. ss.ss.136 ET SEQ., the Occupational Safety & Health Act of
1970, as amended, 29 U.S.C. ss. 651 ET SEQ. (OSHA), and all applicable federal,
state and local environmental laws, ordinances, rules and regulations, as any of
the foregoing may have been or may be from time to time amended, supplemented or
supplanted, and any other federal, state or local laws, ordinances, rules and
regulations, now or hereafter existing relating to regulations or control of
Hazardous Material or materials.

<PAGE>

     "EVENT OF DEFAULT" is defined in Section 14 of this Lease.

     "EXCUSABLE DELAY" is defined in Section 9(b) of this Lease.

     "EXTENSION TERM" is defined in Section 3(b) of this Lease.

     "FIXED RENT" is defined in Section 4 of this Lease.

     "GAAP" means generally accepted accounting principles, consistently
applied.

     "HAZARDOUS MATERIALS" means substances defined as "hazardous substances",
"hazardous materials", "hazardous wastes" or "toxic substances" in any
applicable federal, state or local statute, rule, regulation or determination,
including but not limited to the Comprehensive Environmental Response,
Compensation and Liability Act of 1980, as amended, 42 U.S.C.ss.ss.9601, ET
SEQ.; the -- --- Hazardous Materials Transportation Act, 49 U.S.C.ss.ss.1801, ET
SEQ.; the Resource, Conservation and Recovery Act of 1976, 42 U.S.C. -- ---
ss.ss.6901, ET SEQ.; and asbestos, PCB's, radioactive substances, methane,
volatile hydrocarbons, petroleum or petroleum-derived -- --- substances or
wastes, radon, industrial solvents or any other material as may be specified in
applicable law or regulations.

     "IMPROVEMENTS" means all of the buildings (including the Building),
structures, improvements, and all building fixtures therein now or hereafter
located on the Land, including the Building.

     "INITIAL IMPROVEMENTS" is defined in Section 22 of this Lease.

     "LAND" means the land, but none of the Improvements thereon, described on
EXHIBIT A attached hereto.

     "LANDLORD" is defined in the introductory paragraph of this Lease.

     "LEASE" is defined in the introductory paragraph of this Lease.

     "LEASE EXPIRATION DATE" is defined in the Basic Lease Information.

     "LEASE YEAR" means the one-year period commencing on the Commencement Date
and ending at 11:59 p.m. Boston time on the date immediately prior to the first
anniversary of the Commencement Date, and each successive one-year period
thereafter during the Term.

     "LETTER OF CREDIT" is defined in Section 28(a) of this Lease.

     "MIFA MORTGAGE" means that certain Mortgage, Loan and Security Agreement
and Indenture of Trust dated as of March 1, 1985, as amended from time to time,
naming State Street Bank and Trust Company, as trustee, as mortgagee thereunder.

                                      -2-
<PAGE>

     "MORTGAGE" shall mean a mortgage on the Premises given by Landlord to a
Mortgagee to secure a loan, including the MIFA Mortgage and the UNUM Mortgage.

     "MORTGAGEE" shall mean any holder of a Mortgage with respect to the
Premises or any part thereof, including the mortgagees from time to time of the
MIFA Mortgage and the UNUM Mortgage.

     "NON-DISTURBANCE AGREEMENT" is defined in Section 16(a) of this Lease.

     "OPERATING EXPENSES" is defined in Section 6(a) of this Lease.

     "OVERDUE RATE" means 18% per annum or, if lower, the maximum annual
interest rate allowed by law for business or commercial loans (not primarily for
personal, family or household purposes).

     "PERMITTED ENCUMBRANCES" means:

     (a)  Any liens for taxes, assessments and other governmental charges and
          any liens of mechanics, materialmen and laborers for work or services
          performed or materials furnished in connection with the Premises,
          which are not due and payable;

     (b)  the easements, rights-of-way, encroachments, encumbrances, restrictive
          covenants or other matters of record as of the date of this Lease and
          which affect the title to the Premises or any part thereof; and

     (c)  this Lease and the rights of Tenant hereunder.

     "PERSON" means any individual, corporation, partnership, limited liability
company, joint venture, association, joint stock company, trust, trustee(s) of a
trust, unincorporated organization, or government or governmental authority,
agency or political subdivision thereof.

     "PREMISES" is defined in Section 1 of this Lease.

     "PRIMARY TERM" is defined in Section 3(a) of this Lease.

     "PROPERTY TAXES" is defined in Section 5(a)(i) of this Lease.

     "PROPERTY TAX STATEMENT" is defined in Section 5(a)(ii) of this Lease.

     "RENT" means Fixed Rent and Additional Rent.

     "ROOF" is defined in Section 12(a) of this Lease.

     "SITE ASSESSMENTS" is defined in Section 25(d) of this Lease.

     "SITE REVIEWERS" is defined in Section 25(d) of this Lease.

                                      -3-
<PAGE>

     "SUBORDINATION AGREEMENT" is defined in Section 16(a) of this Lease.

     "TENANT'S TRADE FIXTURES" means all personal property of Tenant in or on
the Premises which is not necessary for the operation of the Improvements.

     "TERM" means the Primary Term and the Extension Terms, if any.

     "UNUM MORTGAGE" means that certain Mortgage and Security Agreement dated as
of May 9, 1989, as amended from time to time, naming UNUM Life Insurance Company
as mortgagee thereunder.

1. DEMISE OF PREMISES; CONDITION OF PREMISES; QUIET ENJOYMENT:

     (a)  Landlord hereby demises and leases to Tenant, and Tenant hereby leases
          and rents from Landlord, the Land and the Improvements, together with
          any easements, rights, and appurtenances in connection therewith or
          belonging thereto (collectively, the "PREMISES").

     (b)  EXCEPT AS EXPRESSLY SET FORTH IN SECTION 8(B), TENANT ACKNOWLEDGES AND
          AGREES THAT THE LAND AND THE IMPROVEMENTS ARE LEASED TO TENANT IN "AS
          IS", "WHERE-IS" CONDITION, SUBJECT TO THE EXISTING STATE OF TITLE, AND
          WITHOUT EXPRESS OR IMPLIED WARRANTY OF LANDLORD WITH RESPECT TO THE
          CONDITION, QUALITY, REPAIR OR FITNESS OF THE PREMISES FOR A PARTICULAR
          USE OR TITLE THERETO. ALL SUCH WARRANTIES ARE HEREBY WAIVED AND
          RENOUNCED BY TENANT.

     (c)  Landlord covenants with Tenant, that upon the payment of the Fixed
          Rent and Additional Rent and the performance of all the terms of this
          Lease, Tenant shall, at all times during the Term, peaceably and
          quietly enjoy the Premises without any disturbance from Landlord or
          from any person claiming by, through, or under Landlord. Any exercise
          by Landlord of its rights to come upon the Premises as set forth in
          this Lease shall not constitute a violation of this Section.

2. USE:

     Tenant may use and occupy the Premises for research and development; light
manufacturing and assembly, including pharmaceutical manufacturing and assembly;
and administration and general office purposes. In all events, Tenant shall not
use or occupy the same, or knowingly permit them to be used or occupied,
contrary to any statute, rule, order, ordinance, requirement or regulation
applicable thereto, or in any manner which would violate any certificate of
occupancy affecting the same or which would make void or voidable any insurance
then in force with respect thereto, or which would cause structural injury to
the Premises or cause the value or usefulness of the Premises, or any portion
thereof, to diminish, or which would constitute a public or private nuisance or
waste, and Tenant agrees that it will promptly, upon discovery of any such use,
take all necessary steps to compel the discontinuance of such use. Tenant shall
not use, suffer or permit the Premises, or any portion thereof, to be

                                      -4-
<PAGE>

used by Tenant, any third party or the public, as such, without restriction or
in such manner as might impair Landlord's title to the Premises, or in such
manner as might reasonably make possible a claim or claims of adverse usage or
adverse possession by the public, as such, or third Persons, or of implied
dedication of the Premises, or any portion thereof. Nothing contained in this
Lease and no action by Landlord shall be construed to mean that Landlord has
granted to Tenant any authority to do any act or make any agreement that may
create any such third party or public right, title, interest, lien, charge or
other encumbrance upon the estate of the Landlord in the Premises, except
Permitted Exceptions.

3. TERM:

     (a)  The primary term of this Lease (the "PRIMARY TERM") shall be for a
          period of approximately ten (10) years, beginning on the Commencement
          Date and ending on the Lease Expiration Date.

     Tenant shall have the right, at its option, to renew the Primary Term of
this Lease, for up to two (2) renewal terms (each an "EXTENSION TERM"), which
shall renew the Primary Term for an additional five (5) years each. Each
Extension Term shall commence on the day after the expiration of the preceding
term and shall expire on the fifth (5th) anniversary of the Lease Expiration
Date, in the case of the first Extension Term, and on the tenth (10th)
anniversary of the Lease Expiration Date, in the case of the second Extension
Term. The option to renew the Term of this Lease as described above shall be
exercised by Tenant by written notice to Landlord given at least eighteen (18)
months prior to the Lease Expiration Date or expiration of the first Extension
Term, as the case may be. If such notice is not given in a timely fashion, the
option to renew this Lease shall terminate. Subject to the provisions of Section
4(a)(ii), the terms and conditions of this Lease shall apply to each Extension
Term with the same force and effect as if such Extension Term had originally
been included in the Primary Term of the Lease. The right of Tenant to the
Extension Terms shall be conditioned upon (i) Tenant not being in default under
this Lease beyond any applicable grace period on the date on which notice of
exercise of the renewal option is given and on the Lease Expiration Date or
expiration of the first Extension Term, as the case may be, and (ii) this Lease
being in full force and effect as of the Lease Expiration Date or expiration of
the first Extension Term, as the case may be.

     In the event that Tenant assigns or sublets its interest in fifty percent
(50%) or more of the floor area of the Premises pursuant to Section 24 and such
assignment or sublease is in force at any time during the twenty-four months
prior to the expiration of the Primary Term or any Extension Term, then any
remaining options for Extension Terms shall immediately terminate and such
assignee or subtenant shall only be permitted to occupy the Premises until the
expiration of the then current Primary Term or the first Extension Term, as
applicable. In calculating the measurement of the floor area of the Premises
which have been assigned or sublet pursuant to the foregoing sentence, subleases
or assignments to Affiliates of Tenant shall not be included, it being the
intention of the parties that assignments or subleases to Affiliates of the
Tenant shall not operate to cause the termination of Tenant's extension rights
as set forth herein.

                                      -5-
<PAGE>

4. RENTAL:

     (a)  Tenant shall pay to Landlord the following amounts as fixed monthly
          rent (the "FIXED RENT") for the Premises:

          (i)  During the Primary Term of this Lease, Tenant shall pay to
               Landlord the amount of Fixed Rent specified in the Basic Lease
               Information with respect to the Primary Term.

          (ii) During the Extension Terms, if any, Tenant shall pay to Landlord
               the amount of Fixed Rent specified in the Basic Lease Information
               with respect to the Extension Terms, which amount shall be
               calculated in accordance with the provisions of Section 26.

     (b)  Throughout the Term of this Lease, Tenant shall pay, as Additional
          Rent, all other amounts of money and charges required to be paid by
          Tenant under this Lease, whether or not such amounts of money or
          charges are designated Additional Rent.

     (c)  Tenant shall pay all Fixed Rent to Landlord, in advance, on or before
          the first day of each and every calendar month during the Term of this
          Lease. Tenant shall pay all Additional Rent when due. Tenant shall pay
          all Fixed Rent to Landlord without notice, demand, deduction or
          offset, in lawful money of the United States of America, at the
          address of Landlord specified in the Basic Lease Information or, at
          the election of Tenant, by wire transfer or other electronic means (or
          otherwise so there are collected funds available to Landlord on the
          due date), or to such other person or at such other place as Landlord
          may from time to time designate in writing.

     (d)  Tenant acknowledges that the late payment by Tenant of any Fixed Rent
          or reimbursement of Additional Rent advanced by Landlord will cause
          Landlord to incur costs and expenses, the exact amount of which is
          extremely difficult and impractical to fix. If any Fixed Rent or
          Additional Rent advanced by Landlord is not received by Landlord on or
          before its due date or if reimbursement for Additional Rent advanced
          by Landlord is not received by Landlord within five (5) business days
          after written demand, Tenant shall pay to Landlord interest on such
          delinquent amount at the Overdue Rate until paid. In no event shall
          payment of interest at the Overdue Rate be deemed to grant to Tenant a
          grace period or extension of time within which to pay any Rent or
          prevent Landlord from exercising any right or enforcing any remedy
          available to Landlord upon Tenant's failure to pay all Rent due under
          this Lease on its due date or within any applicable grace or cure
          period, including the right to terminate this Lease. All amounts of
          money payable by Tenant to Landlord hereunder, if not paid when due,
          shall bear interest from the due date thereof until paid at the
          Overdue Rate.

     (e)  It is the intention of Landlord and Tenant that, except as otherwise
          expressly provided in this Lease, the Fixed Rent payable by Tenant to
          Landlord during the entire Term of this Lease shall be absolutely net
          of all costs and expenses incurred in connection with the management,
          operation, maintenance and repair of the Premises in accordance with
          this Lease. Except as otherwise expressly set forth herein, Landlord
          shall have no obligations or liabilities whatsoever with respect to
          the operation, maintenance or repair of the Premises during the term
          of this Lease, and Tenant shall operate, maintain and repair the
          Premises in accordance with this

                                      -6-
<PAGE>

          Lease and shall pay all costs and expenses incurred in connection
          therewith before such costs or expenses become delinquent. Without
          limiting the generality of the foregoing, throughout the entire term
          of this Lease, Tenant shall pay, as Additional Rent, all premiums for
          all property and liability insurance covering the Premises, all
          Property Taxes (as defined in Section 5(a)(i)) and all Operating
          Expenses (as defined in Section 6(b)) that accrue during or are
          allocable to the terms of this Lease.

5. PROPERTY TAXES:

     (a)  As used in this Section, these words and terms shall have the
          following meanings:

          (i)  "PROPERTY TAXES" shall mean all taxes, assessments and
               betterments levied, assessed or imposed by any governmental
               authority upon or against the Premises, or payments in lieu
               thereof, including reasonable expenses, which shall include,
               without limitation, any and all payments due to the Town of
               Randolph, Massachusetts for traffic impact fees, water and sewer
               charges and fees, use charges, fire service fees and similar
               payments, as well as all fees of attorneys, appraisers and other
               consultants incurred in connection with any efforts to obtain
               abatements or reductions which may be requested by Tenant.
               Property Taxes shall not include estate, income or franchise
               taxes of Landlord. If, at any time during the Term of this Lease,
               as it may be extended hereunder, any tax or excise on rents or
               other taxes, however described, are levied or assessed against
               Landlord with respect to the rent reserved hereunder in
               substitution for, real estate taxes assessed or levied on the
               Premises, or payments in lieu thereof, such tax or excise on
               rents shall be included in Taxes. For purposes hereof, any
               assessments and betterments shall be amortized, with interest,
               over the longest period permitted by law.

          (ii) "PROPERTY TAX STATEMENT" shall mean a statement in writing signed
               by Landlord, setting forth the amounts payable by Tenant for a
               specified calendar year, tax year or other tax period pursuant to
               this Section and delivered to Tenant not later than 120 days
               after the end of the calendar year, tax year or other tax period
               to which such statement relates, accompanied by a copy of the
               applicable tax bills.

     (b)  During the Term and at the times set forth herein, Tenant shall pay
          directly to the taxing authority and before the due date thereof, as
          Additional Rent, all Property Taxes with respect to the Premises. In
          the event of an abatement or refund in real estate taxes, Tenant shall
          be entitled thereto after deduction by Landlord of any reasonable
          costs paid and incurred in connection with the abatement or refund by
          Landlord. The Tenant shall provide Landlord with evidence of payments
          made to the taxing authority within thirty (30) days after payment of
          same.

     (c)  If Tenant deems that it is reasonable to pursue an abatement of
          Property Taxes and Landlord, in its sole and absolute discretion,
          determines not to do so, then Tenant may apply for an abatement in the
          name of Landlord, with attorneys and appraisers reasonably acceptable
          to Landlord, at the sole expense of Tenant, except that if an
          abatement is obtained, these expenses shall be paid from the
          abatement. Tenant may pursue an abatement of taxes pursuant to this
          Section only if (a) such proceeding will not cause the Premises to be
          subject to any lien, charge or liability of any kind against or expose
          the Premises to a material risk of forfeiture, (b) the

                                      -7-
<PAGE>

          failure to so comply will not subject Landlord or any Mortgagee to any
          liability, civil, administrative or criminal fines or penalties, and
          (c) Tenant prosecutes such proceeding with due diligence, in
          compliance with all Applicable Laws and in good faith.

     (d)  Any obligations under this Section which shall not have been paid at
          the termination or earlier expiration of the Term of this Lease shall
          survive such termination or earlier expiration and shall be paid by
          Tenant within fifteen (15) days after receipt of written notice from
          Landlord of any amounts owed. If Tenant does not pay such amounts with
          such fifteen (15) day period, Tenant also shall pay interest on such
          amounts at the Overdue Rate from the end of such fifteen (15) day
          period until paid.

6. OPERATING EXPENSES:

     (a)  Tenant shall, at Tenant's sole cost and expense, supply the Premises
          with electricity, heating, ventilating and air conditioning, water,
          natural gas, lighting, replacement for all lights, restroom supplies,
          telephone service, window washing, security service, janitor,
          scavenger and disposal services (including hazardous and biological
          waste disposal, if necessitated by Tenant's operations in the
          Premises), and such other services as Tenant determines to furnish to
          the Premises. All of such utilities, supplies and services shall be
          ordered directly by and in the name of Tenant, and Tenant shall pay
          directly any fees or charges associated therewith (including any
          utility deposits or similar expenses). Landlord shall not be in
          default hereunder or be liable for any damage or loss directly or
          indirectly resulting from, nor shall the Fixed Rent or Additional Rent
          be abated or a constructive or other eviction be deemed to have
          occurred by reason of, the installation, use or interruption of use of
          any equipment in connection with the furnishing of any of the
          foregoing services, any failure to furnish or delay in furnishing any
          such services, whether such failure or delay is caused by accident or
          any condition beyond the control of Landlord or Tenant or by the
          making of repairs or improvements to the Premises, or any limitation,
          curtailment, rationing or restriction on use of water, electricity,
          gas or any form of energy serving the Premises, whether such results
          from mandatory governmental restriction or voluntary compliance with
          governmental guidelines.

     (b)  Tenant shall pay as Additional Rent: to the Persons entitled thereto,
          on or before the applicable due dates thereof, the full cost of all of
          the services referred to in Section 6(a) and all other utilities and
          services supplied to the Premises (collectively, "OPERATING
          EXPENSES").

     (c)  Any obligations under this Section which shall not have been paid at
          the termination or earlier expiration of the Term of this Lease shall
          survive such termination or earlier expiration and shall be paid by
          Tenant within fifteen (15) days after receipt of written notice from
          Landlord of any amounts owed. If Tenant does not pay such amounts with
          such fifteen (15) day period, Tenant also shall pay interest on such
          amounts at the Overdue Rate from the end of such fifteen (15) day
          period until paid.

7. NET LEASE; NON-TERMINABILITY:

                                      -8-
<PAGE>

     (a)  This is a net lease and the Fixed Rent, Additional Rent and all other
          sums payable hereunder by Tenant shall be paid without notice (except
          as expressly provided herein), demand, set-off, counterclaim,
          abatement, suspension, deduction or defense. It is the intention of
          the parties hereto that the Fixed Rent shall be an absolutely net
          return to Landlord throughout the term of this Lease.

     (b)  This Lease shall not terminate, nor shall Tenant have any right to
          terminate this Lease, nor shall Tenant be entitled to any abatement or
          reduction of Rent hereunder (except as otherwise expressly provided in
          this Lease), nor shall the obligations of Tenant under this Lease be
          affected, by reason of (i) subject to Section 9, any damage to or
          destruction of all or any part of the Premises from whatever cause,
          (ii) subject to Section 9, the taking of the Premises or any portion
          thereof by condemnation, requisition or otherwise, (iii) the
          prohibition, limitation or restriction of Tenant's use of all or any
          part of the Premises, or any interference with such use, or (iv) any
          default on the part of Landlord under this Lease, or under any other
          agreement to which Landlord and Tenant may be parties. It is the
          intention of the parties hereto that the obligations of Tenant
          hereunder shall be separate and independent covenants and agreements,
          that the Fixed Rent, the Additional Rent and all other sums payable by
          Tenant hereunder shall continue to be payable in all events and that
          the obligations of Tenant hereunder shall continue unaffected unless
          the requirement to pay or perform the same shall have been terminated
          pursuant to any express provision of this Lease.

     (c)  Tenant agrees that it will remain obligated under this Lease in
          accordance with its terms, and that it will not take any action to
          terminate, rescind or avoid this Lease, notwithstanding (i) the
          bankruptcy, insolvency, reorganization, composition, readjustment,
          liquidation, dissolution or winding-up or other proceeding affecting
          Landlord or its successor in interest, or (ii) any action with respect
          to this Lease which may be taken by any trustee or receiver of
          Landlord or its successor in interest or by any court in any such
          proceeding.

     (d)  Tenant waives all rights which may now or hereafter be conferred by
          law to any abatement, suspension, deferment or reduction of the Fixed
          Rent, Additional Rent or any other sums payable under this Lease.

8. REPAIRS, MAINTENANCE AND REPLACEMENTS:

     (a)  Except for those items set forth in Section 8(b) which are the
          responsibility of Landlord, Tenant shall, at its own sole cost and
          expense, keep each and every portion of the Premises, including the
          Building and grounds, in good repair and condition, reasonable wear
          and tear and damage due to fire or other casualty excepted, at all
          times on and after commencement of the Term to and including the date
          of the termination of the Term, by lapse of time or otherwise, so as
          to preserve and protect the useful life, utility and value of the
          Premises, and in all events so as to preserve the effectiveness of any
          warranty relating thereto. Without limiting the foregoing, Tenant
          shall promptly and adequately repair, maintain and replace the
          electrical, sprinkler, plumbing and mechanical systems; the septic
          system and/or sewer system servicing the Building; utility
          connections; the parking lot, driveways and sidewalks on the Premises
          and any

                                      -9-
<PAGE>

          components thereof, and striping of the parking lot; lighting in and
          around the Premises; interior and exterior glass; glazing systems and
          through-wall flashing; water tightness of all walls; landscaping; and
          all damaged or broken fixtures and appurtenances. Tenant shall, upon
          Landlord's request, deliver to Landlord a written statement showing
          all removals and replacements of any such systems or components during
          the preceding calendar year, including manufacturers, model numbers,
          and serial numbers in order to establish a current list of what assets
          are owned by whom. Landlord may, upon five (5) business days prior
          notice, cause independent private inspectors, qualified in the
          specific discipline, to make inspections of any building component or
          part or segments thereof to determine Tenant's compliance under this
          Section 8(a). The cost of such inspection shall be borne by Landlord
          unless the inspection reveals more than DE MINIMIS non-compliance with
          this Section 8(a), in which case the cost of the inspection shall be
          borne by Tenant. Landlord shall endeavor to minimize the interference
          with Tenant's use of the Premises during any such inspection.

     (b)  Landlord, at its sole cost and expense, shall be responsible for the
          repair, maintenance and, if necessary, replacement of the roof and
          roof membrane of the Building and the foundation, floor slab, exterior
          walls and interior support columns of the Building, PROVIDED that if
          any such repairs, maintenance or replacements are caused by or result
          from the negligence or willful misconduct of Tenant, then Landlord
          shall perform such work at Tenant's cost and expense. If Tenant is
          responsible for payment of any repairs, maintenance or replacements
          pursuant to the proviso of the preceding sentence, Tenant shall remit
          payment to Landlord for such costs and expenses within fifteen (15)
          days of receipt of a reasonably detailed invoice therefor from
          Landlord, and any amounts outstanding after such due date shall accrue
          interest at the Overdue Rate. Landlord shall only be obligated to
          perform such repairs, maintenance and replacements if Landlord
          receives actual knowledge (which shall include receipt of written
          notice from Tenant) of the need for same.

     (c)  Landlord may, but is not required to, after five (5) days notice to
          Tenant (except in the case of emergency, in which case Tenant shall be
          given notice contemporaneously with entry), enter the Premises and
          make any repairs, alterations, improvements, additions, replacements
          or maintenance as Landlord deems reasonably necessary and which are
          the responsibility of Tenant pursuant to the provisions of this Lease
          but which Tenant failed to do as required in this Lease after notice
          and the expiration of any applicable grace period, and Tenant shall
          pay Landlord as Additional Rent forthwith upon being billed for same
          by Landlord the cost thereof plus an administrative fee of five
          percent (5%) of such cost, such fee representing Landlord's reasonable
          overhead, fees and other costs or expenses arising from Landlord's
          involvement with such repairs, alterations, improvements, additions,
          replacements and maintenance. Such amount shall be paid by Tenant
          within fifteen (15) days after receipt of written notice from Landlord
          of any amounts owed. If Tenant does not pay such amounts with such
          fifteen (15) day period, Tenant also shall pay interest on such
          amounts at the Overdue Rate from the end of such fifteen (15) day
          period until paid.

     (d)  Tenant shall maintain on the Premises, and turn over to Landlord upon
          expiration or termination of this Lease, current operating manuals for
          the equipment now or hereafter

                                      -10-
<PAGE>

          located on the Premises which were either provided by Landlord or
          obtained by Tenant in connection with its maintenance and repair
          obligations hereunder.

     (e)  Tenant covenants not to install any underground storage tank on the
          Land.

9. DESTRUCTION, DAMAGE OR CONDEMNATION:

     (a)  If (i) all or substantially all of the Premises shall be damaged by
          fire or other casualty or taken under power of eminent domain or
          rendered unusable in Tenant's business by reason of a governmental
          order or decree, (ii) the Premises remaining after damage by fire or
          other casualty or taking by eminent domain is, in the reasonable
          judgment of Tenant, insufficient for the feasible operation of
          Tenant's business, or (iii) in the exercise of reasonable judgment of
          Tenant (or, in the last two years (2) of the Term, Landlord), repair
          and restoration of the Building after damage by fire or other casualty
          or taking by eminent domain will require more than one hundred twenty
          (120) days, then Tenant (and in the last two years of the Term,
          Landlord) shall have the right, exercisable within thirty (30) days of
          receipt of notice of such casualty or condemnation, to terminate this
          Lease. If Landlord elects to terminate this Lease in the last two (2)
          years of any term prior to the last Extension Term, such election may
          be nullified by Tenant giving notice to Landlord exercising its right
          to the next Extension Term within thirty (30) days after Landlord's
          election.

     (b)  If, after damage by fire or other casualty or taking by eminent
          domain, neither party has exercised its rights granted within this
          Section 9 to terminate this Lease, then this Lease shall remain in
          effect and Landlord shall proceed with reasonable diligence, and at
          its expense (but only to the extent of insurance proceeds recovered
          and made available to Landlord plus the amount of any deductible
          actually paid by Tenant to Landlord with respect to casualty and only
          to the extent of a condemnation award actually received with respect
          to eminent domain proceedings), to cause the Premises to be repaired
          and restored as nearly as possible to the condition in which they were
          immediately prior to the casualty or condemnation, subject to
          applicable laws and regulations. Landlord shall not be liable for
          delays in the making of any repairs to the Premises which are due to
          governmental regulations, casualties and strikes, unavailability of
          labor and materials, and other causes beyond the control of Landlord
          ("EXCUSABLE DELAY"), nor shall Landlord be liable for any
          inconvenience or annoyance to Tenant or injury to the business of
          Tenant resulting from reasonable delays in repairing such damage.
          Notwithstanding anything to the contrary herein, if Excusable Delay
          continues for more than thirty (30) days and if as a result Landlord
          will not complete restoration of the Premises within the time period
          contemplated by Section 9(d), then Tenant may terminate this Lease on
          written notice to Landlord.

     (c)  If the Premises, or any part thereof, shall have been rendered unfit
          for use and occupation hereunder, or if Tenant is denied reasonable
          access to the Premises, in either case by reason of casualty or
          condemnation, and the Lease has not otherwise been terminated in
          accordance with this Section 9, then Fixed Rent, Additional Rent and
          other charges due hereunder, or a just and proportionate part thereof,
          according to the nature and extent to which

                                      -11-
<PAGE>

          the Premises shall have been so rendered untenantable, shall be
          suspended or abated until the Premises shall have been restored as
          nearly as practicable to the condition in which they were immediately
          prior to such casualty or condemnation, subject to applicable laws and
          regulations.

     (d)  If neither party has exercised its rights granted within this
          Section 9 to terminate this Lease, and Landlord has proceeded to
          repair and restore the Premises as provided above and does not
          substantially complete repair and restoration of the Premises to
          substantially the same condition which they were in prior to the
          casualty or condemnation within two hundred seventy (270) days after
          such damage, then Tenant may terminate this lease by notice to
          Landlord within fifteen (15) days after the expiration of said two
          hundred seventy (270) day period, Tenant's right of termination being
          its sole remedy with respect to Landlord's failure to restore.

     (e)  In the event of any termination of this Lease pursuant to Section 9,
          this Lease and the Term hereof shall expire as of such effective
          termination date and the Fixed Rent, Additional Rent, and other
          charges shall be apportioned as of such effective termination date.

     (f)  If the Premises or any part thereof shall be damaged by fire or other
          casualty or taken under power of eminent domain, each party hereto
          shall give prompt written notice to the other.

     (g)  Tenant is required by the terms hereof to insure its own personal
          property, and all repairs to and replacements of Tenant's personal
          property shall be made by and at the expense of Tenant, and Landlord
          shall have no liability or responsibility therefor.

10. INSURANCE, HOLD HARMLESS AND INDEMNIFICATION:

     (a)  Landlord shall not be liable to Tenant for any damage to or loss or
          theft of any property or for any bodily or personal injury, illness or
          death of any person in, on or about the Premises arising at any time
          and from any cause whatsoever, except to the extent caused by the
          gross negligence or willful misconduct of Landlord. Tenant waives all
          claims against Landlord arising from any liability described in this
          Section 10(a), except to the extent caused by the gross negligence or
          willful misconduct of Landlord.

     (b)  Tenant shall be solely liable for, and hereby agrees to indemnify and
          defend Landlord against and hold Landlord harmless from all, claims,
          demands, liabilities, damages, losses, costs and expenses, including
          reasonable attorneys' fees and disbursements, arising from or related
          to Tenant's use or occupancy of the Premises, or any condition of the
          Premises arising from Tenant's use or occupancy of the Premises or for
          which Tenant is otherwise responsible, or any default in the
          performance of Tenant's obligations hereunder, or any damage to any
          property (including property of employees and invitees of Tenant) or
          any bodily or personal injury, illness or death of any person
          (including employees and invitees of Tenant) occurring in, on or about
          the Premises or any part thereof or any part of the building or the
          land constituting a part of the Premises (except to the extent caused
          by the negligence or willful misconduct of Landlord) or occurring
          outside the Premises when such damage, bodily or personal injury,
          illness or death is caused by any act or omission of Tenant or its
          agents, officers, employees, contractors, invitees

                                      -12-
<PAGE>

          or licensees. This Section 10(b) shall survive the termination of this
          Lease with respect to any damage, bodily or personal injury, illness
          or death occurring prior to such termination, for a period of six (6)
          years. THE WAIVER PROVISION IN SECTION 10(a) AND THE INDEMNITY
          PROVISION IN THIS SECTION 10(b) ARE INTENDED TO EXCULPATE AND
          INDEMNIFY LANDLORD FROM AND AGAINST ANY LIABILITY OF LANDLORD BASED ON
          ANY APPLICABLE DOCTRINE OF STRICT LIABILITY.

     (c)  Tenant shall, at all times and during the term of this Lease and at
          Tenant's sole cost and expense, obtain and keep in force (i)
          commercial general liability insurance, including contractual
          liability (specifically covering this Lease), cross liability, fire
          legal liability, and premises operations, all on an "occurrence"
          policy form, with a minimum combined single limit in the amount of
          $5,000,000 per occurrence for bodily or personal injury to, illness
          of, or death of persons and damage to property occurring in, on or
          about the Premises, and shall not have a deductible amount greater
          than $10,000, and (ii) business interruption insurance insuring that
          the Fixed Rent will be paid to Landlord for up to one year if the
          Premises are destroyed or rendered untenantable by any cause insured
          against (it being understood that the existence of such insurance does
          not reduce Tenant's obligation to pay Fixed Rent without diminution,
          except as expressly provided for in this Lease). The insurance
          policies specified in the foregoing clauses (i) and (ii) shall name
          Landlord and any Mortgagees as additional insureds. Tenant shall, at
          Tenant's sole cost and expense, be responsible for insuring Tenant's
          furniture, equipment, fixtures, computers, office machines, personal
          property and Tenant's Trade Fixtures.

     (d)  Tenant shall, at all times during the term of this Lease and at
          Tenant's sole cost and expense, obtain and keep in force worker's
          compensation and employer's liability insurance in all states in which
          the Premises and any other operations of Tenant are located and any
          other state in which Tenant may be subject to any statutory or other
          liability arising in any manner whatsoever out of the actual or
          alleged employment of others.

     (e)  Tenant shall, at all times during the term of this Lease and at
          Tenant's sole cost and expense, obtain and keep in force (i) insurance
          against loss or damage to the Premises by fire and all other risks of
          physical loss (including flood coverage, if the Premises are located
          in a Special Flood hazard area, as determined by the Secretary of
          Housing and Urban Development) covered by insurance of the type now
          known as "all risk," with difference in conditions coverage, in an
          amount not less than the full replacement cost of the Premises
          (without deduction for depreciation), with ninety percent (90%)
          co-insurance, with deductibles of no more than $10,000, including the
          cost of debris removal and such endorsements as Landlord may
          reasonably require, with a so-called Standard Mortgagee Clause and
          containing "Replacement Cost," "Inflation Guard" and "Agreed Amount"
          endorsements; (ii) boiler and machinery insurance covering pressure
          vessels, air tanks, boilers, machinery, pressure piping, heating,
          ventilation and air conditioning equipment, and elevator and escalator
          equipment, in the amount of full replacement cost, PROVIDED the
          Premises contain equipment of such nature and insurance against loss
          of occupancy or use arising from any breakdown of any such items, in
          such amounts as Landlord may reasonably determine; and (iii) insurance
          in amounts and against such other risks as Landlord or Mortgagee may
          reasonably require and against such risks as are customarily

                                      -13-
<PAGE>

          insured against by operators of similar properties. The insurance
          policy specified in this Section 10(e) shall name Landlord and any
          Mortgagee as loss payee.

     (f)  All policies of insurance shall be written by a company or companies
          that have been rated as follows by at least 2 out of 3 rating
          agencies: (i) a Best's rating of A:VIII, A:X or better; (ii) a Moody's
          rating of A or better; and/or (iii) a Standard & Poor's rating of A or
          better. All insurance required to be maintained by Tenant under this
          Section 10 shall be selected by the Tenant and approved by the
          Landlord and any Mortgagee. Each policy to be maintained by Tenant
          shall expressly provide that the policy shall not be canceled or
          altered without thirty (30) days' prior written notice to Landlord and
          any Mortgagee and shall remain in effect notwithstanding any such
          cancellation or alteration until such notice shall have been given to
          Landlord and such period of thirty (30) days shall have expired. All
          insurance under this Section 10 to be maintained by Tenant shall be
          primary and noncontributing with any insurance which may be carried by
          Landlord, and shall afford coverage for all claims based on any act,
          omission, event or condition that occurred or arose (or the onset of
          which occurred or arose) during the policy period other than as a
          result of the negligence or willful misconduct of Landlord. Upon the
          issuance of each such policy to be maintained by Tenant, Tenant shall
          deliver a certificate of insurance to Landlord and a copy of each such
          policy for retention by Landlord. In the case of insurance about to
          expire, Tenant shall deliver renewal certificates not less than ten
          (10) days prior to their respective dates of expiration. Tenant may
          maintain the insurance required by this Section 10 under blanket
          insurance policies, PROVIDED that the insurer provides evidence that
          an amount necessary to meet the requirements of this Section 10 has
          been reserved for the Premises.

     (g)  Tenant waives to the extent allowed by the insurer on behalf of all
          insurers under all policies of property, liability and other insurance
          (excluding workers' compensation) now or hereafter carried by Tenant
          insuring or covering the Premises, or any portion or any contents
          thereof, or any operations therein, all rights of subrogation which
          any insurer might otherwise, if at all, have to any claims of Tenant
          against Landlord. Landlord waives on behalf of all insurers under all
          policies of property, liability and other insurance (excluding
          workers' compensation) now or hereafter carried by Landlord insuring
          or covering the Premises or any portion or any contents thereof, or
          any operations therein, all rights of subrogation which any insurer
          might otherwise, if at all, have to any claims of Landlord against
          Tenant. Tenant shall use its best efforts to procure from each of the
          insurers under all policies of property, liability and other insurance
          (excluding workers' compensation) now or hereafter carried by Tenant
          insuring or covering the Premises, or any portion or any contents
          thereof, or any operations therein, a waiver of all rights of
          subrogation which the insurer might otherwise, if at all, have to any
          claims of Tenant against Landlord, to the extent that such a waiver
          can be obtained without payment by Tenant.

11. COMPLIANCE WITH LAWS, COVENANTS:

     (a)  Subject to the provisions of Section 8(b) above, Tenant shall
          throughout the Term promptly comply or cause compliance with or remove
          or cure any violation of any and all

                                      -14-
<PAGE>

          present and future laws, including, without limitation, the
          Occupational Safety and Health Act of 1970, as the same may be amended
          from time to time, ordinances (zoning or otherwise), orders, rules,
          regulations and requirements of all Federal, State, municipal and
          other governmental bodies having jurisdiction over the Premises and
          the appropriate departments, commissions, boards and officers thereof,
          and the orders, rules and regulations of the Board of Fire
          Underwriters where the Premises are situated, or any other body now or
          hereafter constituted exercising lawful or valid authority over the
          Premises, or any portion thereof, or the sidewalks, curbs, roadways,
          alleys or entrances adjacent or appurtenant thereto, or exercising
          authority with respect to the use or manner of use of the Premises, or
          such adjacent or appurtenant facilities, and whether the compliance,
          curing or removal of any such violation and the costs and expenses
          necessitated thereby shall have been foreseen or unforeseen, ordinary
          or extraordinary, and whether or not the same shall involve any change
          in governmental policy, and irrespective of the amount of the costs
          thereof. Tenant, at its sole cost and expense, shall comply with all
          agreements, contracts, easements, restrictions, reservations or
          covenants, if any, running with the land, or hereafter created by
          Tenant or consented to, in writing, by Tenant or requested, in
          writing, by Tenant. Tenant shall also comply with, observe and perform
          all provisions and requirements of all policies of insurance at any
          time in force with respect to the Premises and required to be obtained
          and maintained under the terms of Section 10 hereof and shall comply
          with all development permits issued by governmental authorities issued
          in connection with development of the Premises.

     (b)  If Tenant shall at any time fail to pay any Property Taxes in
          accordance with the provisions of Section 5, or to take out, pay for,
          maintain and deliver any of the insurance policies or certificates of
          insurance provided for in Section 10, or shall fail to make any other
          payment or perform any other act on its part to be made or performed
          hereunder after any required notice and the expiration of any
          applicable grace period, then Landlord, after seven (7) business days
          prior written notice to Tenant (or without notice in situations where
          Landlord determines, in the exercise of commercially reasonable
          discretion, that delay is likely to cause harm to Landlord's interest
          in the Premises), and without waiving or releasing Tenant from any
          obligation of Tenant contained in this Lease, may, but shall be under
          no obligation to do so,

     (i)  make such payment of Property Taxes on behalf of Tenant;

     (ii) take out, pay for and maintain any of the insurance policies to be
          obtained by Tenant pursuant to Section 10; or

     (iii) make any other payment or perform any other act on Tenant's part to
          be paid or performed hereunder, except that any time permitted to
          Tenant to perform any act required to be performed by Tenant hereunder
          shall be extended for such period as may be necessary to effectuate
          such performance, PROVIDED Tenant is continuously, diligently and in
          good faith prosecuting such performance.

                                      -15-
<PAGE>

          Landlord may enter upon the Premises for any such purpose and take all
          such action therein or thereon as may be necessary therefor. All sums,
          reasonable under the circumstances, actually so paid by Landlord and
          all costs and expenses, including reasonable attorney's fees, incurred
          by Landlord in connection with the performance of any such act,
          together with interest thereon at the Overdue Rate, shall be paid by
          Tenant to Landlord on demand and submission of reasonable evidence of
          such expenditures. Landlord shall not be limited in the proof of any
          damages which Landlord may claim against Tenant arising out of or by
          reason of Tenant's failure to provide and keep in force insurance as
          aforesaid, to the amount of the insurance premium or premiums not paid
          or incurred by Tenant, and which would have been payable upon such
          insurance.

     (c)  Tenant covenants and agrees that it shall, at its sole cost and
          expense, comply with all provisions of the Americans With Disabilities
          Act of 1990 as they apply to the Premises and which require
          modifications to the Premises during the Term.

12. [INTENTIONALLY OMITTED]

13. ARBITRATION:

     At the election of either Landlord or Tenant, any controversy or claim
arising out of this Lease, or any dispute or matter that this Lease provides may
be submitted to arbitration, shall be settled by arbitration in accordance with
the Commercial Arbitration Rules of the American Arbitration Association, and
judgment upon the award rendered by any arbitrator may be entered in any court
having jurisdiction thereof; PROVIDED, HOWEVER, that this Section 13 shall not
limit the right of either Landlord or Tenant to obtain any provisional remedy
(including, without limitation, injunctive relief, writs for recovery of
possession similar relief) from any court of competent jurisdiction, as may be
necessary in the sole judgment of the party seeking such provisional remedy, to
protect such party's interests. The arbitrator shall not have the right to add
to, detract from, or in any way alter the provisions of the Lease. Any party
desiring to submit a controversy to arbitration shall give notice of intention
to so by giving notice to the other party in accordance with the provisions
hereof and shall, in accordance with the Commercial Arbitration Rules of the
American Arbitration Association, submit such controversy to arbitration by
submission to the American Arbitration Association at the same time. Arbitration
proceedings shall be conducted by a single arbitrator at the Regional Office of
the American Arbitration Association in Boston, Massachusetts, or at any other
location which the parties may mutually designate. The costs and expenses of
arbitration shall be paid by the party against whom the arbitrator's decision is
adverse.

14. EVENTS OF DEFAULT:

     The occurrence of any one or more of the following events (each an "EVENT
OF DEFAULT") shall constitute a breach of this Lease by Tenant:

     (a)  Tenant fails to pay any Fixed Rent as and when such Fixed Rent becomes
          due and such failure continues for five (5) business days after
          written notice thereof has been delivered to Tenant; or

                                      -16-
<PAGE>

     (b)  Tenant fails to pay any Additional Rent as and when such Additional
          Rent becomes due and payable and such failure continues for more than
          fifteen (15) days after Landlord gives written notice thereof to
          Tenant; or

     (c)  Tenant fails to deliver the Letter of Credit or to maintain the Letter
          of Credit at the times, in the manner and in the amounts required
          pursuant to Section 28; or

     (d)  Tenant fails to perform or breaches any other agreement or covenant of
          this Lease to be performed or observed by Tenant as and when
          performance or observance is due and such failure or breach continues
          for more than thirty (30) days after Landlord provides written notice
          thereof to Tenant; PROVIDED, HOWEVER, that if, by the nature of such
          agreement or covenant, such failure or breach cannot reasonably be
          cured within such period of thirty (30) days, an Event of Default
          shall not exist as long as Tenant commences with due diligence and
          dispatch the curing of such failure or breach within such period of
          thirty (30) days and, having so commenced, thereafter prosecutes with
          diligence and dispatch and completes the curing of such failure or
          breach within 260 days after Tenant's acquisition of knowledge or
          notice of such failure or breach; or

     (e)  Tenant (i) files, or consents by answer or otherwise to the filing
          against it of, a petition for relief or reorganization or arrangement
          or any other petition in bankruptcy or for liquidation or to take
          advantage of any bankruptcy, insolvency or other debtors' relief law
          of any jurisdiction, (ii) makes an assignment for the benefit of its
          creditors, (iii) consents to the appointment of a custodian, receiver,
          trustee or other officer with similar powers of Tenant or of any
          substantial part of Tenant's property, or (iv) takes action for the
          purpose of any of the foregoing; or

     (f)  Without consent by Tenant, a court or government authority enters an
          order, and such order is not vacated within ninety (90) days, (i)
          appointing a custodian, receiver, trustee or other officer with
          similar powers with respect to Tenant or with respect to any
          substantial part of Tenant's property, or (ii) constituting an order
          for relief or approving a petition for relief or reorganization or
          arrangement or any other petition in bankruptcy, insolvency or other
          debtors' relief law of any jurisdiction, or (iii) ordering the
          dissolution, winding-up or liquidation of Tenant; or

     (g)  This Lease or any estate of Tenant hereunder is levied upon under any
          attachment or execution and such attachment or execution is not
          vacated within thirty (30) days.

     Landlord may treat the occurrence of any one or more of the foregoing
Events of Default as a breach of this Lease. For so long as such Event of
Default continues, Landlord, at its option and with or without notice or demand
of any kind to Tenant or any other person, may have any one or more of the
remedies provided in this Lease, in addition to all other remedies and rights
provided at law or in equity.

15. REMEDIES:

                                      -17-
<PAGE>

     In the event of any Event of Default, Landlord may, in addition to, and not
in derogation of any remedies for any preceding breach, with or without notice
of demand (except as otherwise expressly provided herein) and without limiting
Landlord in the exercise of any right or remedy which Landlord may have by
reason of such Event of Default:

     (a)  Landlord shall have the right at any time to give a written
          termination notice to Tenant and, on the date specified in such notice
          (which shall be not less than five (5) days after such notice is
          given), Tenant's right to possession shall terminate and this Lease
          shall terminate.

     (b)  If this Lease shall have been terminated as provided herein, Tenant
          shall pay the Fixed Rent and all other sums payable hereunder up to
          the time of such termination, and thereafter, Tenant, until what would
          have been the balance of the Term then in effect (The Primary Term or
          any Extension Term) in the absence of such termination, shall be
          liable to Landlord for, and shall pay to Landlord, as current damages,
          Fixed Rent and other sums which would be payable hereunder if such
          termination had not occurred, plus the remaining unamortized amount of
          any brokerage fees paid by Landlord in connection with this Lease and
          any remaining unamortized amounts paid by Landlord in connection with
          the Tenant Work, less the net proceeds, if any, of any reletting of
          the Premises, after deducting all expenses reasonably incurred by
          Landlord in connection with such reletting, including, without
          limitation, all repossession costs, brokerage commissions, legal
          expenses, reasonable attorney's fees, advertising and the reasonable
          costs and expenses incurred in preparing the Premises for such
          reletting. Tenant shall pay such current damages to Landlord monthly
          on the days which the Fixed Rent would have been payable hereunder if
          this Lease has not been terminated.

     (c)  At any time after such termination, as liquidated final damages and in
          lieu of all such current damages beyond the date of such demand, at
          Landlord's election, Tenant shall pay to Landlord an amount equal to
          the excess, if any, of the Fixed Rent and other sums which would be
          payable hereunder from the date of such demand over the then fair
          rental value of the Premises for the same period, discounted to
          present value at the rate of seven percent (7%) per annum (assuming
          that, for the purposes of this paragraph, annual payments by Tenant on
          account of Property Taxes and insurance for the Premises would be the
          same as the payments required for the immediately preceding year) for
          what would have been the balance of the Term then in effect (the
          Primary Term or any Extension Term) in the absence of such
          termination.

     (d)  If an Event of Default shall occur and continue beyond all applicable
          notice and cure periods, and if, as a result thereof, Landlord shall
          terminate this Lease or re-enter the Premises and take possession
          thereof by summary proceedings or otherwise, Landlord may (i) re-let
          the Premises or one or more portions thereof, either in the name of
          the Landlord or otherwise, for one or more terms which may, at
          Landlord's option, be equal to or less than or exceed the period which
          would have been the balance of the Term then in effect (the Primary
          Term or any Extension Term) in the absence of any termination of this
          Lease and may grant reasonable concessions, including free rent
          periods and tenant improvement allowances, to the extent advisable and
          necessary to re-let the same and (ii) may make such reasonable
          alterations, repairs and decorations in the Premises as Landlord, in
          its sole judgment considers advisable and

                                      -18-
<PAGE>

          necessary for the purposes of reletting the Premises (including
          construction of tenant improvements) and the making of such
          alterations, repairs and decorations shall not operate or be construed
          to release Tenant from liability hereunder; PROVIDED, HOWEVER that
          Tenant shall not be responsible for any damage to the Premises or
          liability incurred by Landlord with respect thereto from and after the
          date of re-entry by Landlord into the Premises or the acts or
          omissions of any subsequent tenant or occupant of the Premises as a
          result of any such reletting by Landlord. 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 such reletting. Tenant hereby expressly waives any and
          all rights of redemption granted by or under any present or future
          laws in the event of Tenant being evicted or dispossessed, or in the
          event of Landlord obtaining possession of the Premises by reason of a
          default by Tenant in its obligations under this Lease continuing
          beyond all applicable notice and cure periods.

     (e)  Even though Tenant has breached this Lease, this Lease shall continue
          in effect for so long as Landlord does not terminate Tenant's right to
          possession, and Landlord shall have the right to enforce all its
          rights and remedies under this Lease, including the right to recover
          all Rent as it becomes due under this Lease. Acts of maintenance or
          preservation or efforts to relet the Premises or the appointment of a
          receiver upon initiative of Landlord to protect Landlord's interest
          under this Lease shall not constitute a termination of Tenant's right
          to possession unless written notice of termination is given by
          Landlord to Tenant.

     (f)  All agreements and covenants to be performed or observed by Tenant
          under this Lease shall be at Tenant's sole cost and expense and
          without any abatement of Fixed Rent or Additional Rent, except as
          expressly provided for in this Lease.

     (g)  If Tenant abandons or surrenders the Premises, or is dispossessed by
          process of law or otherwise, any movable furniture, equipment,
          Tenant's Trade Fixtures or other personal property belonging to Tenant
          and left in the Premises shall be deemed to be abandoned, at the
          option of Landlord, and Landlord shall have the right to sell or
          otherwise dispose of such personal property in any commercially
          reasonable manner.

     (h)  All reasonable costs and expenses incurred by or on behalf of either
          Landlord or Tenant (including, without limitation, reasonable
          attorney's fees and expenses) in enforcing its rights hereunder or
          occasioned by default by the other party which continues beyond all
          applicable notice and cure periods shall be paid by such other party.

     (i)  Nothing contained in this Lease shall, however, limit or prejudice the
          right of Landlord to prove for 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
          than, equal to, or less than the amount of the loss or damages
          referred to above.

     (j)  Except as otherwise provided in this Lease, any and all rights and
          remedies which either Landlord or Tenant may have under this Lease,
          and at law and equity, shall be cumulative

                                      -19-
<PAGE>

          and shall not be deemed inconsistent with each other, and any two or
          more of all such rights and remedies may be exercised at the same time
          insofar as permitted by law.

16. SUBORDINATION; NON-DISTURBANCE; MORTGAGEE PROTECTION:

     (a)  Tenant agrees at any time hereafter, and from time to time within ten
          (10) days of written request of Landlord, to execute and deliver to
          Landlord an instrument in the form customarily used by any
          institutional investor becoming a Mortgagee subjecting and
          subordinating this Lease to the lien of any Mortgage which at any time
          may be placed upon the Premises, or any portion thereof, by Landlord,
          and to any replacements, renewals, amendments, consolidations,
          modifications, extensions or refinancing thereof, and to each and
          every advance made under any Mortgage. It is agreed, nevertheless,
          that so long as there exists no Event of Default, such subordination
          agreement or other instrument, release or document (a "SUBORDINATION
          AGREEMENT") shall not interfere with, hinder or reduce Tenant's right
          to quiet enjoyment under this Lease, nor the right of Tenant to
          continue to occupy the Premises, and all portions thereof, and to
          conduct its business thereon in accordance with the covenants,
          conditions, provisions, terms and agreements of this Lease, shall
          recognize Tenant's extension and express set-off rights under this
          Lease, shall provide for the release of insurance proceeds and
          condemnation awards for application in accordance with the terms of
          this Lease and shall not increase Tenant's financial obligations or
          increase in any material way any of Tenant's other obligations
          hereunder. The obligation of Tenant to deliver a Subordination
          Agreement shall be contingent upon the holder of the Mortgage
          delivering a non-disturbance agreement to Tenant containing the
          provisions set forth in the preceding sentence (a "NON-DISTURBANCE
          AGREEMENT"). The costs of preparing and recording a Subordination
          Agreement or Non-Disturbance Agreement shall be borne by Landlord, but
          Tenant shall be responsible for its own counsel fees.
          Contemporaneously with the delivery hereof, Landlord's Mortgagees have
          delivered to Tenant a Subordination Agreement and Non-Disturbance
          Agreement which is acceptable to Tenant.

     (b)  Provided Tenant has been advised in writing of the name and address of
          a Mortgagee of the Premises, in the event of any act or omission of
          Landlord constituting a default by Landlord, Tenant shall not exercise
          any remedy until Tenant has given Landlord and such Mortgagee written
          notice of such act or omission, and until a reasonable period of time
          (not to exceed 10 business days) to allow Landlord or the Mortgagee to
          remedy such act or omission shall have elapsed following receipt of
          such notice. However, if such act or omission cannot, with due
          diligence and in good faith, be remedied within such period, except in
          circumstances where Tenant's interests are subject to immediate loss
          or uncorrectable damage Landlord and the Mortgagee shall be allowed
          such further period of time as may be reasonably necessary, PROVIDED
          that it commences remedying the same with due diligence and in good
          faith and thereafter diligently prosecutes such cure, and PROVIDED
          FURTHER that such cure period shall not extend beyond 260 days after
          the notice of such default. Nothing herein contained shall be
          construed or interpreted as requiring any Mortgagee receiving such
          notice to remedy such act or omission.

                                      -20-
<PAGE>

     (c)  If any Mortgagee shall succeed to the rights of Landlord under this
          Lease or to ownership of the Premises, whether through possession or
          foreclosure or the delivery of a deed to the Premises in lieu of
          foreclosure, then such Mortgagee shall automatically be deemed to have
          recognized this Lease and to assume the obligations of Landlord
          hereunder accruing on and after the date such Mortgagee acquired title
          to the Premises, and Tenant shall attorn to and recognize such
          Mortgagee as Tenant's landlord under this Lease (subject to such
          Mortgagee providing any required non-disturbance agreement to Tenant)
          and shall promptly execute and deliver any instrument that such
          Mortgagee may reasonably request to evidence such attornment (whether
          before or after the making of the Mortgage). In the event of any other
          transfer of Landlord's interest hereunder, such transferee shall
          automatically be deemed to have recognized this Lease and to assume
          the obligations of Landlord hereunder accruing on and after the date
          of such transfer, Tenant shall attorn to and recognize such transferee
          as Tenant's landlord under this Lease and shall promptly execute and
          deliver any instrument that such transferee and Landlord may
          reasonably request to evidence such attornment.

     (d)  Upon ten days' advance written notice, Tenant agrees to execute,
          acknowledge and deliver a document in a commercially reasonable form
          consenting to the assignment by Landlord of this Lease to a Mortgagee,
          with such changes therein as may be reasonably requested by the
          Mortgagee.

     (e)  Landlord represents and warrants to Tenant that, as of the date of
          this Lease, the Premises are not encumbered by a Mortgage other than
          the MIFA Mortgage and the UNUM Mortgage.

17. LANDLORD'S RIGHT OF ENTRY:

     Upon 48 hours' advance notice, but subject to Tenant's reasonable security
precautions, Landlord and its designees shall have the right to enter the
Premises at any time during normal business hours and to inspect the same, post
notices of non-responsibility, exhibit the Premises to prospective purchasers
and mortgagees, and examine Tenant's books and records pertaining to the
maintenance of the Premises, insurance policies, certificates of occupancy and
other documents, records and permits in Tenant's possession with respect to the
Premises, all of which shall be customary and adequate and reasonably
satisfactory to Landlord.

                                      -21-
<PAGE>

18. NOTICES:

     Notices, statements, demands, or other communications required or permitted
to be given, rendered or made by either party to the other pursuant to this
Lease or pursuant to any applicable law or requirement of public authority,
shall be in writing (whether or not so stated elsewhere in this Lease) and shall
be deemed to have been properly given, rendered or made, when received by
overnight delivery or overnight courier delivery (even if such delivery is
refused) or facsimile transmission with a confirmation copy sent by overnight
delivery or by overnight courier delivery addressed to the other parties as
follows:

                  To Landlord:

                  TriNet Property Partners, L.P.
                  c/o IStar Financial Inc.
                  3480 Preston Ridge Road, Suite 575
                  Alpharetta, GA  30005-8891
                  Attn:  Vice President, Asset Management

                  With a copy to:

                  Day, Berry & Howard LLP
                  260 Franklin Street
                  Boston, MA  02110
                  Attn:  Lewis A. Burleigh, Esq.

                  To Tenant:

                  Transkaryotic Therapies, Inc.
                  195 Albany Street
                  Cambridge, MA  02139
                  Attn:  Chief Financial Officer

                  With a copy to:

                  Katharine E. Bachman, Esq.
                  Hale and Dorr LLP
                  60 State Street
                  Boston, MA  02109

     Any party listed in this Section 18 may, by notices as aforesaid, designate
a different address for addresses for notice, statements, demands or other
communications intended for it.

                                      -22-
<PAGE>

19. ESTOPPEL CERTIFICATE

     At any time and from time to time, Tenant and Landlord shall, within ten
(10) days after written request by the other, execute, acknowledge and deliver
to the requesting party a certificate certifying: (i) that this Lease is
unmodified and in full force and effect (or, if there have been modifications,
that this Lease is in full force and effect as modified, and stating the date
and nature of each modification); (ii) the Commencement Date, the Commencement
Date and the Lease Expiration Date and the date, if any, to which all Rent and
other sums payable hereunder have been paid; (iii) that no notice has been
received by Tenant or Landlord, as applicable of any default by Tenant or
Landlord, as applicable hereunder which has not been cured, except as to
defaults specified in such certificate; (iv) that, to the best knowledge of
Tenant or Landlord, as applicable, Landlord or Tenant, as applicable, is not in
default under this Lease, except as to defaults specified in such certificate;
and (v) such other matters as may be reasonably requested by Landlord or Tenant,
as applicable or any actual or prospective purchaser or Mortgagee. Any such
certificate may be relied upon by Landlord or Tenant, as applicable and any
actual or prospective purchaser or Mortgagee of the Premises or any part
thereof.

20. MECHANICS' LIENS:

     (a)  Tenant shall not suffer or permit any mechanic's lien or other lien to
          be filed or recorded against the Premises, equipment or materials
          supplied or claimed to have been supplied to the Premises at the
          request of Tenant, or anyone holding the Premises, or any portion
          thereof, through or under Tenant whereby the estate, rights or title
          of Landlord are encumbered. If any such mechanic's lien or other lien
          shall at any time be filed or recorded against the Premises, or any
          portion thereof, Tenant shall cause the same to be discharged of
          record or bonded against to Landlord's satisfaction within sixty (60)
          days after the date of filing or recording of the same. However, in
          the event Tenant desires to contest the validity of any such lien, it
          shall notify Landlord and Landlord's Mortgagee in writing that Tenant
          intends to so contest same and, on or before the due date thereof,
          post a bond or otherwise discharge of record or procure title
          insurance over such lien.

     If Tenant complies with the foregoing and Landlord's Mortgagee does not
object to such contest, and Tenant continues, in good faith, to contest the
validity of such lien by appropriate legal proceedings which shall operate to
prevent the collection thereof and the sale or forfeiture of the Premises, or
any part thereof, to satisfy the same, Tenant shall be under no obligation to
pay such lien until such time as the same has been decreed, by court order, to
be a valid lien on the Premises. Any surplus deposit retained by Landlord, after
the payment of the lien shall be repaid to Tenant. Landlord agrees not to pay
such lien during the period of Tenant's contest in accordance with this Section.
If Tenant fails to discharge, bond or contest any such lien in accordance with
this Section and Landlord pays for the discharge of any such lien or any part
thereof from funds of Landlord, any amount paid by Landlord, together with all
costs, fees and expenses in connection therewith (including reasonable
attorney's fees of Landlord), together with interest thereon at the Overdue
Rate, shall be repaid by Tenant to Landlord on demand by Landlord. Tenant shall
be solely liable for, and agrees to indemnify and defend Landlord against

                                      -23-
<PAGE>

and save Landlord and the Premises, and any portion thereof, harmless from and
against all losses, costs, damages, expenses, liabilities, suits, penalties,
claims, demands and obligations, including, without limitation, reasonable
attorney's fees, resulting from the assertion, filing, foreclosure or other
legal proceedings with respect to any such mechanic's lien or other lien or the
attempt by Tenant to discharge same as above provided.

     (b)  All materialmen, contractors, artisans, engineers, mechanics, laborers
          and any other Person now or hereafter furnishing any labor, services,
          materials, supplies or equipment to Tenant with respect to the
          Premises, or any portion thereof, are hereby charged with notice that
          they must look exclusively to Tenant to obtain payment for the same.
          Notice is hereby given that Landlord shall not be liable for any
          labor, services, materials, supplies, skill, machinery, fixtures or
          equipment furnished or to be furnished to Tenant upon credit, and that
          no mechanic's lien or other lien for any such labor, services,
          materials, supplies, machinery, fixtures or equipment shall attach to
          or affect the estate or interest of Landlord in and to the Premises,
          or any portion thereof.

     (c)  Without Landlord's prior written consent, which shall be given or
          withheld in Landlord's sole discretion, Tenant shall not create,
          permit or suffer, and, subject to the provisions of Section 20(a)
          hereof, shall promptly discharge and satisfy of record, or bond
          against, any other lien, encumbrance, charge, security interest, or
          other right or interest which, as a result of Tenant's action or
          inaction contrary to the provisions hereof, shall be or become a lien,
          encumbrance, charge or security interest upon the Premises, or any
          portion thereof, or the income therefrom, other than Permitted
          Encumbrances.

21. END OF TERM:

     (a)  Upon the expiration or earlier termination of the Term of this Lease,
          Tenant shall surrender the Premises to Landlord in good repair and
          condition, reasonable wear and tear excepted, and broom clean. Tenant
          shall surrender all keys to the Premises to Landlord at the place then
          fixed for notices to Landlord and shall inform Landlord of all
          combinations on locks, safes and vaults, if any. Except as otherwise
          provided herein, Tenant shall at such time remove all of Tenant's
          Trade Fixtures, other personal property from the Premises therefrom
          and the property listed on EXHIBIT C (unless Landlord has previously
          agreed otherwise in writing in accordance with Section 22(b)(ii)
          hereof). Tenant shall repair any damage to the Premises caused by the
          removal of Tenant's Trade Fixtures, other personal property and the
          property listed on EXHIBIT C, and any and all such property not so
          removed shall, at Landlord's option, become the exclusive property of
          Landlord or be disposed of by Landlord, at Tenant's cost and expense,
          without further notice to or demand upon Tenant.

     (b)  If the Premises are not surrendered as above set forth, Tenant shall
          pay to Landlord a sum equal to 150% of the Fixed Rent herein provided
          during each month or portion thereof for which Tenant shall remain in
          possession of the Premises or any part thereof after the termination
          of the Term or of Tenant's rights of possession, whether by lapse of
          time or otherwise. The provisions of this Section 21(b) shall not be
          deemed to limit or constitute a waiver of any other rights or remedies
          of Landlord provided herein, at law or at equity.

                                      -24-
<PAGE>

     (c)  All property of Tenant not removed on or before the last day of the
          Term of this Lease shall be deemed abandoned. Tenant hereby appoints
          Landlord its agent to remove all property of Tenant, including
          Tenant's Trade Fixtures, from the Premises upon termination of this
          Lease and to cause its transportation and storage for Tenant's
          benefit, all at the sole cost and risk of Tenant and Landlord shall
          not be liable for damage, theft, misappropriation or loss thereof and
          Landlord shall not be liable in any manner in respect thereto. Tenant
          shall pay all costs and expenses, reasonable under the circumstances,
          of such removal, transportation and storage. Tenant shall reimburse
          Landlord upon demand for any expenses reasonably and actually incurred
          by Landlord with respect to removal or storage of abandoned property
          and with respect to restoring said Premises to good order, condition
          and repair.

     (d)  Except for surrender upon the expiration or earlier termination of the
          Term hereof, no surrender to Landlord of this Lease or of the Premises
          shall be valid or effective unless agreed to and accepted in writing
          by Landlord.

22. ALTERATIONS:

     (a)  Tenant shall not make any alterations, additions or improvements in or
          to the Premises or any part thereof without Landlord's prior written
          consent (which will not be unreasonably withheld or delayed).
          Notwithstanding the preceding sentence, Tenant may make such
          alterations, additions or improvements without Landlord's consent if
          such alterations, additions or improvements (i) will be in compliance
          with all applicable laws, codes, rules, regulations and ordinances,
          (ii) will not affect in any way the structural, exterior or roof
          elements of the Premises or adversely affect the mechanical,
          electrical, plumbing, utility or life safety systems of the Premises,
          and (iii) will have an estimated project cost of less than Fifty
          Thousand Dollars ($50,000). In no event shall Tenant be permitted to
          install underground storage tanks or fuel systems on the Premises.
          Landlord's refusal to consent to the installation of an underground
          tank or fuel system shall be conclusively presumed to be reasonable.

     (b)  All alterations, additions or improvements requiring Landlord's
          consent shall be made at Tenant's sole cost and expense as follows:

          (i)  Tenant shall submit to Landlord, for Landlord's written approval,
               complete plans and specifications for all work to be done by
               Tenant. Such plans and specifications shall be prepared by
               licensed architect(s) and/or engineer(s), shall comply with all
               applicable codes, ordinances, rules and regulations, shall not
               adversely affect the structural elements of the Premises, shall
               be in a form sufficient to secure the approval of all government
               authorities with jurisdiction over the Premises, and shall be
               otherwise satisfactory to Landlord in Landlord's reasonable
               discretion.

          (ii) Landlord shall notify Tenant in writing within fifteen (15) days
               whether Landlord approves or disapproves such plans and
               specifications; Landlord shall describe the reasons for any such
               disapproval which reasons must be based on either noncompliance
               with law or insurance policies, on reduction of the value or
               utility of the Premises, or on Tenant's refusal to remove such
               alterations or to restore the Premises to their condition
               immediately prior to such

                                      -25-
<PAGE>

               work upon the expiration or earlier termination of this Lease. If
               Landlord does not respond within such 15 day period, Tenant may
               send a second notice, prominently marked "Second Notice--Failure
               to Respond Will Result in Deemed Approval", and if Landlord fails
               to respond within ten (10) business days, the proposed plans and
               specifications shall be deemed approved. Tenant may submit to
               Landlord revised plans and specifications for Landlord's prior
               written approval, which approval shall not be withheld or delayed
               if (a) the work to be done would not adversely affect the value,
               character, rentability or usefulness of the Premises or any part
               thereof, or (b) the work to be done shall be required by any Law
               (hereinafter defined) or (c) Tenant shall agree to remove such
               alterations or restore the Premises to their condition
               immediately prior to such work upon the expiration or earlier
               termination of this Lease. Tenant shall pay all costs, including
               the fees and expenses of the licensed architect(s) and/or
               engineer(s), in preparing such plans and specifications.

          (iii) All material changes in the plans and specifications approved by
               Landlord shall be subject to Landlord's prior written approval on
               the same terms and conditions as set forth above. If Tenant
               wishes to make such change in approved plans and specifications,
               Tenant shall have such architect(s) and/or engineer(s) prepare
               plans and specifications for such change and submit them to
               Landlord for Landlord's written approval. Landlord shall notify
               Tenant in writing promptly whether Landlord approves, approves on
               condition that Tenant reverse the alteration at Tenant's expense
               at the termination or expiration of this Lease, or disapproves
               such change and, if Landlord disapproves such change, Landlord
               shall describe the reasons for disapproval. Tenant may submit to
               Landlord revised plans and specifications for such change for
               Landlord's written approval. After Landlord's written approval of
               such change, such change shall become part of the plans and
               specifications approved by Landlord.

     (c)  Tenant shall obtain and comply with all building permits and other
          government permits and approvals required in connection with the work.
          If Tenant was required to submit plans and specifications for the work
          to Landlord for Landlord's approval, Tenant shall, through Tenant's
          licensed contractor, perform the work substantially in accordance with
          such plans and specifications approved in writing by Landlord or
          deemed approved by Landlord. Tenant shall pay, as Additional Rent, the
          entire cost of all work (including the cost of all utilities, permits,
          fees, taxes, and property and liability insurance premiums in
          connection therewith) actually performed or obtained. Under no
          circumstances shall Landlord be liable to Tenant for any damage, loss,
          cost or expenses incurred by Tenant on account of any plans and
          specifications, contractors or subcontractors, design of any work,
          construction of any work, or delay in completion of any work.

     (d)  Tenant shall give written notice to Landlord of the date on which
          construction of any work to be done by outside contractors will be
          commenced at least ten (10) days prior to such date. Landlord shall
          have the right to post and keep posted on the Premises any notices
          that may be provided by law or which Landlord may deem to be proper
          for the protection of Landlord and the Premises from such liens, and
          to take any other action Landlord deems necessary to remove or
          discharge liens or encumbrances at the expense of Tenant.

                                      -26-
<PAGE>

     (e)  All work shall be done in a good and workmanlike manner employing
          materials of good quality and in compliance with laws, rules, orders
          and regulations of governmental authorities having jurisdiction
          thereof. All work shall be performed in such a manner as to maintain
          harmonious labor relations, not to damage the Building or interfere
          with the construction or operation of the Building. Tenant shall
          indemnify and hold Landlord harmless from additional costs incurred in
          supplying service or repairing damage caused by Tenant's contractors.
          Tenant shall cause each contractor to carry workmen's compensation
          insurance in statutory amounts covering the employees of all
          contractors and subcontractors, and commercial general liability
          insurance with such limits as Landlord may require reasonably from
          time to time during the Term of this Lease, but in no event less than
          the minimum amount of commercial general liability insurance Tenant is
          required to maintain as set forth in Section 10 hereof, and otherwise
          in accordance with the insurance requirements of Section 10.

     (f)  All alterations, additions, fixtures and improvements, whether
          temporary or permanent in character, made in or to the Premises by
          Tenant, and specifically including the Tenant Work, shall become part
          of the Premises and Landlord's property, except as listed on EXHIBIT
          C, and as may be mutually agreed upon by Landlord and Tenant. Upon
          termination of this Lease, Tenant shall, at Tenant's expense, remove
          all movable furniture, equipment, Tenant's Trade Fixtures, office
          machines and other personal property from the Premises and repair all
          damage caused by such removal. Termination of this Lease shall not
          affect the obligations of Tenant pursuant to this Section 22(f) to be
          performed after such termination.

     (g)  Tenant acknowledges that, as of the date hereof, the Building is
          connected to the building commonly known and referred to as 78 Pacella
          Road in Randolph, Massachusetts by a covered walkway (the "LAND
          BRIDGE"). Tenant covenants and agrees that upon the expiration or
          earlier termination of the Term and if requested to do so by Landlord,
          Tenant shall at its own expense remove the Land Bridge and restore the
          Building as a free-standing structure, seal the Building at the former
          connection point of the Land Bridge and otherwise restore that area of
          the Building to substantially the same condition as existed prior to
          construction of the Land Bridge. All work by Tenant in removing the
          Land Bridge and restoring the Building shall be performed in
          compliance with the requirements of this Section 22.

     (h)  Landlord acknowledges that Tenant intends to make the following
          initial improvements to the Premises (collectively, the "INITIAL
          IMPROVEMENTS"):

          (i) Removal of the existing interior improvements in the Premises,
               including existing interior walls, and the installation in the
               Premises of improvements and equipment for the operation by
               Tenant of its pharmaceutical manufacturing activities therein
               (the "INTERIOR WORK"); and

          (ii) the construction on the roof of a penthouse for mechanical
               systems (the "ROOF WORK").

     (i)  Notwithstanding any other term or provision of this Section 22 to the
          contrary, the following provisions shall govern Tenant's rights to
          make the Initial Improvements:

                                      -27-
<PAGE>

          (i)  Tenant may perform the Interior Work without Landlord's consent
               so long as such Interior Work (i) shall be in compliance with all
               applicable laws, codes, rules, regulations and ordinances, (ii)
               shall not affect in any way the structural elements (meaning the
               structural portions of the roof, the exterior and load bearing
               walls, the foundation, the structural columns and floor slabs of
               the Building) or the roof of the Premises or adversely affect the
               mechanical, electrical, plumbing, utility or life safety systems
               of the Premises and (iii) shall be constructed by Tenant in
               accordance with the requirements of clauses (c) through (f) of
               this Section 22. Tenant agrees to indemnify and hold Landlord
               harmless from and against any claims or damage as a result of the
               failure of the Interior Work to comply with any of the foregoing
               clauses (i) through (iii). Tenant shall not be required to obtain
               Landlord's consent to or approval of the plans and specifications
               for the Interior Work, but Tenant agrees to provide Landlord with
               courtesy copies of all such plans and specifications, which shall
               be prepared by licensed architect(s) and/or engineer(s), prior to
               the start of demolition or construction.

          (ii) Tenant shall submit plans and specifications for the Roof Work to
               Landlord for its prior consent and approval in accordance with
               the procedures specified in clause (b) of this Section 22.
               Notwithstanding any other term or provision of clause (b),
               however, Landlord may not withhold, condition or delay its
               consent to the Roof Work so long as such Roof Work (i) shall be
               in compliance with all applicable laws, codes, rules, regulations
               and ordinances, (ii) shall not affect in any way the structural
               elements (meaning the structural portions of the roof, the
               exterior and load bearing walls, the foundation, the structural
               columns and floor slabs of the Building) of the Premises or
               adversely affect the mechanical, electrical, plumbing, utility or
               life safety systems of the Premises, (iii) shall be constructed
               by Tenant in accordance with the requirements of clauses (c)
               through (f) of this Section 22, and (iv) shall be consistent with
               the aesthetic appearance of the Building. Tenant agrees to
               indemnify and hold Landlord harmless from and against any claims
               or damage as a result of the failure of the Roof Work to comply
               with any of the foregoing clauses (i) through (iv).

23. MEMORANDUM OF LEASE:

     The parties agree, upon the written request of either party hereto, to
promptly execute a Memorandum of Lease in recordable form and either of the
parties shall have the right, without notice to the other party, to record such
Memorandum of Lease.

24. SUBLETTING/ASSIGNMENT:

     (a)  Except as otherwise expressly permitted under this Section 24, Tenant
          covenants and agrees that neither this Lease, nor the term hereof, nor
          the estate hereby granted, nor any interest herein or therein, will be
          assigned, sublet, mortgaged, pledged, encumbered or otherwise
          transferred, and that neither the Premises, nor any part thereof, will
          be encumbered in any manner by reason of any act or omission of
          Tenant, or used or occupied, or permitted to be used or occupied, by
          anyone other than Tenant and its employees, or for any use or purpose
          other than as above stated, or be sublet, or offered or advertised for
          subletting, without in each case, Landlord's prior written consent,
          which consent shall not be unreasonably withheld, delayed, or

                                      -28-
<PAGE>

          conditioned. Landlord's acceptance of a check in payment of any
          obligations of Tenant under this Lease from a person other than Tenant
          shall not be construed as an implied consent by Landlord to an
          assignment of this Lease or subletting under it.

     (b)  Landlord's consent shall not be required for an assignment of this
          Lease resulting from the merger or consolidation of Tenant into an
          Affiliate of Tenant, or the sale of all of the assets of Tenant, so
          long as:

          (i)  if Tenant survives such merger or consolidation or sale, Tenant
               shall have a net worth that is at least equal to the net worth of
               Tenant immediately prior to such merger or consolidation;

          (ii) if Tenant does not survive such merger or consolidation or sale,
               the surviving Affiliate of Tenant (A) shall have a net worth that
               is at least equal to the net worth of Tenant immediately prior to
               such merger or consolidation and (B) shall deliver to Landlord
               within ten (10) days after the effective date of such assignment
               a written instrument pursuant to which such Affiliate shall
               assume all of the obligations of Tenant hereunder; and

          (iii) in all cases, Tenant shall provide written notice to Landlord of
               such merger, consolidation, assignment or sublease not later than
               thirty (30) days prior to the effective date thereof (PROVIDED,
               however, that if the shareholders of Tenant are not required to
               have approved or been notified of such transaction at such time,
               Tenant shall provide written notice to Landlord at such later
               time at which Tenant notifies its shareholders of such
               transaction), and shall provide Landlord not later than thirty
               (30) days after the effective date thereof with evidence that the
               net worth requirements specified in the preceding clauses, as
               applicable, will be satisfied.

     (c)  Landlord's consent shall not be required for any sublease of all or
          any part of the Premises to an Affiliate of Tenant so long as
          (I Tenant remains liable as a principal, and not merely as a surety
          or guarantor of performance, for all obligations hereunder, as more
          fully set forth in subsection (e), and (II) the provisions of
          subsections (f) and (g) also are satisfied.

     (d)  Landlord shall not unreasonably withhold, condition or delay its
          consent to any proposed assignment of this Lease or sublease of space
          in the Premises to which subsections (b) and (c) do not apply so long
          as (I Tenant remains liable as a principal, and not merely as a surety
          or guarantor of performance, for all obligations hereunder, as more
          fully set forth in subsection (e), and (II) the provisions of
          subsections (f), (g) and (h) also are satisfied.

     (e)  No assignment or sublease whatsoever shall release Tenant from
          Tenant's obligations and liabilities under this Lease (which shall
          continue as the obligations of a principal and not of a guarantor or
          surety) or alter the primary liability of Tenant to pay all Rent and
          to perform all obligations to be paid and performed by Tenant. The
          acceptance of Rent by Landlord from any other person or entity shall
          not be deemed to be a waiver by Landlord of any provision of this
          Lease. If any assignee, subtenant or successor of Tenant defaults in
          the performance of any obligation to be performed by Tenant under this
          Lease, Landlord may

                                      -29-
<PAGE>

          proceed directly against Tenant without the necessity of exhausting
          remedies against such assignee, subtenant or successor. Landlord may
          consent to amendments or modifications to this Lease with assignees,
          subtenants or successor of Tenant, without notifying Tenant or any
          successor of Tenant and without obtaining any consent thereto from
          Tenant or any successor of Tenant, PROVIDED that Tenant shall not be
          bound by any such amendment or modification to which it has not
          consented.

     (f)  No assignment or sublease shall be valid and no assignee or subtenant
          shall take possession of the premises or any part thereof until an
          executed duplicate original of such assignment or sublease, in
          compliance with this Section 24, has been delivered to Landlord. No
          assignment, subletting or use of the Premises shall affect the purpose
          for which the Premises may be used as stated in Section 2.

     (g)  Any reasonable legal expenses incurred by Landlord by reason of any
          proposed assignment or subletting shall be paid by Tenant whether or
          not the transaction shall be consummated.

     (h)  In the event of any assignment or subletting (other than an assignment
          or a subletting to an Affiliate of Tenant), Tenant shall pay to
          Landlord as Additional Rent hereunder fifty percent (50%) of all sums
          or other economic consideration that Tenant receives as a result of
          such assignment or subletting which exceed in the aggregate the total
          sums which Tenant is obligated to pay Landlord under this Lease (in
          the case of a sublease, prorated to reflect obligations allocable to
          that portion of the Premises), after the payment of Tenant's legal,
          brokerage, tenant improvement and rent concession expenses associated
          therewith.

     (i)  Upon the occurrence of an Event of Default, if the Premises or any
          part thereof are then assigned or sublet, Landlord, in addition to any
          other remedies herein provided or provided by law, may at its option
          collect directly from any assignee or subtenant all rents becoming due
          to Tenant under such assignment or sublease and apply such rent
          against any sums due it by Tenant hereunder, and no such collection
          shall be construed to constitute a notation or a release of Tenant
          from the further performance of its obligations hereunder.

     (j)  The consent by Landlord to an assignment or subletting shall not in
          any way be construed to relieve Tenant from obtaining the express
          consent in writing of Landlord to any further assignment or
          subletting, which consent shall not be unreasonably withheld or
          delayed.

     (k)  Tenant shall not mortgage its interest under this Lease. The foregoing
          prohibition shall not be violated by a lien on all assets of Tenant
          granted to institutional lenders as security for a bank loan or line
          of credit.

25. HAZARDOUS MATERIAL:

     (a)  Tenant (i) shall comply, and cause the Premises to comply, with all
          Environmental Laws applicable to the Premises associated with Tenant's
          use or occupancy thereof (including the making of all submissions to
          governmental authorities required by

                                      -30-
<PAGE>

          Environmental Laws and the carrying out of any remediation program
          specified by such authority), (ii) shall prohibit the use of the
          Premises for the generation, manufacture, refinement, production, or
          processing of any Hazardous Material or for the storage, handling,
          transfer or transportation of any Hazardous Material (other than in
          connection with the operation, business and maintenance of the
          Premises for the permitted uses specified in Section 2 including,
          without limitation, research and development and manufacturing,
          provided that such uses are in compliance with Environmental Laws),
          (iii) shall not permit to remain, install or permit the installation
          on the Premises of any surface impoundments, underground storage
          tanks, or asbestos-containing materials except in compliance with
          Environmental Laws, and (iv) shall cause any alterations of the
          Premises to be done in a way so as to not expose, in violation of any
          applicable law, the persons working on or visiting the Premises to
          Hazardous Materials and in connection with any such alterations shall
          remove any Hazardous Materials present upon the Premises which are not
          in compliance with Environmental Laws or which present a danger to
          persons working on or visiting the Premises in violation of any
          applicable law.

     (b)  Except to the extent of liability resulting from or arising out of the
          acts or negligence of Landlord or its Mortgagee or their agents,
          employees or contractors or their successors and assigns on or about
          the Premises, or in connection with the existence of any Hazardous
          Materials on the Premises prior to the date of this Lease, Tenant
          shall be solely liable for, and agrees to protect, defend, indemnify
          and hold harmless Landlord and its Mortgagee, their respective
          directors, officers, employees and agents, and any successors to
          Landlord's interest in the chain of title to the Premises, their
          direct or indirect partners, directors, officers, employees, and
          agents, from and against any and all liability, including all
          foreseeable and all unforeseeable damages including but not limited to
          reasonable attorney's and consultant's fees, fines, penalties and
          civil or criminal damages, directly or indirectly arising out of
          Tenant's use, generation, storage, treatment, release, threatened
          release, discharge, spill, presence or disposal of Hazardous Materials
          from, on, at, to or under the Premises during the Term of this Lease,
          and including, without limitation, the cost of any required or
          necessary repair, response action, remediation, investigation, cleanup
          or detoxification and the preparation of any closure or other required
          plans, whether such action is required or necessary prior to or
          following transfer of title to the Premises. This agreement to be
          solely liable for and to indemnify and hold harmless shall be in
          addition to any other obligations or liabilities Tenant may have to
          Landlord at common law under all statutes and ordinances or otherwise,
          and shall survive following the date of expiration or earlier
          termination of this Lease for three (3) years. Tenant expressly agrees
          that the representations, warranties and covenants made and the
          indemnities and agreements by Tenant stated in this Lease are not
          personal to Landlord, and the benefits under this Lease may be
          assigned to subsequent parties in interest to the chain of title to
          the Premises, which subsequent parties in interest may proceed
          directly against Tenant to recover pursuant to this Lease. Tenant, at
          its expense, may institute appropriate legal proceedings with respect
          to environmental matters of the type specified in this Section 25(b)
          or any lien for such environmental matters, not involving Landlord or
          its Mortgagee as a defendant (unless Landlord or its mortgagee is the
          alleged cause of the damage), conducted in good faith and with due
          diligence, PROVIDED that such proceedings shall not in any way impair
          the interests of Landlord or Mortgagee under this Lease. Counsel to
          Tenant in such proceedings shall be reasonably approved by Landlord if
          Landlord is a

                                      -31-
<PAGE>

          defendant in the same proceeding. Landlord shall have the right to
          appoint co-counsel, which co-counsel will cooperate with Tenant's
          counsel in such proceedings. The fees and expenses of such co-counsel
          shall be paid by Landlord, unless such co-counsel are appointed
          because the interests of Landlord and Tenant in such proceedings, in
          such counsel's opinion, are or have become adverse, or Tenant or
          Tenant's counsel is not conducting such proceedings in good faith or
          with due diligence.

     (c)  Landlord may from time to time designate one or more environmental
          site reviewers ("SITE REVIEWERS") to visit the Premises from time to
          time and perform environmental site investigations and assessments
          ("SITE ASSESSMENTS") on the Premises for the purpose of determining
          whether there exists on the Premises any environmental condition which
          may result in any liability, cost or expense to Landlord or any other
          owner or occupier of the Premises relating to Hazardous Material. Such
          Site Assessments may include both above and below the ground testing
          for environmental damage or the presence of Hazardous Material on the
          Premises and such other tests on the Premises as may be necessary to
          conduct the Site Assessments in the reasonable opinion of the Site
          Reviewers. Tenant shall supply to the Site Reviewers such historical
          and operational information regarding the Premises as may be
          reasonably requested by the Site Reviewers to facilitate the Site
          Assessments (other than information previously supplied in writing to
          Landlord by Tenant) and shall make available for meetings with the
          Site Reviewers appropriate personnel having knowledge of such matters.
          The cost of performing and reporting all Site Assessments shall be
          paid by Landlord unless the Site Reviewers discover an environmental
          condition caused by Tenant causing the Premises to be in material
          noncompliance with applicable Environmental Laws, in which events such
          cost will be paid by Tenant within thirty (30) days after demand by
          Landlord with interest to accrue at the Overdue Rate after such thirty
          (30) day period. Landlord, promptly after written request by Tenant
          and payment by Tenant to the extent required as aforesaid, shall
          deliver to Tenant copies of reports, summaries or other compilations
          of the results of such Site Assessments. Tenant's sole remedy for
          Landlord's breach of the preceding sentence shall be a mandatory
          injunction, and not a termination of this Lease or a withholding or
          reduction of Rent.

     (d)  Tenant shall notify Landlord in writing, promptly upon Tenant's
          learning thereof, of any:

          (i)  notice or claim to the effect that Tenant is or may be liable to
               any Person as a result of the release or threatened release of
               any Hazardous Material into the environment from the Premises;

          (ii) notice that Tenant is subject to investigation by any
               governmental authority evaluating whether any remedial action is
               needed to respond to the release or threatened release of any
               Hazardous Material into the environment from the Premises; and

          (iii) notice that the Premises are subject to an environmental lien.

     (e)  Notwithstanding any other term or provision of this Section 25 to the
          contrary, in the event that any Hazardous Materials are discovered in
          or about the Premises during the Term

                                      -32-
<PAGE>

          and the presence of such Hazardous Materials is not due to the
          negligence or intentional actions or omissions of Tenant, Landlord
          shall elect by written notice to Tenant either (i) to remove,
          remediate or encapsulate such Hazardous Materials in accordance with
          the requirements of Environmental Laws, in which event this Lease
          shall remain in full force and effect without any abatement of or
          reduction in Rent or (ii) not to perform such removal, remediation or
          encapsulation activities, PROVIDED, however, that Landlord may not
          make the election specified in this clause (ii) if such removal,
          remediation or encapsulation activities are required by applicable
          laws. In the event that Landlord makes the election specified in
          clause (ii) above, Tenant shall have the right, exercisable only in a
          written notice delivered to Landlord within ten (10) days of the date
          of receipt of such written notice, to terminate this Lease as of a
          date not less than sixty (60) days from the date of receipt of such
          notice (or such earlier date as Tenant shall be required to vacate the
          Premises pursuant to the terms of provisions of Environmental Laws).
          If Tenant fails to elect to terminate this Lease within the time
          periods specified above, this Lease shall remain in full force and
          effect without any abatement of or reduction in Rent. The agreements
          of Landlord set forth above shall be in addition to any other
          obligations or liabilities Landlord may have under any Environmental
          Laws.

26. [INTENTIONALLY OMITTED]

27. GRANTING OF EASEMENTS:

     Provided no Event of Default has occurred and is continuing hereunder,
Landlord shall join with Tenant at the request of Tenant (and at Tenant's sole
cost and expense) to (i) sell, assign, convey or otherwise transfer an interest
in the Premises to any person legally empowered to take such interest under the
power of eminent domain, (ii) grant, in the ordinary course of business,
easements, licenses, rights of way, and (iii) release, in the ordinary course of
business, existing easements and appurtenances which benefit the Premises, but
only if Landlord shall have received (x) a certificate of Tenant stating that
such action was taken in the ordinary course of business, does not interfere
with the conduct of Tenant's business, does not materially impair the utility of
the Premises, and does not reduce the Fair Market Rental Value of the Premises
by an amount greater than the consideration (if any) being paid to Landlord in
connection therewith, and (y) a written undertaking by Tenant to remain
obligated under this Lease as if such action had not been taken.

28. LETTER OF CREDIT:

     (a)  As security for the full and faithful performance of every provision
          of this Lease to be performed by Tenant, Tenant shall deposit with
          Landlord not later than March 31, 2005 an irrevocable standby letter
          of credit in the amount determined pursuant to Section 28(b) which
          shall be payable to Landlord from a bank acceptable to Landlord and
          substantially in the form attached hereto as EXHIBIT B or in such
          other form as shall be acceptable to Landlord in its reasonable
          discretion (the "LETTER OF CREDIT"). The Letter of Credit (I) shall
          not contain any conditions to draws by Landlord thereunder other than
          as shall be agreed to or permitted by Landlord in its sole and
          absolute discretion and (II) shall not expire prior to the Lease
          Expiration

                                      -33-
<PAGE>

          Date, as it may be extended pursuant to Section 3(b), PROVIDED,
          HOWEVER, that the Letter of Credit may contain an earlier expiration
          date and provide for automatic renewal on a yearly basis, as long as
          (A) the bank issuing the Letter of Credit is required to provide
          Tenant and Landlord with sixty (60) days' written notice prior to any
          expiration or non-renewal of the Letter of Credit, and (B) Landlord
          actually receives such notice prior to any expiration or non-renewal
          of the Letter of Credit. If an Event of Default has occurred with
          respect to any term, covenant or provision under this Lease, including
          but not limited to making payments of Fixed Rent or Additional Rent,
          Landlord shall have the right, at Landlord's sole discretion and upon
          the expiration of any applicable cure periods set forth under this
          Lease, to draw upon the Letter of Credit any amounts reasonably
          necessary to cure such default by Tenant. Landlord's holding of the
          Letter of Credit shall not bar Landlord from pursuing or enforcing any
          other rights, at law or equity, which Landlord may have against
          Tenant.

     (b)  The amount of the Letter of Credit shall be determined based upon the
          market value of all publicly issued and outstanding equity securities
          of Tenant at the end of the business day on Tuesday, March 1, 2005, if
          any. The amount of the Letter of Credit shall be determined as
          follows:

MARKET CAPITALIZATION AT END OF MARCH 1, 2005:        LETTER OF CREDIT AMOUNT:

         $2 Billion or greater                     No Letter of Credit required

$1.5 Billion or greater but less than $2 Billion             $200,000

$1 Billion or greater but less than $1.5 Billion             $300,000

$500 Million or greater but less than $1 Billion             $400,000

         Less than $500 Million                              $600,000

     Not later than 5 p.m. on Friday, March 4, 2005, Tenant shall provide
Landlord with written documentation of its market capitalization as of the end
of the business day on March 1, 2005. If based upon Tenant' market
capitalization no Letter of Credit is required to be furnished by Tenant, Tenant
shall be relieved of the obligations set forth in this Section 28.

     (c)  Tenant's failure to deliver the Letter of Credit or to maintain the
          Letter of Credit at the times, in the manner and in the amounts
          required hereunder shall be an Event of Default under this Lease.

     (d)  If any portion of the Letter of Credit is drawn upon, Tenant shall,
          within fifteen (15) days after written notice thereof, deposit cash
          with Landlord, or deliver to Landlord a replacement or supplemental
          letter of credit from a bank acceptable to landlord, in an amount
          sufficient to restore the Letter of Credit to its then required
          amount. Landlord shall return the

                                      -34-
<PAGE>

          Letter of Credit to Tenant within thirty (30) days after the
          expiration or earlier termination of this Lease, subject to Tenant's
          satisfactory compliance with the conditions and obligations of this
          Lease. No Mortgagee shall be responsible for the return of or any
          application of the Letter of Credit, whether or not it succeeds to the
          position of Landlord hereunder, unless the Letter of Credit shall have
          been received by such Mortgagee in hand.

     (e)  If Landlord receives notice of non-renewal or early expiration of the
          Letter of Credit pursuant to Section 28(a) of this Lease, then Tenant
          shall have thirty (30) days from the date of such notice, time being
          of the essence, to provide Landlord with a replacement Letter of
          Credit in the then required amount from a bank with a short-term
          unsecured debt rating of "A" or better from Standard & Poor's Ratings
          Services or Moody's Investor Service, Inc. or from such other bank as
          shall be acceptable to Landlord in its sole and absolute discretion.
          Any such replacement Letter of Credit shall be in the form attached
          hereto as EXHIBIT B or in such other form as shall be acceptable to
          Landlord in its reasonable discretion.

     (f)  If (i) Tenant fails to restore the Letter of Credit to its required
          amount after any draws thereunder pursuant to Section 28(d) of this
          Lease, or (ii) the Letter of Credit is scheduled to be reduced despite
          Tenant being in default hereunder as of such date beyond any
          applicable cure periods, or (iii) Tenant fails to provide Landlord
          with a replacement Letter of Credit pursuant to and within the time
          limit specified in Section 28(e) of this Lease, then Landlord shall be
          immediately entitled, without any further precondition whatsoever, to
          draw upon the entire amount of the Letter of Credit and thereafter to
          hold such amount in cash as the security deposit hereunder. Landlord
          may co-mingle such funds with Landlord's other funds, and shall have
          no obligation to pay any interest with respect thereto.

     (g)  Landlord shall have the right to turn over the Letter of Credit to any
          grantee of Landlord's interest in the Premises and, in such event,
          Tenant agrees to look solely to such grantee, and not to Landlord,
          with respect to the Letter of Credit.

29. [INTENTIONALLY OMITTED]

30. BROKERS:

     (a)  Landlord and Tenant represent and warrant to each other that, in
          connection with the Lease specified herein, they have had no dealings
          with any broker, firm or salesman in connection with this transaction.

     (b)  Landlord hereby agrees to pay defend, indemnify and hold harmless
          Tenant from any loss, cost, damage and expense, including, without
          limitation, reasonable attorneys' fees and disbursements, arising out
          of any other and all claims by any person, firm or business entity who
          shall claim to have acted in this transaction on behalf of Landlord.

     (c)  Tenant hereby agrees to defend, indemnify and hold harmless Landlord
          from any loss, cost, damage and expense, including, without
          limitation, reasonable attorneys' fees and

                                      -35-
<PAGE>

          disbursements, arising out of any other and all claims by any person,
          firm or business entity who shall claim to have acted in this
          transaction on behalf of Tenant.

     (d)  The provisions of this Section 30 shall survive the execution and
          delivery hereof.

31. FINANCIAL REPORTING:

     (a)  Tenant shall deliver to Landlord and to any lender or purchaser
          designated by Landlord the following information certified to be true,
          complete and correct by an officer of Tenant within 90 days after the
          end of each fiscal year of Tenant:

          (i)  a balance sheet of Tenant and its consolidated subsidiaries as of
               the end of such year;

          (ii) a statement of profits and losses of Tenant and its consolidated
               subsidiaries for such year; and

          (iii) an audited statement of cash flows of Tenant and its
               consolidated subsidiaries for such year, setting forth in each
               case, in comparative form, the corresponding figures for the
               preceding fiscal year in reasonable detail and scope and
               certified by independent certified public accountants of
               recognized national standing selected by Tenant.

     (b)  Tenant shall deliver to Landlord and to any lender or purchaser
          designated by Landlord the following information certified to be true,
          complete and correct by an officer of Tenant within 45 days after the
          end of each fiscal quarter of Tenant:

          (i)  a balance sheet of Tenant and its consolidated subsidiaries as at
               the end of such quarter;

          (ii) a statement of profits and losses of Tenant and its consolidated
               subsidiaries for such quarter; and

          (iii) a statement of cash flows of Tenant and its consolidated
               subsidiaries for such quarter, setting forth in each case in
               comparative form, the corresponding figures for the similar
               quarter of the preceding year, in reasonable detail and scope,
               and certified to be true and complete by a financial officer of
               Tenant having knowledge thereof.

     (c)  All of the foregoing financial statements all being prepared in
          accordance with GAAP.

     (d)  If Tenant is a reporting company under the Securities and Exchange Act
          of 1934, as amended, the foregoing requirements of this Section 10
          will be satisfied by the delivery of Tenant's Forms 10-K, 10-Q and
          annual reports promptly upon their filing with the Securities and
          Exchange Commission.

                                      -36-
<PAGE>

32. MISCELLANEOUS PROVISIONS:

     (a)  This Lease and all of the covenants and provisions hereof shall inure
          to the benefit of, and be binding upon, the parties hereto and the
          heirs, personal representatives, successors and permitted assigns of
          the parties.

     (b)  The titles and headings appearing in this Lease are for reference only
          and shall not be considered a part of this lease or in any way to
          modify, amend or affect the provisions thereof.

     (c)  This Lease contains the complete agreement of the parties with
          reference to the leasing of the Premises, and may not be amended
          except by an instrument in writing signed by Landlord and Tenant and
          consented to by any Mortgagee.

     (d)  Any provision or provisions of this Lease which shall prove to be
          invalid, void or illegal shall in no way affect, impair or invalidate
          any other provision hereof, and the remaining provisions hereof shall
          nevertheless remain in full force and effect.

     (e)  This Lease may be executed in one or more counterparts, each of which
          shall be an original, and all of which shall constitute one and same
          instrument.

     (f)  The term "Landlord" as used in this Lease shall mean only the owner or
          owners at the time in question of the Premises and in the event of any
          transfer of such title or interest, Landlord named in this Lease (and
          in case of any subsequent transfers, then the grantor) shall be
          relieved from and after the date of such transfer of all liability as
          respects Landlord's obligations thereafter to be performed hereunder,
          PROVIDED that any funds in the hands of Landlord or the then grantor
          at the time of such transfer, in which Tenant has an interest, shall
          be delivered to the grantee. The obligations contained in this Lease
          to be performed by Landlord shall, subject as aforesaid, be binding on
          Landlord's successors and assigns, only during their respective
          periods of ownership.

     (g)  This Lease shall be governed by and construed and enforced in
          accordance with and subject to the laws of the Commonwealth of
          Massachusetts.

     (h)  Any claim based on or in respect of any liability of Landlord under
          this Lease shall be enforced only against the Premises and not against
          any other assets, properties or funds of (i) Landlord or any director,
          officer, shareholder, general partner, limited partner, or direct or
          indirect partners, employee or agent of Landlord or its general
          partners (or any legal representative, heir, estate, successor or
          assign of any thereof), (ii) any predecessor or successor partnership
          or corporation (or other entity) of Landlord or its general partners,
          either directly or through Landlord or its predecessor or successor
          partnership or corporation (or other Person) of Landlord or its
          general partners, and (iii) any other person.

     (i)  Without the written approval of Landlord and Tenant, no Person other
          than Landlord (including its direct and indirect partners), Mortgagee,
          Tenant and their respective successors and assigns shall have any
          rights under this Lease.

                                      -37-
<PAGE>

     (j)  There shall be no merger of the leasehold estate created hereby by
          reason of the fact that the same Person may own directly or
          indirectly, (1) the leasehold estate created hereby or any interest in
          this Lease or such leasehold estate and (2) the fee estate in the
          Premises. Notwithstanding any such combined ownership, this Lease
          shall continue in full force and effect until terminated by an
          instrument executed by both Landlord and Tenant.

     (k)  Landlord and Tenant intend to consummate the execution and delivery of
          this Lease by signing counterpart original signature pages hereto and
          faxing copies of such signature pages to each other. Accordingly, the
          parties agree that counterpart signature pages of both Landlord and
          Tenant, when sent via facsimile and attached to this Lease, shall be
          effective to create a valid and binding agreement between Landlord and
          Tenant hereunder. Upon receipt of original signature pages of each
          party hereto, such counterpart original signature pages may be
          substituted for the facsimile signature pages without affecting the
          continuing validity hereof.

                            [SIGNATURE PAGE FOLLOWS]

                                      -38-
<PAGE>

     IN WITNESS WHEREOF, the parties have hereunto set their hands under seal on
the day and year first above written.

                             LANDLORD:

                             TRINET PROPERTY PARTNERS, L.P A
                             Delaware limited partnership
                             d/b/a TriNet Property Partners Limited Partnership

                              By: TRINET REALTY INVESTORS I, INC.
                                  Its General Partner

                              By: /s/ Susan K. Culbreth
                                 -------------------------------
                                 Name: Susan K. Culbreth
                                 Title:  AVP, Asset Management

                                 TENANT:

                                 TRANSKARYOTIC THERAPIES, INC.

                              By: /s/ Daniel Geffken
                                 -------------------------------
                                 Name: Daniel Geffken
                                 Title: SVP, CFO

<PAGE>

                                    EXHIBIT A
                         Legal Description - Real Estate

<PAGE>

                                    EXHIBIT A

That certain parcel of land situate in Randolph, in the County of Norfolk,
Commonwealth of Massachusetts, bounded and described as follows:

WESTERLY by Fitzgerald Street one hundred ten and 25/100 (110.25) feet;

WESTERLY by the Easterly line of said Fitzgerald Street, two hundred ninety
(290) feet;

NORTHWESTERLY by lot numbered 8, as indicated on plan filed with Certificate No.
84439, three hundred ninety-five and 29/100 (395.29) feet;

NORTHEASTERLY by southwesterly line of Pacella Park Drive, as shown on said plan
and shown on plan filed with Certificate No. 96625, one hundred seventy and
09/100 (170.09) feet;

NORTHEASTERLY by said Pacella Park Drive, as shown on plan filed with
Certificate No. 107135, eighty-one and 28/100 (81.28) feet;

SOUTHEASTERLY by land now or formerly of Pacella Corp., six hundred sixty six
and 48/100 (666.48) feet; and

SOUTHERLY by land now or formerly of Nellie Kelch, thirty-one and 45/100 (31.45)
feet.

Said parcel comprises LOT NUMBERED 13 on a plan drawn by Gale Engineering Co.,
Inc., Surveyors, dated February 13, 1968, as approved by the Land Court, filed
in the Land Registration Office as No. 34183F, a copy of a portion of which is
filed in Norfolk Registry District with Certificate No. 84439, Book 423; and LOT
NUMBERED 17 on a plan drawn by Gale Engineering Co., Inc., Charles E. Gale,
Surveyor, dated August 20, 1973, as approved by said Court, filed in the Land
Registration Office as No. 34183, a copy of a portion of which is filed in
Norfolk Registry District with Certificate No. 96625, Book 484; and LOT NUMBERED
22 on a plan drawn by Gale Engineering Co., Inc., Surveyors, dated June 22,
1978, as approved by said Court, filed in the Land Registration Office as No.
34183L, a copy of a portion of which is filed in Norfolk Registry District with
Certificate No. 107135, Book 536. Excepting and excluding from said parcel so
much of the fee and soil in said Parcella Park Drive as lies opposite said lots
numbered 13 and 17.

There is appurtenant to the above-described land the right to use said Pacella
Park Drive out to Pond Street, as set forth in Document Nos. 290357, 338150 and
383254, as noted in Certificate 119673.

For title, see Certificate 151896.

<PAGE>

                                    EXHIBIT B
                            Form of Letter of Credit

[Letterhead of Issuer]
March 31, 2005
TriNet Property Partners, L.P.
c/o IStar Financial Inc.
3480 Preston Ridge Road, Suite 575
Alpharetta, GA 30005-8891
Attn: Vice President, Asset Management

Ladies and Gentlemen:

     We hereby issue our Irrevocable Letter of Credit No. ________________ in
favor of TriNet Property Partners, L.P. This Letter of Credit is issued in
connection with the lease by Transkaryotic Therapies, Inc. of certain property
located at 76 Pacella Road, Randolph, Massachusetts (the "PREMISES"). This
Letter of Credit shall expire not earlier than [DATE].

     We undertake to honor your draft or drafts At Sight on us not exceeding
U.S. [AMOUNT] when accompanied by a statement on letterhead of TriNet Property
Partners, L.P. or IStar Financial Inc. that the amount of the accompanying draft
is due and owing to TriNet Property Partners, L.P. All drafts must be marked
"Drawn under Irrevocable Letter of Credit No.__________ dated ___________."

     This Irrevocable Letter of Credit shall be valid until such time as we
receive a statement on letterhead of TriNet Property Partners, L.P. or IStar
Financial Inc. notifying us that this Irrevocable Letter of Credit has been
canceled, together with this Irrevocable Letter of Credit for cancellation.
Until such time, drafts drawn hereunder, when accompanied by the statement
referred to above, shall be honored if presented to us at our office at
__________.

     This Irrevocable Letter of Credit may be transferred or assigned by TriNet
Property Partners L.P. to any purchaser or mortgagee of the Premises. Upon (i)
our receipt of a notice of such a transfer or assignment on letterhead of TriNet
Property Partners, L.P. or IStar Financial Inc. and (ii) the delivery of this
Irrevocable Letter of Credit to us for cancellation, we shall issue a new
Irrevocable Letter of Credit on the same terms as are contained herein,
addressed to such purchaser or mortgagee.

     There are no other conditions to this Letter of Credit.

                                                       Very truly yours,

                              [Execution by Issuer]

<PAGE>

                                    EXHIBIT C
                           Tenant's Personal Property

<PAGE>

                                    EXHIBIT C

1.   Items tenant must remove upon lease termination

     Freestanding office and laboratory equipment and furniture including
     biosafety cabinets, ice machines, movable office partitions

2.   Items tenant must leave in building upon lease termination

     Equipment related to base building systems including bathroom fixtures,
     boilers for building heat, roof top air handling and air conditioning
     equipment, air compressors for pneumatic temperature controls, exhaust
     fans, piping systems

3.   At tenant's option, the following fixed equipment may be removed upon lease
     termination

     Laboratory case work that is affixed to the walls

     Steam generators for autoclaves, manifolds for specialty gas systems, water
     purification equipment (RODI skid)

     Clean steam generator

     WFI still

     Automated manufacturing equipment

     Dedicated process equipment, tanks and related instrumentation

     Autoclaves

     Glasswashers

     Process utility systems, pharmaceutical grade compressed air systems,
     process cooling systems

     Stand-by power generators

     Uninterruptible power systems (UPS)<PAGE>

                                                               Exhibit 10.30

                             REIMBURSEMENT AGREEMENT

         This REIMBURSEMENT AGREEMENT is made as of May 18, 2000, by and between
Transkaryotic Therapies, Inc., a Delaware corporation (the "Company") and
William H. Pursley (the "Borrower").

         WHEREAS, the Borrower has been instructed to post a $450,000 bond (the
"Bond") due to the appeal of a district court ruling of an arrearage owed by the
Borrower; and

         WHEREAS, to secure the Bond, the Borrower has requested that the
Company provide the security and collateral for an irrevocable letter of credit,
substantially in the form of EXHIBIT A hereto (the "Letter of Credit"), in an
amount not to exceed $450,000;

         NOW THEREFORE, in consideration of the agreements herein, the parties
hereto agree as follows:

         In order to induce the Company to secure and collateralize the Letter
of Credit, the Borrower hereby agrees upon demand by the Company, to reimburse
or pay to the Company with respect to the Letter of Credit issued, extended or
renewed by the Company hereunder, (a) (i) any amount paid by the Company under
or with respect to such Letter of Credit, and (ii) the amount of any taxes,
fees, charges or other costs and expenses whatsoever incurred by the Company in
connection with any payment made by the Company under, or with respect to, such
Letter of Credit and (b) interest on the unpaid balance of any amounts paid by
the Company under or with respect to the such Letter of Credit from the date on
which such payment was made (the "Inception Date"). The interest rate applicable
during each calendar year or portion thereof from and after the Inception Date
shall be the rate equal to one per cent (1%) per annum above the average yield
in per cent per annum prevailing in the secondary market for one-year United
States Treasury Bills as of the last day in such calendar year on which such
market is open, as reported in Federal Reserve Statistical Release H-15.
Interest shall be computed on the basis of a year of 365 days for the actual
number of days elapsed. All payments made by the Borrower shall be in
immediately available funds.

         If any demand for payment shall be made under the Letter of Credit, the
Company shall promptly notify the Borrower of the date and amount of the demand
for payment and of the date and time when it expects to honor such demand for
payment. The responsibility of the Company to the Borrower shall be only to
determine that the documents delivered under the Letter of

<PAGE>

Credit in connection with such presentment shall be in conformity in all
material respects with the requirements of such Letter of Credit.

         To the extent permitted by applicable law, any sums credited by or due
from the Company to the Borrower, including, but not limited to, wages, bonuses
and other amounts payable to the Borrower by the Company during or after the
termination of the Borrower's employment by the Company, may at any time be
applied to or offset against the Borrower's obligations hereunder.

         Should the indebtedness evidenced by this Reimbursement Agreement or
any part thereof be collected by action at law, or in bankruptcy, receivership
or other court proceedings, or should this Reimbursement Agreement be placed in
the hands of attorneys for collection after default, the Borrower agrees to pay,
upon demand by the holder hereof, in addition to principal and other sums, if
any, due and payable hereon, court costs and reasonable attorneys' fees and
other collection charges and expenses, unless prohibited by law.

         Every amount under this Reimbursement Agreement remaining unpaid for
five (5) days following demand by the Company shall bear interest from and after
the date on which such amount first became overdue at an annual rate which is
two (2) percentage points above the rate specified in this Reimbursement
Agreement. Such interest on overdue amounts under this Reimbursement Agreement
shall be payable on demand and shall accrue and be compounded monthly until the
obligation of the Borrower with respect to the payment of such interest has been
discharged (whether before or after judgment).

         The Borrower and all endorsers and/or guarantors hereof (i) consent and
agree to be bound by the provisions of this Reimbursement Agreement, absolutely
and unconditionally, to pay the principal and interest of this Reimbursement
Agreement and all other charges for which the Borrower may be or become liable
hereunder as herein provided, (ii) waive trial by jury in any action on this
Reimbursement Agreement, (iii) waive presentment, notice of non-payment, notice
of protest, suit and all other conditions precedent in connection with the
collection and enforcement of this Reimbursement Agreement, (iv) waive any right
to the benefit of, or to direct the application of, any security for this
Reimbursement Agreement until all indebtedness hereunder shall have been paid in
full, and (v) waive the right to require the holder hereof to proceed against
any other person or to pursue any other remedy before proceeding against him,
and, except as otherwise required by law, waives the right to require the holder
hereof to proceed against any security before proceeding against him.

<PAGE>

         The Borrower agrees to indemnify and hold harmless the Company and its
officers, employees, affiliates, agents, and controlling persons from and
against all claims, damages, liabilities and losses of every kind arising out of
and in connection to this Reimbursement Agreement absent the gross negligence or
willful misconduct of the Company. Any communication to be made hereunder shall
(a) be made in writing, but unless otherwise stated, may be made by telex,
facsimile transmission or letter, and (b) be made or delivered to the address of
the party receiving notice which is identified with its signature below (unless
such party has by five (5) days written notice specified another address), and
shall be deemed made or delivered, when dispatched, left at that address, or
five (5) days' after being mailed, postage prepaid, to such address. This
Reimbursement Agreement shall be binding upon and inure to the benefit of each
party hereto and its successors and assigns, but the Borrower may not assign its
rights or obligations hereunder. This Reimbursement Agreement may not be amended
or waived except by a written instrument signed by the Borrower and the Company,
and any such amendment or waiver shall be effective only for the specific
purpose given. No failure or delay by the Company to exercise any right
hereunder shall operate as a waiver thereof, nor shall any single or partial
exercise of any right, power or privilege preclude any other right, power or
privilege. The provisions of this Reimbursement Agreement are severable and if
any one provision hereof shall be held invalid or unenforceable in whole or in
part in any jurisdiction, such invalidity or unenforceability shall affect only
such provision in such jurisdiction. This Reimbursement Agreement expresses the
entire understanding of the parties with respect to the transactions
contemplated hereby. This Reimbursement Agreement and any amendment hereby may
be executed in several counterparts, each of which shall be an original, and all
of which shall constitute one agreement. In proving this Reimbursement
Agreement, it shall not be necessary to produce more than one such counterpart
executed by the party to be charged. THIS REIMBURSEMENT AGREEMENT IS A CONTRACT
UNDER THE LAWS OF THE COMMONWEALTH OF MASSACHUSETTS AND SHALL BE CONSTRUED IN
ACCORDANCE THEREWITH AND GOVERNED THEREBY. THE BORROWER AGREES THAT ANY SUIT FOR
THE ENFORCEMENT OF ANY OF THE REIMBURSEMENT DOCUMENTS MAY BE BROUGHT IN THE
COURTS OF THE COMMONWEALTH OF MASSACHUSETTS OR ANY FEDERAL COURT SITTING
THEREIN. THE BORROWER, AS AN INDUCEMENT TO THE COMPANY TO ENTER INTO THIS
REIMBURSEMENT AGREEMENT, HEREBY WAIVES ITS RIGHT TO A JURY TRIAL.

<PAGE>

         IN WITNESS WHEREOF, the undersigned have duly executed this
Reimbursement Agreement as a sealed instrument as of the date first set forth
above.

                                          TRANSKARYOTIC THERAPIES, INC.

                                          /s/ Daniel E. Geffken
                                          --------------------------------
                                          By:      Daniel E. Geffken
                                          Title:   VP, Finance & CFO
                                          Address:

                                          Fax:

                                          /s/ William H. Pursley
                                          ------------------------------
                                          William H. Pursley
                                          Address: 177 Pleasant St.
                                                   Norwell, MA 02061

                                          Fax:

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