<PAGE>

                                                                   Exhibit 10.12

                                Table of Contents

                                TABLE OF CONTENTS
              OF LEASE BETWEEN 46.24 ASSOCIATES L.P., AS LANDLORD,
         AND PTC THERAPEUTICS, INC., AS TENANT, FOR PREMISES LOCATED IN
                 100 CORPORATE COURT, MIDDLESEX BUSINESS CENTER,
                          SOUTH PLAINFIELD, NEW JERSEY

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ARTICLE 1.    DEMISED PREMISES AND TERM..................................     1
ARTICLE 2.    USE AND OPERATION..........................................     3
ARTICLE 3.    RENT.......................................................     3
ARTICLE 4.    SUBORDINATION..............................................     4
ARTICLE 5.    AS-IS; LANDLORD'S WORK; TENANT'S WORK......................     6
ARTICLE 6.    ALTERATIONS AND REPAIRS....................................    11
ARTICLE 7.    INDEMNITY AND INSURANCE....................................    14
ARTICLE 8.    FIRE DAMAGE................................................    16
ARTICLE 9.    WAIVER OF SUBROGATION......................................    17
ARTICLE 10.   CONDEMNATION...............................................    17
ARTICLE 11.   ASSIGNMENT AND SUBLETTING..................................    18
ARTICLE 12.   COMMON AREA MAINTENANCE....................................    20
ARTICLE 13.   UTILITIES..................................................    22
ARTICLE 14.   TAXES......................................................    23
ARTICLE 15.   REMEDIES OF LANDLORD.......................................    24
ARTICLE 16.   WAIVER OF TRIAL BY JURY....................................    27
ARTICLE 17.   ACCESS TO PREMISES.........................................    27
ARTICLE 18.   NO WAIVER..................................................    28
ARTICLE 19.   REQUIREMENTS OF LAW; INSURANCE REQUIREMENTS................    28
ARTICLE 20.   SIGNS......................................................    29
ARTICLE 21.   TENANT'S ADDITIONAL COVENANTS..............................    29
ARTICLE 22.   EASEMENTS FOR UTILITIES....................................    31
ARTICLE 23.   CONSENTS AND APPROVALS.....................................    31
ARTICLE 24.   CONTROL OF TENANT..........................................    31
ARTICLE 25.   END OF TERM HOLDOVER.......................................    31
ARTICLE 26.   AUTHORITY TO EXECUTE.......................................    33
</TABLE>


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                                Table of Contents
                                   (continued)

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ARTICLE 27.   NOTICES....................................................    33
ARTICLE 28.   BROKER.....................................................    33
ARTICLE 29.   MEMORANDUM OF LEASE........................................    33
ARTICLE 30.   AIR AND WATER POLLUTION....................................    33
ARTICLE 31.   SUBDIVISION................................................    36
ARTICLE 32.   THERE IS NO ARTICLE 32 IN THIS LEASE.......................    36
ARTICLE 33.   FINANCING REQUIREMENTS.....................................    36
ARTICLE 34.   RELATIONSHIP OF PARTIES....................................    37
ARTICLE 35.   CAPTIONS...................................................    37
ARTICLE 36.   DEFINITIONS................................................    37
ARTICLE 37.   ENTIRE AGREEMENT...........................................    37
ARTICLE 38.   SUCCESSORS IN INTEREST.....................................    37
ARTICLE 39.   SECURITY...................................................    38
ARTICLE 40.   EXTENSION OPTION(S)........................................    40
</TABLE>


                                       ii
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     THIS LEASE, made as of the 11th day of July 2000, by and between 46.24
ASSOCIATES L.P., a Delaware limited partnership, having a mailing address c/o
National Realty & Development Corp., 3 Manhattanville Road, Purchase, New York
10577 (hereinafter referred to as "Landlord") and PTC THERAPEUTICS, INC., a
Massachusetts corporation, having its principal office at 2 Chestnut Street,
Grafton, Massachusetts 01519 (hereinafter referred to as "Tenant").

                                   WITNESSETH:

     WHEREAS, the Landlord has constructed a building (hereinafter referred to
as "Building") for the purposes of office use, known as Building No. 100 located
within the area designated as Lot No. 46.24 (hereinafter referred to as "Lot No.
46.24") on the attached plot plan (hereinafter referred to as "Plot Plan") which
is annexed hereto as Exhibit "A" and made a part hereof; and

     WHEREAS, Landlord and the owner of the area designated as Lot Not 46.25
(hereinafter referred to as "Lot No. 46.25") on the Plot Plan each has the right
to operate and use the Common Areas (as hereinafter defined) within Lots 46.24
and 46.25; and

     WHEREAS, Tenant is desirous of leasing from Landlord and Landlord is
desirous of leasing to Tenant certain premises in the Building which is situated
within MIDDLESEX BUSINESS CENTER (hereafter referred to as "Center") hereinafter
described, upon and subject to the provisions, agreements, covenants and
conditions set forth herein;

     NOW, THEREFORE, it is mutually agreed as follows:

                      ARTICLE 1. DEMISED PREMISES AND TERM

     Section 1.01.

          (a) In consideration of the rents and additional rents hereinafter
reserved and all of the provisions, agreements, covenants and conditions
hereinafter contained, Landlord hereby leases and demises to Tenant, and Tenant
hereby hires, leases and takes from Landlord approximately 21,700 square feet of
floor space ("Floor Space") in the Building, more particularly indicated and
described by cross-hatching on the Plot Plan (such Floor Space being hereinafter
referred to as the "Demised Premises") located on Lot No. 46.24 in the Center
located in the BOROUGH OF SOUTH PLAINFIELD, COUNTY OF MIDDLESEX and STATE OF NEW
JERSEY, together with all improvements to be constructed thereon by the Landlord
for the use of the Tenant, and all easements, tenements and appurtenances
thereto.

          (b) The parties acknowledge that the Landlord intends to erect or has
erected other buildings on Lot No. 46.24 (which may be different in design and
construction from the Building) which buildings may be constructed at the sole
option of Landlord. Landlord shall have sole control and discretion in
connection with the scope, design and aesthetics of any such additional
construction. Notwithstanding the foregoing, any such other buildings and
improvements associated therewith shall not unreasonably interfere with access
to the Demised Premises or the loading area thereof, nor reduce the number of
parking spaces below the number required by municipal code.


                                      -1-

<PAGE>

          (c) The Demised Premises are demised and let subject to (i) the
existing state of the title thereof; (ii) any state of facts which an accurate
survey or physical inspection thereof might disclose; (iii) all zoning
regulations, restrictions, rules and ordinances now in effect or hereafter
adopted by any governmental authority having jurisdiction; and (iv) any utility,
sewer or drainage easements or agreements and the installations made pursuant
thereto now existing or hereafter granted or installed; all without
representation or warranty by Landlord, except as expressly set forth herein.
Notwithstanding the foregoing, Landlord hereby represents, that, to the best of
Landlord's knowledge: (a) the Building is presently zoned to permit the use of
the Demised Premises for typical office/laboratory purposes; and (b) any
existing utility, sewer or drainage easements or agreements and the
installations made pursuant thereto will not unreasonably interfere with
Tenant's use and occupancy of the Demised Premises. Landlord further represents
to Tenant that Landlord is presently the fee owner of the Building and is
authorized and empowered to enter into this Lease as Landlord and to perform the
obligations of Landlord hereunder.

     Section 1.02. As long as Tenant occupies the Demised Premises, Tenant,
together with its employees, customers, invitees and business guests, shall have
the right to use, in common with Landlord, its successors, assigns, tenants,
subtenants, designees, concessionaires, licensees and any of their customers,
invitees, and business guests, all of the Common Areas (as such term is defined
in Section 12.01 hereof) at any time and from time to time existing within Lot
No. 46.24, except for areas reserved for the exclusive use of other tenants,
occupants, or designees and except for periods of time during which the Common
Areas are being repaired, altered or reconstructed. Neither Landlord nor Tenant
nor anyone holding under or through either of them shall make any charge for the
use of the Common Areas to the other or to the employees, customers, invitees or
business guests of Landlord or Tenant or of anyone else hereinbefore granted the
right to use the Common Areas, except as provided in Article 12 of this Lease.

     Section 1.03. The term ("Term") of this Lease shall commence on that date
("the Commencement Date") which is the first to occur of: (a) the date upon
which the Demised Premises are first occupied by Tenant for the conduct of
business operations at the Demised Premises, or (b) the date which is thirty
(30) days following the date upon which the Landlord's Work (as hereinafter
defined) shall be duly certified by Landlord or Landlord's agent as being
substantially completed, except for those items the completion of which will not
unreasonably interfere with Tenant's use and occupancy of the Demised Premises
as provided herein, and shall expire on the date which is the FIVE (5) years
following the last day of the calendar month in which the Rent Commencement Date
(as hereinafter defined) shall occur ("Expiration Date"). Landlord represents to
Tenant that Landlord's Work shall be performed in accordance with all applicable
codes so as to enable Tenant to apply for and obtain a certificate of occupancy
for the Demised Premises upon completion of Tenant's improvements and Tenant's
fixturing and equipping of the Demised Premises. Tenant may, at any time after
execution of this Lease and prior to the Commencement Date, without incurring
any liability for payment of annual minimum rental or additional rent, measure
the Demised Premises, design and layout of the tenant improvements and Tenant's
Property (hereinafter defined), and place and install its personal property,
furniture, furnishings, signs, telecommunication equipment, equipment and trade
fixtures ("Tenant's Property"), in the Demised Premises at Tenant's risk and
expense. In exercising the foregoing rights, Tenant shall not cause any material
interference with or delay to


                                      -2-

<PAGE>

Landlord, and Tenant's indemnity provided for in this Lease shall apply to
Tenant's entry under this Section.

     Section 1.04. The parties shall, within ten (10) days following request of
the other, execute a written document, in recordable form, expressing the
Commencement Date and Expiration Date of the Term hereof, as such have been
determined in accordance with the provisions of this Lease.

     Section 1.05. The term "Lease Year" is defined to mean twelve (12)
consecutive calendar months; the first Lease Year to commence on the first day
of the succeeding calendar month following the Commencement Date and each
succeeding Lease Year to commence on the anniversary date of the commencement of
the first Lease Year. The portion of the Term prior to the first Lease Year
shall be deemed a "Partial Lease Year" and any obligations of Tenant for such
Partial Lease Year shall be prorated on a per diem basis.

                          ARTICLE 2. USE AND OPERATION

     Section 2.01. Subject to the other provisions of this Lease, Tenant shall
occupy and use the Demised Premises solely for office and laboratory purposes
and incidental uses normally associated therewith, and for no other use. Tenant
hereby covenants and agrees that it, its successors and assigns, or anyone
holding by, through or under them, shall not use, nor permit the use of the
Demised Premises for any other use or purpose. Immediately following
certification under Section 1.03 above, Tenant shall fixture, furnish and equip
the Demised Premises for Tenant's intended business purpose and upon the
Commencement Date, Tenant shall occupy and open for business in the Demised
Premises.

                                 ARTICLE 3. RENT

     Section 3.01. The annual minimum rental during the Term shall be as
follows:

     (A) During the FIRST (1st) and SECOND (2nd) years following the Rent
Commencement Date: ONE HUNDRED EIGHT FOUR THOUSAND FOUR HUNDRED FIFTY AND 00/100
($184,450.00) DOLLARS per annum - FIFTEEN THOUSAND THREE HUNDRED SEVENTY AND
00/100 ($15,370.00) DOLLARS per month;

     (B) During the THIRD (3rd) year following the Rent Commencement Date: ONE
HUNDRED NINETY FIVE THOUSAND THREE HUNDRED AND 00/100 ($195,300.00) DOLLARS per
annum - SIXTEEN THOUSAND TWO HUNDRED SEVENTY FIVE AND 00/100 ($16,275.00)
DOLLARS per month; and

     (C) During the balance of the Term of this Lease: TWO HUNDRED SIX THOUSAND
ONE HUNDRED FIFTY AND 00/100 ($206,150.00) per annum - SEVENTEEN THOUSAND ONE
HUNDRED SEVENTY NINE AND 17/100 ($17,179.17) DOLLARS per month.

     The "Rent Commencement Date" shall be the sixty-first day occurring
following the expiration of the "Rent Concession Period", in accordance with the
provisions hereinafter set


                                      -3-

<PAGE>

forth in Section 5.05 of this Lease, or as otherwise determined in accordance
with said Section 5.05.

     All annual minimum rental payable under this Lease during the Term hereof
shall be paid to the Landlord in advance, on the first day of each calendar
month during the Term hereof at the office of Landlord or such other place or to
such other person or party as Landlord may designate, without prior demand
therefor and without any setoff or deduction whatsoever, except as herein
provided. Annual minimum rent and additional rent shall be prorated for a
fraction of a month, if any, based on the number of days within such fractional
month. Unless and until otherwise designated by Landlord in writing all annual
minimum rent and additional rent payable under this Lease shall be paid to
National Realty & Development Corp., at 3 Manhattanville Road, Purchase, New
York 10577.

     Section 3.02. All taxes, charges, costs and expenses which Tenant assumes
or agrees to pay under any provision of this Lease, together with any and all
other sums and legal fees which may become due, by reason of any default of
Tenant or failure on Tenant's part to comply with the provisions, covenants and
conditions of this Lease on Tenant's part to be performed, and each or any of
them, shall be collectible and recoverable as additional rent, and, in the event
of nonpayment thereof, Landlord shall have all the rights and remedies herein
provided as in the case of nonpayment of annual minimum rent.

                            ARTICLE 4. SUBORDINATION

     Section 4.01. This Lease and all rights of Tenant hereunder are, and shall
be, subject and subordinate to any mortgages, deeds of trust (including blanket
mortgages or deeds of trust covering the Demised Premises and/or the Center
and/or other properties) or any other security interest which has been or which
hereinafter may affect the Demised Premises, and to any ground or underlying
leases of all or part of the Center, and to any renewals, modifications,
consolidations, replacements and extensions thereof (hereinafter collectively
referred to as "Landlord's Financing"). Landlord represents that, as of the date
hereof, the sole holder of Landlord's Financing is The Travelers Life and
Annuity Company, One Tower Square, 2 SHS, Hartford, Connecticut 06183. Tenant
acknowledges that the interest of Landlord under this Lease may be assigned by
Landlord as collateral security to any of the foregoing parties holding
interests to which this Lease is subject and subordinate. In the event of
foreclosure of any such interest, or termination of any such ground of
underlying lease, or in the event of an exercise of the power of sale under any
mortgage or other security interest made by Landlord covering the premises of
which the Demised Premises forms a part, Tenant shall, at the sole option and
direction of any such party, recognize the rights of any such party under and
pursuant to the provisions of such collateral assignment and/or attorn to and
recognize any purchaser at a foreclosure sale of any mortgage or deed of trust
or any such purchaser at a sale exercised in connection with the mortgagee's or
trustee's remedy of power of sale pursuant to any mortgage or deed of trust
affecting the Demised Premises and/or Center or any transferee who acquires the
Demised Premises and/or Center by deed in lieu of foreclosure, and the
successors and/or assigns of such transferee or purchaser. Notwithstanding
anything to the contrary contained herein, this Lease shall not be subject and
subordinate to the lien of Landlord's Financing, unless an instrument, duly
executed by the holder(s) of Landlord's Financing, shall be delivered to Tenant
which instrument shall contain an agreement in substance, to be effective only
so long as Tenant


                                      -4-

<PAGE>

shall not be in default under the provisions of this Lease, that such holder
shall recognize Tenant's rights under this Lease, shall not cut off or terminate
this Lease through foreclosure of the documents securing Landlord's Financing,
and Tenant shall not be disturbed in its possession of the Demised Premises or
the exercise of any of its rights under the Lease, which agreement may also
contains such provisions as are typically included therein by commercial lenders
(such agreement hereinafter referred to as the "Subordination, Non-Disturbance
and Attornment Agreement"). The Subordination, Non-Disturbance and Attornment
Agreement shall be in recordable form and in substance reasonably satisfactory
to Tenant, Landlord and the holder(s) of Landlord's Financing. Tenant
acknowledges that the form annexed hereto as Exhibit D is satisfactory to
Tenant.

     Section 4.02. The provisions of Section 4.01 shall be self-operative, but
Tenant covenants and agrees that it shall, within ten (10) days following
request, at any time or times, execute, acknowledge and deliver to Landlord any
instruments in order to subordinate this Lease and Tenant's rights hereunder, as
aforesaid, said instruments to be in the form required by any mortgagee, ground
lessor or other secured party.

     Section 4.03. If Tenant shall fail or neglect to execute, acknowledge and
deliver any documents required by this Article, Landlord, in addition to any
other remedies, may, as agent or attorney-in-fact of Tenant, execute,
acknowledge and deliver same on behalf of Tenant, and Tenant hereby irrevocably
nominates, constitutes and appoints Landlord as Tenant's proper and legal
attorney-in-fact for such purpose, hereby ratifying all such acts that Landlord
may do as attorney-in-fact of Tenant.

     Section 4.04. Tenant shall, at any time and from time to time, upon not
less than ten (10) days prior notice, execute, acknowledge and deliver to
Landlord a statement in writing certifying that this Lease is unmodified and in
full force and effect (or, if there have been modifications, that the same is in
full force and effect, as modified, and stating the modifications) and the dates
to which the rent and other charges have been paid in advance, if any, and
stating whether or not Landlord is in default in the performance of any
provision, covenant or condition contained in this Lease, and if so, specifying
each such default, and containing any other statements or certifications
required by a mortgagee, and/or ground lessor and/or other secured party, it
being intended that any statement or certification delivered pursuant to this
Section may be relied upon by any party to whom it may be delivered by Landlord.

     Section 4.05. The ground and underlying leases and mortgages referred to in
this Article 4 to which this Lease is subject and subordinate are hereinafter
sometimes called "superior leases" and "superior mortgages", respectively, and
the lessor of a superior lease, or its successor in interest at the time, is
hereinafter sometimes called the "lessor" of such superior lease. No pre-payment
of more than one month's rent shall be valid or binding upon the holder of a
superior mortgage or the lessor of a superior lease unless expressly approved in
writing by such holder or lessor or by any of its predecessors in interest.

     Section 4.06. Tenant agrees not to look to the mortgagee, as mortgagee,
mortgagee in possession, or successor in title to the Demised Premises and/or
the Center, for accountability for any security deposit required by Landlord
hereunder, unless said sums have actually been received by said mortgagee as
security for Tenant's performance of this Lease.


                                      -5-

<PAGE>

                ARTICLE 5. AS-IS; LANDLORD'S WORK; TENANT'S WORK

     Section 5.01. Tenant has examined the Demised Premises and has made a
complete inspection of same and is familiar with the physical condition thereof.
Landlord has not made and does not make any representation as to the physical
condition or any other matter affecting or relating to the Demised Premises,
except as is in this Lease specifically set forth, and Tenant specifically
acknowledges that no such representation has been made, except that Landlord
represents, to the best of its knowledge and except as disclosed in the Phase I
Environmental Assessment prepared by Environmental Management Services dated
June 19, 2000, there are no environmental hazards present within the Demised
Premises. Tenant further acknowledges that Landlord has afforded Tenant the
opportunity for a full and complete investigation, examination, and inspection
of the Demised Premises and Tenant agrees to accept the Demised Premises "as
is", except that Tenant shall replace non-functioning horns, strobes and
pullboxes in the Demised Premises, provided, however, Landlord shall reimburse
Tenant for the one-half of the cost of replacing non-functioning horns, strobes
and pullboxes in the Demised Premises (Landlord reimbursement not to exceed
$3,000), subject to Landlord's receipt and approval of the estimates for such
work, which approval shall not be unreasonably withheld or delayed, and receipt
by Landlord of satisfactory documentation evidencing the payment and lien-free
completion of such work.

     Section 5.02. Landlord or Landlord's contractor may give Tenant notice that
the Landlord's Work is substantially complete to the extent that it is
practicable for Tenant to enter therein for the performance of work by Tenant
necessary to occupy the Demised Premises and open for business, and if such
notice shall be given, Tenant shall promptly thereafter commence all work that
is necessary to open the Demised Premises for business. Subject to the foregoing
provisions of this Section, Tenant shall have the right to install its fixtures
and equipment during construction, provided Tenant does not interfere with the
construction of the Demised Premises or Building, and, further, provided, that
insurance meeting the requirements of Section 7.02 is furnished to Landlord
prior to any such entry. Such entry into the Demised Premises by Tenant prior to
the Commencement Date is and shall be at the Tenant's sole cost and risk, and
the provisions of Section 7.01 and Section 7.02 shall be applicable during any
such period prior to the Commencement Date. Prior to commencing any work, Tenant
shall give Landlord prior written notice of the date on which Tenant intends to
commence such work, which notice shall describe the type of labor (i.e. union or
non-union labor) Tenant intends to hire for its work. Notwithstanding anything
herein to the contrary, Landlord may require Tenant to use union labor for all
work performed in the Demised Premises, the Building and/or in the Center if, in
Landlord's reasonable judgment, the use of non-union labor would delay or
interfere with the progress of any construction within the Building and/or
Center and/or the operation of any business in the Building and/or Center. In
the event that Landlord does not initially require Tenant to use union labor and
a labor dispute subsequently arises due to Tenant's use of non-union labor, then
Tenant shall, within twenty-four (24) hours following notice from Landlord
(which may be oral or written), cause each conflicting labor to leave the
Demised Premises, the Building and Center, and thereafter Tenant shall prosecute
its work only with local union labor. All fixturing and/or other work to be
performed by or on behalf of Tenant (other than Landlord's work hereunder) shall
be done in accordance with plans and specifications therefor submitted to and
approved by Landlord prior to the commencement of such fixturing and/or other
work, which approval shall not be unreasonably withheld, and in accordance with
and subject to the


                                      -6-

<PAGE>

provisions of Article 19 hereof. No changes shall be made in said plans and
specifications nor shall there be any deviation in the prosecution of the work
in accordance with said plans and specifications without Landlord's prior
written approval.

     Section 5.03. If Tenant claims that some or all of the construction
requirements imposed upon Landlord pursuant to the provisions of this Lease have
not been complied with by Landlord upon delivery of notice of substantial
completion of Landlord's Work, as provided herein, Tenant shall, within ten (10)
days of said date (or ten days following the date Tenant opens for the
transaction of business, whichever date is sooner), submit to Landlord a written
list of the work Tenant claims remains to be performed by Landlord, and Landlord
shall have ninety (90) days thereafter to complete such work. If Landlord fails
to complete such work, the sole remedy of Tenant shall be to complete such work
and Tenant shall have the right to set off the cost thereof from the rent due
Landlord in order to reimburse Tenant for the cost and expense of completion of
the work. Upon written request of Landlord, Tenant will, within five (5) days
following request (but not sooner than the date required by the first sentence
of this Section), furnish to Landlord a written statement that Tenant is in
occupancy of the Demised Premises, that the construction of the Demised Premises
has been completed in accordance with Landlord's obligations or in lieu thereof,
a list of the work Tenant claims to be incomplete. Notwithstanding the
foregoing, the aforesaid time period shall not be applicable to latent defects
in the Landlord's Work for which notice may be given to Landlord promptly
following the date upon which Tenant discovers, or reasonably could have
discovered, any such latent defects. Landlord agrees to assign to Tenant all
warranties relating to the Landlord's Work, provided, however, the Landlord
reserves the right to enforce same, jointly with, or independently of Tenant.

     Section 5.04. Landlord shall substantially complete the construction of the
Landlord's Work on or prior to that date which is one hundred twenty (120) days
following the date of issuance of a building permit for the Landlord's Work to
be performed at the Demised Premises.

     If possession of the substantially completed Demised Premises shall not be
delivered to Tenant on or prior to such date, Tenant shall have the right to
cancel this Lease upon notice to Landlord to be given within fifteen (15) days
following such date, unless the substantially completed Demised Premises shall
be delivered to Tenant prior thereto. If Tenant shall not exercise such right of
cancellation, the date by which Landlord is obligated to deliver possession of
the Demised Premises shall be deemed to be automatically extended for an
additional period of ninety (90) days. If possession of the substantially
completed Demised Premises is not delivered to Tenant prior to the expiration of
such extension period, or if Tenant shall cancel this Lease pursuant to the
first sentence of this paragraph, this Lease shall automatically terminate and
be null and void and of no further force and effect, and the parties shall be
mutually released of and from all rights and obligations hereunder. Tenant's
right to cancel this Lease, as provided herein, shall be Tenant's sole remedy
for Landlord's failure to deliver possession on or before the required date.

     If the substantial completion of the Landlord's Work is delayed by reason
of: (i) any act or omission of Tenant or any of its employees, agents or
contractors; or (ii) any failure (not due to any act or omission of Landlord or
any of its employees, agents or contractors) to plan or execute Tenant's work
necessary for Tenant's occupancy of the Demised Premises with reasonable speed
and diligence, or (iii) any changes by Tenant in the plans or specifications for


                                      -7-

<PAGE>

the construction of the Demised Premises or any changes or substitutions
requested by Tenant; or (iv) Tenant's failure to furnish plans and
specifications required to be furnished by Tenant, or subsequent changes
thereto; or (v) Tenant's request for materials, finishes or installations other
than Landlord's typical building standard; or (vi) the performance or
incompletion of work by a party employed or retained by Tenant; then the
Landlord's Work shall be deemed substantially completed on the date when the
same would have been substantially completed but for such delay and, in
addition, Tenant shall pay to Landlord all costs and damages which Landlord may
sustain by reason of such delay.

     Section 5.05.

          (a) Tenant, at Tenant's sole cost and expense, subject to the Tenant
Allowance (as hereinafter defined), shall perform all work necessary to
renovate, fixture and equip the Demised Premises for Tenant's use in accordance
with the provisions of Section 2.01 of this Lease (the "Tenant Improvements").
Tenant covenants and agrees that Tenant shall commence the performance of the
Tenant Improvements within fifteen (15) days following the issuance of a
building permit, and thereafter Tenant shall diligently prosecute such Tenant
Improvements and complete same as soon as possible, but in no event more than
three (3) months from and after the date that the building permit shall have
been issued ("Tenant Improvement Completion Date"). Tenant agrees to apply for
the building permit immediately following Tenant's receipt of notice from
Landlord that Landlord has approved the plans and specifications for the
performance of the Tenant Improvements.

          (b) Subject to completion of Tenant Improvements in accordance with
Tenant's Plans (as hereinafter defined) and the provisions set forth below in
this Section 5.05(B), Landlord shall reimburse Tenant for amounts actually
expended by Tenant for a portion of the construction of the Tenant Improvements,
in an amount not to exceed the sum of $217,000.00 (the "Tenant Allowance"). Such
reimbursement shall be in the form of a credit to be taken by Tenant against the
first payments of annual minimum rental payable hereunder. The portion of the
Tenant Improvements for which the Tenant Allowance shall be paid shall be only
that portion thereof that is office installation work (e.g. partitioning, doors,
electrical, etc., including, without limitation, upgrading and replacing of
existing mechanical systems in the Demised Premises) and in no event shall the
Tenant Allowance be used for any work related to Tenant's trade fixtures or
equipment (such portion of the Tenant Improvements for which Tenant may receive
the Tenant Allowance is hereinafter called the "Tenant Allowance Work").
Supplementing the foregoing, Landlord acknowledges and agrees that the work
described in Exhibit E annexed hereto shall be deemed to be Tenant Allowance
Work. Pending the completion of the Tenant Allowance Work (which "completion"
shall be deemed to include the delivery to Landlord of the documentation
required pursuant to Subparagraph (C) of this Section 5.05, the annual minimum
rental payable pursuant to Section 3.01 of this Lease shall be abated (the
period for which annual minimum rental is abated is referred to herein as the
"Rent Concession Period"). Notwithstanding anything to the contrary set forth
herein, in the event that the Tenant Improvements have not been completed and
the documentation required pursuant to Subparagraph (C) of this Section 5.05
have not been delivered to Landlord on or before the Tenant Improvement
Completion Date, Tenant shall make immediate payment to Landlord of any monthly
minimum rental payments that have been abated during the Rent Concession Period,
the Rent Commencement Date shall be deemed to be the Commencement Date of this


                                      -8-

<PAGE>

Lease and Tenant will immediately commence payment of annual minimum rental
amounts as set forth in 3.01. Landlord shall be entitled to draw upon the letter
of credit for the purpose of collecting such unpaid minimum rental payments.
Notwithstanding the foregoing, in the event that the completion of the Tenant
Improvements and the delivery to Landlord of the documentation required pursuant
to Subparagraph (C) of this Section 5.05 has not occurred by the Tenant
Improvement Completion Date by reason of the causes set forth in Section 5.06
below, then the Tenant Improvement Completion Date shall be extended for such
period of delay, but in no event shall any such delay extend for more than an
additional three (3) months following the Tenant Improvement Completion Date. It
is further acknowledged and agreed by Tenant that in the event that the monies
expended by Tenant for the completion of the Tenant Allowance Work are less than
the amount of the Tenant Allowance, Tenant shall not be entitled to any credit
for the unused portion thereof, nor is Tenant entitled to any additional sums
from Landlord in the event that the monies expended by Tenant in connection with
the completion of the Tenant Allowance Work or the Tenant Improvements exceeds
the amount of the Tenant Allowance.

          (c) The Tenant Improvements shall be effected solely in accordance
with the plans and specifications approved by Landlord (such plans and
specifications hereinafter referred to as "Tenant's Plans"). The Tenant
Improvements shall be performed in accordance with the foregoing and the
following provisions of this Article 5:

     1. All work shall be done in a good and workmanlike manner.

     2. Tenant and its contractor and any subcontractor shall agree to employ
only such labor as will not result in jurisdictional disputes or strikes or
result in causing disharmony with other workers employed at the Building. Tenant
will inform Landlord in writing of the names of any contractor or subcontractor
Tenant proposes to use in the Demised Premises within a reasonable time prior to
the beginning of work by such contractor or subcontractor. A copy of any
contract or subcontract affecting Tenant Improvements, the Demised Premises or
the Building shall be submitted to Landlord prior to commencement of the work
provided for therein.

     3. The Tenant Improvements shall be effected in compliance with all
applicable laws, ordinances, rules and regulations of governmental bodies having
or asserting jurisdiction thereover and Tenant shall procure and furnish to
Landlord copies of all governmental permits and authorizations which may be
required in connection with such work, prior to the commencement thereof.

     4. Tenant, at its expense, and with diligence and dispatch, shall procure
the cancellation or discharge of all notices of violation arising from or
otherwise connected with work performed or alleged to have been performed by its
contractor(s) or subcontractor(s) and which shall be issued by the Borough of
South Plainfield or any other public authority having or asserting jurisdiction.
Tenant shall defend, indemnify and save harmless Landlord against any and all
mechanic's and other liens and financing or title retention devices filed in
connection therewith and against all costs, expenses and liabilities (including
reasonable attorney's fees) incurred in connection with any such lien, financing
statement, conditional bill of sale, chattel mortgage or other financing or
title retention devices, or any action or proceeding brought


                                      -9-

<PAGE>

thereon. Tenant shall keep the Land, the Building and the Demised Premises free
and clear of all liens for any work or material claimed to have been furnished
to Tenant or to the Demised Premises on Tenant's behalf, and all work to be
performed by Tenant shall be done in a manner which will not interfere with or
disturb other tenants or occupants of the Building. All notices of intention,
mechanic's liens, financing statements, conditional bills of sale, chattel
mortgages and other financing or title retention devices filed against Tenant,
the Demised Premises, or the Building for work claimed to have been done for or
materials claimed to have been furnished to Tenant shall be cancelled and
discharged of record by Tenant at its expense within ten (10) days after such
filing, by payment or filing of the bond required by law.

     Neither Tenant nor any of its agents, employees, representatives,
contractors or subcontractors shall have any power or authority to do any act or
thing or to make any contract or agreement which will bind Landlord or which may
create or be the foundation for any mechanic's lien or other lien or claim upon
or against Landlord or Landlord's interest in the Real Property; and further,
Landlord shall have no responsibility to Tenant or to any architect, engineer,
contractor, subcontractor, supplier, material man, workman or other person, firm
or corporation who shall engage in or participate in the performance of Tenant
Improvements, any additional work or any installation, alteration or improvement
to be performed or made by Tenant under any of the terms of this Lease, or
otherwise, unless Landlord shall expressly undertake such obligation by an
agreement in writing, signed by Landlord, and made between Tenant and Landlord
or such other party. Notice is hereby given that Landlord shall not be liable
for any labor or materials furnished or to be furnished to Tenant upon credit
and that no mechanic's or other lien for any such labor or materials shall
attach to or affect the reversion or other estate or interest of Landlord in and
to the Demised Premises, the Land and/or the Building. A copy of the foregoing
provisions of this paragraph shall be included in any contract entered into by
or on behalf of Tenant for the performance of or the furnishing or installation
of Tenant Work, any additional work, or any installation, alteration or
improvement to the Demised Premises.

     5. During the progress of the work to be done by Tenant, said work shall be
subject to inspection by representatives of Landlord, which shall be permitted
access and the opportunity to inspect at all reasonable times, but this
provision shall not in any way whatsoever create any obligation on Landlord to
conduct an inspection or impose any liability on Landlord for the failure of any
such work.

     6. Prior to commencement of any Tenant Work, Tenant or Tenant's contractor
shall furnish to Landlord policies of insurance or certificates thereof
evidencing the existence of the insurance coverages required by Section 7.02
hereof, including without limitation comprehensive general liability and
builder's risk insurance. Upon request by Landlord, Tenant's contractors and/or
subcontractors shall furnish to Landlord Performance Bonds and/or Completion
Bonds, in form and substance reasonably satisfactory to Landlord.

     7. Upon completion of the work, Tenant shall, at its sole cost and expense,
remove all debris from the Demised Premises and the Building, and clean the
same. If it is necessary for Landlord to do any work to clean the Building
and/or the Center or any part thereof, Tenant shall reimburse Landlord, upon
demand therefor, Landlord's cost of cleaning same, plus Landlord supervision
charges of fifteen (15%) percent.


                                      -10-

<PAGE>

     8. Upon completion of Tenant Improvements, Tenant shall submit to Landlord
in form and substance satisfactory to Landlord and counsel for Landlord the
following:

     (a) A Certificate of Completion by a licensed architect or engineer, which
Certificate shall certify that all Tenant Improvements has been completed in
accordance with the approved plans and specifications;

     (b) A certificate by Tenant, or if Tenant is a corporation by an executive
officer of Tenant, that the entire cost of Tenant Improvements has been paid and
the amount thereof, that all those who furnished work or materials have been
paid in full, and that no party has filed any lien or possesses any claim which
is unpaid or remains undischarged;

     (c) A Certificate of Occupancy, or an equivalent permit or certificate,
required by any governmental authorities prior to opening for business within
the Demised Premises;

     (d) A final release and lien waiver signed by Tenant's general contractor
and all subcontractors and materialmen, together with a certificate by the
general contractor to the effect that all those who furnished work or materials
to the Demised Premises have been paid in full and that the release and waiver
has been signed by all those who furnished work or materials to the Demised
Premises; and

     (e) Final and complete "as-built" plans (architectural and mechanical) for
the Demised Premises.

     Section 5.06. If there shall be a delay in the completion of the Landlord's
Work or repair or restoration of the Demised Premises or Center or any portion
thereof caused by strikes, riots, acts of God, shortages of labor or materials,
national emergency, governmental restrictions, laws or regulations, the act or
failure to act of Tenant, including without limitation, delays in delivering
construction criteria and plan approval, or for any other cause or causes beyond
Landlord's control, at Landlord's option such delay shall not be a violation of
this Lease, and the time periods set forth in this Lease for any such work
shall, at Landlord's option, be extended for a period of time equal to the
period of delay.

     Section 5.07. The Plot Plan shows the approximate location of existing
buildings, buildings under construction, proposed buildings and certain areas
reserved for related site improvements and future construction at the option of
Landlord. Landlord shall have the right to develop the Center in the manner it
sees fit and in the sole and absolute discretion of Landlord: to construct or
not construct any buildings other than the Building, to change the nature or
identity of the occupants of any such buildings, and to vary the floor areas,
stories and heights, sizes, shapes and design of any such buildings and the
divisions or portions thereof.

                       ARTICLE 6. ALTERATIONS AND REPAIRS

     Section 6.01. No alterations or additions shall at any time be made by or
at the instance of Tenant without Landlord's prior written consent, except that
Tenant may make alterations, the cost or value of which is not greater than
$10,000.00, without Landlord's consent, provided such alterations do not affect
the exterior or load bearing structural integrity of the Building or materially
or adversely affect the building systems serving the Demised Premises. All work,


                                      -11-

<PAGE>

repairs, and/or alterations made by or at the instance of Tenant shall be done
in a good and workmanlike manner, with first class materials, in compliance with
any applicable governmental rules and regulations, and subject to Article 19
hereof, and the cost thereof shall be paid by Tenant in cash or its equivalent,
so that the Demised Premises shall at all times be free of liens for labor or
materials supplied or claimed to have been supplied to the Demised Premises. Any
alterations, installations, repairs, additions or improvements (inclusive of
paneling and other wall coverings), except Tenant's trade fixtures, shall, at
the option of Landlord, become the property of Landlord and shall remain upon
and be surrendered with the Demised Premises, as part thereof, at the expiration
or sooner termination of the Term. If Tenant is in default hereunder or is
dispossessed, or vacates the premises, voluntarily or otherwise, and fails to
remove any property, equipment and fixtures within ten (10) days following
notice by Landlord, then and in that event, the said property, equipment and
fixtures shall be deemed, at the option of Landlord, to be abandoned; or in lieu
thereof, at the Landlord's option, Landlord may remove and store or dispose of
such property and charge the cost and expense of removal, storage and disposal
to Tenant, provided, however, Landlord's option to elect that such alterations
either remain with the Demised Premises or be removed at the Tenant's expense,
and the Landlord's determination as to whether any particular fixtures are
"trade fixtures", shall be made within thirty days (30) following Tenant's
written request to Landlord to make such determination with respect to any
particular installation of any of such alterations or fixtures. Trade fixtures
shall be defined as fixtures and equipment used by Tenant in the operation of
its business, but not including any fixtures and equipment which are part of the
operation of the Demised Premises or the Building.

     Section 6.02. Anything to the contrary contained herein notwithstanding, it
is expressly understood and agreed that Tenant may install, connect and operate
such machinery, fixtures and equipment as may be deemed necessary by the Tenant
for its business, subject to compliance with applicable rules and regulations of
governmental bodies and bureaus having jurisdiction thereover. Subject to the
terms and conditions of this Lease, the machinery, fixtures and equipment
belonging to Tenant shall, at all times, be considered and intended to be
personal property of Tenant, and not part of the realty, and subject to removal
by Tenant, provided, at the time of such removal, that Tenant is not in default
pursuant to any of the terms, covenants, provisions or conditions of this Lease.
Tenant, at its own cost and expense, shall pay for any damage to the Demised
Premises or Building caused by the installation thereof or such removal, and
this obligation shall survive the expiration or sooner termination of the Term.

     Section 6.03. Landlord shall, following reasonable notice from Tenant, make
all necessary repairs and replacements to the exterior structural portions of
the Demised Premises, including the roof and foundations thereof, provided,
however, Landlord shall not be required to make any repairs or replacements
caused by any act, omission, or negligence of Tenant, any subtenant, or
concessionaire, or their respective employees, agents, invitees, licensees or
contractors, including any repairs to the roof necessitated by roof penetrations
made by Tenant, it being understood that Landlord shall be responsible for any
roof repairs arising out of Landlord's Work. Tenant shall make all other repairs
and replacements to the Demised Premises. Tenant shall maintain throughout the
Term, including any extension term hereof, a protective service maintenance
contract with a contractor approved by Landlord, which approval shall not be
unreasonably withheld, providing for periodic maintenance of the H.V.A.C. system
serving the Demised Premises, including without limitation periodic changing of
any and all filters, changing of belts, lubricating of equipment and maintenance
of operating levels of freon in


                                      -12-

<PAGE>
accordance with manufacturers specifications. Said contract shall provide for
maintenance inspection and service not less than two (2) times per year. A copy
of any such maintenance contract shall be delivered to Landlord on a yearly
basis or more often if required by Landlord. Tenant shall keep all glass clean
and in good condition, and Tenant shall replace any glass which may be damaged
or broken with glass of the same quality. Tenant shall keep the sidewalk, if
any, adjacent to the Demised Premises free and clear of trash, litter and
rubbish.

     Section 6.04. To the extent permitted by law, nothing contained in this
Lease shall authorize Tenant to do any act which may create or be the foundation
for any lien, mortgage or other encumbrance upon the reversion or other estate
of Landlord, or of any interest of Landlord in the Demised Premises, or upon or
in the Building or Center of which the same form a part; it being agreed that
should Tenant cause any alterations, changes, additions, installations,
improvements or repairs to be made to the Demised Premises, or cause materials
to be furnished or labor to be performed therein or thereon, neither Landlord
nor the Demised Premises shall, under any circumstances, be liable for the
payment of any expense incurred or for the value of any work done or materials
furnished to the Demised Premises or any part thereof. Tenant shall, upon
request of Landlord, deliver such documents as may be required by Landlord in
order to effectuate the lien protection required by this paragraph and Section
6.01 hereof, including without limitation, waivers of lien in advance from all
contractors. All such alterations, changes, additions, improvements, repairs,
materials and labor shall be at Tenant's sole expense and Tenant shall be solely
and wholly responsible to contractors, subcontractors, laborers and materialmen
furnishing labor and material to the Demised Premises and Building or any part
thereof. If, because of any act or omission of Tenant, any mechanic's or other
lien or order for the payment of money shall be filed against the Demised
Premises or the Building or improvements thereon or therein, or upon the Center,
or against Landlord (whether or not such lien or order is valid or enforceable
as such), Tenant shall, at Tenant's own cost and expense, within ten (10) days
after notice of the filing thereof, cause the same to be canceled and discharged
of record, or furnish Landlord with a surety bond issued by a surety company
reasonably satisfactory to Landlord, protecting Landlord from any loss because
of nonpayment of such lien or claim, and Tenant hereby indemnifies and saves
harmless Landlord from and against any and all costs, expenses, claims, losses
or damages, including reasonable counsel fees, resulting therefrom or by reason
thereof.

     Section 6.05. Except for the repair obligations of Landlord under Section
6.03 above and the restoration obligations of Landlord under and as set forth in
Articles 8 and 10 hereof, the Tenant shall take good care of the Demised
Premises and, at its cost and expense, keep and maintain in good repair the
interior and exterior of the Demised Premises, including, but not limited to the
air conditioning and heating plant, the plumbing pipes and fixtures belonging
thereto; and shall repair or replace all mechanical and working parts used in
connection with the air conditioning, electrical, heating and plumbing plants,
fixtures and systems; and shall keep the water and sewer pipes and connections,
including the gutters, leaders, and roof drains, free from other obstructions;
and shall generally maintain and repair the interior and exterior of the Demised
Premises and shall, at the end or the expiration of the Term (or Extension Term,
whichever is applicable), deliver up the Demised Premises in good order and
condition, damages by the elements, ordinary wear and tear excepted. Tenant
covenants and agrees that it shall not cause or permit any waste (other than
reasonable wear and tear), damage or disfigurement to the Demised Premises, or
any overloading of the floors of the Building.


                                      -13-

<PAGE>

     Section 6.06. Landlord hereby acknowledges that Tenant may obtain financing
for its laboratory and/or office equipment, and that in such event, Tenant may
grant a security interest to such lender or equipment lessor in connection with
such financing and/or leasing. Landlord further acknowledges that such financing
or leasing by Tenant shall not be deemed to be a violation of the provisions of
Section 6.04 so long as the lien of such lender or equipment lessor extends
solely to the trade fixtures or other property of the Tenant located at the
Demised Premises, and does not attach to, affect in any manner whatsoever, the
building or property of the Landlord located at the Building, including, without
limitation, the building fixtures and equipment located in the Demised Premises.

                       ARTICLE 7. INDEMNITY AND INSURANCE

     Section 7.01.

          (a) To the extent not covered by the insurance required to be
maintained by Landlord hereunder, Tenant hereby indemnifies and saves harmless
Landlord from and against any claims and all loss, cost, liability, damage
and/or expense, including, but not limited to reasonable counsel fees, penalties
and fines, incurred in connection with or arising from (i) any default by Tenant
in the observance or performance of any of the provisions, covenants or
conditions of this Lease on Tenant's part to be observed or performed, (ii) the
use or occupancy or manner of use or occupancy of the Demised Premises by Tenant
or any person claiming through or under Tenant, or (iii) any acts, omissions, or
negligence of Tenant or any such person, or any contractor, agent, servant,
employee, visitor or licensee of Tenant, or any such person, in or about the
Demised Premises. If any action or proceeding shall be brought against Landlord
based upon any such claim, Tenant, upon notice from Landlord, shall cause such
action or proceeding to be defended, at Tenant's expense, by counsel acting for
Tenant's insurance carriers in connection with such defense or by other counsel
reasonably satisfactory to Landlord.

          (b) To the extent not covered by insurance required to be maintained
by Tenant hereunder, Landlord hereby indemnifies and saves harmless Tenant from
and against any claims and all loss, cost, liability, damage and/or expense,
including, but not limited to reasonable counsel fees, penalties and fines,
incurred in connection with or arising from (i) any default by Landlord in the
observance or performance of any of the provisions, covenants or conditions of
this Lease on Landlord's part to be observed or performed, or (ii) any acts,
omissions, or negligence of Landlord or any such person, or any contractor,
agent, servant, employee, visitor or licensee of Landlord, or any such person,
in or about the Demised Premises. If any action or proceeding shall be brought
against Tenant based upon any such claim, Landlord, upon notice from Tenant,
shall cause such action or proceeding to be defended, at Landlord's expense, by
counsel acting for Landlord's insurance carriers in connection with such defense
or by other counsel reasonably satisfactory to Tenant.

     Section 7.02. Tenant shall, during the Term (including any extension term)
and during any period prior to the commencement of the Term during which Tenant
or anyone acting by or on behalf of Tenant enters the Demised Premises, at
Tenant's own cost and expense, maintain and provide: (a) comprehensive general
liability insurance for the benefit and protection of Landlord and Tenant (said
policy to name Landlord, ground lessor, if any, and any other parties designated
by Landlord, as co-insureds) in an amount not less than $1,000,000 for injuries
or


                                      -14-

<PAGE>

death to any one person, and not less than $3,000,000 for injuries or death to
more than one person in any one accident or occurrence and for damage to
property in an amount not less than $500,000 arising out of any one accident or
occurrence; (b) plate glass insurance covering all plate glass in the Demised
Premises; (c) worker's compensation insurance covering all persons employed in
connection with Tenant's use and occupancy of the Demised Premises or any
construction or alteration work therein; (d) insurance against loss or damage to
Tenant's contents, including without limitation, trade fixtures and equipment,
by fire, lightning, and other risks from time to time included under standard
"extended coverage" policies, and vandalism and malicious mischief, in amounts
sufficient to prevent Landlord and Tenant from becoming co-insurers of any loss
under such policy, but in any event, not less than 100 percent of the full
insurable value of such property; (e) boiler and pressure vessel insurance on
all of Tenant's equipment, parts thereof and appurtenances attached or connected
to the Demised Premises which by reason of their use or existence are capable of
bursting, erupting, collapsing or exploding, in the minimum amount of Five
Hundred Thousand ($500,000.00) Dollars for damage to property resulting from
such perils; and (f) insurance covering such other risks as may be reasonably
requested by Landlord occasioned by or attributable to the use or occupancy or
manner of use or occupancy of the Demised Premises by Tenant. Said policies
shall be issued by companies satisfactory to Landlord and licensed to do
business in the state in which the Demised Premises is located. Said policies or
certificates thereof shall be delivered to Landlord at the commencement of the
Term (or prior thereto in the event of earlier entry by Tenant upon the Demised
Premises), together with proof of payment of premium therefor, and renewal
policies or certificates therefor shall be delivered to Landlord not less than
twenty (20) days prior to the expiration dates thereof. Said policies and/or
certificates shall contain an undertaking by the insurer to give Landlord not
less than twenty (20) days written notice of any cancellation or change in scope
or amount of coverage of said policies.

     Section 7.03.

          (a) Landlord shall, during the Term, maintain and provide general
hazard insurance during the course of construction (including "builder's risk
endorsements") against loss or damage to the Building by fire, lightning and
other risks from time to time included under standard "Extended Coverage"
policies, vandalism and malicious mischief, in amounts not less than 100 percent
of the full replacement value of the Building and any other building or portion
thereof covered by such insurance and rent loss insurance covering all minimum
and additional rental payable hereunder. Tenant shall pay its proportionate
share of the cost of maintaining and providing such insurance, which
proportionate share shall be a fraction having as its numerator the number of
square feet of floor area within the Demised Premises and as its denominator,
the total number of square feet of floor area of all buildings within Lot 46.24.

          (b) Such payment shall be made to Landlord, at Landlord's Option,
either annually within thirty (30) days of demand therefor or in monthly
installments on or before the first day of each calendar month, in advance, in
an amount estimated by Landlord. Periodically, Landlord shall furnish Tenant
with a written statement of the actual amount of Tenant's proportionate share of
said insurance costs. If the total amount paid by Tenant under this section for
any period during the Lease Term shall be less than the actual amount due from
Tenant for such period, as shown on such statement, Tenant shall pay to Landlord
the difference between the amount paid by Tenant and the actual amount due, such
deficiency to be paid within ten (10)


                                      -15-
<PAGE>

days after demand therefor by Landlord; and if the total amount paid by Tenant
hereunder for any such period shall exceed the actual amount due from Tenant for
such period, the excess shall promptly be applied by Landlord to the next
accruing monthly installments thereof or, at Landlord's option, to any other
charges payable by Tenant. For the calendar years in which this Lease commences
and terminates, the provisions of this section shall apply and Tenant's
liability for its proportionate share thereof for such years shall be subject to
a pro rata adjustment based on the number of days of said calendar years during
the Lease Term. Prior to or at the commencement of the Lease Term and from time
to time thereafter throughout the Lease Term, Landlord will notify Tenant in
writing of Landlord's estimate of Tenant's monthly installments due hereunder.
Tenant's obligations under this section shall survive the expiration of the
Lease Term.

     Section 7.04. Insurance coverages required of Tenant hereunder shall be
reviewed on an annual basis and Landlord may require that said coverages shall
be updated in accordance with the provisions hereinabove set forth as to amounts
and scope of coverage.

     Section 7.05. In the event of any insured loss covered under the terms and
conditions of this Lease, and for which Tenant is obligated to maintain
insurance coverage, all insurance carriers' checks in satisfaction of the same
shall be made payable to the Landlord and the holder of the first mortgage
covering the Building and Tenant waives any and all rights to be designated a
payee on such loss payment, except as to losses under the coverage in Section
7.02(d) above.

                             ARTICLE 8. FIRE DAMAGE

     Section 8.01. If the Demised Premises shall be partially damaged by fire or
other insured casualty, the damages shall be repaired by and at the expense of
Landlord and the annual minimum rental until such repairs shall be made shall
abate equitably according to the part of the Demised Premises which is unusable
by Tenant or, if by reason thereof, the Demised Premises are rendered
untenantable, said rental shall totally abate until such repairs shall be made.
Notwithstanding the foregoing, if the Demised Premises or the Building shall be
damaged to such extent that Landlord shall decide to demolish same, or not to
rebuild same, then, and in such event, Landlord may terminate this Lease upon
notice to Tenant given within ninety (90) days following such event, and upon
the date specified in such notice, which date shall not be less than thirty (30)
days nor more than sixty (60) days following the giving of said notice, this
Lease shall terminate and Tenant shall vacate and surrender the Demised Premises
to Landlord. Any annual minimum rental prepaid by Tenant beyond said date shall
be promptly refunded to Tenant. Notwithstanding any of the foregoing provisions
of this Article, if Landlord or the holder of any superior mortgage shall be
unable to collect all of the insurance proceeds (including rent insurance
proceeds) applicable to damage or destruction of the Demised Premises or the
Building by fire or other cause, by reason of some action or inaction on the
part of the Tenant or any of its employees, agents or contractors, then, without
prejudice to any other remedies which may be available against Tenant, the
abatement of Tenant's rents provided for in this Article shall not be effective
to the extent of the uncollected insurance proceeds.

     Section 8.02. If this Lease shall not be terminated as provided above in
this Article, Landlord shall, at its expense, proceed with the restoration of
the Demised Premises, provided, Landlord's obligations hereunder shall not
exceed the scope of Landlord's initial construction


                                      -16-

<PAGE>

obligations under this Lease and further provided, that Landlord's restoration
obligations shall be subject to building and zoning laws then in effect. No
penalty shall accrue for reasonable delay which may arise by reason of
adjustment of insurance on the part of Landlord. Landlord shall use diligent
efforts to adjust insurance promptly. If Landlord shall so restore the Demised
Premises, Tenant shall repair, restore and redecorate the Demised Premises and
reoccupy and reopen the Demised Premises, within fifteen (15) days following
notice of restoration, in a manner and to the condition existing prior to the
event of damage, except to the extent that Landlord is obligated above, and
Tenant shall hold in trust the proceeds of all insurance carried by Tenant on
its property for the purpose of such repair and restoration.

     Section 8.03. Nothing hereinabove contained with respect to Tenant's right
to abate the rent under proper conditions shall be construed to limit or affect
Landlord's right to payment under the rental loss coverage to be provided
pursuant to Section 7.03 hereof.

                        ARTICLE 9. WAIVER OF SUBROGATION

     Section 9.01. Landlord, its officers, agents, employees, subsidiaries and
affiliated entities and corporations shall not be liable for any damage to or
destruction of any of Tenant's goods, merchandise, fixtures, furniture or
property of whatsoever nature, caused by fire or any other cause whatsoever,
including, without limitation, the negligence of any such parties, and Tenant
hereby releases and waives any right of recovery against Landlord, its officers,
agents, employees, subsidiaries and affiliated entities and corporations for any
such loss. Tenant shall procure a waiver of subrogation on the part of the
insurer against such parties by an endorsement to all insurance policies whereby
the insurer recognizes the provisions of this Article.

     Section 9.02. Tenant, its officers, agents, employees, subsidiaries and
affiliated entities and corporations shall not be liable for any damage to or
destruction of any of Landlord's goods, merchandise, fixtures, furniture or
property of whatsoever nature, caused by fire or any other cause whatsoever,
including, without limitation, the negligence of any such parties, and Landlord
hereby releases and waives any right of recovery against Tenant, its officers,
agents, employees, subsidiaries and affiliated entities and corporations for any
such loss. Landlord shall procure a waiver of subrogation on the part of the
insurer against such parties by an endorsement to all insurance policies whereby
the insurer recognizes the provisions of this Article.

                            ARTICLE 10. CONDEMNATION

     Section 10.01. If the whole of the Demised Premises shall be taken by any
governmental authority under the power of condemnation, eminent domain, or
expropriation, or in the event of a conveyance in lieu thereof, the Term shall
cease as of the day possession shall be taken by such governmental authority. If
more than 25 percent of the Demised Premises shall be so taken or conveyed,
either Landlord or Tenant shall have the right to terminate this Lease upon
notice to the other party, effective as of the day possession shall be taken by
such governmental authority. If this Lease is so terminated, annual minimum
rental shall be prorated as of the date that possession must be surrendered to
the condemning authority.

     Section 10.02. If this Lease continues after a partial taking, the annual
minimum rental shall abate equitably as to the part of the Demised Premises
which is taken. If this Lease


                                      -17-

<PAGE>

continues after any such taking or conveyance, Landlord shall make all necessary
repairs and restorations so as to restore the remainder of the Demised Premises
to a complete architectural unit. Landlord's reconstruction obligations shall
not exceed the amount of the award or compensation for the taking, shall not
exceed the scope of Landlord's initial construction obligations hereunder, and
shall be subject to building and zoning laws then in effect.

     Section 10.03. If so much of the Center, Common Areas or Building shall be
so taken or conveyed so that in the reasonable exercise of Landlord's judgment,
the continued operation of the Building for use by its tenants is unfeasible,
then, in such event, Landlord may, by notice to Tenant, delivered not later than
thirty (30) days following the date that possession of the premises taken or
conveyed is delivered to the governmental authority, terminate this Lease, and
rent shall be pro rated as of the date that possession must be surrendered to
the condemning authority.

     Section 10.04. Tenant and not Landlord shall be entitled to any portion of
the award made to Tenant for the value of Tenant's removable trade fixtures and
equipment other than equipment necessary for the operation of the Building. All
compensation awarded for the taking of the Building, the fee and the leasehold
shall belong to and be the property of Landlord, and Tenant shall not be
entitled to and hereby waives any damages for the unexpired portion of the Term,
or injury to its leasehold interest.

                      ARTICLE 11. ASSIGNMENT AND SUBLETTING

     Section 11.01. Tenant, for itself, its heirs, distributees, executors,
administrators, legal representatives, successors and assigns, as the case may
be, expressly covenants that it shall not assign, mortgage or encumber this
agreement, nor sublet or underlet nor suffer or permit the Demised Premises or
any part thereof to be used by others without the prior written consent of
Landlord in each instance. If, with consent of Landlord, this Lease may be
assigned, or the Demised Premises or any part thereof be underlet or occupied by
anybody other than Tenant, Landlord may collect rent from the assignee,
undertenant or occupant and apply the amount collected to the rent herein
reserved, but no such assignment, underletting, occupancy or collecting shall be
deemed to relieve Tenant or any guarantor of this Lease or guarantor of the
obligations of Tenant hereunder of any of its or their obligations hereunder nor
be deemed a waiver of this covenant, or the acceptance of the assignee,
undertenant or occupant as tenant; or a release of Tenant or any guarantor of
this Lease or any guarantor of the obligations of Tenant hereunder from its or
their obligations under the covenants, provisions and conditions hereof; it
being understood and agreed that Tenant and any guarantor of this Lease or any
guarantor of the obligations of Tenant hereunder shall at all times, including
during any extension term, remain obligated as primary obligors under this
Lease. The consent by Landlord to an assignment or underletting shall not in any
wise be construed to relieve Tenant or any other Tenant, assignee, undertenant,
or occupant of the Demised Premises from obtaining the express consent in
writing of Landlord to any further assignment or underletting, and no such
assignment or subletting shall be made to anyone who shall occupy the Demised
Premises for any use other than as specifically permitted by the terms of this
Lease. Notwithstanding anything contained in this Lease to the contrary, in the
event that it shall be found by a court of competent jurisdiction that Landlord
was unreasonable in withholding its consent to the assignment of this Lease or
the subletting of all or any portion of the Demised Premises, Tenant's sole
remedy shall be limited to specific


                                      -18-

<PAGE>

performance and Tenant shall not be entitled to damages or any other affirmative
relief or remedy as a result thereof. In the event of a leveraged buy-out or
other take-over of Tenant, Landlord's consent to an assignment of this Lease or
subletting of the Demised Premises to the successor entity shall not be deemed
to have been unreasonably withheld if said successor entity shall not have a net
worth (in the event of a corporate entity, on a market value basis) as certified
to by a certified public accountant at least equal to the net worth of Tenant
upon the date of execution of this Lease.

     Section 11.02. Supplementing the provisions of Section 11.01 of this Lease,
provided Tenant is not in default under any of the terms, covenants, conditions
and provisions of the Lease, Landlord shall not unreasonably withhold or delay
or condition its consent to any proposed assignment of this Lease, or subletting
of all or any portion(s) of Demised Premises. Any assignment or transfer of this
Lease and any subletting of all or a portion of the Demised Premises shall be
subject to Landlord's prior written consent and subject to the terms of all of
the sections of this Article 11 and shall be made only if, and shall not be
effective until, the assignee or subtenant shall execute, acknowledge and
deliver to Landlord a recordable agreement, in form and substance satisfactory
to Landlord and counsel for Landlord, whereby the assignee or subtenant shall
assume for the benefit of Landlord the obligations and performance of this Lease
and agree to be personally bound by and upon all of the covenants, agreements,
terms, provisions and conditions hereof on the part of Tenant to be performed or
observed, and whereby Tenant (and any guarantor of this Lease or of the Tenant's
obligations hereunder) covenants and agrees to remain liable as a primary
obligor for the due performance of all of the covenants, agreements, terms,
provisions and conditions of this Lease on the part of Tenant to be performed or
observed. In the event of any assignment of this Lease or any subletting of all
or any portion of the Demised Premises, the obligations of Tenant and any
guarantor of this Lease or any guarantor of the obligations of Tenant under this
Lease as a primary obligor shall be unaffected and shall remain in full force
and effect.

     Section 11.03. In the event that Tenant desires to assign this Lease or
sublet all or a portion of the Demised Premises, Tenant shall first notify
Landlord in writing of its intention, and such notice shall include the
information described in the last sentence of Section 11.04 hereof and state the
name of the proposed assignee or subtenant, together with its full address and a
description of its proposed use (but nothing contained herein shall permit, nor
obligate Landlord to permit, a use other than the use permitted by Section 2.01
of this Lease, it being understood that any change in use shall be subject to
Landlord's consent, which Tenant agrees may, notwithstanding anything contained
herein to the contrary, be unreasonably withheld). Tenant shall include
therewith such financial information as may be available concerning the proposed
assignee or subtenant, including without limitation current updated financial
statements (which financial information Tenant, and/or the proposed assignee or
subtenant shall supplement on demand if required by Landlord). In addition,
Tenant shall simultaneously tender a duplicate original of the instrument of
assignment or sublease and a termination and surrender agreement in proper form,
reasonably satisfactory to counsel for Landlord ("Surrender Agreement") executed
in and on behalf of Tenant. Thereafter, Landlord shall have sixty (60) days in
which to decide whether to accept a surrender of the Demised Premises or to
respond to the notification above, it being understood that during such sixty
(60) day period Landlord shall have the right to negotiate with such assignee
and/or subtenant, without Landlord incurring any obligation whatsoever to
Tenant, for all or a portion of the Demised Premises or such other or greater or


                                      -19-

<PAGE>

lesser area of the Center as Landlord shall determine in its sole discretion. In
the event that Landlord shall accept the Surrender Agreement, Landlord shall
execute the Surrender Agreement and this Lease shall terminate as of the
sixtieth day following the day that Landlord received Tenant's notification
("Surrender Date"), with the same force and effect as if such date were the
Expiration Date. Upon the termination of this Lease pursuant hereto, Tenant
shall pay all annual minimum rent and additional rent on a pro rata basis for
each day prior to the Surrender Date. In the event that any item of additional
rent cannot be calculated as of the Surrender Date, Tenant hereby covenants to
pay its pro rata share promptly upon being billed therefor and this obligation
shall survive the Surrender Date.

     Section 11.04. Tenant hereby covenants and agrees to tender to Landlord
upon receipt fifty (50%) percent of any annual minimum rent or additional rent
or lump sum or installment payment or sum which Tenant shall receive from or on
behalf of any assignee(s) or subtenant(s) or any occupant by, through or under
Tenant, which is in excess of the annual minimum rent or additional rent payable
by Tenant in accordance with the provisions of this Lease (or in the event of a
subletting of less than the whole of the Demised Premises, the annual minimum
rent or additional rent allocable to that portion of the Demised Premises
affected by such sublease) less the actual bona-fide expenses paid by Tenant in
connection with such subletting or assignment (e.g. cost of alterations, and
brokerage, legal and architectural and engineering fees). At the time of
submission of the proposed assignment or sublease to Landlord, Tenant shall
certify to Landlord in writing whether or not the assignee or subtenant has
agreed to pay any such monies to Tenant or any designee of Tenant other than as
specified and set forth in such instruments, and if so Tenant shall certify the
amounts and time of payment thereof in reasonable detail.

     Section 11.05. Notwithstanding anything to the contrary contained in this
Article, Tenant may assign this Lease or sublet any portion of the Demised
Premises at any time during the term of this lease, without obtaining Landlord's
consent, upon Tenant giving Landlord prior written notice, to (a) another
corporation succeeding to substantially all of the assets of Tenant as a result
of a consolidation or merger or to a corporation to which all or substantially
all of the assets of Tenant have been sold; (b) a wholly-owned subsidiary
corporation; or (c) an affiliated corporation (defined as any corporation whose
majority of shares are owned or controlled by the same persons owning or
controlling the majority of shares of Tenant); provided: (i) documentation in
compliance with Section 11.02 above shall be delivered to Landlord prior to the
effective date of such assignment or sublease, and (ii) Tenant shall remain
primarily liable under all terms and conditions of this Lease (unless Tenant's
corporate existence ends as a matter of law pursuant to such consolidation or
merger).

                       ARTICLE 12. COMMON AREA MAINTENANCE

     Section 12.01. As used in this Lease, the term "Common Area Operating
Costs" shall include the total cost and expense incurred by Landlord in
operating, lighting, striping, maintaining, cleaning, landscaping, repairing
(including replacement and resurfacing) managing, signing, equipping and
insuring the Common Areas within Lot Nos. 46.24 and 46.25 plus ten (10%) percent
of the foregoing costs to cover Landlord's administrative and overhead costs.
Such costs and expenses shall include, without limitation (including appropriate
reserves): cleaning; fire and police protection and general security (Landlord
not incurring or assuming any obligation to provide such protection or security
or any liability for the failure of the same);


                                      -20-

<PAGE>

repairing and replacing paving; keeping the Common Areas supervised, drained,
reasonably free of snow, ice, rubbish and other obstructions, and in a neat,
clean, orderly and sanitary condition; the charges for rubbish containers and
removal (except that at Landlord's option, Tenant shall be directly responsible
for contracting for and for providing (subject to Landlord's approval of the
provisions and conditions of the agreement therefor) rubbish containers and
removal); the maintenance of any and all fire protection systems servicing Lot
Nos. 46.24 and 46.25; the cost of public liability insurance; keeping the Common
Areas suitably lighted; maintaining signs (other than Tenant's signs), markers,
painted lines delineating parking spaces, and other means and methods of
pedestrian and vehicular traffic control; constructing, maintaining and
repairing of onsite and offsite traffic controls; maintaining adequate roadways,
entrances and exits; maintaining any plantings and landscaped areas; Lot Nos.
46.24 and 46.25 management fees incurred by Landlord, including management fees
payable to parties or entities owned or controlled by Landlord or any of them;
maintenance and repair of all utilities, utility conduits and storm drainage
systems situated within or servicing Lot Nos. 46.24 and 46.25; fees for required
licenses and permits; and depreciation of machinery and equipment used in the
operation and maintenance of the Common Areas and personal property taxes and
other charges incurred in connection with such equipment. The term "Common
Areas" shall be defined as all paved areas, driveways, truckways, walkways, and
landscaped and planted areas within Lot Nos. 46.24 and 46.25. Landlord shall
maintain, light, clean and repair (including snow removal) the Common Areas so
that such Common Areas may be used for their intended purposes, and in order to
enable Landlord to perform its obligations as aforesaid, Landlord may incur such
Common Area Operating Costs as Landlord, in its sole discretion, may determine,
in the performance of Landlord's obligations hereunder to maintain the Common
Areas.

     Section 12.02. During the initial term of this Lease and during any
extension term hereof, Tenant shall pay Landlord Tenant's proportionate share of
Common Area Operating Costs incurred or expended by Landlord as aforesaid. Such
payment shall be made to Landlord in monthly installments on or before the first
day of each calendar month, in advance, in an amount estimated by Landlord.
Following the expiration of each calendar year during the Term hereof, Landlord
shall furnish Tenant with a written statement of the actual amount of Tenant's
proportionate share of the Common Area Operating Costs for such year. If the
total amount paid by Tenant under this section for any calendar year during the
Term shall be less than the actual amount due from Tenant for such year, as
shown on such statement, Tenant shall pay to Landlord the difference between the
amount paid by Tenant and the actual amount due, such deficiency to be paid
within ten (10) days after demand therefor by Landlord; and if the total amount
paid by Tenant hereunder for any such calendar year shall exceed such actual
amount due from Tenant for such calendar year, such excess shall promptly be
applied by Landlord to the next accruing monthly installments of Tenant's
proportionate share of Common Area Operating Costs or, at Landlord's option, to
any other charges payable by Tenant. For the calendar years in which this Lease
commences and terminates, the provisions of this section shall apply, and
Tenant's liability for its proportionate share of any Common Area Operating
Costs for such years shall be subject to a pro rata adjustment based on the
number of days of said calendar years during the Term. Prior to or at the
commencement of the Term and from time to time thereafter throughout the Term,
Landlord will notify Tenant in writing of Landlord's estimate of Tenant's
monthly installments due hereunder. Landlord shall have the right to make
special assessments from time to time for extraordinary Common Area Operating
Costs and Tenant shall pay any such special assessment within ten (10) days
following Landlord's billing therefor.


                                      -21-

<PAGE>

Extraordinary Common Area Operating Costs shall include, without limitation, any
charge not anticipated by Landlord in determining Landlord's estimate of
Tenant's proportionate share of Common Area Operating Costs for the year in
question and any charges, costs and expenses incurred by Landlord which might
cause the amounts paid by Tenant pursuant to Landlord's estimate of Tenant's
proportionate share of Common Area Operating Costs for the year in question to
be less than the amount actually due from Tenant for such year pursuant to this
Section 12.02. Tenant's obligations under this section shall survive the
expiration of the Term. Tenant's proportionate share of Common Area Operating
Costs shall be a fraction, having as its numerator, the number of square feet of
floor area within the Demised Premises and as its denominator, the total number
of square feet of floor area of all buildings within Lot Nos. 46.24 and 46.25
or, at Landlord's option, the portion thereof affected by such cost, including
the Demised Premises. Notwithstanding the foregoing provisions of this Article,
in the event the obligations of Tenant under this Article 12 are specifically
identifiable separate charges relating to Tenant and/or the Demised Premises,
then, and in such event, the obligations of Tenant under this Article 12 may, at
Landlord's option, be measured and payable in accordance with such separate and
specifically identifiable charge and not by the provisions of the preceding
sentence.

     Section 12.03. Tenant, its concessionaires, officers, employees, and agents
may use the Common Areas, subject to such reasonable rules and regulations as
Landlord may from time to time impose, including the designation of specific
areas in which vehicles owned or operated by Tenant, its concessionaires,
officers, employees and agents must be parked. Tenant shall abide by such rules
and regulations and cause its concessionaires, officers, employees, agents,
customers and invitees to conform thereto. Landlord may, at any time, close
temporarily any Common Areas to make repairs or changes therein or to effect
construction repairs or changes within Lot Nos. 46.24 and 46.25, and Landlord
may do such other acts in and to the Common Areas as in its reasonable judgment
may be desirable to improve the convenience thereof. In the event that any such
temporary closures of the Common Areas shall exceed two (2) business days,
Landlord shall use diligent efforts to arrange for appropriate alternate parking
for Tenant.

     Section 12.04. Notwithstanding anything to the contrary herein contained,
Landlord hereby reserves the right (and Tenant hereby consents thereto) to
construct or permit the construction, use and maintenance within the Common
Areas of Lot Nos. 46.24 and 46.25 including without limitation, the parking
areas, of various commercial type buildings, structures, and appurtenances, and
equipment incidental thereto, subject, however, to the provisions of the last
sentence of Section 1.01(b).

                              ARTICLE 13. UTILITIES

     Section 13.01. Tenant shall pay, as and when they shall be due and payable,
all water charges, taxes, water rates and/or meter charges, sprinkler charges
(standby or otherwise), sewer taxes, sewer charges, sewer fees, and sewer rental
taxes and charges for utilities, including, without limitation, the charges for
gas, electricity, and other utilities furnished to Tenant and consumed in the
Demised Premises. Tenant shall heat the Demised Premises whenever the weather
shall require. If Landlord, or any property of Landlord, shall be held
responsible for any expense covered by this Article, Tenant shall pay Landlord
the amount thereof within five (5) days following written request. Landlord
shall not be responsible to Tenant for any failure or


                                      -22-

<PAGE>

interruption of any such services, irrespective of the cause thereof, except the
negligence or misconduct of Landlord, or Landlord's employees agents, or
contractors.

                                ARTICLE 14. TAXES

     Section 14.01.

          (a) Subject to the reimbursement obligations of Tenant hereinafter set
forth, Landlord shall pay during the Term of this Lease, all real estate taxes
assessed or imposed upon or respecting the land and improvements within and upon
Lot No. 46.24. The term "real estate taxes" for purposes of this Lease shall
exclude income, franchise, estate or inheritance taxes levied against Landlord
or taxes based upon rental receipts, but shall include any taxes levied in lieu
of or as a substitute for real estate taxes. Tenant shall pay to Landlord, as
additional rent, at the time and in the manner set forth in Section 14.01 (b),
Tenant's proportionate share of such taxes, which proportionate share shall be a
fraction having as its numerator the number of square feet of floor area within
the Demised Premises and as its denominator, the total number of square feet of
floor area of all buildings within Lot 46.24. Notwithstanding the foregoing, if
the improvements within the Demised Premises and/or the balance of the
improvements or any part thereof upon Lot No. 46.24 shall receive a separate
assessment based upon the certification of the Tax Assessor, then the taxes
payable by Tenant for such improvements may, at Landlord's option, be based
thereon.

          (b) All amounts payable by Tenant pursuant to this Article shall be
paid to Landlord in monthly installments on or before the first day of each
calendar month, in advance, in an amount estimated by Landlord; provided, that
in the event Landlord is required under any mortgage encumbering Lot No. 46.24
to escrow real estate taxes, Landlord may, but shall not be obligated to, use
the amount required to be so escrowed as a basis for its estimate of the monthly
installments due from Tenant hereunder. As soon as shall be reasonably
practicable following the expiration of each calendar year during the Term,
Landlord shall furnish Tenant with a written statement of the actual amount of
Tenant's share of the taxes for such year. If the total amount paid by Tenant
under this Section for any calendar year during the Term shall be less than the
actual amount due from Tenant for such year, as shown on such statement, Tenant
shall pay to Landlord the difference between the amount paid by Tenant and the
actual amount due, such deficiency to be paid within ten (10) days after demand
therefor by Landlord; and if the total amount paid by Tenant hereunder for any
such calendar year shall exceed such actual amount due from Tenant for such
calendar year, such excess shall be applied by Landlord to the next accruing
monthly installments of taxes due from Tenant or, at Landlord's option, to any
other charges payable by Tenant. For the calendar years in which this Lease
commences and terminates the provisions of this Section shall apply, and
Tenant's liability for its share of taxes for such years shall be subject to a
pro rata adjustment based on the number of days of said calendar years during
the Term. Prior to or at the commencement of the Term and from time to time
thereafter throughout the Term, Landlord may notify Tenant in writing of
Landlord's estimate of Tenant's monthly installments due hereunder. Landlord
shall have the right to make special assessments from time to time for
extraordinary real estate taxes and Tenant shall pay any such special assessment
within ten (10) days following Landlord's billing therefor. Extraordinary real
estate taxes shall include, without limitation, any charge not anticipated by
Landlord in determining Landlord's estimate of Tenant's proportionate share of
real estate taxes


                                      -23-

<PAGE>

for the year in question and any real estate taxes incurred by Landlord which
might cause the amounts paid by Tenant pursuant to Landlord's estimate of
Tenant's proportionate share of real estate taxes for the year in question to be
less than the amount actually due from Tenant for such year pursuant to this
Section 14.01(b). Tenant's obligations under this Section shall survive the
expiration of the Term.

     Section 14.02. Tenant shall be liable for all taxes on or against property
and trade fixtures and equipment placed by Tenant in or about the Demised
Premises, and all taxes on Tenant's right to occupy the Demised Premises. If any
such taxes are levied against Landlord or Landlord's property, and if Landlord
pays same, or if the assessed valuation of Landlord's property is increased by
the inclusion therein of a value placed upon such property, and if the Landlord
pays the taxes based on such increased assessment, Tenant, upon demand, shall
repay to Landlord the taxes so paid by Landlord or the portion of such taxes
resulting from such increase in assessment.

                        ARTICLE 15. REMEDIES OF LANDLORD

     Section 15.01.

          (a) If Tenant shall default in the payment of the annual minimum
rental reserved herein, or in the payment of any item of additional rent or
other monies due hereunder, or any part of same, and any such default shall
continue for more than five (5) days after written notice of such default; or

          (b) If Tenant shall default in the observance of any of the
provisions, covenants and conditions of this Lease (other than a default covered
by subsection (a) above and other than sections hereof which provide a specific
period or date for performance), and such default shall continue for more than
twenty (20) days after written notice of such default, or for such other period
provided in the relevant section hereof provided, however, that Tenant shall not
be in default if Tenant commences to cure such default within said twenty (20)
day period and thereafter diligently pursues said cure; or

          (c) If Tenant shall fail to occupy the Demised Premises and open for
business at the commencement of the Term of this Lease, as above provided, or if
the Demised Premises shall be abandoned, deserted or vacated for a period
exceeding three (3) consecutive months, or if Tenant shall sublet the Demised
Premises or assign this Lease, except as herein provided, or if Tenant shall be
in default under any other obligations of Tenant to Landlord of any nature
whatsoever, including in connection with any other lease between Tenant and any
of the Landlords or between Tenant and any entity in which any partner of
Landlord holds an interest; or

          (d) If Tenant or any guarantor of Tenant's obligations hereunder shall
make an assignment for the benefit of creditors, or if any such party shall file
or have filed against it a petition in bankruptcy, or be adjudicated a bankrupt
by any court and such adjudication shall not be vacated within thirty (30) days,
or if Tenant or any guarantor of Tenant's obligations hereunder takes the
benefit of any insolvency act, or if Tenant or any guarantor of Tenant's
obligations hereunder be dissolved voluntarily or involuntarily or have a
receiver of its property


                                      -24-

<PAGE>

appointed in any proceedings other than bankruptcy proceedings and such
appointment shall not be vacated within thirty (30) days after it has been made,
or if any levy, sale or execution of any kind is made upon or of any property of
Tenant in the Demised Premises; or

          (e) If, within any period of three hundred and sixty-five consecutive
days: (i) Tenant shall default (the "First Default") in any of its obligations
under this Lease and notice thereof shall be given to Tenant as provided above;
and (ii) Tenant shall default under this Lease for a second time (the "Second
Default") (notwithstanding that Tenant may have cured the First Default) and
notice thereof shall be given to Tenant as provided above, and (iii) Tenant
shall default under this Lease for a third time (the "Third Default")
(notwithstanding that Tenant may have cured the First Default and/or the Second
Default) and notice thereof shall be given to Tenant as provided above, and the
First Default, Second Default and Third Default shall be similar (without
limiting the definition of the term "similar", with respect to non-monetary
defaults, all monetary defaults shall be deemed to be similar to each other);

then, upon the happening of any one or more of the defaults or events specified
above, at the option of Landlord: (1) this Lease and the Term hereof shall
wholly cease and terminate, with the same force and effect as though such
termination was the date of the expiration of the Term of this Lease, and
thereupon, or at any time thereafter, Landlord may re-enter said premises either
by force, or otherwise, and have possession of the same and/or may recover
possession thereof by summary proceeding, or otherwise (but Tenant shall remain
liable to Landlord as hereinafter provided); or (2) Landlord may, without
further notice, exercise any remedy available at law or in equity.

     Section 15.02. In case of any default, event, re-entry, expiration,
termination and/or dispossession by summary proceedings, or otherwise, Tenant
shall, nevertheless, remain and continue liable to Landlord in a sum equal to
all annual minimum rental and additional rent herein reserved for the balance of
the Term herein demised as the same may become due and payable pursuant to the
provisions of this Lease. Landlord may repair or alter the Demised Premises in
such manner as to Landlord may seem necessary or advisable, and/or let or relet
the Demised Premises and any and all parts thereof for the whole or any part of
the remainder of the original Term hereof or for a longer period, in Landlord's
name, or as the agent of Tenant, and, out of any rent so collected or received,
Landlord shall, first, pay to itself, the expense and cost of retaking,
repossessing, repairing and/or altering the Demised Premises, and the expense of
removing all persons and property therefrom, second, pay to itself, any cost or
expense sustained in securing any new tenant or tenants, and third, pay to
itself, any balance remaining on account of the liability of Tenant to Landlord
for the sum equal to the annual minimum rental and additional rent reserved
herein and unpaid by Tenant for the remainder of the Term herein demised. Any
entry or re-entry by Landlord, whether had or taken under summary proceedings or
otherwise, shall not absolve or discharge Tenant from liability hereunder.

     Section 15.03. Should any rent so collected by Landlord after the payment
aforesaid be insufficient fully to pay to Landlord a sum equal to all annual
minimum rental and additional rent herein reserved, the balance or deficiency
shall be paid by Tenant on the rent days herein specified; that is, upon each of
such rent days Tenant shall pay to Landlord the amount of the deficiency then
existing and Tenant shall be and remain liable for any such deficiency, and the
right of Landlord to recover from Tenant the amount thereof, or a sum equal to
the amount of all


                                      -25-

<PAGE>

annual minimum rental and additional rent herein reserved if there shall be no
reletting, shall survive the issuance of any dispossessory warrant or other
termination hereof.

     Section 15.04. Suit or suits for the recovery of such deficiency or damage,
or for a sum equal to any installment or installments of annual minimum rental
or additional rent hereunder, may be brought by Landlord from time to time at
Landlord's election, and nothing herein contained shall be deemed to require
Landlord to await the date on which this Lease or the Term hereof would have
expired by limitation had there been no such default by Tenant or no such
termination or cancellation.

     Section 15.05. Tenant hereby expressly waives service of any notice of
intention to re-enter subsequent to the giving of the aforesaid notices under
Section 15.01 above. Tenant hereby expressly waives any and all right to recover
or regain possession of the Demised Premises or to reinstate or to redeem this
tenancy or this Lease as is permitted or provided by or under any statute, law,
or decision now or hereafter in force and effect.

     Section 15.06. Tenant shall reimburse Landlord, within five (5) days
following written demand, for any reasonable counsel fees or collection charges
actually incurred or expended by Landlord by reason of Tenant's default in the
performance of any provision, covenant, or condition of this Lease and any such
amounts, at the option of Landlord, may be recovered in the same action or
proceeding forming the basis of the default or in another action or proceeding.

     Section 15.07. Notwithstanding any other remedy provided for hereunder and
without the requirement of notice, except as provided in this Section, if Tenant
shall not comply with any of its obligations hereunder, Landlord shall have the
right, at Landlord's sole option, at anytime in the event of an emergency or
otherwise after ten (10) days notice to Tenant, to cure such breach at Tenant's
expense. Tenant shall reimburse Landlord, within ten (10) days following demand,
as additional rent, for all costs and expenses incurred by Landlord in curing
such breach, together with interest computed thereon at the rate of eighteen
(18%) percent per annum or the maximum rate permitted by law, whichever shall be
the lesser.

     Section 15.08. Notwithstanding anything to the contrary contained in this
Lease, if Tenant fails to pay any rent, additional rent or any other money item
due hereunder within thirty (30) days after same are due and payable, Landlord
shall have the right (in addition to any other rights or remedies of Landlord
and without the requirement of any notice) to commence immediate legal
proceedings or action for dispossession and damages or Landlord may avail itself
of any other remedies at law or in equity and include in such action or
proceeding any amounts then due and payable as of the date of the commencement
of such action or proceeding. Notwithstanding anything contained in this Lease,
if Tenant fails to pay any monetary items due hereunder on the date on which the
same are due and payable, a late charge of four ($.04) cents for each ONE
($1.00) DOLLAR so overdue shall become immediately due and payable to the
Landlord as damages for failure to make prompt payment and the same shall be
considered as additional rent hereunder payable together with the next
installment of monthly rent. In addition, all such unpaid monetary items shall
bear interest at the maximum rate permitted by law from the date such monies
were due until the date on which Landlord shall receive payment.


                                      -26-

<PAGE>

     Section 15.09. The rights and remedies whether herein or elsewhere provided
in this Lease shall be cumulative and the exercise of any one right or remedy
shall not preclude the exercise of or act as a waiver of any other right or
remedy of Landlord hereunder, or which may be existing at law, or in equity, by
statute or otherwise.

     Section 15.10. Tenant covenants and agrees to give any mortgagee and/or
ground lessor of the Center or any portion thereof notice of any default by
Landlord under this Lease and such mortgagee and/or ground lessor shall be
afforded the right (but shall not have the obligation) to cure any default by
Landlord within such reasonable period of time as may be required by such
mortgagee and/or ground lessor.

                       ARTICLE 16. WAIVER OF TRIAL BY JURY

     Section 16.01. It is mutually agreed by and among Landlord, Tenant and any
guarantor of the obligations of Tenant hereunder, that the respective parties
hereto shall and they hereby do waive trial by jury in any action, proceeding,
or counterclaim brought by the parties hereto on any matters whatsoever arising
out of or in any way connected with this Lease, the relationship of Landlord and
Tenant, Tenant's use or occupancy of the Demised Premises, and/or any claim of
injury or damage, and any emergency, summary or statutory remedy. If Landlord
commences any summary proceeding, or any other action for collection of rent or
additional rent hereunder, Tenant shall not interpose any counterclaim or cross
claim of any nature in any such proceeding or action, nor shall Tenant move to
consolidate any such claim with any claim being maintained by Landlord.

                         ARTICLE 17. ACCESS TO PREMISES

     Section 17.01. Landlord and its designees shall have the right to enter
upon the Demised Premises at all times during normal business hours and upon
twenty four (24) hours telephonic notice to Tenant's designated representation
at the Demised Premises (except in emergency situations) to inspect and examine
same, to make repairs, additions, alterations, or improvements to the Demised
Premises, the Building within which the Demised Premises are located or any
property owned or controlled by Landlord within such Building. In the case of
emergency situations, Landlord may have access to the Demised Premises but shall
still be required to give telephonic notice to Tenant's designated
representative at the Demised Premises within a reasonable time following
Landlord's gaining access to the Demised Premises. Any work performed by
Landlord shall be performed in such a manner so as not to interfere with any
ongoing experiments being conducted by Tenant at the Demised Premises.
Landlord's rights of entry as aforesaid, and the taking of all property into and
upon the Demised Premises that may be required in connection therewith, shall
not be considered an eviction of Tenant, in whole or in part, constructive or
otherwise, and Landlord shall not be liable to Tenant for any expense, damage,
or loss or interruption of the business of Tenant by reason thereof, and the
rent reserved hereunder shall continue without abatement during the period of
any such entry and while such repairs, alterations, improvements or additions
are being made. Landlord or Landlord's designees shall have the right to enter
the Demised Premises at all times to show the Demised Premises to prospective
purchasers, mortgagees or lessees of the Demised Premises, the Building or the
Center. During the six month period prior to the expiration of the Term hereof,
Landlord may exhibit the Demised Premises to prospective tenants and Landlord
may place upon the


                                      -27-

<PAGE>

Demised Premises notices reading, "To Let" or "For Rent", which notices Tenant
shall allow to be posted conspicuously without molestation.

                              ARTICLE 18. NO WAIVER

     Section 18.01. No delay or omission of the exercise of any right by either
party hereto shall impair any such right or shall be construed as a waiver of
any default or as acquiescence therein. One or more waivers of any provision,
covenant, or condition of this Lease by either party shall not be construed by
the other party as a waiver of a subsequent breach of any other or the same
provisions, covenant, or condition. No requirements whatsoever of this Lease
shall be deemed waived or varied because of either party's failure or delay in
taking advantage of any default, and Landlord's acceptance of any payment from
Tenant with actual or constructive knowledge of any default shall not constitute
a waiver of Landlord's rights in respect to such default, nor of any subsequent
or continued breach of any such default or any other requirement of this Lease.

     Section 18.02. No payment by Tenant or receipt and acceptance by Landlord
of a lesser amount than the rent or other sum stipulated to be paid or reserved
shall be deemed an accord and satisfaction or a modification or waiver of any
rights or obligations or liabilities hereunder notwithstanding any statement,
written or oral, accompanying such payment, or by way of endorsement or
otherwise; and Landlord may accept any such payment whether by check, draft or
other means whatsoever without prejudice to Landlord's right to recover the
balance owing, or to pursue any other remedy in this Lease or at law or in
equity provided. Landlord may apply such payment to any sums then due and
payable by Tenant to Landlord as Landlord shall determine in its sole
discretion. Landlord may, at Landlord's option, accept payment of rent or any
other charge hereunder from any person or entity other than the Tenant named
herein and the same shall not constitute a recognition by Landlord of, or vest
in said person or entity, any rights hereunder.

             ARTICLE 19. REQUIREMENTS OF LAW; INSURANCE REQUIREMENTS

     Section 19.01. In Tenant's performance of its rights and obligations under
this Lease, including without limitation, any pre-term right, obligation or
entry into the Demised Premises, Tenant covenants and agrees to comply with all
laws, orders, and regulations of federal, state, city, county, governmental and
municipal authorities, fire insurance rating organizations and fire insurance
underwriters, and insurance companies issuing coverage respecting the Demised
Premises and Tenant shall make all alterations or installations necessary to
comply therewith. Tenant shall secure all permits or approvals necessary to
operate its business within the Demised Premises and shall only operate its
business within the Demised Premises in compliance with all laws, orders and
regulations of federal, state, city and county, governmental and municipal
authorities, fire insurance rating organizations and fire insurance
underwriters, and insurance companies issuing coverage respecting the Demised
Premises.

     Section 19.02. Tenant shall not use or occupy the Demised Premises or do or
permit anything to be done therein in any manner which shall make it impossible
for Landlord and/or Tenant to obtain at standard rates any insurance required or
desired, or which will invalidate or increase the cost to Landlord of any
insurance. Landlord hereby acknowledges that Tenant shall


                                      -28-

<PAGE>

be permitted to use and occupy the Demised Premises for the chemical and
biological laboratory research contemplated to be conducted in the Demised
Premises, provide same is conducted in accordance with industry standards and
the requirements of all applicable governmental authorities.

     Section 19.03. If, by reason of Tenant's failure to comply with the
provisions of Section 19.01 above, or if, by reason of any act or failure to act
of Tenant, its agents, servants, contractors, employees or licensees, or if, by
reason of the use of the Demised Premises, the fire insurance rates applicable
to the Demised Premises, or of the Building or any other premises in said
Building, shall be increased above the rate applicable to the occupancy
permitted hereunder, Tenant shall pay to Landlord, within three (3) days
following demand, the amount of additional premium for fire insurance payable by
reason thereof.

     Section 19.04. No abatement, diminution, or reduction in annual minimum
rental or any sums constituting additional rent shall be claimed by or allowed
to Tenant for any inconvenience or interruption, cessation or loss of business
caused directly or indirectly, by any present or future laws, ordinances, rules
or regulations, requirements or orders of federal, state, county, township or
municipal governments or any other lawful authority whatsoever, or by
priorities, rationing, or curtailment of labor or materials, or by war, civil
commotion, strikes or riots, or any manner or thing resulting therefrom, or by
any other cause or causes beyond the control of Landlord, nor shall this Lease
be affected by any such causes.

                                ARTICLE 20. SIGNS

     Section 20.01. Tenant shall not place, install or maintain any sign upon or
outside the Demised Premises or in the Center until approved by Landlord, nor
shall Tenant place, install or maintain any sign within one-half mile of the
Center; nor shall Tenant place, install or maintain any awning, canopy, aerial,
antenna or the like in or upon the Demised Premises, the Building or the Center.
Landlord's approval of Tenant's signs shall not be unreasonably withheld,
conditioned or delayed. Any sign must conform to all applicable rules,
regulations, codes and directives of governmental agencies having jurisdiction,
and Tenant shall, at its expense, apply for and obtain all permits necessary in
connection therewith. If Landlord shall submit to Tenant a general sign criteria
or specification, Tenant shall comply therewith. Tenant shall be solely
responsible for all maintenance and repairs respecting its signs.

                    ARTICLE 21. TENANT'S ADDITIONAL COVENANTS

     Section 21.01. Tenant covenants and agrees for itself, its officers,
employees, contractors, agents, servants, licensees, invitees, subtenants,
concessionaires, and all others doing business with Tenant (hereinafter for the
purposes of this Article, collectively referred to as "Tenant") that:

          (a) Tenant shall execute such further assurances and/or guarantees
which are stated by Landlord as intended to be necessary to secure the approval
of Tenant's credit rating;

          (b) Tenant shall not encumber or obstruct the Center or sidewalks in
and about the Demised Premises;


                                      -29-

<PAGE>

          (c) Tenant shall not display, advertise or sell its products or goods
in the Common Areas of the Center or sidewalk in and about the Demised Premises;

          (d) Intentionally omitted.

          (e) Tenant shall not cause or permit trash, refuse, dirt or other
rubbish to accumulate on the Demised Premises or in the Center and shall cause
same to be promptly removed;

          (f) Tenant shall not injure, overload, deface, commit waste or
otherwise harm the Demised Premises or any part thereof;

          (g) Tenant shall not commit any nuisance;

          (h) Tenant shall not permit the emission from the Demised Premises of
any objectionable noise or odor. Normal laboratory practices conducted in
accordance with industry standards and the requirements of governmental
authorities shall be excepted from the foregoing;

          (i) Tenant shall not burn any trash, rubbish, dirt or refuse within
the Center;

          (j) Tenant shall use the Demised Premises only for business and
commercial purposes (subject to the provisions of Article 2 hereof) and Tenant
shall not use, allow or permit any industrial, manufacturing or processing
activities within the Demised Premises, except as may be expressly permitted by
Section 2.01 of this Lease;

          (k) Tenant shall conform and comply with all nondiscriminatory and
uniformly applicable rules and regulations which Landlord may promulgate for the
management and use of the Center;

          (l) Tenant shall not use any advertising medium that may constitute a
nuisance, such as loudspeakers, sound amplifiers or phonographs, in a manner to
be heard outside the Demised Premises;

          (m) Intentionally omitted.

          (n) Tenant shall not place a load on any floor of the Demised Premises
exceeding the floor load per square foot which such floor was designed to carry;

          (o) Tenant shall not install, operate or maintain in the Demised
Premises any electrical equipment which will overload the electrical system
therein or any part thereof beyond the capacity for proper and safe operation,
as determined by Landlord, in relation to the overall system and requirements
for electricity in the Building;

          (p) Tenant shall not install, operate, or maintain any electrical
equipment in the Demised Premises which does not bear underwriters approval; and

          (q) No portion of the Demised Premises shall be used or occupied for
the sale, dispensing, storage or display of food, foodstuffs, or food products
for consumption on or off the


                                      -30-
<PAGE>

Demised Premises, provided that the foregoing shall not prohibit the use and
occupancy of the Demised Premises as permitted by Section 2.01 hereof, and
further provided that the foregoing shall not prohibit vending machines,
refrigerators, microwave ovens or other food service areas maintained by Tenant
for the use of Tenant's employees and visitors.

                      ARTICLE 22. EASEMENTS FOR UTILITIES

     Section 22.01. Landlord or its designee shall have the right and Tenant
shall permit Landlord or its designee to erect, use, maintain and repair pipes,
cables, conduits, plumbing, vents and wires in, to and through the Demised
Premises as and to the extent that Landlord may now or hereafter deem necessary
or appropriate for the use or proper operation and maintenance of the Demised
Premises, or the Building or any other portion of the Center. Landlord's rights
under this Article shall be exercised, as far as practicable, in such manner as
to avoid unreasonable interference with Tenant's occupancy of the Demised
Premises.

                       ARTICLE 23. CONSENTS AND APPROVALS

     Section 23.01. With respect to any provision of this Lease providing that
Landlord shall not unreasonably withhold or unreasonably delay any consent or
any approval, Tenant, in no event, shall be entitled to make, nor shall Tenant
make, any claim for, and Tenant hereby waives any claim for money damages; nor
shall Tenant claim any money damages by way of setoff, counterclaim or defense,
based upon any claim or assertion by Tenant that Landlord has unreasonably
withheld or unreasonably delayed any consent or approval; but Tenant's sole
remedy shall be an action or proceeding to enforce any such provision, or for
specific performance, injunction or declaratory judgment.

                         ARTICLE 24. CONTROL OF TENANT

     Section 24.01. If Tenant hereunder is a corporation (other than a
corporation whose shares are regularly and publicly traded on a duly recognized
stock exchange), Tenant represents that ownership and power to vote its entire
outstanding capital stock is vested in the officers executing this Lease or the
members of their immediate families. If there shall be any change in the
ownership of and/or power to vote the majority of said outstanding capital
stock, without the prior written consent of Landlord, then, and in such event,
Landlord shall have the option to terminate this Lease upon not less than thirty
(30) days notice to Tenant.

                        ARTICLE 25. END OF TERM HOLDOVER

     Section 25.01. If the last day of the Term falls on a Sunday, or legal
holiday, this Lease shall expire on the business day immediately following. Upon
the expiration or other termination of the Term of this Lease, Tenant shall quit
and surrender to Landlord the Demised Premises, together with all buildings and
improvements thereon, "broom-clean" and in good order and condition, ordinary
wear and tear and damage by the elements excepted, and Tenant shall thereupon
remove all property of Tenant which shall be deemed to include, without
limitation, the removal of all of Tenant's laboratory equipment and fixtures
such as laboratory hoods and benches, including the capping of all utilities for
such equipment, but shall not include the removal of the acid neutralization pit
and tank. In the event Tenant fails to remove such property, Landlord may cause
all of the said property to be removed, stored and/or disposed of at


                                      -31-

<PAGE>

the expense of Tenant. Tenant shall pay all costs and expenses thereby incurred.
Any property not so removed shall be deemed to have been abandoned by Tenant and
may be retained or disposed of by Landlord as Landlord, in its sole discretion,
shall determine and Tenant hereby releases Landlord from all claims for loss or
damage to such property arising out of such retention or disposition thereof.
Tenant's obligations under this Article shall survive the expiration or other
termination of the Term.

     Section 25.02. If Tenant remains in possession of the Demised Premises at
the expiration or earlier termination of the Term hereof, Tenant, at Landlord's
option, shall be deemed to be occupying the Demised Premises as a tenant from
month to month, at a monthly rental equal to the greater of (i) one and one-half
times the sum of the monthly installment of annual minimum rent payable during
the last month of the Term hereof or (ii) twice the sum of the then prevailing
market rate rent, as determined by Landlord at its sole and absolute discretion,
plus all additional rent coming due hereunder. Acceptance by Landlord of rent
after the expiration or earlier termination of the Term hereof shall not
constitute a consent to a month-to-month tenancy or result in a renewal. In the
event of such holdover, Tenant's occupancy of the Demised Premises, except as
aforesaid, shall be subject to all other conditions, provisions and obligations
of this Lease, but only insofar as the same are applicable to a month to month
tenancy. Such month to month tenancy shall be terminable by Landlord upon one
(1) month's notice to Tenant, and if Landlord shall give such notice, Tenant
shall quit and surrender the Demised Premises to Landlord as above provided. In
the event that (a) Tenant shall remain in possession of the Demised Premises at
the expiration or earlier termination of the Term hereof and Landlord shall not
have elected to deem Tenant to be occupying the Demised Premises as a tenant
from month-to-month or (b) Landlord shall terminate any month-to-month tenancy
of the Demised Premises and Tenant shall fail to quit and surrender the Demised
Premises to Landlord upon the termination date as above provided, then, in
either such event, Tenant shall be liable to Landlord for all losses, damages,
claims, costs and/or expenses incurred by Landlord by reason of Tenant's failure
to deliver timely possession of the Demised Premises to Landlord, including,
without limitation, any consequential and incidental damages so incurred by
Landlord, including, without limitation, any losses, damages, claims, costs
and/or expenses incurred in connection with or arising from the inability of
Landlord to lease and deliver possession of the Demised Premises, or any portion
thereof, to any third party and/or the termination or cancellation of any lease
of the Demised Premises, or any portion thereof to any third party.

     Section 25.03. Notwithstanding anything to the contrary contained in this
Lease, if Landlord shall be unable to provide possession of the Demised Premises
because of the holding-over or retention of possession of any prior tenant,
undertenant or occupants, or for any other reason whatsoever, Landlord shall not
be subject to any liability for the failure to give possession on the date
herein provided, if any, and the validity of this Lease shall not be impaired
under such circumstances, but the Term shall be extended proportionately until
after Landlord shall have given Tenant written notice that the Demised Premises
are ready for Tenant's occupancy. If permission is given to Tenant to enter into
possession of the Demised Premises or to occupy premises other than the Demised
Premises prior to the date specified as the commencement of the Term, Tenant
covenants and agrees that such occupancy shall be deemed to be under all of the
terms, covenants, conditions and provisions of this Lease.


                                      -32-

<PAGE>

                        ARTICLE 26. AUTHORITY TO EXECUTE

     Section 26.01. Landlord and Tenant do hereby respectively represent to the
other that it has the capacity to enter into this Agreement.

                              ARTICLE 27. NOTICES

     Section 27.01. All notices to be given pursuant to this Lease shall be in
writing and sent by prepaid certified or registered U.S. mail, return receipt
requested, or by a recognized overnight courier service which requires
acknowledgment of receipt of delivery from addressee, to the address of the
parties below specified or at such other address as may be given by written
notice in the manner prescribed in this paragraph. Landlord's address for notice
shall be c/o National Realty & Development Corp., 3 Manhattanville Road,
Purchase, New York 10577. Tenant's address for notices given prior to the
Commencement Date shall be the address first set forth above for Tenant.
Tenant's address for notices given on or subsequent to the Commencement Date
shall be the address of the Demised Premises. Notice shall be deemed to be given
upon delivery to the U.S. Postal Service or recognized overnight courier
service. Unless Landlord shall otherwise inform Tenant in writing to the
contrary, any notice given to Tenant by National Realty & Development Corp.
shall, for the purposes of this Lease, be deemed to be a notice given to Tenant
by Landlord.

                               ARTICLE 28. BROKER

     Section 28.01. Tenant covenants, warrants and represents that it has dealt
with no broker except Colliers Houston & Co., 200 Cottontail Lane, Somerset, New
Jersey 08873 ("Colliers/Houston") respecting this Lease and that no
conversations, correspondence or negotiations were had with any broker except
with said Colliers/Houston concerning the renting or leasing of the Demised
Premises. Tenant shall hold Landlord and National Realty & Development Corp.
harmless and defend (by counsel satisfactory to Landlord) said parties against
any claims for a brokerage commission arising out of any conversations,
correspondence or negotiations with any broker except said Colliers/Houston.
Landlord shall pay any commissions owing to said Colliers/Houston in accordance
with separate agreement.

                        ARTICLE 29. MEMORANDUM OF LEASE

     Section 29.01. Tenant agrees not to record this Lease. The parties agree,
upon request of either, to execute, in recordable form, a short form lease
entitled "Memorandum of Lease", it being the intention of the parties that this
Lease will not be recorded, but only a memorandum thereof. Such short form lease
shall contain those provisions of this Lease as shall be desired in the
reasonable discretion of counsel for the parties hereto, provided that in no
event shall such short form lease contain any provisions relevant to the annual
minimum rent and/or additional rent payable under this Lease.

                      ARTICLE 30. AIR AND WATER POLLUTION

     Section 30.01.


                                      -33-

<PAGE>

          (a) Tenant hereby indemnifies and saves Landlord harmless against any
claim, damage, liability, costs, penalties or fines which the Landlord may
suffer as a result of air, land or water pollution caused by Tenant in its use
or occupancy or manner of use or occupancy of the Demised Premises or in its
storage, handling, possession, transportation and/or disposal of any Hazardous
Waste or Hazardous Substance (as such terms are hereafter defined) within or
about the Demised Premises. Tenant covenants and agrees to notify Landlord
immediately of any claim or notice served upon it with respect to any such claim
that Tenant is causing air, land or water pollution; and Tenant, in any event,
will take immediate steps to halt, remedy and cure any pollution of air, land or
water caused by Tenant by its use of the Demised Premises, at its sole cost and
expense.

          (b) Landlord hereby represents to Tenant that Landlord has not
received any notice or directive, and is not aware of any claim, from any
environmental agency having jurisdiction over the Demised Premises regarding any
violation of the Environmental Statutes at the Demised Premises. Landlord agrees
to indemnify and hold the Tenant harmless from and against any and all claims
brought by any such environmental agency relating to the Demised Premises proven
to have arisen prior to the date that Landlord delivers possession of the
Demised Premises to Tenant. In no event shall Tenant be held responsible for the
actions of the prior occupant of the Demised Premises.

     Section 30.02.

          (a) Tenant shall comply with all state and federal environmental laws,
including the Spill Compensation and Control Act ("SCCA") (N.J.S.A. 58:10-23.11
et seq.) and Industrial Site Recovery Act ("ISRA") (N.J.S.A. 13:1K-6 et seq.) as
the same may have been or may hereafter be amended (collectively, the
"Environmental Statutes") as the same may relate to Tenant's use and occupancy
or manner of use and occupancy of the Demised Premises or any act or failure to
act of Tenant. Tenant shall supply Landlord on demand with any information
Landlord may require in order to enable Landlord to comply with the
Environmental Statutes, including, without limitation, ISRA, whether upon the
transfer of title or closing of operations at the Demised Premises, or for any
reason whatsoever.

          (b) Tenant shall not use the Demised Premises for the purpose of
refining, producing, storing, handling, transferring, processing or transporting
said "Hazardous Substances", as such term is defined in N.J.S.A. 5B:10-23.llb(k)
of the New Jersey Spill Compensation and Control Act (N.J.S.A. 58:10-23.11 et
seq.), except in de minimus quantities in strict compliance with the
requirements of all applicable governmental authorities.

          (c) Tenant shall not use the Demised Premises to generate,
manufacture, refine, transport, treat, store, handle or dispose of "Hazardous
Substances", or "Hazardous Wastes", as such terms are defined in N.J.A.C.
7:1-3.3.

          (d) Tenant shall not cause or permit to exist, as a result of an
intentional or unintentional action or omission on its part, a releasing,
spilling, leaking, pumping, emitting, pouring, emptying or dumping of a
"Hazardous Substance", as such term is defined in N.J.S.A. 58:10-23.llb(k) into
waters of the State of New Jersey or onto the lands from which it might flow or
drain into said waters, or into waters outside the jurisdiction of the State of
New Jersey where


                                      -34-

<PAGE>

damage may result to the lands, waters, fish, shellfish, wildlife, biota, air
and other resources owned, managed, held in trust or otherwise controlled by the
State of New Jersey. Landlord acknowledges that proper disposal of a Hazardous
Substance in accordance with the requirements of all applicable governmental
authorities shall not be a violation of this Section 30.02 (d).

          (e) Tenant shall not use the Demised Premises as a "Major Facility",
as such term is defined in N.J.S.A. 58:10-23.lb(1).

          (f) Tenant shall not install nor permit to be installed in the Demised
Premises friable asbestos or any substance containing asbestos and deemed
hazardous by federal or state regulations respecting such material. Landlord
acknowledges that the Demised Premises contains asbestos and Tenant shall not be
responsible in any manner therefor.

     Section 30.03. Tenant represents that Tenant has not received a summons,
citation, directive, letter or other communication, written or oral, from the
New Jersey Department of Environmental Protection concerning any intentional or
unintentional action or omission on Tenant's part resulting in the releasing,
spilling, leaking, pumping, pouring, emitting, emptying or dumping of "Hazardous
Substances", as such term is defined in N.J.S.A. 58:10-23.llb(k), into the
waters or onto the lands of the State of New Jersey, or into the waters outside
the jurisdiction of the State of New Jersey resulting in damage to the lands,
waters, fish, shellfish, wildlife, biota, air and other resources owned,
managed, held in trust or otherwise controlled by the State of New Jersey.

     Section 30.04.

          (a) In the event that Tenant does not expeditiously proceed with any
compliance required by any State or Federal authority under the Environmental
Statutes, Landlord may elect to undertake such compliance in order to protect
its interest in the Demised Premises. Any monies expended by Landlord in efforts
to comply with any environmental statute (including but not limited to: the
costs of hiring consultants, undertaking sampling and testing, performing any
cleanup necessary or useful in the compliance process and attorney's fees),
together with interest at the maximum rate permitted by law, will be added to
and payable with the next payment of annual minimum rental due from Tenant, or
will be payable on demand of Landlord.

          (b) Tenant will provide Landlord with all information as to the use or
manner of use of the Demised Premises by Tenant, and an environmental audit of
the Demised Premises which is designed to describe any materials on the Demised
Premises which would require a filing and/or any disclosure under the
Environmental Statutes in the event of any transfer or closure, or which would
require remedial action under any other Environmental Statutes.

          (c) In the event that Tenant receives notice from the Department of
Environmental Protection or any other governmental authority or bureau having or
asserting jurisdiction thereover under SCCA of a discharge on or about the
Demised Premises, or any other notice of violation of the Environmental Statutes
or any alleged or claimed violation thereof, Tenant will immediately send a copy
of such notice to Landlord and Tenant will


                                      -35-

<PAGE>

promptly proceed to remedy the condition described in the notice. Tenant shall
take all action necessary to ensure that the SCCA administrator does not spend
Spill Fund monies to clean up the site. In the event that the SCCA administrator
should spend money cleaning up property owned by Landlord due to Tenant's use or
occupancy or manner of use or occupancy of the Demised Premises or the act or
failure to act of Tenant, and/or a lien is imposed on the Demised Premises or
any portion of the parcel of which it forms a part or any property of Landlord,
Landlord may take such actions as it deems necessary to remove such lien,
including satisfaction thereof, or may require it to be bonded by Tenant, and
Tenant agrees to defend, indemnify and hold Landlord free and harmless from and
against all loss, costs, damage and expense (including attorney's fees and
costs) Landlord may sustain by reason of the assertion against Landlord by any
party of any claim in connection therewith. Landlord may demand such security,
in amounts and types which it deems appropriate in its sole discretion, for the
purpose of protecting its property from any such lien or to guarantee cleanup.

                            ARTICLE 31. SUBDIVISION

     Section 31.01. Landlord shall have the right at any time during the Term or
any extension term hereof, and Tenant hereby consents thereto, to subdivide Lot
No. 46.24 into such additional lot or lots as Landlord may in its sole
discretion elect and/or to expand Lot No. 46.24 as Landlord may in its sole
discretion elect, provided that the whole of the Building shall remain entirely
within one such subdivision. Notwithstanding anything contained in this Lease to
the contrary, in the event of any such subdivision or expansion of Lot No. 46.24
by Landlord then, at Landlord's option, (i) references in this Lease to Lot No.
46.24 may be deemed to be to the original (pre-subdivision or pre-expansion) Lot
No. 46.24 or any portion(s) thereof of which the Demised Premises forms a part,
and (ii) in calculating Tenant's proportionate share(s), Landlord may use as the
denominator of the fraction(s) representing Tenant's proportionate share(s) the
building(s) or portions thereof within said original Lot No. 46.24 or any
portion(s) thereof of which the Demised Premises forms a part. In the event of
such subdivision or expansion, Tenant agrees to execute an agreement in
recordable form setting forth the description of Lot No. 46.24 as so subdivided
or expanded and as renamed and/or renumbered.

                ARTICLE 32. THERE IS NO ARTICLE 32 IN THIS LEASE

                       ARTICLE 33. FINANCING REQUIREMENTS

     Section 33.01. Landlord intends to procure the funds for construction of
the Center from one or more lenders. If any such lender disapproves the credit
rating of Tenant for purposes of such financing, or if any such lender shall
require or suggest changes in this Lease as a condition of its approval of this
Lease for such financing and if within ten (10) days following notice from
Landlord (a) Tenant fails to execute such further assurances and/or guarantees
which are stated by Landlord as intended to be necessary to secure the approval
of Tenant's credit rating, or (b) if Tenant fails to execute, acknowledge and
deliver any amendments to this Lease setting forth the changes which are stated
by Landlord to be needed in connection with the approval of this Lease for
purposes of such financing, or if, for any reason, other than Landlord's willful
default, such financing in amount and interest rate satisfactory to Landlord
cannot be obtained, Landlord may terminate this Lease at any time prior to
Landlord's giving of notice of substantial completion. If this Lease be
terminated, it shall become null and void and the parties shall be automatically


                                      -36-

<PAGE>

released, as of the date of termination, from any and all liability, rights or
obligations hereunder, except that Landlord shall return any security deposited
by Tenant hereunder.

                      ARTICLE 34. RELATIONSHIP OF PARTIES

     Section 34.01. Nothing herein contained shall be deemed or construed by the
parties hereto, nor by any third party, as constituting the Landlord a partner
of Tenant in the conduct of Tenant's business, or as creating the relationship
of principal and agent or joint venturers between the parties hereto, it being
the intention of the parties hereto that the relationship between them is and
shall at all times be and remain that of Landlord and Tenant only. Tenant agrees
upon the demand of Landlord to deliver to Landlord and any mortgagee of Landlord
the most recently available financial statements of Tenant and any guarantor of
this Lease, certified to by a certified public accountant, and updated to the
extent reasonably requested by Landlord or any such mortgagee.

                              ARTICLE 35. CAPTIONS

     Section 35.01. The Article captions contained herein are for convenience
only and do not define, limit, or construe the contents of such Articles and are
in no way to be construed as a part of this Lease.

                            ARTICLE 36. DEFINITIONS

     Section 36.01. Words of any gender used in this Lease shall be held to
include any other gender, and words in the singular number shall be held to
include the plural, when the sense requires.

     Section 36.02. If any provision of this Lease or the application thereof to
any person or circumstances shall, to any extent, be invalid or unenforceable,
the remainder of this Lease, or the application of such provision to persons or
circumstances other than those as to which it is held invalid or unenforceable,
shall not be affected thereby and each provision of this Lease shall be valid
and be enforced to the fullest extent permitted by law.

                          ARTICLE 37. ENTIRE AGREEMENT

     Section 37.01. This instrument of Lease contains the entire and only
agreement between the parties concerning the Demised Premises. No prior oral or
written statements or representation, if any, of any party hereto or any
representative of a party hereto, not contained in this instrument, shall have
any force or effect. This Lease shall not be modified in any way, except by a
writing executed by Landlord and Tenant. No oral agreement or representations
shall be deemed to constitute a lease other than this agreement. This agreement
shall not be binding until it shall have been executed and delivered by Landlord
and Tenant. The submission of this Lease to Tenant prior to its execution by
Landlord shall not be an offer to lease.

                       ARTICLE 38. SUCCESSORS IN INTEREST

     Section 38.01. All provisions herein contained shall bind and inure to the
benefit of the respective parties hereto, their heirs, personal representatives,
successors and assigns, as the case


                                      -37-

<PAGE>

may be. In the event Landlord or any successor-lessor (owner) of the Demised
Premises shall convey or otherwise dispose of the Demised Premises and/or the
Center and/or the Tax Lot of which the Demised Premises forms a part, all
liabilities and obligations of Landlord or such successor-lessor (owner), as
Landlord under this Lease shall terminate upon such conveyance or disposal.

     Section 38.02. If Landlord, or any successor in interest to Landlord, shall
be an individual, joint venture, tenancy-in-common, trustee, trust, estate,
executor, conservator, personal representative, limited liability company,
limited liability partnership, partnership, general or limited, firm, company or
corporation, there shall be no personal liability on the part of such
individual, trustee, executor, conservator or personal representative or on the
part of any members, managers, partners, directors, officers and/or shareholders
of such joint venture, tenancy-in-common, trustee, trust, estate, executor,
conservator, personal representative, limited liability company, limited
liability partnership, partnership, general or limited, firm, company or
corporation or on the part of such joint venture, tenancy-in-common, trustee,
trust, estate, executor, personal representative, limited liability company,
limited liability partnership, partnership, general or limited, firm, company,
or corporation as to any of the provisions, covenants or conditions of this
Lease. Tenant hereby acknowledges that it shall look solely to the real property
interest of Landlord in Lot No. 46.24 (or, in the event of a subdivision of said
Lot, such subdivided portion thereof which includes the Demised Premises) for
the satisfaction or assertion of any claims, rights and remedies of Tenant
against Landlord, in the event of breach by Landlord of any of the terms,
provisions, covenants or conditions of this Lease.

                              ARTICLE 39. SECURITY

     Section 39.01. Tenant has delivered to Landlord a letter of credit in the
amount of TWO HUNDRED SEVENTEEN THOUSAND AND 00/100 ($217,000.00) DOLLARS as
security for the faithful performance and observance by Tenant of the terms,
provisions, covenants and conditions of this Lease, including without limitation
the completion of the Tenant Allowance Work and the Tenant Improvements pursuant
to the provisions of Article 5 of this Lease. Landlord and Tenant acknowledge
and agree that upon completion of the Tenant Improvements and delivery to
Landlord of the documentation required pursuant to Subparagraph (C) of Section
5.05 of this Lease, said $217,000.00 Letter of Credit shall be reduced to the
amount of $46,110.00, which amount shall thereafter serve as the security
deposit under this Lease. At any time during which Landlord shall be holding a
letter of credit as the security deposit under this Lease, Tenant shall have the
right to substitute a cash deposit for said letter of credit by delivering to
Landlord a check in the amount of the letter of credit then being held by the
Landlord. Upon receipt and clearance of the funds, Landlord shall return the
letter of credit to Tenant for cancellation. Thereafter, all references herein
to the security deposit herein shall be deemed to refer to such cash security
deposit.

     Upon delivery of this Lease to Landlord as executed by Tenant, Tenant shall
deliver to Landlord an irrevocable, unconditional Letter of Credit from Fleet
Bank (or another money center bank reasonably acceptable to Landlord), in the
form annexed hereto as Exhibit C in the amount of $217,000.00, which letter of
credit shall serve as security for the faithful performance and observance by
Tenant of the terms, provisions, covenants and conditions of this Lease. Said
letter of credit shall name National Realty & Development Corp. as sole
beneficiary and shall


                                      -38-

<PAGE>

expire on the Expiration Date hereof; provided, however, said letter of credit
may provide that it will expire prior to the Expiration Date (but in no event
prior to the one (1) year anniversary of the Commencement Date) if said letter
of credit is renewed by Tenant, without amendment, and evidence of such renewal
is delivered to Landlord prior to that date which is thirty (30) days prior to
the expiration date thereof. The letter of credit shall provide that partial
drawings shall be permitted. If, for any reason, such letter of credit shall
expire without National Realty & Development Corp. (as agent of Landlord) having
drawn thereon for any reason, including, without limitation, the inadvertent
failure to do so by National Realty & Development Corp., then Tenant shall
deliver to National Realty & Development Corp. a replacement of such letter of
credit or a cash deposit to bring the security deposit required hereunder to the
appropriate balance. Said letter of credit shall specifically provide that
Landlord and National Realty & Development Corp. will receive not less than
forty-five (45) days written notice of the election of the issuing bank to not
renew the same. Whether or not Landlord or National Realty & Development Corp.
shall receive notice of cancellation or non-renewal of the letter of credit,
Tenant shall deliver to National Realty & Development Corp. a replacement of
such letter of credit prior to that date which is thirty (30) days prior to the
cancellation date, expiration date or non-renewal date of the letter of credit.
Tenant's failure to deliver evidence of the renewal of the letter of credit or a
replacement letter of credit as aforesaid shall, in either case, be deemed a
default under this Lease, and without further notice, National Realty &
Development Corp. shall be entitled to draw upon the expiring letter of credit
in the entire amount thereof.

     In the event Tenant defaults in respect of any of the provisions, covenants
or conditions of this Lease, including, but not limited to, defaults in the
payment of annual minimum rent or additional rent, beyond the applicable notice
and cure periods provided for herein, or in the event that that Tenant has
vacated, abandoned or deserted the performance of the Tenant Improvements or is
not diligently pursuing the same to completion or Tenant has failed to pay for
the furnishings, installation or construction of Tenant Improvements (including
the Tenant Allowance Work) or any portion thereof, or in the event that Tenant
has failed to complete the Tenant Improvements by the Tenant Improvements
Completion Date, then National Realty & Development Corp. may, on Landlord's
behalf, from time to time draw upon the security deposit and use, apply, or
retain the whole or any part thereof to the extent required for the payment of
any annual minimum rent (including payment of annual minimum rental previously
abated as set forth in Section 5.05 of this Lease) and additional rent or any
other sum as to which Tenant is in default or for any sum which Landlord may
expend or may be required to expend by reason of Tenant's default, beyond the
applicable notice and cure periods provided herein, in respect of any of the
provisions, covenants and conditions of this Lease, including, but not limited
to, reasonable counsel fees and other collection charges, or with respect to any
damages or deficiency in the re-letting, repairing or altering of the Demised
Premises, whether such damages or deficiency accrued before or after summary
proceedings or re-entry by Landlord, or in connection with the removal of the
Installations (hereinafter defined) (the amount which National Realty &
Development Corp. may draw determined as set forth in this sentence is
hereinafter referred to as the "default amount").

     In the event National Realty & Development Corp. (as agent of Landlord)
shall draw upon a letter of credit deposited as a security deposit hereunder and
the amount drawn by National Realty & Development Corp. shall be in excess of
the default amount, the excess shall be held by in a non-interest-bearing
account at a commercial bank or financial institution as a


                                      -39-

<PAGE>

security deposit hereunder to be used for the purposes set forth herein. After
the expiration of the Lease, and after delivery of entire possession of the
Demised Premises to Landlord, and after applying or retaining any portion of the
security required to cure any and all defaults by Tenant under this Lease, the
letter of credit and the cash security deposit, if any, then held by Landlord
shall be returned to Tenant without interest. If, due to Tenant's default
hereunder, Landlord shall be entitled to apply or retain any portion of said
security, Tenant shall, within five (5) days following demand, secure for the
sole benefit of Landlord, a new or additional letter of credit naming Tenant as
beneficiary and complying with the requirements set forth herein or deliver to
Landlord a cash security deposit sufficient to comply with this Section,
including the required amount. Tenant shall not assign or encumber the security
deposited hereunder and neither Landlord or its successors or assigns shall be
bound by any such assignment or encumbrance. In the absence of evidence
satisfactory to Landlord of any assignment of the right to receive the security,
or the remaining portion thereof, Landlord may return the security to the
original tenant regardless of any number of assignments of the Lease itself. In
the event of a sale of the Demised Premises or larger premises of which the
Demised Premises form a part, Landlord shall have the right to transfer the cash
security and the beneficiary rights under any letter of credit to the purchaser
who shall hold the same for the benefit of Tenant in accordance with the terms
of this Lease, and Landlord and National Realty & Development Corp., after
giving notice to Tenant, shall be deemed released by Tenant from all liability
for the return of such security and Tenant shall look solely to the new owner
for the release or the return thereof. Tenant shall, upon request, deliver
confirmation of said transfer of beneficiary rights and a replacement letter of
credit naming the transferee as beneficiary if necessary or if requested.
Landlord agrees to return any letter of credit it is then holding with respect
to this Lease to the issuing bank if required by the issuing bank to receive a
replacement letter of credit. No holder of any mortgage upon the Demised
Premises or the larger property of which the Demised Premises forms a part shall
be responsible in connection with the security deposited hereunder unless such
mortgagee shall have in fact received such security or be named beneficiary
thereof and acknowledged such receipt or beneficiary status in writing to
Tenant. In the event of a foreclosure of the Demised Premises, or the larger
property of which the Demised Premises forms a part, Tenant shall, on demand of
mortgagee, reissue the letter of credit in compliance with this Section, naming
the mortgagee, or such other party as may be designated by mortgagee, as the
sole beneficiary. Tenant acknowledges that Tenant is to perform certain
obligations under this Lease prior to the Commencement Date of the term of this
Lease and that the security deposit may be applied by Landlord (or by National
Realty & Development Corp. on behalf of Landlord) in the event Tenant shall
default under any such obligations beyond any applicable notice and cure periods
notwithstanding that the Commencement Date may not yet have occurred.

                        ARTICLE 40. EXTENSION OPTION(S)

     Section 40.01. Tenant shall have the option, provided it is not in default
hereunder, to extend the Term for TWO (2) successive additional term of FIVE (5)
years each, upon the same terms and conditions as provided herein, except that
the annual minimum rental during said extension period shall be as provided
below, and except that Tenant shall have no further extension options. Tenant
shall give written notice to Landlord not less than twelve (12) months prior to
the last day of the prior term of its election to extend the Term hereof, or
such option shall be deemed waived. If Tenant shall exercise such extension
option(s), the parties will, at the request of either, execute an agreement in
form for recording, evidencing such extension. If


                                      -40-

<PAGE>

Tenant shall exercise such extension option(s), all references in this Lease to
the Term hereof shall be deemed to mean the term as so extended, except where
expressly otherwise provided.

     Section 40.02. As of the first day of each extension term ("adjustment
date"), the annual minimum rental shall be adjusted by multiplying the annual
minimum rental payable hereunder during the last Lease Year of the prior Term,
times a fraction having as its numerator the "Index" (hereinbelow defined) as of
the adjustment date and as its denominator the Index in effect upon the
commencement date of the initial term hereof; provided, however, the annual
minimum rental payable subsequent to the adjustment date shall not be less than
twenty-five (25%) percent greater than the annual minimum rental payable during
the last preceding Lease Year of the prior Term.

     Section 40.03. The "Index" shall be defined as the United States Department
of Labor, Bureau of Labor Statistics, "Consumer Price Index-All Urban Consumers
- (CPI-U) N.Y., N.Y. - Northeastern N.J. (1982-84=100)". If publication of such
Index shall be discontinued, the adjustments in the annual minimum rental
provided for in this Lease shall thereafter be computed on the basis of such
other official price index as shall be most nearly comparable thereto, and
conversion tables, if any, issued upon the promulgation of such other official
index, are to be used where applicable in making the computation hereunder.

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

ATTEST:                                 46.24 ASSOCIATES L.P.


                                        By: MIDDLESEX REALTY CORP.,
                                            General Partner


                                        By: /s/ Robert C. Baker
                                            -----------------------------------
                                        Title: President

                                                       (LANDLORD)


                                        PTC THERAPEUTICS, INC.


                                        By: /s/ Stuart Peltz
                                            ------------------------------------
                                        Title: PRESIDENT

                                                        (TENANT)


                                      -41-

<PAGE>

                                    EXHIBIT B

                          WORK LETTER TO BE ATTACHED TO
                        LEASE WITH PTC THERAPEUTICS, INC.
                               100 CORPORATE COURT
                            MIDDLESEX BUSINESS CENTER
                          SOUTH PLAINFIELD, NEW JERSEY

Landlord agrees to perform the Landlord's Work set forth in this Exhibit B. Any
work not expressly specified herein and any work necessary to comply with codes
attributable to Tenant's use shall be furnished and installed at the sole cost
and expense of Tenant. Except as specifically set forth below, any existing
construction within the Demised Premises shall be accepted by Tenant in "as is"
condition in accordance with the provisions of Section 5.01 of this Lease.
Landlord shall:

1.   Provide a watertight roof and windows.

2.   INTENTIONALLY OMITTED.

3.   Replace stained or damaged ceiling tiles.

4.   Repair exterior fence enclosure.

5.   Provide a canopy over the side entrance.

6.   Replace broken windows and glass doors.

7.   Provide HVAC in good working order.

8.   Relamp light fixtures as needed.

9.   The blue or brown mesh remaining along the window line in the lab and in
     the cooler will be removed.

10.  The Landlord will clean or replace all HVAC distribution supply or return
     duct (flexible pipes), VAV boxes and registers, diffusers or grills.

11.  Landlord shall remove the asbestos linings present in the fume hoods
     located in the Demised Premises.

12.  The existing acid neutralization tank will be put by Landlord into clean
     operating condition consistent with all applicable governmental
     regulations;

                                  MISCELLANEOUS

A. All "Tenant Extras" furnished by Landlord as may be hereafter agreed to,
shall be computed at Landlord's cost, plus a twenty-one (21%) percent
administrative fee.


                                      -44-

<PAGE>

B. Credits to Tenant based upon deletions and reductions below Building standard
set forth above, shall be computed based upon Landlord's unit cost therefor,
without factor of overhead and profit.

C. All prices, if any, set forth in this Work Letter are predicated upon
quotations now in the hands of Landlord. Such quotations, by their terms, expire
at various intervals and accordingly these prices are subject to variation based
upon market conditions following the expiration of such quotations.

D. All prices are subject to inclusion of applicable taxes, but Landlord's
overhead and profit shall be computed without regard to such taxes.

E. Landlord shall furnish Tenant with a statement(s) computing the net Tenant
extras or credits due to Landlord or Tenant, as the case may be. Any amount due
to Landlord shall be due and payable in full simultaneously with the delivery by
Tenant to Landlord of the authorization for such work. Any credit due Tenant
shall give rise to a reduction in the first installments of minimum rent and
additional rent until such credit has been exhausted.

F. Prior to or promptly after execution of this Lease, Tenant shall furnish
Landlord with design criteria and specifications necessary to enable Landlord to
comply with its obligations above. All authorizations, deletions and
implementations of the foregoing Work Letter shall be in writing and confirmed
by authorized representatives of Landlord and Tenant.

G. If there shall be any conflict between the provisions of this Work Letter and
the final approved Plans, the final approved Plans shall govern and control.

H. Landlord reserves the right to substitute for any materials and equipment
specified herein, materials and equipment of substantially equal quality,
provided Tenant's architect approves of the same, which approval shall not be
unreasonably withheld or delayed.

I. Unless specifically stated in this Exhibit B or this Lease to the contrary,
and notwithstanding anything contained on any plans or drawings, Tenant, and not
Landlord, shall be responsible for furnishing and installing at its sole cost
and expense any and all furniture, Tenant fixtures, appliances, shelving,
cabinetry, phone systems, computer wiring and the like for the Demised Premises
in accordance with the provisions of this Lease.


                                      -45-

<PAGE>

                                    EXHIBIT C

                                     [BANK]

[NAME ALL LANDLORDS]
c/o National Realty & Development Corp.
3 Manhattanville Road
Purchase, New York 10577

RE: Irrevocable Letter of Credit No. _________

Accountee: [Name of Tenant]

Gentlemen:

     We hereby issue our Irrevocable Letter of Credit No. _____________ in favor
of [Name All Landlords] at the request of [Name of Tenant] whose address is
________________ __________________________________, for an aggregate amount of
[Amount as required by Lease] and _____/100 Dollars (U.S. $___) effective
immediately.

     Funds are available against your signed draft(s) drawn on [Name of Bank]
signed by an authorized representative of National Realty & Development Corp.
mentioning this Letter of Credit No. _____ accompanied by a written statement
signed by an authorized representative of National Realty & Development Corp.
requesting to draw upon a specified dollar amount on Letter of Credit No.
________ as follows:

          "This drawing in the amount of $_______ is pursuant to Lease dated
          ___________________, 2000 between [Name All Landlords], as Landlord,
          and [Name of Tenant], as Tenant."

     This Letter of Credit shall expire on [Expiration Date of the Lease].

     The beneficiaries named above shall be given not less than thirty (30) days
written notice of the cancellation or non-renewal of the Letter of Credit. The
beneficiaries of this Letter of Credit may draw upon the entire amount of the
Letter of Credit if they shall receive notice of its cancellation or non-renewal
or if it shall expire prior to the Expiration Date (as defined in the Lease) of
the Lease. Partial drawings are permitted under this Letter of Credit.

                                     [BANK]


                                      -46-

<PAGE>

                                    EXHIBIT D

                        SUBORDINATION, NONDISTURBANCE AND
                              ATTORNMENT AGREEMENT

                                  by and among

                        PTC THERAPEUTICS, INC., as Tenant

                                       and

                      46.24 ASSOCIATES, L.P., as Mortgagor

                                       and

              THE TRAVELERS LIFE AND ANNUITY COMPANY, as Mortgagee

                                Dated: June, 2000

Record and Return to: Windels, Marx, Davies & Ives
                      120 Albany Street Plaza
                      New Brunswick, New Jersey 08901
                      Attn: Howard P. Lakind, Esq.


                                      -47-

<PAGE>

             SUBORDINATION, NONDISTURBANCE AND ATTORNMENT AGREEMENT

     THIS SUBORDINATION, NONDISTURBANCE AND ATTORNMENT AGREEMENT, made this ___
day of April, 2000 by and among

     PTC THERAPEUTICS, INC., a Massachusetts corporation, having its principal
office at 2 Chestnut Street, Grafton, Massachusetts 01519 (the "Tenant"),

     46.24 ASSOCIATES, L.P., a Delaware limited partnership with its principal
office located 3 Manhattanville Road, Purchase, New York 10577 (the
"Mortgagor"),

     and

     THE TRAVELERS LIFE AND ANNUITY COMPANY, having an office located at One
Tower Square, 2 SHS, Hartford, Connecticut 06183 (the "Mortgagee").

                                   WITNESSETH:

     WHEREAS, the Tenant has entered into a certain Lease dated ______________,
2000 (the "Lease"), with Mortgagor as landlord, covering all or a portion of
those premises (the "Leasehold Premises") in the Borough of South Plainfield,
County of Middlesex, State of New Jersey, all as more particularly described in
SCHEDULE "A" attached hereto and made a part hereof (the "Mortgaged Premises");
and

     WHEREAS, the Mortgagee has agreed to make or has made a mortgage loan in
the aggregate principal amount of $4,609,851.06 to the Mortgagor (the "Loan"),
which Loan is secured by a certain First Mortgage and Security Agreement dated
May 16, 1984, as modified by certain Note and Mortgage Modification Agreement,
dated as of February 14, 1995 but effective as of May 1, 1994 and modified by
that certain Mortgage Modification Agreement dated as of April 30, 1999 granted
by the Mortgagor to the Mortgagee upon the Mortgaged Premises (the "Mortgage");
and

     WHEREAS, the execution and delivery of this Subordination, Nondisturbance
and Attornment Agreement is a condition to the making of the Loan.

     NOW, THEREFORE, in consideration of the sum of One Dollar ($1.00) by each
party in hand paid to the other, receipt of which is hereby acknowledged, and in
consideration of the premises and. the mutual covenants and agreements
hereinafter contained, the parties hereto, intending to be legally bound hereby,
hereby agree as follows:

1.   The Tenant hereby covenants and agrees:

     (a)  subject to this Agreement, the Lease and the Tenant's leasehold estate
          and any and all estates, options, liens and charges therein contained
          or created thereby are, and shall b, and remain, subject and
          subordinate in all respects to the lien and effects of the Mortgage
          and to all of the terms, conditions, and provisions thereof, with the
          same force and effect as if the Mortgage had been executed, delivered
          and duly recorded prior to the execution and delivery of the Lease;


                                      -48-

<PAGE>

     (b)  from time to time, upon request by the Mortgagee, it shall forthwith
          provide the Mortgagee within ten (10) business days of such request
          with an estoppel certificate certifying that, to the best of its
          knowledge, no defaults, claims, offsets or events, or situations
          which, with the passage of time, could become a default or the basis
          for a claim or offset against the Mortgagor by the Tenant, exist under
          the Lease or, if the same exist, certifying and describing such items
          as are in existence;

     (c)  it will forward to the Mortgagee copies of any notice, claim or demand
          given or made by the Tenant to or on the Mortgagor, in all cases
          concurrently with forwarding same to the Mortgagor, such copies to be
          provided to the Mortgagee by the same method of sending or mailing as
          the statement, notice, claim or demand was made or given to or on the
          Mortgagor;

     (d)  without the prior written consent of the Mortgagee (i) no rent or
          other sums due under the Lease shall be paid more than thirty (30)
          days in advance of the due date therefor established by the Lease,
          except the security deposit, if any, (ii) no modifications shall be
          made in the provisions of the Lease nor shall the term be extended or
          renewed, except as provided therein, (iii) the Lease shall not be
          terminated except as provided therein and in this agreement nor shall
          the Tenant tender or accept a surrender of the Lease, (iv) it shall
          only sublet the Leasehold Premises or assign the Tenant's interest in
          the Lease in accordance with the provisions of said Lease, and (v) it
          shall not subordinate the Lease except to the Mortgage;

     (e)  in the event of any act or omission by the Mortgagor which would give
          the Tenant the right to terminate the Lease or to claim a partial or
          total eviction, reduce rents or to credit or offset any amounts
          against future rents, the Tenant will not exercise such right (i)
          until it shall have given written notice of such act or omission to
          the Mortgagee, and (ii) until a reasonable time for remedying such act
          or omission shall have elapsed following such giving of notice, and if
          it so elects, the Mortgagee shall have the right to cure any default
          by the Mortgagor under the Lease, including, if necessary to cure any
          such default, the right of access to the Leasehold Premises in
          accordance with the terms of the Lease;

     (f)  notices required to be given to the Mortgagee under this Agreement
          will be given to any successor-in-interest of the Mortgagee under the
          Mortgage provided that, prior to the event for which notice is
          required to be given to the Mortgagee, such successor-in-interest of
          the Mortgagee shall have given written notice to the Tenant of its
          acquisition of the Mortgagee's interest therein, and designated the
          address to which such notice is to be directed;

     (g)  if the holder of the Mortgage (as now or hereafter constituted), or
          anyone claiming from or through any such holder, shall enter into and
          lawfully become possessed of the Mortgaged Premises, or shall succeed
          to the rights of the Mortgagor under the Lease, either through
          foreclosure of said Mortgage or otherwise howsoever, (i) the Tenant
          shall attorn to, and recognize, such holder or


                                      -49-

<PAGE>

          anyone claiming from or through such holder as its landlord under the
          Lease for the unexpired balance of the term of the Lease and any
          extension or renewal thereof, subject to all of the terms and
          conditions of the Lease provided such successor landlord recognizes
          Tenant's rights under the Lease, and (ii) the Tenant shall make all
          payments payable by the Tenant under the Lease directly to the holder
          of the Mortgage upon such holder's written instructions to the Tenant;
          and if, by operation of law, tie institution of any action or other
          proceedings by the Mortgagee under the Mortgage or the entry into and
          taking possession of the Mortgaged Premises shall result in the
          cancellation or termination of the Lease or the Tenant's obligations
          thereunder, the Tenant shall, upon request, execute and deliver a new
          lease of the Leasehold Premises pursuant to the Lease, containing the
          same terms and conditions as the Lease, except that the term and any
          extension thereof shall be the unexpired term and unexpired extended
          term or terms of the Lease as of the date of execution and delivery of
          said new lease;

     (h)  the Mortgagee shall have no responsibility, liability or obligation to
          cure any defaults by the Mortgagor under the Lease, nor be subject to
          claims, defenses or offsets under the Lease or against the Mortgagor
          possessed by the Tenant and which arose or existed prior to actual
          foreclosure of the Mortgage or recording of a deed in lieu of
          foreclosure or entry under and taking possession of the Mortgaged
          Premises by the Mortgagee except to the extent such claim, defense or
          offset is continuing as of the date of Mortgagee takes possession of
          the Mortgaged Premises. If the Mortgagee forecloses the Mortgage or
          takes title to the Mortgaged Premises pursuant to a deed in lieu of
          foreclosure or enters upon and takes actual possession of the
          Mortgaged Premises, the Mortgagee or any other purchaser at such
          foreclosure sale shall do so free and clear of all prior defaults,
          claims, defenses or offsets which the Tenant might have against any
          prior landlord (including the Mortgagor), and shall not be liable or
          responsible to the Tenant for any act or omission of any prior
          landlord (including the Mortgagor) except to the extent such act is
          continuing as of the date the Mortgagee succeeds to the interest of
          Landlord under the Lease, or be responsible or liable far any deposit
          or security which was delivered by the Tenant to any prior landlord
          (including the Mortgagor) but which was not subsequently delivered to
          the Mortgagee, or be bound by any rent or additional rent which the
          Tenant might have paid for more than the current month to any prior
          landlord (including the Mortgagor) but which was not subsequently
          delivered to the Mortgagee, or be obligated or liable to the Tenant
          with respect to the construction and completion of any improvements on
          the Mortgaged Premises for the Tenant's use, enjoyment or occupancy,
          or be bound by any restriction on competition beyond the Mortgaged
          Premises contained in the Lease, or be bound by any amendment or
          modification of the Lease made without the Mortgagee's prior written
          consent;

     (i)  the institution of any action or other proceedings by the Mortgagee
          under the Mortgage in order to realize upon the Mortgagor's interest
          in the Mortgaged Premises shall not, by operation of law or otherwise,
          result in the cancellation or termination of the Lease or the Tenant's
          obligations thereunder;


                                      -50-

<PAGE>

     (j)  any right of Tenant to make any claim or receive any proceeds arising
          out of taking by eminent domain shall be subject and subordinate to
          the rights of the Mortgagee; and

     (k)  Tenant hereby indemnifies and saves Mortgagee harmless against any
          claim, damage, liability, costs, penalties or fines which the
          Mortgagee may suffer as a result of air, land or water pollution
          caused by Tenant in its use or occupancy or manner of use or occupancy
          of the Mortgaged Premises or in its storage, handling, possession,
          transportation and or disposal of any hazardous or toxic substances,
          waste or materials (including, without limitation, PCB's or asbestos)
          within the Mortgaged Premises.

2.   The Mortgagee hereby agrees:

     (a)  so long as the Tenant is not in default (beyond all applicable periods
          given the Tenant under the Lease to cure such default) and shall pay
          the rents and additional rents thereunder, and shall fully comply with
          and perform all the terms, covenants, conditions and provisions of the
          Lease on the part of the Tenant thereunder to be complied with and
          performed (i) the Tenant's possession and occupancy of the Leasehold
          Premises and the Tenant's rights and privileges under the Lease, or
          any extension or renewal thereof which may be effected in accordance
          with the terms of the Lease, shall not be disturbed by the Mortgagee
          or any successor-in-interest to the Mortgagee; (ii) the Mortgagee
          shall not join the Tenant as party to any action or proceeding brought
          as a result of a default under the Mortgage for the purposes of
          terminating the Tenant's interest and estate under the Lease, and
          subject further to the condition that the Mortgagee shall not be bound
          by any rent or other payment which the Tenant might have paid more
          than thirty (30) days in advance of the time stipulated for payment
          under the Lease or by any amendment or modification of the Lease made
          without its written consent; and

     (b)  if the interest of the Mortgagor shall vest in the Mortgagee by reason
          of foreclosure or any other procedures brought by it, or in any other
          manner, the Mortgagee and its successors-in-interest shall have the
          option, but not the obligation to cure any defaults of the Mortgagor,
          and, upon such vesting, agrees to be bound by all of the undischarged
          obligations of Mortgagor under the Lease occurring after such
          foreclosure or other action.

3.   The Tenant hereby represents and warrants that:

     (a)  the Lease is in full force and effect;

     (b)  neither the Tenant nor, to the best knowledge of the Tenant, the
          Mortgagor is in default in the performance of or compliance with any
          provision of the Lease;

     (c)  the Tenant has not received any notice of default or termination of
          the Lease;


                                      -51-

<PAGE>

     (d)  the Lease is a complete statement of the agreement of the parties
          thereto with respect to the leasing of the Leasehold Premises;

     (e)  the Tenant has no option under the Lease to purchase all or any
          portion of the Mortgaged Premises; and

     (f)  the Tenant is the sole owner of the leasehold estate created thereby.

4.   The Tenant acknowledges that Mortgagor has executed or will execute an
     Absolute Assignment of Leases and Rents to the Mortgagee. The Mortgagor
     hereby irrevocably authorizes and directs the Tenant, upon receipt from the
     Mortgagee of written notice to do so, to pay all rents and other monies
     payable by the Tenant under the Lease to or at the direction of the
     Mortgagee. The Mortgagor irrevocably releases the Tenant from any liability
     to the Mortgagor for all payments so made, and the Mortgagor agrees to
     defend, indemnify and hold the Tenant harmless from and against any and all
     claims, demands, losses, or liabilities asserted by, through, or under the
     Mortgagor (except by the Mortgagee) for any and all payments so made. The
     Tenant agrees that upon receipt of such notice it will pay all monies then
     due and becoming due from the Tenant under the Lease to or at the direction
     of the Mortgagee notwithstanding any provision of the Lease to the
     contrary. Such payments shall continue until the Mortgagee directs the
     Tenant otherwise in writing. The Tenant agrees that neither the Mortgagee's
     demanding or receiving any such payments, nor the Mortgagee's exercising
     any other right, remedy, privilege, power or immunity granted by the Lease
     or this Agreement will operate to impose any liability upon the Mortgagee
     for the performance of any obligation of the Mortgagee under the Lease
     unless and until the Mortgagee elects otherwise in writing or unless the
     Mortgagee takes possession of the Mortgaged Premises and assumes the
     functions of a landlord.

5.   Any notice, demand or consent hereunder shall be in writing any may be
     given, sent by a nationally recognized overnight courier service that
     provides a receipt for delivery, sent by facsimile, or mailed by registered
     or certified mail, return receipt requested, addressed, to the Mortgagee at
     the address set forth on the first page of this Agreement. Any party may
     designate a new address by notice in writing to the other party. Any notice
     given in accordance herewith shall be effective upon delivery, sending or
     deposit in the United States mails in accordance herewith.

6.   This Agreement shall be binding upon and inure to the benefit of the
     successors and assigns of each of parties hereto. The term "Mortgagee"
     shall include the respective holders from time to time of the Mortgage (as
     now or hereafter constituted), the term "Mortgagor' shall be synonymous
     with the term "Landlord" during the term of the Mortgage and the terms
     "Landlord" and "Tenant" shall include the holder from time to time of the
     lessor's interest, and the holder from time to time of the lessee's
     interest, respectively, in the Lease.

7.   Any claim by the Tenant against the Mortgagee under the Lease or this
     Agreement shall be satisfied solely out of the interest of the Mortgagee in
     the Mortgaged Premises and the


                                      -52-

<PAGE>

     proceeds thereof and the Tenant shall not seek recovery against or out of
     any other assets of the Mortgagee.

8.   This Agreement shall be governed by and construed under the laws of the
     State of New Jersey.

9.   This Agreement may be executed in separate counterparts, all of which shall
     constitute a single instrument.

     IN WITNESS WHEREOF, the Tenant, the Mortgagor and the Mortgagee have caused
this Subordination, Nondisturbance and Attornment Agreement to be duly executed
and delivered, all as of the day and year above written.

[Attest:] [WITNESS:]                    TENANT:

                                        PTC THERAPEUTICS, INC.


By:                                     By:
    ---------------------------------       ------------------------------------
Name and Title:                         Name and Title:
                ---------------------                   ------------------------


                                        MORTGAGOR:

                                        46.24 ASSOCIATES, L.P.


-------------------------------------
*** Attest/Witness ***


By:                                     By:
    ---------------------------------       ------------------------------------
    *** Attestor/Witness Name ***           Middlesex Realty Corp., President


                                        MORTGAGEE:

                                        THE TRAVELERS LIFE AND ANNUITY COMPANY


                                        By:
                                            ------------------------------------
                                        Name: William P. Geary
                                        Title:
                                               ---------------------------------


                                      -53-

<PAGE>

                                  SCHEDULE "A"

                   ATTACHED TO AND MADE A PART OF THAT CERTAIN
                  SUBORDINATION, NONDISTURBANCE AND ATTORNMENT
                 AGREEMENT, DATED AS OF __________________, 2000

                      Description of the Mortgaged Premises


                                      -54-

<PAGE>

                                    EXHIBIT E

<TABLE>
<S>                           <C>
PTC TENANT FIT UP LIST

6/21/2000 SCOPE OF WORK

DEMOLITION                    CEILING TILE REMOVAL
                              WALL REMOVAL
                              OBSOLETE SYSTEMS AND WIRING REMOVAL
                              DISPOSAL AND CLEAN UP

CONSTRUCTION                  FLOOR PLAN CHANGES: 5-7 OFFICES
                              CEILING REPLACEMENT
                              NMR ROOM CONSTRUCTION
                              INSTALL SHOWERS
                              CONSTRUCT RECEPTION AREA
                              ADDITIONAL EXECUTIVE OFFICE
                              RENOVATE or REPLACE WINDOW TREATMENTS
                              UPGRADE LUNCHROOM FACILITIES, DISHWASHER ETC.

PAINTING                      ENTIRE INTERIOR

CARPET                        ENTIRE ADMINISTRATIVE AREA
                              SELECTED OUTER OFFICES

PHONE SYSTEM                  NEW SYSTEM AND WIRING

WIRING                        COMPLETE NEW WIRING FOR VOICE/DATA
                              SYSTEMCHECK, RENOVATE A-V SYSTEM FOR LARGER
                              MEETING ROOM

SECURITY                      NEW KEY CARD ENTRY SYSTEM
                              UPGRADE FIRM ALARM
                              UPGRADE INTERNAL SECURITY SYSTEM

CASEWORK                      RENOVATE/REPLACE 10 (MIN) ISLANDS FOR CASE
                              WORK AND THE INSTALLATION OF WORKSPACE
                              CARRELS FOR TECHNICAL ST 12/15

FUME HOODS                    REPLACE EXISTING FUME HOODS WITH LARGER
                              MODELS
                              BENCH TOP WITH 2 FLAMMABLE CABINETS BELOW
                              EACH
                              INSTALL ADDITIONAL HOODS
                              UPGRADE PLUMBING AND WIRING FOR EACH HOOD
                              UPGRADE EXHAUST SYSTEMS, DUCTS, FANS etc.
</TABLE>


                                      -55-

<PAGE>

<TABLE>
<S>                           <C>
                              "MAKE-UP" AIR SYSTEM FOR HOODS INSTALLED
                              (NEEDED TO BALANCE HVAC)

ARCHITECTURAL & ENGINEERING   BUILDING DRAWNINGS FOR FLOOR PLAN AND "AS
                              BUILT" MECHANICALS

WATER TREATMENT               RE-COMMISSION, UPGRADE DEIONIZED WATER
                              SYSTEM
                              REPLACE MILLIPORE WATER FILTRATION SYSTEM
                              (OBSOLETE
                              REPLACE MONITORING AND CHEMICAL DELIVERY
                              SYSTEM FOR ACID TANK

FIRE PROTECTION               HORNS/STROBE SYSTEM BROUGHT TO CODE (SPLIT
                              WITH NATIONAL)
                              15-20 NEW FIRE EXTINGUISHERS

BUILDING SYSTEMS              COMPRESSOR UPGRADE
                              REPAIR GENERATOR (DOOR), START-UP INSPECTION,
                              LOAD TESTING AND MAINTENANCE CONTRACT
                              INSTALL VACUUM SYSTEM FOR LAB USE

ELECTRICAL                    WIRING FOR NEW CONSTRUCTION
                              SYSTEM TRACE FOR ALL CIRCUITS AND PANEL RE-
                              LABELING SYSTEM UPGRADE FOR "UPS"

PLUMBING                      SYSTEM TRACE AND INTEGRITY CHECK FOR LAB
                              WATER SYSTEM
                              SHOWER INSTALLATION
                              SAFETY STATION (SHOWERS, EYEWASH) UPGRADE
                              SYSTEM TRACE AND INTEGRITY CHECK FOR
                              SPECIALIZED GA

GLASSWARE CLEANING            REPLACE STEAM GENERATOR
                              REPLACE STERILIZER (RECONDITIONED UNIT)
                              REPLACE WASHER

COLD ROOM                     SYSTEM CHECK AND RE-COMMISSION, INCLUDING
                              CONTROL SYSTEMS
</TABLE>


                                      -56-
<PAGE>
                    FIRST MODIFICATION AND EXTENSION OF LEASE

      This FIRST MODIFICATION and EXTENSION OF LEASE (this "Modification") is
made as of the 1st day of December, 2003 (the "Building 200 Premises
Commencement Date") by and between 46.24 ASSOCIATES L.P., a Delaware limited
partnership, for the purposes of this Modification, having its office and P.O.
Address c/o National Realty & Development Corp., 3 Manhattanville Road,
Purchase, New York 10577 (hereinafter referred to as "Landlord"), and PTC
THERAPEUTICS, INC. a Delaware corporation, having an office at 100 Corporate
Court, Middlesex Business Center, South Plainfield, NJ 07080 (hereinafter
referred to as "Tenant").

                              W I T N E S S E T H:

      WHEREAS, Landlord, and Tenant entered into that certain lease (herein
referred to as the "Lease") dated as of July 11, 2000, as amended by letter
agreements dated July 10, 2000 and December 14, 2000, by which Tenant leased
from Landlord, and Landlord leased to Tenant, certain premises in building #100
(the "Building") of the Middlesex Business Center (the "Center") in the BOROUGH
OF SOUTH PLAINFIELD, COUNTY OF MIDDLESEX, and STATE OF NEW JERSEY, which
premises consist of approximately 21,700 square feet and are more particularly
described in the Lease (such premises are herein referred to as the "Existing
Premises"); and

      WHEREAS, Tenant is currently occupying certain space (the "Additional
Premises"), also located in building #100 of the Center, which premises are
directly adjacent to the Existing Premises, which Tenant initially occupied
pursuant to a Sub-Tenancy Agreement dated June 1, 2001, between Catalyst
Communications, Inc. ("Catalyst") as sublessor, and Tenant as Sublessee. (The
Existing Premises, together with the Additional Premises, constitute the total
leasable area of the Building, 30,000 square feet.)

      WHEREAS, Landlord and Tenant now desire to modify the Lease in certain
respects;

      NOW, THEREFORE, for TEN and 00/100 ($10.00) DOLLARS and other good and
valuable consideration, the receipt and adequacy of which is hereby
acknowledged, the parties hereto agree as follows:

      1. Tenant hereby leases from Landlord, and Landlord hereby leases to
Tenant, for a term commencing on January 1, 2003 (the "Effective Date") and
ending on the Revised Expiration Date (as hereinafter defined) (or that date on
which the Lease shall be sooner terminated) approximately 8,300 square feet of
floor space in the Building more particularly indicated and described by
hatching on the left (\\\) on the plot plan annexed hereto as "Exhibit A" and
hereby made a part hereof (such 8,300 square feet of floor space is hereinafter
referred to as the "Additional Premises"). From and after the Effective Date,
the Additional Premises shall be deemed to be part of the Demised Premises, as
if the same was included within the Demised Premises as the same is defined by
the Lease (so that from and after the Effective Date the Demised Premises shall
consist of approximately 30,000 square feet). From and after the Effective Date,
the plot plan attached to the Lease as Exhibit A thereto shall be deemed

<PAGE>

deleted from the Lease and the plot plan attached as Exhibit A to this
Modification shall be deemed substituted therefore.

      2. Tenant has examined the Additional Premises and has made a complete
inspection of same and is familiar with the physical condition thereof. Landlord
has not made and does not make any representation as to the physical condition
or any other matter affecting or relating to the Additional Premises, except as
is in this Modification specifically set forth, and Tenant specifically
acknowledges that no such representation has been made, except that Landlord
represents, to its knowledge, without independent investigation, that except as
disclosed in the Phase I Environmental Assessment prepared by Environmental
Management Services dated June 19th, 2000, there were no environmental hazards
present within the Additional Premises prior to Tenant's occupancy thereof.
Tenant further acknowledges that Landlord has afforded Tenant the opportunity
for a full and complete investigation, examination, and inspection of the
Additional Premises and Tenant accepts the Additional Premises "as is".

      3. Tenant hereby leases from Landlord, and Landlord hereby leases to
Tenant, for a term commencing on December 1, 2003 and ending on the Revised
Expiration Date (or that date on which the Lease shall be sooner terminated)
approximately 11,500 square feet of floor space in the building known as 200
Corporate Court in the Center, which floor space is more particularly indicated
and described by cross hatching on the plot plan annexed hereto as "Exhibit A"
and hereby made a part hereof (such 11,500 square feet of floor space is
hereinafter referred to as the "Building 200 Premises"). From and after December
1, 2003 the Building 200 Premises shall be deemed to be part of the Demised
Premises, as if the same was included within the Demised Premises as the same is
defined by the Lease (so that from and after the Building 200 Premises
Commencement Date the Demised Premises shall consist of approximately 41,500
square feet).

      4. A. Tenant has examined the Building 200 Premises and has made a
complete inspection of same and is familiar with the physical condition thereof.
Landlord has not made and does not make any representation as to the physical
condition or any other matter affecting or relating to the Building 200
Premises, except as is in this Modification specifically set forth, and Tenant
specifically acknowledges that no such representation has been made, except that
Landlord represents, to its knowledge, without independent investigation, except
as disclosed in the Phase I Environmental Assessment prepared by Environmental
Management Services dated June 19th, 2000, there were no environmental hazards
present within the Building 200 Premises prior to Tenant's occupancy thereof.
Tenant further acknowledges that Landlord has afforded Tenant the opportunity
for a full and complete investigation, examination, and inspection of the
Building 200 Premises and Tenant accepts the Building 200 Premises "as is"
except as otherwise set forth herein.

      B. Tenant, at Tenant's expense, shall pursuant to plans and specifications
prepared by Tenant and approved by Landlord and otherwise subject to provisions
of the law, including without limitation the provisions of the Lease: (i)
perform such work as is needed so that the Building 200 Premises are demised
separately from the remainder of the building of which such premises are a part,
(ii) install demising walls with respect to the Building 200 Premises in the
locations shown on the plan attached hereto as Exhibit A-1 which is hereby made
a part hereof, (iii) paint such demising walls a color of Tenant's choosing from
Landlord's standard paint


                                      -2-
<PAGE>

selections, and (iv) separate the utilities currently servicing the Building 200
Premises so that such premises are separately metered and that such meters
measure only the consumption for the Building 200 Premises.

      C. Tenant shall be responsible for performing such work as is needed so
that the interior portion of the Additional Premises and Building 200 Premises
are compliant with the ADA. Landlord represents that it has performed such work
as is needed so that the exterior portion of the Additional Premises and the
exterior of the Building 200 Premises are compliant with the Americans with
Disabilities Act (the "ADA").

      5. Landlord and Tenant agree that the Term of the Lease shall expire,
notwithstanding anything to the contrary in Section 1.03 of the Lease, on July
31, 2009 (the "Revised Expiration Date").

      6. Effective as of the Effective Date, the annual minimum rental payable
under Section 3.01 of the Lease shall be as follows, notwithstanding anything in
Section 3.01 of the Lease to the contrary,

            (A) From the Rent Commencement Date (as defined in the Lease)
            through December 31, 2002 (inclusive): ONE HUNDRED EIGHTY FOUR
            THOUSAND FOUR HUNDRED FIFTY AND 00/100 ($184,450.00) DOLLARS PER
            ANNUM - FIFTEEN THOUSAND THREE HUNDRED SEVENTY AND 83/100
            ($15,370.83) DOLLARS PER MONTH; and

            (B) From and including January 1, 2003 until March 31, 2004: TWO
            HUNDRED FIFTY SEVEN THOUSAND SEVEN HUNDRED THIRTY AND 04/100
            ($257,730.04) DOLLARS PER ANNUM - TWENTY ONE THOUSAND FOUR HUNDRED
            SEVENTY SEVEN AND 50/100 ($21,477.50) DOLLARS PER MONTH.

            (C) From April 1, 2004 (the "Building 200 Rent Commencement Date")
            through July 31, 2009: THREE HUNDRED SEVENTY THREE THOUSAND FIVE
            HUNDRED AND 00/100 ($373,500.00) DOLLARS PER ANNUM - THIRTY ONE
            THOUSAND ONE HUNDRED TWENTY FIVE AND 50/100 ($31,125.00) DOLLARS PER
            MONTH;

      7. Provided that (i) Tenant is in compliance with the provisions of that
certain License Agreement dated September 22, 2003 by and between Landlord and
Tenant (the "License Agreement") with respect to Renovations Work, and (ii)
Tenant has complied with the provisions of Section 5.05(c) of the Lease as same
apply to the Renovations Work pursuant to said License Agreement and (iii)
Tenant has completed all work necessary to renovate, fixture and equip the
Additional Premises and Building 200 Premises for use in accordance with the
provisions of Article 2 of the Lease (the "Additional Tenant Improvements"), and
(iv) Tenant complies with the requirements of Section 5.05(C) of the Lease, and
provided further that the Lease shall not be terminated prior to the dates
Tenant is entitled to such credits, Tenant shall be entitled to a credit of
$31,125.00 against the payment of the monthly installments of annual minimum
rent due under the Lease for the months of July 2004 and August 2004, and a
credit of


                                      -3-
<PAGE>

$31,125.00 against the payment of annual minimum rent due under the Lease for
the months of June 2009 and July 2009 (and such credits shall be in lieu of the
rent abatement set forth in that certain letter agreement dated December 14,
2000 between Landlord and Tenant.)

      8. Section 5.05(B) of the Lease is hereby amended in its entirety to read
as follows:

      "Subject to completion of the Additional Tenant Improvements in accordance
with Tenant's plans and specifications which shall be approved by Landlord in
advance, and the provisions set forth in Section 5.05(C) of the Lease, Landlord
shall reimburse Tenant for amounts actually expended by Tenant for a portion of
the construction of the Additional Tenant Improvements, in an amount not to
exceed the sum of $159,700.00, and for partitioning and installation of separate
HVAC systems (the "HVAC Improvements") in an amount not to exceed $6,000 (both
amounts together, the "Tenant Allowance"). Such reimbursement shall be in the
form of a credit to be taken by Tenant against the first payments of annual
minimum rental payable hereunder which accrue subsequent to the completion of
the Additional Tenant Improvements and the HVAC Improvements, which shall be
credited starting no earlier than August 31, 2004 until exhausted.

      The portion of the Additional Tenant Improvements for which the Tenant
Allowance shall be paid shall be only that portion thereof that is office
installation work (e.g. partitioning, doors, electrical, etc., including,
without limitation, upgrading and replacing of existing mechanical systems in
the Demised Premises) and in no event shall the Tenant Allowance be used for any
work related to Tenant's trade fixtures or equipment (such portion of the
Additional Tenant Improvements for which Tenant may receive the Tenant Allowance
is hereinafter called the "Tenant Allowance Work"). It is acknowledged and
agreed by Tenant that in the event that the monies expended by Tenant for the
completion of the Tenant Allowance Work and the HVAC Improvements are less than
the amount of the Tenant Allowance, Tenant shall not be entitled to any credit
for the unused portion thereof, nor is Tenant entitled to any additional sums
from Landlord in the event that the monies expended by Tenant in connection with
the completion of the Tenant Allowance Work, the HVAC Improvements or the
Additional Tenant Improvements exceeds the amount of the Tenant Allowance."

      9. Tenant and Landlord acknowledge that Tenant has held annual minimum
rent and additional rent accruing with respect to the Additional Premises for
the period of time from and after January 1, 2003 in escrow pending resolution
of the status of the Catalyst Lease and the Catalyst Sublease (as defined
herein). Upon execution of this Modification by Tenant, Tenant shall pay to
Landlord annual minimum rent and additional rent for the Additional Premises for
the period from January 1, 2003 through the last day of January 2004 in the
amount of ONE HUNDRED SIXTEEN THOUSAND NINETY FIVE AND 57/100 ($116,095.57)
DOLLARS (which together with rent previously paid by Tenant with respect to the
Existing Premises, the Landlord accepts in full satisfaction of the amount owed
pursuant to Section 6(B), above, for the period from January 1, 2003 through
February 29 , 2004, subject to year end reconciliation for additional rent.). As
between Landlord and Tenant, Landlord hereby waives any rights or remedies it
may have (either under the Lease, the Catalyst Lease, or the Catalyst Sublease)
with respect to such payments, the underlying rent or costs to which the
payments relate, or the timing of such payments.

                                      -4-
<PAGE>


      10. Landlord represents and warrants, and Tenant acknowledges, that the
lease by and between Landlord and Catalyst Communications, Inc. ("Catalyst") by
which Catalyst leased the Additional Premises (the "Catalyst Lease") was
terminated as to the Additional Premises effective as of December 31, 2002 and
that, accordingly, that certain sublease by and between Catalyst and Tenant by
which Tenant subleased the Additional Premises from Catalyst also terminated as
of December 31, 2002 (the "Catalyst Sublease"). In recognition of Tenant's
payments hereunder, Landlord hereby indemnifies and saves harmless Tenant from
and against any claims and all loss, cost, liability, damage and/or expense,
including but not limited to reasonable counsel's fees, penalties and fines,
incurred in connection with or arising from the payment of annual minimum rent
or additional rent from January 1, 2003 forward under the Catalyst Lease or the
Catalyst Sublease, Tenant's good faith efforts to preserve rents on the
Additional Premises in an escrow account pending resolution of issues between
Landlord and Catalyst, or any other financial issues regarding the payment of
rent or additional rent to Landlord by Catalyst or to Catalyst by Tenant.

      11. Article 40 of the Lease is hereby deleted and replaced with the
following quoted language:

      "ARTICLE 40. OPTIONS FOR EXTENSION AND ADDITIONAL SPACE

      Section 40.01. Tenant shall have the option, provided it is not in default
      hereunder, to extend the term of this Lease for ONE (1) successive
      additional term of FIVE (5) years, from August 1, 2009 through July 31,
      2014, upon the same terms and conditions as provided herein, except that
      the fixed annual rent during said extension period shall be as provided
      below, and except that Tenant shall have no further extension options.
      Tenant shall give written notice to Landlord prior to November 1, 2008 of
      its election to extend the term hereof, or such option shall be deemed
      waived. If Tenant shall exercise such extension option, the parties will,
      at the request of either, execute an agreement in form for recording,
      evidencing such extension. If Tenant shall exercise such extension option,
      all references in this Lease to the term hereof shall be deemed to mean
      the term as so extended, except where expressly otherwise provided.

      Section 40.02. If Tenant shall duly elect to extend the term of this Lease
      as herein provided, the fixed annual rent payable by Tenant during said
      extension term shall be FOUR HUNDRED TWENTY NINE THOUSAND FIVE HUNDRED
      TWENTY FIVE AND 00/100 ($429,525.00) DOLLARS per annum- THIRTY FIVE
      THOUSAND SEVEN HUNDRED NINETY THREE AND 001/000 ($35,793.75) DOLLARS per
      month.

      Section 40.03. If at any time Landlord proposes to lease space within the
      building known as 200 Corporate Court in the Center, or enters into
      discussions with a potential tenant(s) for some or all of such space,
      Landlord shall give Tenant notice thereof (the "Start Notice") in order to
      provide Tenant with a reasonable right of first negotiation with respect
      to such additional space upon substantially similar terms and conditions
      as provided herein, except that the fixed annual rent applicable to such
      space shall be as negotiated in good faith by the parties. In the event
      that Landlord and Tenant do not enter into a lease for such space within
      thirty (30) days of the Start Notice, then Tenant


                                      -5-
<PAGE>

      shall, at its expense, within thirty (30) days of Landlord's request,
      undertake all actions necessary so that the utilities serving the Building
      200 Premises are located solely within the Building 200 Premises, and not
      otherwise in Building 200, and shall also take all actions necessary so
      that no utilities serving the portion of Building 200 not within the
      Building 200 Premises are located within the Building 200 Premises, such
      that the Building 200 Premises and the other portions of Building 200 can
      be used by two (2) (or more) unrelated tenants without any utilities
      located other than within the particular tenant's demised premises."

      12. Tenant covenants, warrants and represents that it has dealt with no
broker other than Colliers Houston & Co. respecting this Modification and that
no conversations, correspondence or negotiations were had with any broker
(except with Colliers Houston & Co. concerning the negotiation of the Lease)
concerning the renting or leasing of the Additional Premises or Building 200
Premises. Tenant shall hold Landlord and National Realty & Development Corp.
harmless and defend (by counsel satisfactory to Landlord) said parties against
any claims for a brokerage commission arising out of any conversations,
correspondence or negotiations with any broker except said Colliers Houston &
Co. regarding the Lease. Landlord shall pay any commissions owing to said
Colliers Houston & Co. with respect to this Modification in accordance with
separate agreement.

      13. Upon execution of this Modification by Tenant, Tenant shall deliver to
Landlord adequate and proper insurance policies with respect to the Additional
Premises and the Building 200 Premises including, without limitation,
comprehensive general liability insurance in the amounts specified in and in
accordance with the provisions of Article 7 of this Lease.

      14. Section 24.01 of the Lease is hereby deleted and replaced with the
following quoted language:

      "Tenant represents that its officer(s) executing this lease have been duly
      authorized to do so by formal action of a duly-elected Board of Directors.
      Until such time as Tenant is a corporation whose shares are regularly and
      publicly traded on a recognized stock exchange, Tenant shall upon written
      request provide to Landlord a capitalization table showing ownership (by
      class and entity) of Tenant's capital stock prepared or reviewed by a
      certified public accountant."

Landlord hereby waives any right of termination of the Lease that may have
accrued to Landlord pursuant to the former language of Section 24.01 of the
Lease.

      15. Except as expressly modified herein, all of the terms and conditions
of the Lease shall continue unmodified and in full force and effect. Capitalized
terms used herein without definition shall have the meaning given to such terms
in the Lease. Obligations under this Agreement shall be deemed obligations under
the Lease and that a default hereunder shall constitute a default under the
Lease.

IN WITNESS WHEREOF, the parties have hereunto set their hands and seals as of
the day and year first above written.

                                      -6-
<PAGE>

<TABLE>
<CAPTION>

<S>                                                       <C>
WITNESS:                                                  46.24 ASSOCIATES L.P., a Delaware limited partnership

                                                          By:    Middlesex Realty Corp., general partner

/s/ Jennifer H. Lawrence                                         By:  /s/ Robert C. Baker
--------------------------------------------                         -------------------------------------------
                                                                 Name:  Robert C. Baker
                                                                 Title:  President

                                                                           (LANDLORD)

                                                          PTC THERAPEUTICS, INC., a Delaware corporation

                                                          By:    /s/ Mark E. Boulding
--------------------------------------------                  --------------------------------------------------
                                                          Name:  Mark E. Boulding
                                                          Title:  Secretary of the Corporation

                                                                            (TENANT)
</TABLE>


                                      -7-
<PAGE>



State of New York
                     } SS:
County of Westchester

      On the 17th day of February in the year 2004 before me, the undersigned, a
Notary Public in and for said State, personally appeared Robert C. Baker,
personally known to me or proved to me on the basis of satisfactory evidence to
be the individual whose name is subscribed to the within instrument and
acknowledged to me that he executed the same in his capacity as President of
MIDDLESEX REALTY CORP., general partner of 46.24 ASSOCIATES, INC., and that by
his signature on the instrument, the individual or the corporation upon behalf
of which the individual acted, executed the instrument.


                                                   Notary Public

STATE OF NEW JERSEY        )
                           } SS.:
COUNTY OF MIDDLESEX        )

         On the 9th day of February in the year 2004 before me, the undersigned,
a Notary Public in and for said State, personally appeared Mark E. Boulding,
personally known to me or proved to me on the basis of satisfactory evidence to
be the individual whose name is subscribed to the within instrument and
acknowledged to me that he executed the same in his capacity as Secretary of PTC
THERAPEUTICS, and that by his signature on the instrument, the individual or the
corporation upon behalf of which the individual acted, executed the instrument..


                                                   Notary Public


                                      -8-
<PAGE>


                                    EXHIBIT A

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                                    EXHIBIT A


<PAGE>


                                   EXHIBIT A-1



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