Document:

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                                                                   EXHIBIT 10.23

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                     RADNOR TECHNOLOGY AND RESEARCH CENTER

                                     BETWEEN

                         RADNOR PROPERTIES-145 KOP, L.P.
                        (a Delaware limited partnership)

                                   AS LANDLORD

                                      -AND-

                                 CENTOCOR, INC.
                          (a Pennsylvania corporation)

                                    AS TENANT

                              DATED: March 8, 2002

                                   PREMISES:

                          135,125 RENTABLE SQUARE FEET
                      COURT LEVEL, THIRD AND FOURTH FLOORS
                                RESEARCH BUILDING
                      RADNOR TECHNOLOGY AND RESEARCH CENTER
                            145 KING OF PRUSSIA ROAD
                           RADNOR, PENNSYLVANIA 19087

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

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                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
PARAGRAPH                                                                                      PAGE
---------                                                                                      ----
<S>                                                                                            <C>
1.    DEMISED PREMISES; USE..................................................................   1
      1.1.   LETTING AND DEMISED PREMISES; USE...............................................   1
      1.2.   RADNOR TECHNOLOGY AND RESEARCH CENTER...........................................   2
      1.3.   COMMON FACILITIES...............................................................   2
      1.4.   RENTABLE SQUARE FEET............................................................   2
      1.5    USE OF PARKING FACILITIES.......................................................   2

2.    TERM; COMMENCEMENT.....................................................................   3
      2.1.   DURATION........................................................................   3
      2.2.   CONDITION OF THE DEMISED PREMISES...............................................   3

3.    MINIMUM RENT; INCREASES IN MINIMUM RENT; SECURITY DEPOSIT..............................   4
      3.1.   AMOUNT AND PAYMENT..............................................................   4
      3.2.   ADDRESS FOR PAYMENT.............................................................   4
      3.3.   NON-WAIVER OF RIGHTS............................................................   4
      3.4.   ADDITIONAL SUMS DUE; NO SET-OFF.................................................   4
      3.5.   PERSONAL PROPERTY AND OTHER TAXES...............................................   4

4.    INCREASES IN TAXES AND OPERATING EXPENSES..............................................   5
      4.1.   DEFINITIONS.....................................................................   5
      4.2.   GENERAL ALLOCATION PROCEDURES...................................................   9
      4.3.   TENANT'S SHARE OF TAXES AND OPERATING EXPENSES..................................   9
      4.4.   DISPUTES........................................................................  10
      4.5.   SURVIVAL........................................................................  10

5.    SERVICES...............................................................................  11
      5.2.   WATER AND SEWER.................................................................  15
      5.3.   PAYMENT FOR SERVICES............................................................  16
      5.4.   ELEVATOR; ACCESS................................................................  16
      5.5.   JANITORIAL......................................................................  16
      5.6.   SECURITY........................................................................  17
      5.7.   REPAIRS.........................................................................  17
      5.8.   SYSTEM CHANGES..................................................................  18
      5.9.   DIRECTORY.......................................................................  18
      5.10.  OVERHEAD FEE....................................................................  18
      5.11.  LIMITATION REGARDING SERVICES...................................................  18
      5.12.  TENANT'S RIGHT TO MAKE REPAIRS..................................................  19

6.    CARE OF DEMISED PREMISES...............................................................  19
      6.1.   INSURANCE AND GOVERNMENTAL REQUIREMENTS.........................................  19
      6.2.   ACCESS..........................................................................  19
      6.3.   CONDITION AND REPAIRS...........................................................  20
      6.4.   SURRENDER.......................................................................  20
      6.5.   SIGNS...........................................................................  21
</TABLE>

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                       -i-

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<TABLE>
<S>                                                                                            <C>
      6.6.   CARE; INSURANCE.................................................................  21
      6.7.   ALTERATIONS; ADDITIONS..........................................................  21
      6.8.   MECHANICS' LIENS................................................................  22
      6.9.   VENDING MACHINES................................................................  22
      6.10.  RULES AND REGULATIONS...........................................................  22
      6.11.  ENVIRONMENTAL COMPLIANCE........................................................  22
      6.12.  DE-COMMISSIONING................................................................  24

7.    SUBLETTING AND ASSIGNING...............................................................  24
      7.1.   GENERAL RESTRICTIONS............................................................  24
      7.3.   PROCEDURE FOR APPROVAL OF TRANSFER..............................................  25
      7.4.   RECAPTURE.......................................................................  26
      7.5.   CONDITIONS......................................................................  26
      7.6.   SPECIAL CONDITIONS FOR TRANSFERS TO AFFILIATES OF TENANT........................  26
      7.7.   NO RELEASE......................................................................  27

8.    FIRE OR OTHER CASUALTY.................................................................  27

9.    REGARDING INSURANCE AND LIABILITY......................................................  27
      9.1    DAMAGE IN GENERAL...............................................................  27
      9.2.   INDEMNITY.......................................................................  28
      9.3.   TENANT'S INSURANCE..............................................................  29
      9.4    LANDLORD'S INSURANCE............................................................  29
      9.5.   WAIVER OF SUBROGATION...........................................................  30
      9.6.   LIMITATION ON PERSONAL LIABILITY................................................  30
      9.7.   SUCCESSORS IN INTEREST TO LANDLORD, MORTGAGEES..................................  31
      9.8.   SURVIVAL........................................................................  31

10.   EMINENT DOMAIN.........................................................................  31

11.   INSOLVENCY.............................................................................  31

12.   DEFAULT................................................................................  32
      12.1.  EVENTS OF DEFAULT...............................................................  32
      12.2.  ACCELERATED RENT COMPONENT......................................................  33
      12.3.  RE-ENTRY........................................................................  33
      12.4.  CONTINUING LIABILITY............................................................  34
      12.5.  CREDIT..........................................................................  34
      12.6.  NO DUTY TO RELET................................................................  34
      12.7.  CONFESSION OF JUDGMENT..........................................................  34
      12.8.  BANKRUPTCY......................................................................  35
      12.9.  WAIVER OF DEFECTS...............................................................  36
      12.10. NON-WAIVER BY LANDLORD..........................................................  36
      12.11. PARTIAL PAYMENT.................................................................  36
      12.12. OVERDUE PAYMENTS................................................................  36
      12.13. CUMULATIVE REMEDIES.............................................................  36
</TABLE>

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                      -ii-

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<TABLE>
<S>                                                                                            <C>
13.   SUBORDINATION..........................................................................  37
      13.1.  GENERAL.........................................................................  37
      13.2.  RIGHTS OF MORTGAGEE.............................................................  37
      13.3.  MODIFICATIONS...................................................................  37
      13.4   SNDA............................................................................  38

14.   NOTICES................................................................................  38
      14.1.  IF TO LANDLORD..................................................................  38
      14.2.  IF TO TENANT....................................................................  39

15.   HOLDING OVER...........................................................................  39

16.   RESERVATIONS IN FAVOR OF LANDLORD......................................................  39

17.   COMPLETION OF IMPROVEMENTS; DELAY IN POSSESSION........................................  40
      17.2.  TENANT IMPROVEMENTS.............................................................  40
      17.3.  ACCEPTANCE......................................................................  40

18.   COMMUNICATION AND COMPUTER LINES.......................................................  40
      18.1.  LANDLORD RESERVATION............................................................  41
      18.2.  REMOVAL OF LINES................................................................  41
      18.3.  COMMUNICATION CONTRACTORS.......................................................  42

19.   LANDLORD'S RELIANCE....................................................................  42

20.   PRIOR AGREEMENTS; AMENDMENTS...........................................................  43

21.   CAPTIONS...............................................................................  43

22.   LANDLORD'S RIGHT TO CURE...............................................................  43

23.   ESTOPPEL STATEMENT.....................................................................  44

24.   BROKER.................................................................................  44

25.   MISCELLANEOUS..........................................................................  44
      25.1.  CERTAIN INTERPRETATIONS.........................................................  44
      25.2.  PARTIAL INVALIDITY..............................................................  44
      25.3.  GOVERNING LAW...................................................................  45
      25.4.  FORCE MAJEURE...................................................................  45
      25.5.  LIGHT AND AIR...................................................................  45
      25.6.  RECORDING.......................................................................  45

26.   QUIET ENJOYMENT........................................................................  45

27.   CONFIDENTIALITY........................................................................  45

28.   MONUMENT SIGN..........................................................................  45
</TABLE>

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                      -iii-

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<TABLE>
<S>                                                                                            <C>
29.   RIGHT OF FIRST REFUSAL TO PURCHASE.....................................................  46
      29.1   GRANT...........................................................................  46
      29.2   OFFER TO PURCHASE...............................................................  46
      29.3   EXERCISE........................................................................  46
      29.4   AGREEMENT OF PURCHASE AND SALE..................................................  47
      29.5   FAILURE TO EFFECTIVELY EXERCISE.................................................  47
      29.6   SPECIAL PROVISIONS RELATING TO AN OFFER FROM A USER.............................  47
      29.7   MISCELLANEOUS...................................................................  48

30.   RENEWAL OPTION.........................................................................  48
      30.1   GRANT OF OPTION.................................................................  48
      30.2   PROCEDURE.......................................................................  49
      30.3   TERMS OF OPTION.................................................................  49
      30.4   FAILURE TO EXERCISE.............................................................  49
      30.5   TIME OF THE ESSENCE.............................................................  50

31.   LANDLORD'S DEFAULT.....................................................................  50

32.   TENANT'S RIGHT OF FIRST OFFER..........................................................  50
      32.1.  LANDLORD'S RFO NOTICE...........................................................  51
      32.2   DEFINITION OF AVAILABLE.........................................................  51
      32.3.  EXERCISE........................................................................  51
      32.4.  LEASE TERMS.....................................................................  52
      32.5.  FAILURE TO EXERCISE.............................................................  52

INDEX OF CERTAIN DEFINED TERMS...............................................................   1
</TABLE>

                              SCHEDULE OF EXHIBITS

                 EXHIBIT               TITLE (REFERENCE)
                 A                     FLOOR PLAN OF THE DEMISED PREMISES

                 B                     LEGAL DESCRIPTION

                 C                     Intentionally Omitted

                 D                     JANITORIAL SERVICES

                 E                     RULES AND REGULATIONS

                 F                     RESPECTING IMPROVEMENTS TO THE
                                       DEMISED PREMISES

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                      -iv-

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                       G                           ESTOPPEL CERTIFICATE

                       H                           DECOMMISSIONING STANDARDS

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                      -v-

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                      RADNOR TECHNOLOGY AND RESEARCH CENTER
                                      LEASE

THIS LEASE (the "Lease") is made this 8th day of March, 2002 by and between
RADNOR PROPERTIES-145 KOP, L.P., a Delaware limited partnership (hereinafter
called "Landlord"), and CENTOCOR, INC., a Pennsylvania corporation (hereinafter
called "Tenant").

      1. DEMISED PREMISES; USE.

            1.1. LETTING AND DEMISED PREMISES; USE. Landlord, for the term and
subject to the provisions and conditions hereof, leases to Tenant, and Tenant
rents from Landlord, the space (hereinafter referred to as the "Demised
Premises" and more particularly delineated on the floor plan attached hereto as
Exhibit "A" and made a part hereof) being, for purposes of the provisions hereof
135,125 rentable square feet, located on the court level and third (3rd) and
fourth (4th) floors of the research building (hereinafter referred to as the
"Research Building") known as the Research Building of Radnor Technology and
Research Center, or such other name as Landlord may from time to time designate,
located at 145 King of Prussia Road, Radnor Township, Delaware County,
Pennsylvania 19087, a legal description of the land (the "Land") which is
attached hereto as Exhibit "B", to be used by Tenant only for general office and
laboratory purposes and associated incidental uses and for no other purpose
without the prior written consent of Landlord. Tenant shall, at its sole cost
and expense, obtain and maintain all approvals, permits, licenses or
authorizations of any nature required in connection with the operation of
Tenant's business specific to the Demised Premises. Landlord makes no
representation that the Demised Premises are consistent with applicable
Governmental Requirements (as defined below) for Tenant's business or are
suitable for Tenant's business. Tenant shall comply with all laws relating to
the Demised Premises and Tenant's use, occupancy and operation thereof,
including, without limitation, (i) health, safety and building codes, and any
permit or license requirements, and (ii) any Governmental Requirements. In
connection with the foregoing, Tenant, at Tenant's own cost, shall be obligated
to secure and obtain all required permits, approvals and licenses for or with
respect to the design, build out and operation of the Demised Premises,
including, but not limited to any approval or permit requirements of the
Pennsylvania Department of Health, Pennsylvania Licenses and Inspections or the
Radnor Zoning Department and Tenant shall be obligated to keep in force and
renew all thereof before the same, or any of them, shall expire. Prior to
commencing business in the Demised Premises, Tenant shall provide copies of all
such permits, approvals and licenses to Landlord.

      Landlord has provided Tenant with current Certificates of Occupancy for
the Research Building as currently configured prior to Tenant's possession.
Tenant shall not be responsible for the costs of state and local governmental
requirements directly associated with multi-tenanting the Research Building.

      Tenant shall not use or occupy or permit anything to be done in or on the
Demised Premises, in whole or in part, in a manner which would in any way
violate any certificate of occupancy affecting the Demised Premises, make void
or voidable any insurance then in force

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

<PAGE>

with respect thereto, or which may make it more costly or impossible to obtain
fire or other insurance thereon, cause structural or other material injury to
the Research Building or any part thereof, constitute a public or private
nuisance, or which may violate any present or future, ordinary or extraordinary
Governmental Requirements

            1.2. RADNOR TECHNOLOGY AND RESEARCH CENTER. Radnor Technology and
Research Center consists of approximately 18.924 acres of ground and certain
buildings and other improvements thereon, all located at or about 145 King of
Prussia Road, in Radnor Township, Delaware County, Pennsylvania (the "Center").
Landlord reserves the right, in its sole discretion, at any time and from time
to time, to expand and/or reduce the amount of ground and/or improvements of
which the Center consists, provided such expansion or reduction shall not
materially affect Tenant's permitted use of the Research Building.

            1.3. COMMON FACILITIES. Tenant and its agents, employees and
invitees, shall have the right to use, in common with all others granted such
rights by Landlord, in a proper and lawful manner, the common sidewalks and
other outdoor areas within the Center, the parking areas surrounding the
Research Building, the common entranceways, lobbies and elevators furnishing
access to the Demised Premises, and (if the Demised Premises includes less than
a full floor) the common lobbies, hallways and toilet rooms on the floor on
which the Demised Premises is located. Such use shall be subject to the terms of
this Lease and to such reasonable rules and regulations as Landlord may from
time to time prescribe with respect thereto, including, without limitation, the
reservation of any particular parking spaces or parking areas for the exclusive
use of other tenants of the Center.

            1.4. RENTABLE SQUARE FEET. Tenant understands, acknowledges and
agrees (i) that the amount of rentable square feet set forth in Paragraph 1.1
above is calculated based on certain assumptions, and (ii) that such amount of
rentable square feet is hereby accepted by Tenant for all purposes of this
Lease, including, without limitation, for purposes of determining minimum rent,
Tenant's Proportionate Share of applicable items of Taxes and Operating Expenses
and other items which are based upon the computation of square footage.

            1.5. USE OF PARKING FACILITIES. Subject to the other provisions of
this Lease, and excluding those parking spaces designated by Landlord as being
reserved, Tenant shall have free non-exclusive use, in common with all other
tenants, licensees, and invitees of the Center, of the surface parking spaces in
the Center ("Non-Reserved Spaces"), for Tenant, Tenant's employees, Tenant's
business invitees and Tenant's agents, each day of the week; provided, however,
that at no time during any day during the term of this Lease shall the number of
Non-Reserved Spaces actually occupied by Tenant, Tenant's employees, business
invitees and agents exceed two hundred fifty seven (257) spaces (such figure
being a maximum number of spaces which may be utilized by or for Tenant at any
one time, but Landlord does not represent or guarantee that such number of
spaces will in fact be available at any one time at the Center for Tenant's
use). Tenant shall not park any trucks or any delivery vehicles in the parking
areas or driveways, except as specifically designated by Landlord from time to
time, and shall confine all truck parking, loading and unloading to times and
locations specifically designated by Landlord from time to time. Tenant shall
require all trucks servicing Tenant to be promptly loaded or unloaded and
removed from the site. Landlord hereby reserves the exclusive right with respect
to the use of

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                       -2-

<PAGE>

parking facilities, roadways, sidewalks, driveways, islands and walkways for
advertising purposes. Tenant covenants and agrees to enforce the provisions of
this Lease against Tenant's employees and business invitees. Landlord may from
time to time circulate parking stickers for the purpose of identifying motor
vehicles of Tenant and Tenant's employees and/or circulate validation tickets
for the purpose of identifying Tenant's business invitees. Landlord shall have
the right, but not the obligation: (a) to police said parking facilities, (b) to
provide parking attendants, (c) to cause unauthorized and/or unregistered motor
vehicles (but only upon 48 hours verbal or written notice to Tenant for first
time offenders) to be towed away at the sole risk and expense of the owner of
such motor vehicles, (d) to designate certain areas of the parking facilities
for the exclusive use of motor vehicles having handicapped designations on their
license plates and/or for the exclusive use of visitors to the Center, (e) to
use any portion of the parking facilities from time to time and/or to deny
access to the same temporarily in order to repair, maintain or restore such
facilities or to construct improvements under, over, along, across and upon the
same for the benefit of the site and to grant easements in the parking
facilities to any authorities, (f) to adopt and modify from time to time rules
and regulations for parking and vehicular ingress, egress, speed, no parking, no
standing, and for times and places for move-in, move-out and deliveries, (g) to
designate fire lanes, loading zones and restricted parking from time to time and
to tow violators immediately with no notice and (h) to designate from time to
time specific areas for the parking of Tenant's employees cars. Landlord shall
use commercially reasonable efforts to insure that the rules and regulations
promulgated by Landlord will be enforced in a non-discriminatory manner.

      2. TERM; COMMENCEMENT.

            2.1. DURATION. The term of this Lease shall commence (the
"Commencement Date") on the delivery to Tenant of a fully executed Lease on
which date the Demised Premises shall be delivered to Tenant and unless extended
or sooner terminated as herein provided, the initial term of this Lease shall
continue until, and shall expire on March 31, 2007.

            2.2. CONDITION OF THE DEMISED PREMISES. Tenant acknowledges that
Tenant has had the opportunity to examine the Demised Premises prior to the
execution of this Lease. Tenant agrees to accept the Demised Premises on the
Commencement Date in its then "AS IS WHERE IS" condition without any obligation
on the part of Landlord to perform any work, except as specifically required
under this Lease. However, Landlord shall, at Landlord's expense, (i) install a
sprinkler system for the entire Research Building by April 1, 2002, (ii) remove
and replace by March 31, 2002, the sink traps identified (in red) on Table 1 of
the Mercury Monitoring report issued by Tim Allers dated February 25, 2002 and
(iii) replace the gravel filter in the acid waste pretreatment system to allow
for further testing of the acid waste piping and to take reasonable corrective
action, if necessary, to ensure the proper and safe operation of the acid waste
pretreatment system. Subsequent to the Commencement Date of the Lease, Landlord
and Tenant shall jointly assemble a binder containing the results of the
equipment inspection and testing performed by Landlord and Tenant prior to the
Commencement Date. The binder shall be used as the standard for determining the
condition of the equipment at the Commencement Date for purposes of Paragraph
6.4.

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                       -3-

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      3. MINIMUM RENT; INCREASES IN MINIMUM RENT; SECURITY DEPOSIT.

            3.1. AMOUNT AND PAYMENT. Minimum rent for the Demised Premises shall
commence on April 1, 2002 and accrue during the term as follows:

<TABLE>
<CAPTION>
                                            ANNUAL               MONTHLY MINIMUM
        LEASE PERIOD                     MINIMUM RENT                 RENT
------------------------------           -------------           ---------------
<S>                                      <C>                     <C>
April 1, 2002 - March 31, 2003           $3,781,323.60            $315,110.30
April 1, 2003 - March 31, 2004           $3,894,763.32            $324,563.61
April 1, 2004 - March 31, 2005           $4,011,606.24            $334,300.52
April 1, 2005 - March 31, 2006           $4,131,954.48            $344,329.54
April 1, 2006 - March 31, 2007           $4,255,913.16            $354,659.43
</TABLE>

Minimum rent shall be payable during the term hereof, in advance, in the monthly
installments as set forth above, the first installment to be payable upon the
execution of this Lease and subsequent installments to be payable on the first
day of each successive month of the term hereof following the first month of
such term.

            3.2. ADDRESS FOR PAYMENT. All rent and other sums due to Landlord
hereunder shall be payable to Radnor Properties-145 KOP, L.P., c/o The
Rubenstein Company, L.P., 4100 One Commerce Square, 2005 Market Street,
Philadelphia, Pennsylvania 19103, or to such other party or at such other
address as Landlord may designate, from time to time, by written notice to
Tenant.

            3.3. NON-WAIVER OF RIGHTS. If Landlord, at any time or times, shall
accept rent or any other sum due to it hereunder after the same shall become due
and payable, such acceptance shall not excuse delay upon subsequent occasions,
or constitute, or be construed as, a waiver of any of Landlord's rights
hereunder.

            3.4. ADDITIONAL SUMS DUE; NO SET-OFF. All sums payable by Tenant
under this Lease, whether or not stated to be rent, minimum rent or additional
rent, shall be collectible by Landlord as rent, and upon default in payment
thereof Landlord shall have the same rights and remedies as for failure to pay
rent (without prejudice to any other right or remedy available therefor). All
minimum rent, additional rent and other sums payable by Tenant under this Lease
shall be paid, when due, without demand, offset, abatement, diminution or
reduction. Additional rent shall include all sums which may become due by reason
of Tenant's failure to comply with any of the terms, conditions and covenants of
the Lease to be kept and observed by Tenant and any and all damages, costs and
expenses (including without limitation thereto reasonable attorney fees) which
Landlord may suffer or incur by reason of any default of Tenant.

            3.5. PERSONAL PROPERTY AND OTHER TAXES. As additional rent, Tenant
shall pay monthly or otherwise when due, whether collected by Landlord or
collected directly by the governmental agency assessing the same, any taxes
imposed or calculated on Tenant's rent or with respect to Tenant's use or
occupancy of the Demised Premises or Tenant's business or right to do business
in the Demised Premises, including, without limitation, a gross receipts tax or
sales tax on rents or a business privilege tax or use or occupancy tax, whether
such tax exists at

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                       -4-

<PAGE>

the date of this Lease or is adopted hereafter during the term of this Lease or
during any renewal or extension thereof; but nothing herein shall be taken to
require Tenant to pay any income, estate, inheritance or franchise tax imposed
upon Landlord. In addition to the foregoing, Tenant shall be responsible to pay
when due all taxes imposed upon all fixtures or personal property of Terlant.

      4. TAXES AND OPERATING EXPENSES.

            4.1. DEFINITIONS. As used in this Paragraph 4, the following terms
shall be defined as hereinafter set forth:

                  (A) "TAXES" shall mean all real estate taxes and assessments
of whatever kind, general or special, ordinary or extraordinary, foreseen or
unforeseen, imposed upon the Research Building or with respect to the ownership
of the Research Building and the Center and the parcel of land on which the
Research Building and the Center are located, and any existing or future
improvements to the Research Building or the Center or to the parcel of land on
which the Research Building or the Center is located, all of the foregoing as
allocable and attributable to each given calendar year which occurs during the
term of this Lease (and any renewals and extensions thereof). If, due to a
future change in the method of taxation, any franchise, income, profit or other
tax, however designated, shall be levied or imposed in addition to or in
substitution, in whole or in part, for any tax which would otherwise be included
within the definition of Taxes, such other tax shall be deemed to be included
within Taxes as defined herein. Taxes also shall include amounts paid to anyone
engaged by Landlord to contest the amount or rate of taxes, provided that the
amounts so paid do not exceed the savings procured. Tenant acknowledges that the
exclusive right to protest, contest or appeal Taxes shall be in Landlord's sole
and absolute discretion and Tenant hereby waives any or all rights now or
hereafter conferred upon it by law to independently contest or appeal any Taxes.

                  (B) "OPERATING EXPENSES" shall mean Landlord's actual
out-of-pocket expenses, adjusted as set forth herein and as allocable and
attributable to each given calendar year which occurs during the term of this
Lease (and any renewals and extensions thereof), in respect of the operation,
maintenance, repair, replacement and management of the Research Building and the
Center (after deducting any reimbursement, discount, credit, reduction or other
allowance received by Landlord) and shall include, without limitation: (A) wages
and salaries (and taxes and insurance imposed upon employers with respect to
such wages and salaries) and fringe benefits paid to persons employed by
Landlord to render services in the normal operation, maintenance, cleaning,
repair and replacement of the Research Building and the Center and any security
personnel for the Research Building and the Center, excluding any overtime wages
or salaries paid for providing extra services exclusively for any specific
tenants; (B) costs of independent contractors hired for, and other costs in
connection with, the operation, security, maintenance, cleaning, repair and
replacement of the Research Building and related facilities and amenities in the
Center; (C) costs of materials, supplies and equipment (including trucks) used
in connection with the operation, security, maintenance, cleaning, repair and
replacement of the Research Building and related facilities and amenities in the
Center; (D) costs of electricity, steam, water, sewer, fuel (including, without
limitation, diesel and heating fuel), compressed air, and other gases and other
utilities used at the Research Building or the Center, together with the

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                       -5-

<PAGE>

cost of providing the services specified in Paragraph 5 hereof, to the extent
such utilities and/or services are not separately chargeable to an occupant of
the Research Building or an occupant elsewhere in the Center; (E) cost of
insurance for public and general liability insurance and insurance relating to
the Research Building and the Center, including fire and extended coverage or
"All-Risk" coverage, if available, and coverage for elevator, boiler, sprinkler
leakage, water damage, and property damage, plate glass, personal property owned
by Landlord, fixtures, and rent protection (all with such coverages and in such
amounts as Landlord may elect or be required to carry), but excluding any charge
for increased premiums due to acts or omissions of other occupants of the
Research Building or elsewhere in the Center because of extra risk which are
reimbursed to Landlord by such other occupants; (F) costs of tools, supplies and
services; (G) costs of capital improvements to the Research Building and Center,
but excluding (i) improvements of a purely cosmetic nature, (ii) improvements
which do not provide any benefit to Tenant, and (iii) improvements which
substantially increase the facilities available to Tenant unless Landlord
obtains Tenant's prior written approval (by way of example and without
limitation: new structured parking garage or a new lobby in Other Center
Buildings); (H) costs of alterations and improvements to the Research Building
or the common areas of the Center made pursuant to any Governmental
Requirements, but excluding costs of alterations and improvements which are
required pursuant to any Governmental Requirement existing, and as interpreted,
as of the date of Landlord's execution of this Lease; (I) legal and accounting
fees and disbursements necessarily incurred in connection with the ownership,
maintenance and operation of the Research Building and the Center, and the
preparation, determination and certification of bills for Taxes and Operating
Expenses pursuant to this and other leases at the Research Building and the
Center; (J) sales, use or excise taxes on supplies and services and on any of
the other items included in Operating Expenses; (K) costs of redecorating,
repainting, maintaining, repairing and replacing the common areas of the
Research Building and the Center (including seasonal decorations); (L)
management fees payable to the managing agent for the Research Building and the
Center (provided, however, that if management fees are paid to any affiliate of
Landlord, then the amount thereof to be included in Operating Expenses shall not
exceed such amount as is customarily being charged for similar services rendered
to comparable buildings in the geographical sub market within which the Center
is located, but in no event less than three percent (3%) or greater than four
(4%) percent, provided, however, such management fees shall not be charged on
the cost of utilities and shall not exceed three percent (3%) for the first
three years of the lease term); (M) the cost of telephone service, postage,
office supplies, maintenance and repair of office equipment and similar costs
related to operation of the Research Building's and the Center's management and
superintendent's offices whether or not located at the Center; (N) the cost of
licenses, permits and similar fees and charges related to operation,
maintenance, repair and replacement of the Research Building and the Center,
other than any of the foregoing relating to tenant improvements; and (O) without
limiting any of the foregoing, any other expenses or charges which, in
accordance with sound accounting and management principles generally accepted
with respect to a first-class suburban laboratory building, would be construed
as an operating expense. Operating Expenses (including such as are stated above
which relate or are applicable to the Center) shall include, without limitation,
any and all sums for landscaping, ground and sidewalk maintenance, sanitation
control, extermination, cleaning, lighting, snow removal, parking area and
driveway striping and repairing, fire protection, fire safety, policing,
security systems, public liability and property damage insurance, and expenses
for the upkeep, maintenance, repair, replacement and operation of the Center,
all as payable in respect of or

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

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allocable to the Research Building by virtue of the ownership thereof and/or
under and pursuant to the Declaration (as hereinafter defined). The term
"Operating Expenses" shall not include: (a) the cost of redecorating or special
cleaning or similar services to individual tenant spaces, not provided on a
regular basis to other tenants of the Research Building; (b) wages or salaries
paid to executive personnel of Landlord not providing full-time service at the
Center; (c) any charge for depreciation or interest paid or incurred by
Landlord; (d) leasing commissions, finders fees and all other leasing expenses
incurred in procuring tenants in the Research Building; (e) Taxes; (f) any costs
incurred in the ownership of the Research Building, as opposed to the operation
and maintenance of the Research Building, including Landlord's income taxes,
excess profit taxes, franchise taxes or similar taxes on Landlord's business;
preparation of income tax returns; corporation, partnership or other business
form organizational expenses; franchise taxes; filing fees; or other such
expenses; or any costs incurred in cleaning up any environment hazard or
condition in violation of any environmental law (except to the extent caused by
Tenant); (g) legal fees for the negotiation or enforcement of leases; (h)
expenses in connection with services or other benefits of a type which are not
Research Building standard but which are provided to another tenant or occupant;
(i) any items to the extent such items are required to be reimbursed to Landlord
by Tenant (other than through Tenant's additional rent), or by other tenants or
occupants of the Research Building or by third parties; (j) depreciation, except
in the form of a "sinking fund" for periodic replacement of carpeting and for
periodic repainting (both in common areas only); or interest paid on any
mortgage, or ground rents paid under land leases, except for payment of any
triple-net expenses required by such leases; (k) the cost of constructing tenant
improvements or installations for any tenant in the Research Building, including
any relocation costs; (1) brokerage commissions, origination fees, points,
mortgage recording taxes, title charges and other costs or fees incurred in
connection with any financing or refinancing of the Research Building; (m)
attorneys' fees and disbursements, incurred in connection with the leasing of
space in the Research Building (including without limitation the enforcement of
any lease or the surrender, termination or modification of any lease of space in
the Research Building); (n) advertising and promotional expenses, brochures with
respect to the Research Building; (o) cost of repairs or replacements occasioned
by fire, windstorm or other casualty, the costs of which are covered by
insurance or reimbursed by governmental authorities in eminent domain; (p)
overhead and profit increment paid to subsidiaries or affiliates of Landlord for
services on or to the Property, to the extent that the costs of such services
exceed market-based costs for such services rendered by unaffiliated persons or
entities of similar skill, competence and experience; (q) penalties, fines,
legal expenses, or late payment interest incurred by Landlord due to violation
by Landlord, or Landlord's agents, contractors or employees, of either the
payment terms and conditions of any lease or service contract covering space in
the Research Building or Landlord's obligations as owner of the Research
Building (such as late payment penalties and interest on real estate taxes, late
payment of utility bills); (r) any compensation paid to clerks, attendants or
other persons in any commercial concession operated by Landlord in the Research
Building from which Landlord receives any form of income whatsoever, whether or
not Landlord actually makes a profit from such concession; or (s) costs of
maintenance provided to other tenants' space to the extent that such services
are not provided to Tenant. If Landlord is not furnishing any particular work or
service (the cost of which, if performed by Landlord, would constitute an
Operating Expense) to a tenant who has undertaken to perform such work or
service in lieu of performance by Landlord, Operating Expenses shall
nevertheless be deemed to include the amount Landlord would reasonably have
incurred if

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Landlord had in fact performed the work or service at its expense with the
understanding that if such work is not provided to Tenant by Landlord, then such
expense shall not be deemed an Operating Expense. The costs of electric
consumption and water, sewer, gas, diesel, heating oil and other utility
services to the Demised Premises (including, without limitation, for HVAC usage)
are not included as Operating Expenses of the Research Building and shall be
paid for by Tenant separately in accordance with Paragraph 5 of this Lease.

                        (1) In determining Operating Expenses for any year, if
less than 100% of the rentable square feet of the Research Building shall have
been occupied by tenants at any time during such year, Operating Expenses shall
be deemed for such year to be an amount equal to the like expenses which
Landlord reasonably determines would normally be incurred had such occupancy
been 100% throughout such year.

                        (2) In the event Landlord shall make a capital
expenditure as described in Paragraph 4.1(B)(G) during any year, the annual
amortization of such expenditure (determined on a straight line method over the
useful life of the improvement, but in no event to exceed twelve (12) years),
plus any reasonable interest or financing charges thereon (or, if such
improvements are funded from reserves, a reasonable sum imputed in lieu of such
financing charges), shall be deemed an Operating Expense for each year of such
period.

                  (C) "GOVERNMENTAL REQUIREMENTS" shall mean all requirements
under any federal, state or local statutes, rules, regulations, ordinances, or
other requirements of any duly constituted public authority having jurisdiction
over the Research Building (including, without limitation, the Demised Premises)
including, but not limited to, requirements under applicable Radnor Township
building, zoning and fire codes and federal, state and local requirements and
regulations governing accessibility by persons with physical disabilities, all
present and future federal, state, and local statutes, rules, and regulations
respecting the environment, including, but not limited to, the Comprehensive
Environmental Response, Compensation and Liability Act of 1980, as amended, 42
U.S.C., Section 9601, et seq. (CERCLA); the Resource Conservation and Recovery
Act, as amended, 42 U.S.C., Section 6901, et seq. (RCRA); the Pennsylvania
Hazardous Sites Cleanup Act, 35 P.S. Section 6020.101 et seq.; the Pennsylvania
Solid Waste Management Law, 35 P.S. Section 6018.101 et seq.; and the
Pennsylvania Clean Streams Law, 35 P.S. 691.1 et seq.; Federal Water Pollution
Control Act, 33 U.S.C. Section 4321; the Clean Air Act, 42 U.S.C. Section 7401;
the National Environmental Control Policy Act, 42 U.S.C. Section 4321; the
Refuse Act, 33 U.S.C. Section 1801-181-2; the Toxic Substance Control Act, 15
U.S.C. Section 2601; the Federal Insecticide, Fungicide and Rodenticide Act, 7
U.S.C. Section 136; and the Safe Drinking Water Act, 42 U.S.C. Section 300F; The
Pennsylvania Infectious and Chemotherapeutic Waste Disposal Act, 35 P.S. Section
7330.101 - 7330.906 and the Pennsylvania Low Level Radioactive Waste Disposal
Act and 35 P.S. 6019.1-6019.6; the Pennsylvania Land Recycling and Environmental
Standards Act, 35 P.S. 6026-101-6026-909; the Atomic Energy Act of 1954 42
U.S.C. Section 2210 et. seq. and all regulations promulgated by the Nuclear
Regulatory Commission, including and not limited to 10 C.F.R. Parts 20, 20, 40,
50, 51, 70 and 72; The DELCORA Standards, Rules, and Regulations of 1991 as
amended and codified and any administrative or court order applicable to the
Demised Premises relating to Waste.

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

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                  (D) "TENANT'S PROPORTIONATE SHARE" shall be Fifty Nine and
356/10,000 percent (59.0356%). This is equal to the ratio of the rentable square
feet of the Demised Premises, as set forth above, to the total rentable square
feet of space in the Research Building, which is 228,887 rentable square feet.
The ratio of the rentable square feet of the Research Building to the total
rentable square feet of office and laboratory space in the Center (which is
427,109 rentable square feet) shall be Fifty Three and 5,898/10,000 percent
(53.5898%).

                  (E) "TENANT'S SHARE OF TAXES AND OPERATING EXPENSES" shall
mean, with respect to any calendar year, the product of (A) Tenant's
Proportionate Share, multiplied by, (B) the amount of the total of Taxes and
Operating Expenses for such calendar year. Notwithstanding anything contained
herein to the contrary, total Taxes for the Center shall be allocated sixty
percent (60%) to the Research Building and forty percent (40%) to the other
Center Buildings.

                  (F) "TENANT'S ESTIMATED SHARE" shall mean, with respect to any
calendar year, the product of (A) Tenant's Proportionate Share, multiplied by
(B) the amount of Landlord's good faith estimate of the total of Taxes and
Operating Expenses for such calendar year.

                  (G) "DECLARATION" shall mean any future declarations,
covenants, restrictions and easements, together with all existing or future
amendments, addenda and supplements thereto, executed by Landlord (or Landlord's
predecessor in title to the Center) and placed of record, submitting the Center
or portion thereof to a system of reciprocal easements, restrictions, benefits
and burdens for the use and maintenance thereof by owners and tenants, and to
which all such owners and tenants shall be subject.

            4.2.GENERAL ALLOCATION PROCEDURES. Landlord and Tenant acknowledge
the following:

                  (A) To the extent practicable and known exactly, all Operating
Expenses will be accounted for and attributed separately for the Research
Building and for the other buildings which presently comprise the Center (the
"Other Center Buildings"). To the extent allocations of an item of Operating
Expenses in accordance with the foregoing sentence is not practicable and known
exactly, allocations will be made between and among the Research Building and
the Other Center Buildings proportionately among all thereof (based upon the
respective square footage of each), or equally among all thereof, or based on
usage and hours of operation or in such other proportions as may reasonably be
determined by Landlord in the exercise of prudent management practices.

                  (B) Notwithstanding the foregoing, and to the extent deemed
reasonable by Landlord, all common area and other charges under and as permitted
by the Declaration will be charged and allocated among the Research Building,
the Other Center Buildings, and any other building, facility or property subject
to the Declaration, all in accordance with the terms and provisions of the
Declaration.

            4.3.TENANT'S SHARE OF TAXES AND OPERATING EXPENSES.

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                  (A) For and with respect to each calendar year which occurs
during the term of this Lease (and any renewals or extensions thereof) there
shall accrue, as additional rent, Tenant's Share of Taxes and Operating
Expenses, appropriately prorated for any partial calendar year occurring within
the term.

                  (B) Landlord shall furnish to Tenant, on or before December 31
of each calendar year during the term hereof, a statement for the next
succeeding calendar year setting forth Tenant's Estimated Share and the
information on which such estimate is based. On the first day of the new
calendar year, Tenant shall pay to Landlord, on account of Tenant's Estimated
Share, an amount equal to one-twelfth (1/12) of Tenant's Estimated Share, and on
the first day of each succeeding month up to and including the time that Tenant
shall receive a new statement of Tenant's Estimated Share, Tenant shall pay to
Landlord, on account of Tenant's Estimated Share, an amount equal to one-twelfth
(1/12) of the then applicable Tenant's Estimated Share.

                  (C) Landlord shall furnish to Tenant, on or before May 31 of
each calendar year during the term hereof, a statement (the "Expense Statement")
prepared by Landlord or its agent or accountants setting forth for the previous
calendar year: (A) the actual amount of Taxes and Operating Expenses for the
previous calendar year; (B) the Tenant's Proportionate Share; (C) the Tenant's
Share of Taxes and Operating Expenses; (D) the Tenant's Estimated Share; and (E)
a statement of the amount due to Landlord, or to be credited to Tenant, as a
final adjustment in respect of Tenant's Share of Taxes and Operating Expenses
for the previous calendar year (the "Final Adjustment Amount"). The Final
Adjustment Amount shall be calculated by subtracting the Tenant's Estimated
Share from the Tenant's Share of Taxes and Operating Expenses. On the first day
of the first calendar month (but in no event sooner than thirty [30] days)
following delivery of the Expense Statement to Tenant, Tenant shall pay to
Landlord the Final Adjustment Amount calculated as set forth in the Expense
Statement. If the Final Adjustment Amount is a negative quantity, then Landlord
shall credit Tenant with the amount thereof against the next payment of minimum
rent due by Tenant hereunder, except that with respect to the last year of the
Lease, if an Event of Default has not occurred, Landlord shall refund Tenant the
amount of such payment in respect of the Final Expense Adjustment within thirty
(30) days after Landlord provides the Expense Statement for such final year of
the Lease. In no event, however, shall Tenant be entitled to receive a credit
greater than the payments made by Tenant as payments of Tenant's Estimated Share
for the calendar year to which the Final Adjustment Amount relates.

            4.4. DISPUTES. The information set forth on all statements furnished
to Tenant pursuant to this Paragraph 4, including each Expense Statement, and
all documents relating to Tenant's Estimated Share, Tenant's Share of Taxes and
Operating Expenses, the Final Adjustment Amount, and all supportive
documentation and calculations, shall be deemed approved by Tenant unless,
within thirty (30) days after submission to Tenant, Tenant shall notify Landlord
in writing that it disputes the correctness thereof, specifying the basis for
such assertion. Pending the resolution of any dispute, however, Tenant shall
continue to make payments in accordance with the statement or information as
furnished.

            4.5. SURVIVAL. Notwithstanding anything herein contained to the
contrary, Tenant understands and agrees that additional rent for increases of
Taxes and Operating Expenses described in this Paragraph 4 are attributable to
and owing for a specific twelve (12) month

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

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<PAGE>

period, and are generally determined in arrears. Accordingly, Tenant agrees
that, at any time following the expiration of the term of this Lease, or after
default by Tenant with respect to this Lease, Landlord may bill Tenant for (i)
the entire amount of accrued and uncollected additional rent attributable to
increases in Taxes and Operating Expenses under this Paragraph 4, and (ii) any
unpaid charges for usage, services or other amounts with respect to any period
during the term of this Lease; and the amount of such bill shall be due and
payable to Landlord within thirty (30) days after rendering thereof.

      5. SERVICES. Landlord agrees that during the term of the Lease, Landlord
shall provide services as set forth in this Paragraph 5. Tenant shall begin
paying electricity, water and sewer, fuel oil and gas on March 1, 2002.

                  (A) STANDARD CENTRAL HVAC SERVICES. Landlord shall provide
heat, ventilation and air-conditioning ("HVAC") during "Business Hours"(which
shall mean twenty-four hours a day, seven days a week) as follows:

                        (1) COURT LEVEL. Tenant shall operate, maintain and
service all air handling and exhaust equipment that services the court level.
Landlord shall provide access to the existing "Building Automation System" to
Tenant for operation of this equipment. Landlord's sole obligation with respect
to the HVAC system for the court level is to supply no greater than 1,292
gallons per minute ("GPM") of 45 degree chilled water at outdoor design
conditions of 95(degrees) Dry Bulb/78 (degrees) Wet Bulb and to supply required
steam to the air handling unit's preheat coils not to exceed a rate of 5,136
lbs/hr at outdoor design conditions of zero degrees Fahrenheit. All costs
associated with the operation and maintenance of the HVAC system on the Court
will be borne by Tenant and capital items in accordance with Paragraph
4.1(B)(3). Landlord shall supply required steam for the HVAC system for the
court level for purposes of humidification at a rate not to exceed 2,104
lbs/hour. Landlord shall furnish required steam for the trim humidifiers within
the court level as reasonably required to maintain Tenant's space humidification
requirements, but in no event to exceed the design capacity.

                        (2) THIRD AND FOURTH FLOORS. Landlord shall provide
conditioned air (nominal 55 degrees F) at outdoor design conditions of
95(degrees) Dry Bulb/78 (degrees) Wet Bulb and for winter conditions 55(degrees)
Dry Bulb at 65% relative humidity at outdoor conditions of 0 degrees F up to a
total maximum rate of 104,000 cubic feet per minute ("CFM") to the Third and
Fourth Floors. Landlord shall provide Tenant with access to the Building
Automation System for the limited purpose of controlling space temperature set
points and humidity on the Third and Fourth floors. Air flow to the floors is
supplied by nine (9) air handling units, which serve floors 1 through 4 of the
Research Building. Landlord shall have the right to approve Tenant's allocation
of the available CFM from each of the air handling units. Landlord shall furnish
exhaust air up to a maximum rate of 92,500 CFM. Exhaust is furnished to the
floors by 2 exhaust fans, which serve floors 1 through 4 of the Research
Building. Landlord shall have the right to approve Tenant's allocation of the
available CFM to each of the Exhaust fans.

                        (3) HOT WATER. Landlord shall provide hot water to
reheat coils in the Demised Premises at rates and temperatures as Tenant
reasonably requires, but in no event to exceed design conditions.

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

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                        (4) OPERATION AND MAINTENANCE. Landlord shall operate
and maintain the Central Plant's systems required to provide the air, exhaust,
chilled water and steam to the Demised Premises as set forth above. Landlord
agrees to provide Tenant access to all Central Plant areas and maintenance
records. Landlord further agrees to cooperate with Tenant in implementing a
preventative maintenance program to minimize the risk of Central Plant downtime
and an emergency response program to reduce the duration of Central Plant
failures. These programs will include, at a minimum, the following steps: (a)
adequate and reasonable spare parts inventory; (b) periodic joint detailed
inspections and tests of equipment; (c) scheduled preventative maintenance
procedures for each piece of major equipment; (d) to the extent possible,
maximum 4 hour response time on service contracts; (e) special procedures that
allow for Tenant to accelerate (at Tenant's cost) the repair and/or replacement
of inoperative equipment in the event where industry standard response times may
jeopardize Tenant's intended use of the Demised Premises.

                        (5) HVAC SERVICES. Tenant shall pay the cost of
supplying the Demised Premises (and any common areas if Tenant occupies a full
floor) with heat, ventilation and air conditioning during Business Hours at such
rates as Landlord shall specify from time to time to cover all of Landlord's
estimated costs and expenses in connection with supplying such service,
including without limitation the costs of heating oil, diesel, labor,
maintenance, equipment, electricity and other utilities, and applicable sales or
use taxes thereon, such amounts to be paid by Tenant within thirty (30) days
after submission by Landlord of a statement to Tenant setting forth the amount
due.

                        (6) SUPPLEMENTAL HVAC EQUIPMENT. If Tenant requires air
conditioning in addition to the rates and quantities that are set forth above
(e.g., due to above-standard densities of personnel or heat generating
equipment, including, but not limited to, computer, communications, or telephone
switching equipment, whether due to energy consumption, configuration,
concentration, location or otherwise, or for conference or training facilities,
or for other similar or dissimilar items, uses or requirements of Tenant),
Tenant may, or upon Landlord's written request shall, arrange for the
installation of a separate air conditioning unit, subject to Landlord's prior
written reasonable approval and satisfaction of the other provisions regarding
Tenant improvements or alterations set forth in this Lease. Tenant shall be
responsible for the cost and installation of such unit for its intended purpose,
and for the maintenance, repair, replacement, operation and utilities (including
electricity, and, as applicable, gas, steam, chilled water, water and sewer) of
the same and for any additional sub-meter needed to account for the electricity
and any other utilities utilized to operate such unit. If Landlord, in its sole
discretion, permits Tenant to attach a separate air-conditioning unit to the
cooling tower, Tenant shall pay for the condenser water made available to such
unit from the cooling tower (whether or not actually used) in connection with
any such supplemental air conditioning, at such rates as Landlord shall
establish from time to time, such amounts to be paid by Tenant within thirty
(30) days after submission by Landlord of a statement to Tenant setting forth
the amount due. The cost of supplying electricity for supplemental heat,
ventilation and air conditioning equipment for the Demised Premises may be
reflected in Tenant's electric bill as described in Paragraph 5(C) below. In the
alternative, Tenant may, subject to Landlord's reasonable approval, make
modifications to the existing air handling equipment to increase the available
capacity. If such modifications are made Tenant shall be entitled to 50% of the
total additional

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

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<PAGE>

capacity developed. Tenant shall be responsible for all costs associated with
the modifications including, but not limited to, engineering and constructions
costs.

                  (B) HVAC SYSTEM INADEQUACY. Landlord shall not be responsible
for any failure or inadequacy of the Research Building's HVAC system if such
failure or inadequacy results from the occupancy of the Demised Premises by
persons in excess of the density anticipated or for which the system was
designed, or if Tenant uses the Demised Premises in a manner for which it was
not designed, or if Tenant installs or operates machines, appliances or
equipment (whether due to energy consumption, configuration, concentration,
location or otherwise), which exceed the maximum wattage per square foot
contemplated by, or generate more heat than anticipated in, the design of the
Research Building's HVAC system.

                  (C) ELECTRICITY. Landlord shall provide electricity to the
Demised Premises. Tenant is entitled to connect to the Research Building's
service a total of 500 KW for appliances (208/120v) and 250 KW (277v) for
lighting for the Third and Fourth floors combined and a total of 250 KW for
appliances (208/120v) and 125 KW (277v) for lighting for the court level. Tenant
may, subject to Landlord's reasonable approval, make modifications to the
existing electric distribution system to increase the electrical service to
Tenant. Tenant may, subject to Landlord reasonable approval, reallocate electric
capacity between lighting and appliance services. Landlord agrees to reasonably
cooperate with Tenant in seeking rebates with the electric provider. Tenant
shall be entitled to 100% of any rebates attributable solely to Tenant's
electricity usage and occupancy of the Demised Premises. Tenant shall pay for
all electricity consumed in the Demised Premises (including electricity for
outlets, general lighting, any supplemental HVAC equipment as described below,
any Additional Electric Equipment as described in Paragraph 5(G), and any
special lighting equipment serving the Demised Premises), as follows:

                        (1) Tenant shall pay such rates as Landlord is charged
by the electric provider(s).

                        (2) For areas of the Demised Premises now or hereafter
separately-metered, Tenant shall pay for amounts of electricity based on such
meters, and any meter-reading charges incurred by Landlord, or which Landlord
may reasonably establish from time to time. For areas of the Demised Premises
not separately metered, Tenant shall pay for amounts of electricity based on the
reasonable estimates of Landlord's engineer, or at either party's request,
Landlord shall install (at the cost of the requesting party) separate meters,
and Tenant shall thereafter pay based on such meters. In the alternative, for
areas of the Demised Premises not separately metered, but metered together with
other space in the Research Building, Landlord may from time to time elect to
allocate the electricity charges between the Demised Premises and such other
space based on the ratio of the rentable area of the Demised Premises and the
rentable area of such other space; provided, if such other space is not fully
occupied during any billing period, Landlord may make an adjustment in the
foregoing computation such that only the average rentable square footage of such
other space actually occupied during such billing period is used.

                        (3) All such charges shall be payable as additional Rent
within thirty (30) days after such billing. Landlord may reasonably estimate
Tenant's electricity

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                                      -13-

<PAGE>

charges in advance, on a monthly basis, and bill and reconcile such amounts
periodically (with Landlord to provide any necessary credit or refund and Tenant
to pay any additional amount due).

                        (4) Tenant acknowledges that the Center has one central
plant (the "Central Plant") which provides chilled water to service the Research
Building and the Other Center Buildings. All costs to operate the Central Plant
will be allocated among the Research Building and Other Center Buildings on the
basis of actual usage of chilled water as metered by Landlord. Landlord may
install meters to measure the chilled water to the court level air handling
units at either party's request and Landlord will make an allocation within the
Research Building based of the court level's percentage of the total chilled
water usage of the Research Building. The party requesting the metering shall
pay for the expenses of such metering.

                        (5) Emergency Generator. With respect to the electric
allocation set forth in Paragraph 5(C), Tenant shall be entitled to the use of
emergency power furnished by the Research Building's generator not to exceed a
maximum demand load of 250 KW from buss duct F to service the court level, Third
and Fourth floors. Tenant shall limit transformer capacity to 250 KW, but may
increase connected load up to a reasonable diversity factor. A portion of this
250 KW is presently connected to equipment and receptacles in the Demised
Premises. Subject to Landlord's consent, Tenant may reallocate the distribution
of this emergency power to meet its specific needs. Tenant's use of emergency
power shall not interfere with the life safety equipment connected to the
generator. Tenant may, subject to Landlord's reasonable approval, make
modifications to the existing electric distribution system to utilize Tenant's
Proportionate Share of the excess connected load capacity of the existing
generator.

                  (D) STEAM CENTRAL PLANT. Landlord's costs for gas and fuel oil
used in the generation of steam and hot water in the Central Plant will be
allocated to the Research Building and to the Other Center Buildings on the
basis of actual usage of steam as metered by Landlord. Within the Research
Building, the Research Building's cost will be allocated using the methodology
outlined in Paragraph 5 (C)(2). Tenant may, subject to Landlord's reasonable
approval, make modifications to the steam generation and distribution system to
allow the system pressure to operate at 75 psi. Tenant shall bear all costs
associated with the modifications including, without limitation, increased
energy consumption and maintenance costs.

                        Landlord shall cooperate with Tenant in changing the gas
service from interruptible to un-interruptible in order to eliminate or minimize
the need to burn oil in the boilers. All costs associated with the rate change
shall be borne by tenants in the Research Building pursuant to its pro rata
share. Landlord reserves the right to burn oil in the boilers if necessary to
maintain facility services in the event gas is not available.

                  (E) ACID WASTE PRETREATMENT SYSTEM. All laboratory sinks and
fume hoods are drained into a common acid waste collection and pretreatment
system (the "Acid Waste Pretreatment System. Landlord shall be responsible for
obtaining, in Landlord's name, a DELCORA Wastewater Discharge Permit. Tenant
shall fully cooperate on a timely basis with Landlord in completing the permit
application, supplying and updating required information and obtaining and
maintaining the permit. The Acid Waste Pretreatment System will be available to
other tenants in the Research Building and Tenant agrees to cooperate with
Landlord and such

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                      -14-
<PAGE>

other tenants to facilitate the shared use of the Acid Waste Pretreatment
System. Landlord will test the Acid Waste Pretreatment System on a regular basis
and upon Tenant's request provide Tenant with copies of the tests. Landlord will
be responsible to maintain and if necessary replace the Acid Waste Pretreatment
System.

                  (F) SPECIAL RESEARCH BUILDING SYSTEMS. The Research Building
includes existing special laboratory systems. Landlord makes no representation
or warranty with respect to such systems except as provided below:

                        (1) Exhaust System: Fume hoods are located on all floors
and are vertically connected throughout the Research Building. Tenant
acknowledges that introduction of potentially explosive compounds into the fume
hoods without prior written approval of Landlord is expressly prohibited. Tenant
shall be responsible for the installation, maintenance, removal and replacement
of the filters on the fume hoods within the Demised Premises and the Tenant
installed systems on the roof and Landlord shall be responsible for the
installation, maintenance, removal and replacement of the filters on the roof.
Tenant shall supply Landlord with a list of uses including the chemicals and
processes for each hood and the location of such hood within the Demised
Premises. Tenant agrees to cooperate with Landlord and other Research Building
tenants to facilitate the shared use of the system. Landlord will provide Tenant
with a similar list with respect to the other Research Building tenants.

                        (2) Compressed Air. Landlord shall supply compressed air
to the Demised Premises by operation of the existing equipment. Landlord shall
be responsible for the operation of the system and Tenant shall be responsible
for the maintenance and replacement of the system within the Demised Premises.
Tenant agrees to cooperate with Landlord and other Research Building tenants to
facilitate the shared use of the system.

                  (G) ADDITIONAL ELECTRICAL EQUIPMENT. Tenant will not install
or use electrically-operated equipment in excess of the design capacity of the
Demised Premises (as established by Landlord if not so set forth) and Tenant
will not install or operate in the Demised Premises any electrically-operated
equipment or machinery other than that commonly used in a normal operation
without first obtaining the prior written consent of the Landlord. Landlord may
reasonably condition any consent required under this Paragraph 5 (G) upon the
installation of separate meters (and transformers or electrical panels) for such
equipment or machinery at Tenant's expense and the payment by Tenant of
additional rent as compensation for the additional consumption of electricity
occasioned by the operation of such additional equipment or machinery, at the
rates and in the manner set forth in Paragraph 5(C) above. Tenant shall replace,
at its sole cost, all light bulbs and tubes, and ballasts within the Demised
Premises.

                  (H) REGULATORY COMPLIANCE. The furnishing of the foregoing
heating, ventilation, air conditioning and electricity services shall be subject
to any statute, ordinance, rule, regulation, resolution or recommendation for
energy conservation which may be promulgated by any governmental agency or
organization which Landlord shall be required to comply with or which Landlord
determines in good faith to comply with.

            5.2. WATER AND SEWER. Landlord shall furnish the Research Building
with water (i) for drinking, lavatory, toilet and sanitary sewer purposes drawn
through fixtures installed by

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Landlord, (ii) necessary for the operation of the Research Building's fire
safety devices, and (iii) by the Research Building's HVAC system, necessary for
the operation of such system. The cost of usage of such services attributable to
the Demised Premises shall be paid for by Tenant pursuant to a statement
furnished by Landlord to Tenant setting forth the amount due as a result of such
usage reasonably attributable to the Demised Premises, and the total amount set
forth in such statement shall be due and payable by Tenant within thirty (30)
days after submission thereto by Landlord of such statement. Landlord agrees to
conduct a water conservation study when the Research Building is substantially
occupied on the court level and floors 2-4 and to use the findings of the study
as a basis of allocating costs of water and sewer until such time as a follow up
study is reasonably warranted.

            5.3. PAYMENT FOR SERVICES. Landlord and Tenant acknowledge to the
extent practicable and known exactly, all the services will be accounted for and
attributed separately for the Research Building and for the Other Center
Buildings. To the extent allocations of a service in accordance with the
foregoing sentence is not practicable and known exactly, allocations will be
made between and among the Research Building and the Other Center Buildings
proportionately among all thereof based upon the (i) respective square footage
of each, or (ii) equally among all thereof, (iii) or based on usage and hours of
operation, (iv) or in such other proportions as may reasonably be determined by
Landlord in the exercise of prudent management practices that would result in a
more accurate allocation. In the event a cost was inadvertently excluded such
cost shall be allocated in the manner set forth above within a reasonable time
from discovery.

            5.4. ELEVATOR; ACCESS. Landlord shall provide passenger elevator
service to the Demised Premises. Tenant and its employees and agents shall have
access to the Demised Premises at all times, subject to compliance with such
security measures as shall be in effect for the Research Building. Elevator
services for freight shall be supplied in common with service to other tenants
and for other Research Building requirements at reasonable times for routine
deliveries in the ordinary course of Tenant's business. Unusual or unusually
large deliveries requiring use of the freight elevators shall be scheduled in
advance with Landlord so as not to interfere with the operations of the Research
Building or other tenants.

            5.5. JANITORIAL. Landlord shall provide janitorial service to the
common areas of the Research Building as specified on Exhibit "D" annexed
hereto, subject to change. Tenant shall participate and comply with any
recycling or similar program which may be promulgated by any authorities with
which Landlord shall be required to comply or with which Landlord determines in
good faith to comply. Tenant shall arrange for and provide janitorial services
for the Demised Premises (restrooms on the court level, third (3rd) floor and
fourth (4th) floors), subject to the following conditions: (i) Tenant's
janitorial services provider ("Tenant's Janitor") shall be subject to Landlord's
reasonable prior approval, (ii) the level and quality of such janitorial
services shall be equal to or greater than the level and quality of janitorial
services provided by Landlord to other tenant spaces in the Research Building or
to such level as Landlord would have provided, (iii) Tenant provides such other
information as may be reasonably requested by Landlord in order for Landlord to
determine whether to approve Tenant's Janitor, (iv) Tenants' Janitor shall be
subject to the terms and conditions imposed on Tenant's contractors under
Exhibit "F" attached hereto, and shall agree in writing to be bound by

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the rules and regulations of the Research Building, and (v) Tenant shall comply
with all Governmental Requirements in removing and disposing of all trash and
waste generated in the Demised Premises. Landlord shall have no obligation to
provide janitorial services within the Demised Premises. In the event that
Tenant fails to provide janitorial services to the Demised Premises at the
aforementioned level and quality, as determined by Landlord, and such failure
continues for more than thirty (30) days after written notice from Landlord
(provided however, that Landlord shall not be required to give any such notice
more than once during any twelve (12) month period) then Landlord may resume
providing janitorial services to the Demised Premises, and in which event
Landlord shall furnish to Tenant a statement setting forth the amount due for
the janitorial services, and the total amount set forth in such statement shall
be due and payable by Tenant monthly, in arrears.

            5.6. SECURITY. Landlord provides a security card or code type access
system at the main entrance to the Research Building for Tenant's convenience.
Tenant and Tenant's employees, as well as other tenants of the Research
Building, will have access to the Research Building using such access system.
Tenant, its employees and invitees shall close and secure the entrances to the
Research Building upon entering and exiting the Research Building. Landlord
makes no representation that the access system or any future system employed at
the Research Building to monitor access to the Research Building will prevent
unauthorized access to the Research Building or the Demised Premises, and Tenant
acknowledges that no security guards are provided by Landlord. Accordingly,
Tenant agrees that Tenant shall be responsible for security of the Demised
Premises and the security and safety of Tenant's employees, invitees, officers,
directors, contractors, subcontractors and agents. In furtherance of the
foregoing, Landlord assumes no liability or responsibility for Tenant's personal
property whether such are located in the Demised Premises or elsewhere in the
Research Building or the Center. Tenant further acknowledges that Landlord may
(but shall have no obligation to) alter current security measures in the
Research Building, and Tenant agrees that it shall cooperate fully, and shall
cause its employees and invitees to cooperate fully, with any requests of
Landlord in connection with the implementation of any new security procedures or
other arrangements. Subject to Landlord's approval of the system, Tenant may (at
its sole cost and expense) install a security/access system ("Security System")
in the Demised Premises and at the Research Building entrance. Tenant shall
provide Landlord with the card keys to the Security System to allow Landlord
access to the Demised Premises. Landlord may require that Tenant remove the
Security System prior to expiration or termination of the Lease and restore the
Demised Premises and the Research Building to the condition existing on the
Commencement Date of this Lease, all at Tenant's sole cost and expense. The
Security System shall not interfere with or otherwise affect the electrical,
mechanical, structural, life safety or other building systems of the Research
Building and/or the ordinary operation of the Research Building. The provisions
of this Paragraph shall survive the expiration or termination of this Lease.

            5.7. REPAIRS. Landlord shall make (i) all structural repairs to the
Research Building and (ii) all repairs to the exterior windows and glass and all
repairs to the common areas of the Research Building. In the event that any
repair is required by reason of the negligence or abuse of Tenant or its agents,
employees, invitees or of any other person using the Demised Premises with
Tenant's consent, express or implied, Landlord may make such repair and add the
cost thereof to the first installment of rent which will thereafter become due,
unless

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Landlord shall have actually recovered such cost through insurance proceeds.
Landlord shall not otherwise be responsible to make any repairs to the Demised
Premises.

            5.8. SYSTEM CHANGES. Tenant shall not install any equipment of any
kind or nature whatsoever which would or might necessitate any changes,
replacement or additions to the water, plumbing, heating, air conditioning or
the electrical systems servicing the Demised Premises or any other portion of
the Research Building; nor install any plumbing fixtures in the Demised
Premises; nor use in excess of normal use any of the utilities, the common areas
of the Research Building, the janitorial or trash removal services, or any other
services or portions of the Research Building without the prior written consent
of the Landlord, and in the event such consent is granted, the cost of any such
installation, replacements, changes, additions or excessive use shall be paid
for by Tenant within thirty (30) day upon being billed therefor in the case of
charges in excessive use.

            5.9. DIRECTORY. Landlord shall install and maintain a directory of
tenants in the lobby area of the Research Building, on which shall be listed the
name of Tenant. In the event Landlord permits Tenant to add more names to the
directory (which Landlord may grant or deny in its sole discretion), Tenant
shall pay the actual cost of lobby directory signage over an allowance of one
(1) directory space per Tenant.

            5.10. OVERHEAD FEE. Notwithstanding anything to the contrary
contained in this Paragraph 5, Landlord reserves the right to impose a
reasonable administrative overhead charge whenever Landlord provides or
arranges, upon Tenant's request, for additional or above standard services, not
to exceed fifteen percent (15%) of such charge(s).

            5.11. LIMITATION REGARDING SERVICES. It is understood that Landlord
does not warrant that any of the services referred to in this Paragraph 5 will
be free from interruption from causes beyond the control of Landlord. Landlord
reserves the right, without any liability to Tenant, and without being in breach
of any covenant of this Lease, to interrupt or suspend service of any of the
heating, ventilating, air-conditioning, electric, sanitary, elevator or other
Research Building systems serving the Demised Premises, or the providing of any
of the other services required of Landlord under this Lease, whenever and for so
long as may be necessary by reason of accidents, emergencies, strikes or the
making of repairs or changes which Landlord is required by this Lease or by law
to make or in Landlord's commercially reasonable judgment deems advisable, or by
reason of difficulty in securing proper supplies of fuel, steam, water,
electricity, gas, labor or supplies, or by reason of any other cause beyond
Landlord's reasonable control, including without limitation, mechanical failure
and governmental restrictions on the use of materials or the use of any of the
Research Building systems. In each instance, however, Landlord shall exercise
commercially reasonable diligence to eliminate the cause of interruption and to
effect restoration of service, and shall give Tenant reasonable notice, when
practicable, of the commencement and anticipated duration of such interruption.
Tenant shall not be entitled to any diminution or abatement of rent or other
compensation nor shall this Lease or any of the obligations of the Tenant be
affected or reduced by reason of the interruption, stoppage or suspension of any
of the Research Building systems or services arising out of the causes set forth
in this Paragraph.

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<PAGE>

            5.12. TENANT'S RIGHT TO MAKE REPAIRS. If Tenant provides notice to
Landlord of an event or circumstance which requires the action of Landlord,
pursuant to the Lease, with respect to repair and/or maintenance of the HVAC
system (including the Central Plant) and electricity (including the generator)
which materially or adversely affects the conduct of Tenant's business in the
Demised Premises, and Landlord fails to commence corrective action within ten
(10) business days after the receipt of such notice (or such longer period as is
reasonably required to remedy the situation, provided Landlord uses commercially
reasonable efforts to remedy such failure), then Tenant after three (3)
additional business days' notice to Landlord specifying that Tenant intends to
take such required action and identifies Tenant's reasonable estimate of the
costs related thereto may proceed to take the required action. Tenant shall use
only Williard Inc., its successors or assigns, contractors which have performed
acceptable work in the Research Building or contractors which have done
comparable work in other research laboratory buildings (which contractors shall
be subject to Landlord's reasonable approval). Promptly following completion of
any work taken by Tenant pursuant to the provisions of this Paragraph, Tenant
shall deliver a detailed invoice of the work completed, the materials used and
the costs relating thereto. If Landlord does not object to such costs then,
Landlord shall reimburse Tenant within forty (40) days of receipt of such
invoice the amount of the product of (a) (100%-Tenant's Proportionate Share)
multiplied by (b) Tenant's reasonable costs and expenses in taking such action.
If, however, Landlord delivers to Tenant, within thirty (30) days after receipt
of Tenant's invoice, a written objection to the payment of such invoice, setting
forth with reasonable detail Landlord's reasons for its claim that such action
did not have to be taken by Landlord pursuant to the Lease or that the charges
are excessive (in which case Landlord shall pay the amount it contends would not
have been excessive), then Tenant shall not then be entitled to payment.

      6. CARE OF DEMISED PREMISES. Tenant agrees, on behalf of itself, its
employees and agents, that during the term of this Lease, Tenant shall comply
with the covenants and conditions set forth in this Paragraph 6.

            6.1. INSURANCE AND GOVERNMENTAL REQUIREMENTS. At all times during
the term of this Lease and any extension or renewal hereof, Tenant, at its cost,
shall comply with, and shall promptly correct any violations of, (i) all
requirements of any insurance underwriters, or (ii) any Governmental
Requirements relating to Tenant's use and occupancy of the Demised Premises.
Tenant shall indemnify, defend and hold Landlord harmless from and against any
and all loss, damages, claims of third parties, cost of correction, expenses
(including reasonable attorney's fees and cost of suit or administrative
proceedings) or fines arising out of or in connection with Tenant's failure to
comply with Governmental Requirements. The provisions of this Paragraph 6.1
shall survive the expiration or termination of this Lease.

            6.2. ACCESS. Tenant shall give Landlord, its agents and employees,
access to the Demised Premises at all reasonable times (with oral notice given
at least twenty hours prior to access, unless Tenant agrees otherwise), and at
any time in the case of an emergency with no notice, without charge or
diminution of rent, to enable Landlord (i) to examine the same and to make such
repairs, additions and alterations as Landlord may be permitted to make
hereunder or as Landlord may deem advisable for the preservation of the
integrity, safety and good order of the Research Building or any part thereof;
and (ii) to show the Demised Premises to prospective

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<PAGE>

mortgagees and purchasers and in the last twenty four (24) months of the term to
prospective tenants with a Tenant provided escort. If representatives of Tenant
shall not be present on the Demised Premises to permit entry upon the Demised
Premises by Landlord or its agents or employees, at any time when such entry by
Landlord is necessary or permitted hereunder, Landlord may enter the Demised
Premises by means of a master key (or, in the event of any emergency, forcibly)
without any liability whatsoever to Tenant and without such entry constituting
an eviction of Tenant or a termination of this Lease. Landlord shall not be
liable by reason of any injury to or interference with Tenant or Tenant's
business arising from the making of any repairs, alterations, additions or
improvements in or to the Demised Premises or the Research Building or to any
appurtenance or any equipment therein. Notwithstanding the foregoing to the
contrary and subject to Landlord's reasonable consent, Tenant shall have the
right to designate on a plan of the Demised Premises a certain portion of the
Demised Premises as "secure areas" to which access shall be restricted. Such
designation shall indicate the sensitive nature of the activities performed
therein and the need to protect the intellectual product associated therewith.
Landlord agrees to reasonably cooperate with Tenant to minimize any resulting
disruption, loss or risk of loss. Should Landlord need to enter into the "secure
areas" in the normal course of periodic inspections, Landlord shall so notify
Tenant and Tenant shall make access to such "secure areas" available to Landlord
within forty-eight (48) hours thereafter (unless Tenant agrees otherwise) with a
Tenant provided escort. In the event of an emergency, Landlord shall attempt to
notify Tenant prior to entry to a "secure area", unless such notification is not
feasible under the circumstances, then Landlord may enter such "secure area"
without any liability whatsoever to Tenant and without such entry constituting
an eviction of Tenant or a termination of this Lease.

            6.3. CONDITION AND REPAIRS. Tenant shall keep the Demised Premises
and all improvements, installations and systems therein in good order and
condition and repair all damage to the Demised Premises and replace all interior
glass broken by Tenant, its agents, employees or invitees, with glass of the
same quality as that broken, except for glass broken by fire and extended
coverage type risks. Tenant shall make all repairs to the Demised Premises
including, but not limited to, the mechanical, electrical, plumbing systems, and
Special Research Building Systems and Shared Building Systems, using Landlord
approved contractors. If the Tenant refuses or neglects to make such repairs, or
fails to diligently prosecute the same to completion, after written notice from
Landlord of the need therefor, Landlord may make such repairs at the expense of
Tenant and such expense shall be collectible as additional rent. Any such
repairs and any labor performed or materials furnished in, on or about the
Demised Premises shall be performed and furnished by Tenant in strict compliance
with all applicable laws, regulations, ordinances and requirements of all duly
constituted authorities or governmental bodies having jurisdiction over the
Research Building, and any reasonable regulations imposed by Landlord pertaining
thereto. Without limitation of the foregoing, Landlord shall have the right to
designate any and all contractors and suppliers to furnish materials and labor
for such repairs. Any contractors performing services for Tenant on or about the
Demised Premises or Research Building shall be subject to the requirements
governing work by Tenant's contractors as set forth in Exhibit "F" attached
hereto and made a part hereof.

            6.4. SURRENDER. Upon the termination of this Lease in any manner
whatsoever, Tenant shall remove Tenant's goods and effects and those of any
other person claiming under

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<PAGE>

Tenant, and quit and deliver up the Demised Premises to Landlord peaceably and
quietly in as good order and condition as at the inception of the term of this
Lease or as the same hereafter may be improved by Landlord or Tenant, reasonable
use and wear thereof, damage from fire and other insured casualty and repairs
which are Landlord's obligation excepted. Goods and effects not removed by
Tenant at the termination of this Lease, however terminated, shall be considered
abandoned and Landlord may dispose of and/or store the same as it deems
expedient, the cost thereof to be charged to Tenant.

            6.5. SIGNS. Tenant shall not place signs on or about any part of the
Research Building, or on the outside of the Demised Premises or on the exterior
doors, windows or walls of the Demised Premises, except on doors and then only
of a type and with lettering and text approved by Landlord.

            6.6. CARE; INSURANCE. Tenant shall not overload, damage or deface
the Demised Premises or do any act which might make void or voidable any
insurance on the Demised Premises or the Research Building or which may render
an increased or extra premium payable for insurance (and without prejudice to
any right or remedy of Landlord regarding this subparagraph, Landlord shall have
the right to collect from Tenant, upon demand, any such increase or extra
premium).

            6.7. ALTERATIONS; ADDITIONS. Except for "Minor Improvements" (as
defined below), Tenant shall not make any alteration of or addition to the
Demised Premises without the prior written approval of Landlord. Such approval
shall not be unreasonably withheld or delayed for nonstructural interior
alteration, provided that (i) no Research Building systems, structure, or areas
outside of the Demised Premises are affected by such proposed alteration, and
(ii) reasonably detailed plans and specifications for construction of the work,
including but not limited to any and all alterations having any impact on or
affecting any electrical systems, plumbing, HVAC, sprinkler system and interior
walls and partitions, are furnished to Landlord in advance of commencement of
any work. All such alterations and additions, as well as all fixtures,
equipment, improvements and appurtenances installed in and affixed to the
Demised Premises at the inception of this Lease term (but excluding Tenant's
trade fixtures and modular furniture systems and the items on the Equipment
Criteria Matrix dated 2/18/02 and prepared Johnsrud & Associates Architects,
LLC) shall, upon installation, become and remain the property of Landlord and
shall only be required to be removed by Tenant, at Tenant's sole cost, upon
termination or expiration of the Lease if Landlord indicates in writing such
requirement at the time of Landlord's approval. All such alterations and
additions shall be maintained by Tenant in the same manner and order as Tenant
is required to maintain the Demised Premises generally and, at Landlord's
option, upon termination of the term hereof, shall be removed at Tenant's cost
without damage to the Demised Premises upon surrender. All alterations and
additions by Tenant shall be performed in accordance with the plans and
specifications therefor submitted to and approved by Landlord, in a good and
workerlike manner and in conformity with all Governmental Requirements. In
addition, all such alterations and additions shall be performed in strict
compliance with the requirements governing work by Tenant's contractors as set
forth in Exhibit "F" hereto. The term "Minor Improvements" as used herein shall
mean cosmetic and non-structural alterations or additions to the Demised
Premises, which (i) do not affect any Building systems, structure, or areas
outside of the Demised Premises, and (ii) the cost

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of which, in the aggregate does not exceed $50,000.00. Tenant shall supply
Landlord with a copy of plans and specifications for any Minor Improvements
prior to installation and Landlord shall notify Tenant within thirty (30) days
of receipt whether Tenant will be required to remove such Minor Improvements and
restore the Demised Premises to the condition existing prior to the installation
of any such Minor Improvements, and repair any damage caused by such removal at
the expiration or sooner termination of the Lease.

            6.8. MECHANICS' LIENS. Tenant, within ten (10) days after notice
from Landlord, (i) shall discharge (by bonding or otherwise) any mechanics' hen
for material or labor claimed to have been furnished to the Demised Premises on
Tenant's behalf (except for work contracted for by Landlord), (ii) shall deliver
to Landlord satisfactory evidence thereof, and (iii) shall indemnify and hold
harmless Landlord from any loss incurred in connection therewith.

            6.9. VENDING MACHINES. Tenant shall not install or authorize the
installation of any coin operated vending machines within the Demised Premises,
except machines for the purpose of dispensing coffee, snack foods and similar
items to the employees and business visitors of Tenant for consumption upon the
Demised Premises, the installation and continued maintenance and repair of which
shall be at the sole cost and expense of Tenant.

            6.10. RULES AND REGULATIONS. Tenant shall observe the rules and
regulations annexed hereto as Exhibit "E", as the same may from time to time be
amended by Landlord for the general safety, comfort and convenience of Landlord,
occupants and tenants of the Research Building.

            6.11. ENVIRONMENTAL COMPLIANCE. Tenant shall not transport, use,
store, maintain, generate, manufacture, handle, dispose, release or discharge
any "Waste" (as defined below) upon or about the Research Building or Center, or
permit Tenant's employees, agents, contractors, and other occupants of the
Demised Premises to engage in such activities upon or about the Center, Research
Building or the Demised Premises. However, the foregoing provisions shall not
prohibit the transportation to and from, and use, storage, maintenance and
handling within, the Demised Premises of substances customarily used in offices
and the substances attached to the letter dated January 24, 2002 from William
Habig, Ph.D. Director, Environmental Health and Safety to James P. Mullarkey,
Esquire (as such attachments may be amended with Landlord's approval), provided:
(a) such substances shall be used and maintained only in such quantities as are
reasonably necessary for such permitted use of the Demised Premises, strictly in
accordance with applicable Governmental Requirements and the manufacturers'
instructions therefor, (b) such substances shall not be disposed of, released or
discharged in the Center or Research Building, and shall be transported to and
from the Demised Premises in compliance with all applicable Governmental
Requirements, and as Landlord shall reasonably require, (c) Tenant shall make
arrangements at Tenant's expense for disposal of any substances required (by
Governmental Requirements or Landlord's trash removal contractor) to be disposed
of separately from ordinary trash directly with a qualified and licensed
disposal company at a lawful disposal site (subject to scheduling and approval
by Landlord), and shall ensure that disposal occurs frequently enough to prevent
unnecessary storage of such substances in the Demised Premises, and (d) any
remaining such substances shall be completely, properly

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<PAGE>

and lawfully removed from the Research Building upon expiration or earlier
termination of this Lease.

                  (A) Tenant shall promptly notify Landlord of: (a) any
enforcement, cleanup or other regulatory action taken or threatened by any
governmental or regulatory authority with respect to the presence of any Waste
on the Demised Premises or the migration thereof from or to the Research
Building or Center, (b) any demands or claims made or threatened by any party
against Tenant or the Demised Premises relating to any loss or injury resulting
from any Waste, (c) any release, discharge or nonroutine, improper or unlawful
disposal or transportation of any Waste on or from the Demised Premises, and (d)
any matters where Tenant is required by any Governmental Requirement to give a
notice to any governmental or regulatory authority respecting any Waste on the
Demised Premises. Landlord shall have the right (but not the obligation) to join
and participate as a party in any legal proceedings or actions affecting the
Demised Premises initiated in connection with any environmental, health or
safety Governmental Requirement. At such times as Landlord may reasonably
request, Tenant shall provide Landlord with a written list identifying any Waste
then used, stored, or maintained upon the Demised Premises and the use and
approximate quantity of each such material. Tenant shall also furnish Landlord
with a copy of any material safety data sheet ("MSDS") issued by the
manufacturer as well as any written information concerning the removal,
transportation and disposal of the same, and such other information as Landlord
may reasonably require or as may be required by Governmental Requirement. The
term "Waste" for purposes hereof shall mean any hazardous or radioactive
material, polychlorinated biphenyls, friable asbestos or other hazardous or
medical waste substances as defined by the CERCLA, as amended, or by any other
federal, state or local law, statute, rule, regulation or order (including any
Governmental Requirements) concerning environmental matters, or any matter which
would trigger any employee or community "right-to-know" requirements adopted by
any such body, or for which any such body has adopted any requirements for the
preparation or distribution of a MSDS.

                  (B) If any Waste is released, discharged or disposed of by
Tenant or any other occupant of the Demised Premises, or their employees, agents
or contractors, in or about the Research Building or Center in violation of the
foregoing provisions, Tenant shall immediately, properly and in compliance with
applicable Governmental Requirements clean up and remove the Waste from the
Research Building or Center and clean or replace any affected property at the
Research Building or Center (whether or not owned by Landlord), at Tenant's
expense. Such clean up and removal work shall be subject to Landlord's prior
written approval (except in emergencies), and shall include, without limitation,
any testing, investigation, and the preparation and implementation of any
remedial action plan required by any governmental body having jurisdiction or
reasonably required by Landlord. If Tenant shall fail to comply with the
provisions of this Paragraph within five (5) days after written notice by
Landlord, or such shorter time as may be required by any Governmental
Requirement or in order to minimize any hazard to any person or property,
Landlord may (but shall not be obligated to) arrange for such compliance
directly or as Tenant's agent through contractors or other parties selected by
Landlord, at Tenant's expense (without limiting Landlord's other remedies under
this Lease or applicable Governmental Requirement). If any Waste is released,
discharged or disposed of on or about the Research Building or Center and such
release, discharge, or disposal is not caused

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                                      -23-
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by Tenant or other occupants of the Demised Premises, or their employees, agents
or contractors, such release, discharge or disposal shall be deemed casualty
damage under Paragraph 8 to the extent that the Demised Premises or common areas
serving the Demised Premises are affected thereby; in such case, Landlord and
Tenant shall have the obligations and rights respecting such casualty damage
provided under Paragraph 8.

            6.12. DE-COMMISSIONING. Prior to the end of the lease term, Tenant
shall, at its sole cost and expense and in compliance with all Governmental
Requirements, complete the de-commissioning of the Demised Premises in
accordance with the standards established by Governmental Requirements and in
accordance with the standards set forth on Exhibit "H" annexed hereto to. Tenant
shall promptly (and prior to the end of the lease term) provide to Landlord
copies of all applicable closure certifications from governmental authorities
with jurisdiction over the de-commissioning.

      7. SUBLETTING AND ASSIGNING.

            7.1. GENERAL RESTRICTIONS. Tenant shall not assign this Lease or
sublet all or any portion of the Demised Premises (either a sublease or an
assignment hereinafter referred to as a "Transfer") without first obtaining
Landlord's prior written consent thereto, which shall not be unreasonably
withheld, conditioned or delayed. By way of example and without limitation, the
parties agree it shall be reasonable for Landlord to withhold consent: (1) if
the financial condition of the proposed transferee is not comparable, in
Landlord's reasonable determination, to the financial condition Landlord would
require of any prospective tenant leasing comparable space; (2) if the proposed
use within the Demised Premises conflicts with the use provision set forth
herein or is incompatible, inconsistent, or unacceptable with the character, use
and image of the Research Building or the tenancy at the Research Building in
Landlord's reasonable opinion, or conflicts with exclusive use rights granted to
another tenant of the Research Building or Center; (3) if the business
reputation and experience of the proposed transferee is not sufficient, in
Landlord's reasonable opinion, for it to operate a business of the type and
quality consistent with other tenants in the Center; (4) if the document
creating the Transfer is not reasonably acceptable to Landlord; (5) the nature
of the fixtures and improvements to be performed or installed are not consistent
with general use and the terms of this Lease; (6) if the proposed transferee is
an existing tenant of Landlord (except if Landlord has no other available space)
or is currently negotiating or has negotiated within the prior twelve (12)
months with Landlord for other space in the Center (or any other building owned
by an affiliate of Landlord); (7) if the proposed user is a governmental or
quasi-governmental agency; (8) if the proposed transferee will be using or if
Landlord has reasonable cause to believe that it is likely to use Waste at the
Demised Premises other than those types of Waste normally used in general
laboratory operations in compliance with applicable Governmental Requirements;
or (9) if Landlord has reasonable cause to believe that the proposed
transferee's assets, business or inventory would be subject to seizure or
forfeiture under any laws related to criminal or illegal activity. If Landlord
consents to a Transfer, such consent, if given, will not release Tenant from its
obligations hereunder and will not be deemed a consent to any further Transfer.
Tenant shall furnish to Landlord, in connection with any request for such
consent, reasonably detailed information as to the identity and business history
of the proposed assignee or subtenant, as well as the proposed effective date of
the Transfer and, prior to the execution thereof, a complete set of the final

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documentation governing such Transfer, all of which shall be satisfactory to
Landlord in form and substance. If Landlord consents to any such Transfer, the
effectiveness thereof shall nevertheless be conditioned on the following: (i)
receipt by Landlord of a fully executed copy of the full documentation governing
the Transfer, in the form and substance approved by Landlord, (ii) any sublessee
shall acknowledge that its rights arise through and are limited by the Lease,
and shall agree to comply with the Lease (with such exceptions as may be
consented to by Landlord), and (iii) any assignee shall assume in writing all
obligations of Tenant hereunder from and after the effective date of such
Transfer. Tenant shall not advertise or otherwise disseminate any information
regarding the Research Building or the Demised Premises (including, without
limitation, rental rates or other terms upon which Tenant intends to Transfer)
to potential assignees and/or subtenants without in each instance obtaining
Landlord's prior written approval and consent as to the specific form and
content of any such advertisement, statement, offering or other information
(including, without limitation, approval of rental rates and terms). Landlord's
acceptance of any name for listing on the Research Building Directory will not
be deemed, nor will it substitute for, Landlord's consent, as required by this
Lease, to any Transfer, or other occupancy of the Demised Premises. Tenant shall
not mortgage or encumber this Lease.

            7.2. Intentionally Omitted.

            7.3.  PROCEDURE FOR APPROVAL OF TRANSFER. If Tenant wishes to
request Landlord's consent to a Transfer, Tenant shall submit such request to
Landlord, in writing, together with reasonably detailed financial information
and information as to the identity and business information and business history
of the proposed transferee, as well as the proposed effective date of the
Transfer and the area or portion of the Demised Premises which Tenant wishes to
Transfer (the "Transfer Space"). If Landlord fails to respond or request
additional information from Tenant within sixty (60) days after receipt of
Tenant's proper request for approval, Tenant shall submit an additional request
to Landlord, setting forth the same information and further notifying Landlord
on such request, on a covering letter in all capital letters and bold-face type,
that Landlord's failure to respond or request additional information from Tenant
within an additional ten (10) business days shall be deemed an approval (such
notice is hereinafter referred to as an "Automatic Approval Notice"). If
Landlord fails to respond or request additional information from Tenant within
such additional ten (10) business days, such failure to so respond shall be
deemed a consent to the Transfer. If Landlord requests additional information,
Landlord shall respond within the later of (i) ten (10) business days after
receipt of all requested information, or (ii) the expiration of the sixty (60)
day period set forth above; and Landlord's failure to do so shall be deemed a
consent to the Transfer so long as such additional information shall include (on
a covering letter in all capital letters and in bold-face type) an Automatic
Approval Notice. If Landlord consents to any such Transfer, such consent shall
be given on Landlord's form of consent (which consent shall include, among other
things, an acknowledgment by the transferee that its rights arise through and
are limited by the Lease, that the transferee agrees to comply with the Lease
(with such exceptions as may be consented to by Landlord), and a written
acknowledgment by Tenant evidencing that Tenant is not released from its
obligations under this Lease), which consent document shall be executed by
Tenant and the transferee of Tenant. It shall nevertheless be a condition to the
deemed effectiveness thereof that Landlord be furnished with a fully executed
copy of the full documentation governing the

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Transfer, in the form and substance approved by Landlord, and that Tenant shall
pay Landlord's expenses in connection with the proposed Transfer. It shall not
be unreasonable for Landlord to object to Transfer document provisions which,
inter alia, attempt to make Landlord a party to the Transfer document or impose
any obligation on Landlord to the subtenant.

            7.4. RECAPTURE. Upon receipt of Tenant's request for consent to a
proposed Transfer, Landlord may elect to recapture the Transfer Space.
Landlord's election to recapture must be in writing and delivered to Tenant
within thirty (30) days of Landlord's receipt of Tenant's request for permission
to transfer all or a portion of the Demised Premises. Landlord's recapture shall
be effective (the "Effective Date") on a date selected by Landlord, which date
shall be (i) on or before the date which is thirty (30) days after the proposed
effective date of the Transfer, as specifically set forth in Tenant's written
request to Landlord for consent to a proposed Transfer, or (ii) if Tenant's
written request to Landlord for consent to a proposed Transfer does not contain
a proposed effective date, then on or before the date which is thirty (30) days
after Landlord's election to recapture the Transfer Space; and with respect to
the Transfer Space, this Lease shall be terminated and Tenant shall be released
under this Lease, subject to any continuing liabilities or obligations of Tenant
which remain delinquent or uncured with respect to the period prior to the
Effective Date.

            7.5. CONDITIONS. In the event Landlord consents to a Transfer of all
or any portion of the Demised Premises, Landlord may condition its consent,
inter alia, on agreement by Tenant and its assignee and/or sublessee, as the
case may be, that fifty (50%) percent of any rental payable under such Transfer
arrangement which exceeds the amount of rental payable hereunder be payable to
Landlord (after deduction by Tenant for the reasonable and necessary costs
associated with such Transfer amortized over the remaining term of the Lease) as
consideration of the granting of such consent. Nothing herein shall, however, be
deemed to be a consent by Landlord of any Transfer or a waiver of Landlord's
right not to consent to any Transfer. Any purported Transfer not in accordance
with the terms hereof shall at Landlord's option, to be exercised at any time
after Landlord becomes aware of any such purported Transfer, be void, and may at
Landlord's option be treated as an event of default hereunder.

            7.6. SPECIAL CONDITIONS FOR TRANSFERS TO AFFILIATES OF TENANT.
Notwithstanding anything to the contrary set forth above, Tenant shall be
permitted without Landlord's prior written consent, and subject to the terms of
this subparagraph 7.6, to transfer all or a portion of the Demised Premises to
an "Affiliate" of Tenant. For purposes of this subparagraph, Affiliate shall
mean; (i) a corporation which owns fifty percent (50%) of the outstanding common
stock of Tenant, or (ii) a corporation which has fifty percent (50%) of its
common stock owned by Tenant, or (iii) a partnership which owns fifty percent
(50%) of the common stock of Tenant, or (iv) a partnership which has fifty
percent (50%) or more of its interest in partnership profits owned by Tenant, or
(v) an entity which is the surviving entity in a merger pursuant to state
corporation or partnership law with the Tenant, or (vi) Johnson & Johnson or any
of its affiliates or subsidiaries. The effectiveness of such Transfer to an
Affiliate of Tenant shall nevertheless be conditioned on the following: (a)
Landlord receiving a fully executed copy of the full documentation governing the
Transfer, in the form and substance approved by Landlord, and (b) such sublessee
shall acknowledge that its rights arise through and are limited by the Lease,
and shall agree to comply with the Lease (with such exceptions as may be
consented to by Landlord),

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and (c) a written acknowledgment by Tenant evidencing that Tenant is not
released from its obligations under this Lease.

            7.7. NO RELEASE. Notwithstanding any assignment of this Lease or
subletting of all or part of the Demised Premises, whether or not Landlord's
consent is required and/or obtained, the tenant specifically named in the
introductory paragraph of this Lease shall remain fully liable under all of the
terms and provisions of this Lease.

      8. FIRE OR OTHER CASUALTY. In case of damage to the Demised Premises or
those portions of the Research Building providing access or essential services
thereto, by fire or other casualty, Landlord shall, at its expense, cause the
damage to be repaired to a condition as nearly as practicable to that existing
prior to the damage, with reasonable speed and diligence, subject to delays
which may arise by reason of adjustment of loss under insurance policies,
Governmental Regulations, and for delays beyond the control of Landlord,
including a "force majeure" event (as defined below). Landlord shall not,
however, be obligated to repair, restore, or rebuild any of Tenant's property or
any alterations or additions made by or on behalf of Tenant. Landlord shall not
be liable for any inconvenience or annoyance to Tenant, or Tenant's visitors, or
injury to Tenant's business resulting in any way from such damage or the repair
thereof except, to the extent and for the time that the Demised Premises are
thereby rendered untenantable, the rent shall proportionately abate. In the
event the damage shall involve the Research Building generally and shall be so
extensive that Landlord shall decide, at its sole discretion, not to repair or
rebuild the Research Building, or if the casualty shall not be of a type insured
against under standard fire policies with extended type coverage, or if the
holder of any mortgage, deed of trust or similar security interest covering the
Research Building shall not permit the application of adequate insurance
proceeds for repair or restoration, this Lease shall, at the sole option of
Landlord, exercisable by written notice to Tenant given within sixty (60) days
after Landlord is notified of the casualty-and to the extent thereof, be
terminated as of a date specified in such notice (which shall not be more than
ninety [90] days thereafter), and the rent (taking into account any abatement as
aforesaid) shall be adjusted to the termination date and Tenant shall thereupon
promptly vacate the Demised Premises. Furthermore, in the case of any such
casualty, Landlord shall promptly furnish to Tenant an estimate of the time
necessary to repair and restore the Research Building so as to permit the use of
the Demised Premises for the use permitted hereunder. If such estimated period
for completion of the repair and restoration of the Research Building exceeds
three hundred (300) days from the date of casualty, Tenant may, but only within
twenty (20) days after Tenant's receipt of the estimate, terminate this Lease by
written notice to Landlord. If Tenant does not so terminate, this Lease (subject
to the provisions set forth herein), shall remain in effect regardless of
whether the actual restoration time differs from the estimate; provided,
however, in the event the actual restoration time exceeds three hundred thirty
(330) days from the date of the casualty, Tenant shall have the further right to
terminate this Lease by written notice to Landlord, but only within twenty (20)
days after the expiration of such three hundred thirty (330) day period.

      9. REGARDING INSURANCE AND LIABILITY.

            9.1. DAMAGE IN GENERAL. Tenant agrees that Landlord (and its
successors and/or assigns) and its Research Building manager and their
respective partners, officers, employees

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and agents and any mortgagees shall not be liable to Tenant, and Tenant hereby
releases such parties, for any personal injury or damage to or loss of personal
property in the Demised Premises from any cause whatsoever unless such damage,
loss or injury is the result of the negligence or willful misconduct of Landlord
(or its successors and/or assigns), its Research Building manager, or their
partners, officers, employees or agents or any mortgagees, and Landlord (and its
successors and/or assigns) and its Research Building manager and their partners,
officers, employees or agents or any mortgagees shall not be liable to Tenant
for any such damage or loss whether or not the result of their negligence or
willful misconduct to the extent Tenant is compensated therefor by Tenant's
insurance or would have been compensated therefor under commonly available
commercial policies, and Landlord shall in no event be liable to Tenant for any
consequential damages.

            9.2. INDEMNITY.

                  (A) Tenant shall defend, indemnify and save harmless Landlord
(and its successors and/or assigns) and its agents and employees against and
from all liabilities, obligations, damages, penalties, claims, costs, charges
and expenses, including reasonable attorneys' fees, which may be imposed upon or
incurred by or asserted against Landlord and/or its agents or employees by
reason of any of the following which shall occur during the term of this Lease,
or during any period of time prior to the Commencement Date hereof or after the
expiration date hereof when Tenant may have been given access to or possession
of all or any part of the Demised Premises:

                        (1) any work or act done in, on or about the Demised
Premises or any part thereof at the direction of Tenant, its agents,
contractors, subcontractors, servants, employees, licensees or invitees, except
if such work or act is done or performed by Landlord or its agents or employees;

                        (2) any negligence or other wrongful act or omission on
the part of Tenant or any of its agents, contractors, subcontractors, servants,
employees, subtenants, licensees or invitees;

                        (3) any accident, injury or damage to any person or
property occurring in, on or about the Demised Premises or any part thereof,
unless caused by the negligence or willful misconduct of Landlord, its employees
or agents; and

                        (4) any failure on the part of Tenant to perform or
comply with any of the covenants, agreements, terms, provisions, conditions or
limitations contained in this Lease on its part to be performed or complied
with.

                  (B) Landlord shall defend, indemnify and save harmless Tenant
and its agents and employees against and from all liabilities, obligations,
damages, penalties, claims, costs, charges and expenses, including reasonable
attorneys' fees, which may be imposed upon or incurred by or asserted against
Tenant and/or its agents or employees by reason of any of the following which
shall occur during the term of this Lease:

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                        (1) any negligence or other intentional wrongful act on
the part of Landlord or any of its agents, contractors, subcontractors,
servants, employees, subtenants, licensees or invitees; and

                        (2) any accident, injury or damage to any person or
property occurring in an area in the Research Building under the exclusive
custody and control of Landlord, unless caused by the negligence or willful
misconduct of Tenant, its employees or agents;

provided, however, that Landlord shall not be liable for and shall not indemnify
and protect Tenant with respect to any losses associated with Tenant's lost
business opportunities, lost profits, business losses or any consequential
damages. The foregoing indemnity by Landlord shall only apply to liabilities,
obligations, damages, penalties, claims, costs, charges and expenses, including
reasonable attorneys' fees, to the extent the same are not covered by the
insurance Tenant is required to carry hereunder (and, if Tenant fails in any
respect to secure and maintain the insurance required hereunder, only to the
extent the same would not have been covered if Tenant had secured and maintained
the insurance required hereunder).

            9.3. TENANT'S INSURANCE. At all times during the term hereof, Tenant
shall maintain in full force and effect with respect to the Demised Premises and
Tenant's use thereof, commercial general liability insurance, naming Landlord,
Landlord's agent and any mortgagees (and such other parties as Landlord may
request) as additional insureds, covering injury to persons in amounts at least
equal to $10,000,000.00 per occurrence and $10,000,000.00 general aggregate.
Each such policy shall provide that it shall not be cancelable without at least
thirty (30) days prior written notice to Landlord and to any mortgagee named in
an endorsement thereto and shall be issued by an insurer and in a form Accord 27
(or equivalent) to Landlord. Tenant shall lodge with Landlord duplicate
originals or certificates of such insurance, in a form acceptable to Landlord,
at or prior to the Commencement Date of the term hereof, together with evidence
of paid-up premiums, and shall lodge with Landlord renewals thereof at least
fifteen (15) days prior to expiration. In addition to the foregoing, Tenant
shall also be responsible, at Tenant's own cost, to keep and maintain (i)
insurance in respect of and covering Tenant's own furniture, furnishings,
equipment and other personal property, and all improvements made by or on behalf
of Tenant, all insured for the replacement cost thereof, against all risks and
hazards, including but not limited to sprinkler and leakage damage, and theft,
and (ii) workers' compensation insurance with respect to and covering all
employees of Tenant. Tenant shall also carry, at Tenant's own cost and expense,
such other insurance, in amounts and for coverages and on such other terms as
Landlord may from time to time deem commercially reasonable and appropriate.
Tenant assumes all risk of loss of any or all of its personal property.

            9.4. LANDLORD'S INSURANCE. Throughout the term of this Lease,
Landlord will insure the Research Building (excluding any property with respect
to which Tenant is obligated to insure pursuant to Paragraph 9.3 above) with,
what is referred to as, "All Risk" Insurance covering the Research Building
against damage by fire and standard extended coverage perils and public
liability insurance, and shall carry rent insurance, and boiler and machinery
insurance coverage; provided, however, that the foregoing insurances shall only
be required hereunder to the extent such insurance is available at reasonable
rates. All insurance coverage required by

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Landlord shall be in such reasonable amounts and with such reasonable
deductibles as are required by any mortgagee or ground lessor (if any), or if
none, as are determined by Landlord in its good-faith discretion, taking into
consideration the insurance and deductibles as would be carried by a prudent
owner of a similar buildings in the general area of the Research Building.
Landlord may, but shall not be obligated or required to, carry any excess or
other forms of insurance relating to the Research Building as it or the
mortgagee or ground lessor (if any) of Landlord may require or reasonably
determine are available. All insurance carried by Landlord relating to the
Research Building or common areas (including, without limitation, insurance in
excess of that required hereunder) shall be included as an Operating Expense
pursuant to Paragraph 4.1 of this Lease. Notwithstanding its inclusion as an
Operating Expense or any contribution by Tenant to the cost of insurance
premiums by Tenant as provided herein, Tenant acknowledges that it has no right
to receive any proceeds from any such insurance policies carried by Landlord.
Tenant further acknowledges that the exculpatory provisions of this Lease as set
forth in Paragraph 9 and the provision regarding Tenant's insurance are designed
to insure adequate coverage as to Tenant's property and business without regard
to fault and to avoid Landlord's obtaining similar coverage for said loss for
its negligence or that of its agents, servants or employees which could result
in additional costs includable as part of Operating Expenses which are payable
by Tenant. Landlord will not be required to carry insurance of any kind on
Tenant's personal property, equipment furniture or improvements of Tenant under
this Lease and it shall be Tenant's responsibility (at Tenant's sole cost and
expense) to repair any damage thereto. Landlord's insurance may be maintained
through blanket policies of insurance with Landlord and Landlord's affiliates
and through self-insurance programs of Landlord.

            9.5. WAIVER OF SUBROGATION. Each party hereto hereby waives any and
every claim which arises or which may arise in its favor and against the other
party hereto during the term of this Lease or any extension or renewal thereof
for any and all loss of, or damage to, any of its property located within or
upon or constituting a part of the Research Building, to the extent that such
loss or damage is covered under an insurance policy or policies and to the
extent such policy or policies contain provisions permitting such waiver of
claims. Each party shall cause its insurers to issue policies containing such
provisions.

            9.6. LIMITATION ON PERSONAL LIABILITY. Anything in this Lease,
either expressed or implied, to the contrary notwithstanding, Tenant
acknowledges and agrees that each of the covenants, undertakings and agreements
herein made on the part of Landlord, while in form purporting to be covenants,
undertakings and agreements of Landlord, are, nevertheless, made and intended
not as personal covenants, undertakings and agreements of Landlord, or for the
purpose of binding Landlord personally or the assets of Landlord, except
Landlord's interest in the Research Building and the Center and if applicable,
any insurance proceeds; and that no personal liability or personal
responsibility is assumed by, nor shall at any time be asserted or enforceable
against Landlord, any partner of Landlord, any parent or subsidiary of Landlord
or any parent, subsidiary or partner of any partner of Landlord, or any of their
respective heirs, personal representatives, successors and assigns, or officers
or employees on account of this Lease or on account of any covenant, undertaking
or agreement of Landlord in this Lease contained, all such personal liability
and personal responsibility, if any, being expressly waived and released by
Tenant.

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            9.7. SUCCESSORS IN INTEREST TO LANDLORD, MORTGAGEES. The term
"Landlord" as used in this Lease means the fee owner of the Research Building,
or, if different, the party holding and exercising the right, as against all
others (except space tenants of the Research Building) to possession of the
entire Research Building. Landlord as above-named represents that it is the
holder of such rights as of the date hereof. In the event of the voluntary or
involuntary transfer of such ownership or right to a successor-in-interest of
Landlord, Landlord shall be freed and relieved of all liability and obligation
hereunder which shall thereafter accrue and Tenant shall look solely to such
successor-in-interest for the performance of the covenants and obligations of
the Landlord hereunder which shall thereafter accrue. The liability of any such
successor in interest to Landlord under or with respect to this Lease shall be
strictly limited to and enforceable only out of its or their interest in the
Research Building and Center, and shall not be enforceable out of any other
assets. No mortgagee or ground lessor which shall succeed to the interest of
Landlord hereunder (either in terms of ownership or possessory rights) shall:
(i) be liable for any previous act or omission of a prior Landlord, (ii) be
subject to any rental offsets or defenses against a prior Landlord, (iii) be
bound by any amendment of this Lease made without its written consent, (iv) be
bound by payment by Tenant of rent in advance in excess of one (1) month's rent,
(v) be liable for any construction of the improvements to be made to the Demised
Premises, or for any allowance or credit to Tenant for rent, construction costs
or other expenses, or (vi) be liable for any security deposit not actually
received by it. Subject to the foregoing, the provisions hereof shall be binding
upon and inure to the benefit of the successors and assigns of Landlord.

            9.8. SURVIVAL. The provisions of this Paragraph 9 shall survive
termination of this Lease.

      10. EMINENT DOMAIN. If the whole or a substantial part of the Research
Building shall be taken or condemned for public or quasi-public use under any
statute or by right of eminent domain or private purchase in lieu thereof by any
competent authority, Tenant shall have no claim against Landlord and shall not
have any claim or right to any portion of the amount that may be awarded as
damages or paid as a result of any such condemnation or purchase; and all right
of the Tenant to damages therefor are hereby assigned by Tenant to Landlord.
Landlord shall, upon receiving written notification from the condemning
authority relating to a taking or condemnation of the Research Building, notify
Tenant of the same within ten (10) business days of Landlord's receipt of such
notice. The foregoing shall not, however, deprive Tenant of any separate award
for moving expenses, business dislocation damages or for any other award which
would not reduce the award payable to Landlord. Upon the date the right to
possession shall vest in the condemning authority, this Lease shall, at the
option of Landlord or (only in the case of condemnation or taking of the entire
Research Building or such partial taking as results in the untenantability of
the Demised Premises) at the option of Tenant, cease and terminate with rent
adjusted to such date and Tenant shall have no claim against Landlord for the
value of any unexpired term of this Lease.

      11. INSOLVENCY. Each of the following shall constitute an event of default
by Tenant under this Lease, upon the occurrence of any such event of default
Landlord shall have, without need of any notice, the rights and remedies
enunciated in Paragraph 12 of this Lease for events of default hereunder: (i)
the commencement of levy, execution or attachment proceedings against

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Tenant, any principal (which shall be defined as any individual or entity having
a direct or indirect ownership interest in Tenant of more than 25%) thereof or
any partner therein or any surety or guarantor thereof (hereinafter a "Surety")
or any of the assets of Tenant, or the application for or appointment of a
liquidator, receiver, custodian, sequester, conservator, trustee, or other
similar judicial officer; or (ii) the insolvency, under either the bankruptcy or
equity definition, of Tenant or any principal thereof or partner therein or any
Surety; or (iii) the assignment for the benefit of creditors, or the admission
in writing of an inability to pay debts generally as they become due, or the
ordering of the winding-up or liquidation of the affairs of Tenant or any
principal thereof or partner therein or any Surety; or (iv) the commencement of
a case by or against Tenant or any principal thereof or partner therein or any
Surety under any insolvency, bankruptcy, creditor adjustment, debtor
rehabilitation or similar laws, state or federal, or the determination by any of
them to request relief under any insolvency, bankruptcy, creditor adjustment,
debtor rehabilitation or similar proceeding, state or federal, including,
without limitation, the consent by any of them to the appointment of or taking
possession by a receiver, liquidator, assignee, trustee, custodian, sequester or
similar official for it or for any of its respective property or assets (unless,
in the case of involuntary proceedings, the same shall be dismissed within
thirty [30] days after institution).

      12. DEFAULT.

            12.1. EVENTS OF DEFAULT. If Tenant fails to pay rent or any other
sums payable to Landlord hereunder when due and such default shall continue for
five (5) days after it is due, or if Tenant shall fail to perform or observe any
of the other covenants, terms or conditions contained in this Lease within
twenty (20) days (or such longer period as is reasonably required to correct any
such default, provided Tenant promptly commences and diligently continues to
effectuate a cure [but in any event within thirty (30) days]) after written
notice thereof by Landlord; provided, however, that Landlord shall not be
required to give any such notice more than once within any twelve (12) month
period, and provided that the events hereinafter enumerated shall be deemed
events of default under this Lease without any notice, grace or cure period: (a)
if any of the events specified in Paragraph 11 occur, or (b) if Tenant fails to
take actual bona-fide occupancy of the Demised Premises within two hundred
seventy (270) days after the Commencement Date, or Tenant vacates or abandons
the Demised Premises during the term hereof without (with respect to either
events) properly maintaining the Demised Premises in accordance with the Lease
and properly operating the building and laboratory systems and equipment within
the Demised Premises on a regular basis, or (c) if any corporate surety or
guarantor of this Lease merges with another entity, or liquidates or dissolves
or changes control or if any surety or guarantor of this Lease fails to comply
with all of the provisions of its surety ship or guaranty agreement, then, and
in any of such cases (notwithstanding any former breach of covenant or waiver
thereof in a former instance) (each of the foregoing an "Event of Default"),
Landlord, in addition to all other rights and remedies available to it by law or
equity or by any other provisions hereof, may at any time thereafter:

                  (A) upon three (3) days' notice to Tenant, declare to be
immediately due and payable, on account of the rent and other charges herein
reserved for the balance of the term of this Lease (taken without regard to any
early termination of such term on account of an Event

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                      -32-
<PAGE>

of Default), a sum equal to the Accelerated Rent Component (as hereinafter
defined), in which event Tenant shall remain liable to Landlord as hereinafter
provided; and/or

                  (B) whether or not Landlord has elected to recover the
Accelerated Rent Component, terminate this Lease on at least five (5) days'
notice to Tenant and, on the date specified in such notice, this Lease and the
term hereby demised and all rights of Tenant hereunder shall expire and
terminate and Tenant shall thereupon quit and surrender possession of the
Demised Premises to Landlord in the condition elsewhere herein required in which
event Tenant shall remain liable to Landlord as herein provided.

            12.2. ACCELERATED RENT COMPONENT. For purposes hereof, the
"Accelerated Rent Component" shall mean the aggregate of:

                  (A) all rent and other charges, payments, costs and expenses
due from Tenant to Landlord and in arrears at the time of the election of
Landlord to recover the Accelerated Rent Component;

                  (B) the minimum rent reserved for the then entire unexpired
balance of the term of this Lease (taken without regard to any early termination
of the term by virtue of an Event of Default), plus all other charges, payments,
costs and expenses herein agreed to be paid by Tenant up to the end of such term
which shall be capable of precise determination at the time of Landlord's
election to recover the Accelerated Rent Component; and

                  (C) Landlord's good faith estimate of all charges, payments,
costs and expenses herein agreed to be paid by Tenant up to the end of such term
which shall not be capable of precise determination as aforesaid (and for such
purposes no estimate of any component of additional rent to accrue pursuant to
the provisions of Paragraph 4 hereof shall be less than the amount which would
be due if each such component continued at the highest monthly rate or amount in
effect during the twelve [12] months immediately preceding the Event of
Default).

            12.3. RE-ENTRY. In any case in which this Lease shall have been
terminated, or in any case in which Landlord shall have elected to recover the
Accelerated Rent Component and any portion of such sum shall remain unpaid,
Landlord may, without further notice, enter upon and repossess the Demised
Premises, by force, summary proceedings, ejectment or otherwise, and may
dispossess Tenant and remove Tenant and all other persons and property from the
Demised Premises and may have, hold and enjoy the Demised Premises and the rents
and profits there from. Landlord may, in its own name, as agent for Tenant, if
this Lease has not been terminated, or in its own behalf, if this Lease has been
terminated, relet the Demised Premises or any part thereof for such term or
terms which may be greater or less than the period which would otherwise have
constituted the balance of the term of this Lease) and on such terms, conditions
and provisions (which may include concessions or free rent) as Landlord in its
sole discretion may determine. Landlord may, in connection with any such
reletting, cause the Demised Premises to be redecorated, altered, divided,
consolidated with other space or otherwise changed or prepared for reletting. At
Landlord's option, such reletting shall or shall not be deemed a surrender and
acceptance of the Demised Premises.

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

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<PAGE>

            12.4. CONTINUING LIABILITY. Tenant shall, with respect to all
periods of time up to and including the expiration of the term of this Lease (or
what would have been the expiration date in the absence of default or breach)
remain liable to Landlord as follows:

                  (A) In the event of termination of this Lease on account of an
Event of Default, Tenant shall remain liable to Landlord for damages equal to
the rent and other charges payable under this Lease by Tenant as if this Lease
were still in effect, less the net proceeds of any reletting after deducting all
costs incident thereto (including without limitation all repossession costs,
brokerage and management commission, operating and legal expenses and fees,
alteration costs and expenses of preparation for reletting, and interest
relating thereto) and to the extent such damages shall not have been recovered
by Landlord by virtue of payment by Tenant of the Accelerated Rent Component
(but without prejudice to the right of Landlord to demand and receive the
Accelerated Rent Component), such damages shall be payable to Landlord monthly
upon presentation to Tenant of a bill for the amount due.

                  (B) In the event and so long as this Lease shall not have been
terminated after an Event of Default, the rent and all other charges payable
under this Lease shall be reduced by the net proceeds of any reletting by
Landlord (after deducting all costs incident thereto as above set forth) and by
any portion of the Accelerated Rent Component paid by Tenant to Landlord, and
any amount due to Landlord shall be payable monthly upon presentation to Tenant
of a bill for the amount due.

            12.5. CREDIT. In the event: Landlord, after an Event of Default,
shall recover the Accelerated Rent Component from Tenant and it shall be
determined at the expiration of the term of this Lease (taken without regard to
early termination for an Event of Default) that a credit is due Tenant because
the net proceeds of reletting, as aforesaid, plus the amounts paid to Landlord
by Tenant exceed the aggregate of rent and other charges accrued in favor of
Landlord to the end of such term, Landlord shall retain such excess.

            12.6. NO DUTY TO RELET. Landlord shall in no event be responsible or
liable for any failure to relet the Demised Premises or any part thereof, or for
any failure to collect any rent due upon a reletting, except to the extent of
Landlord's obligations under law. Without limiting the foregoing general
statement of Landlord's rights in such regard, Landlord shall have no obligation
to relet all or any portion of the Demised Premises in preference or priority to
any other space Landlord may have available for rent or lease elsewhere in the
Center or otherwise.

            12.7. CONFESSION OF JUDGMENT. UPON FIVE (5) BUSINESS DAYS NOTICE,
LANDLORD SHALL HAVE THE FOLLOWING RIGHTS TO CONFESS JUDGMENT AGAINST TENANT AND
ALL PERSONS CLAIMING THROUGH TENANT, FOR POSSESSION OF THE DEMISED PREMISES:

                  (A) WHEN THIS LEASE SHALL BE TERMINATED BY REASON OF AN EVENT
OF DEFAULT BY TENANT AFTER ANY APPLICABLE NOTICE AND CURE PERIOD AND ANY AGREED
UPON EXTENSIONS, EITHER DURING THE ORIGINAL TERM OF THIS LEASE OR ANY RENEWAL OR
EXTENSION THEREOF, AND ALSO WHEN THE TERM HEREBY CREATED OR ANY EXTENSION
THEREOF SHALL HAVE EXPIRED, IT SHALL BE LAWFUL FOR ANY ATTORNEY TO APPEAR FOR
TENANT IN

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                      -34-
<PAGE>

ANY AND ALL SUITS OR ACTIONS WHICH MAY BE BROUGHT FOR POSSESSION AND/OR
EJECTMENT; AND AS ATTORNEY FOR TENANT TO CONFESS JUDGMENT IN EJECTMENT AGAINST
TENANT AND ALL PERSONS CLAIMING UNDER TENANT FOR THE RECOVERY BY LANDLORD OF
POSSESSION OF THE DEMISED PREMISES, FOR WHICH THIS LEASE SHALL BE LANDLORD'S
SUFFICIENT WARRANT. UPON SUCH CONFESSION OF JUDGMENT FOR POSSESSION, IF LANDLORD
SO DESIRES, A WRIT OF EXECUTION OR OF POSSESSION MAY ISSUE FORTHWITH, WITHOUT
ANY PRIOR WRIT OR PROCEEDINGS WHATSOEVER. IF FOR ANY REASON AFTER SUCH ACTION
SHALL HAVE BEEN COMMENCED, THE SAME SHALL BE DETERMINED AND THE POSSESSION OF
THE DEMISED PREMISES SHALL REMAIN IN OR BE RESTORED TO TENANT, THEN LANDLORD
SHALL HAVE THE RIGHT UPON ANY SUBSEQUENT OR CONTINUING EVENT OF DEFAULT, OR
AFTER EXPIRATION OF THE LEASE, OR UPON THE TERMINATION OF THIS LEASE AS
HEREINBEFORE SET FORTH, TO BRING ONE OR MORE FURTHER ACTIONS AS HEREINBEFORE SET
FORTH TO RECOVER POSSESSION OF THE DEMISED PREMISES.

                  (B) In any action of ejectment, Landlord shall cause to be
filed in such action an affidavit made by Landlord or someone acting for
Landlord setting forth the facts necessary to authorize the entry of judgment,
of which facts such affidavit shall be conclusive evidence. If a true copy of
this Lease shall be filed in such action (and the truth of the copy as asserted
in the affidavit of Landlord shall be sufficient evidence of same), it shall not
be necessary to file the original Lease as a warrant of attorney, any rule of
court, custom or practice to the contrary notwithstanding.

                  (C) Intentionally Omitted.

                  (D) The right to enter judgment against Tenant and to enforce
all of the other provisions of this Lease herein provided for, at the option of
any assignee of this Lease, may be exercised by any assignee of Landlord's
right, title and interest in this Lease in Tenant's own name, notwithstanding
the fact that any or all assignments of such right, title and interest may not
be executed and/or witnessed in accordance with the Act of Assembly of May 28,
1715, 1 Sm. L. 94, and all supplements and amendments thereto that have been or
may hereafter be passed. Tenant hereby expressly waives the requirements of such
Act of Assembly and any and all laws regulating the manner and/or form in which
such assignments shall be executed and witnessed.

                  (E) Tenant acknowledges that it has been represented by
counsel in connection with the negotiation of this Lease, that it has read and
discussed with such counsel the provisions herein relating to confession of
judgment, and that it understands the nature and consequences of such
provisions.

            12.8. BANKRUPTCY. Nothing contained in this Lease shall limit or
prejudice the right of Landlord to prove for and obtain as damages incident to a
termination of this Lease, in any bankruptcy, reorganization or other court
proceedings, the maximum amount allowed by any statute or rule of law in effect
when such damages are to be proved.

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                      -35-

<PAGE>

            12.9. WAIVER OF DEFECTS. Tenant waives the right to trial by jury
and any notices to quit as may be specified in the Landlord and Tenant Act of
Pennsylvania, Act of April 6, 1951 (68 P.S.C.A. Section 250.101 et seq.), as the
same may have been or may hereafter be amended, and agrees that the notices
provided in this Lease shall be sufficient in any case where a longer period may
be starutorily specified. The acceptance by Landlord of any partial payment(s)
by or for Tenant hereunder shall not constitute Landlord's acceptance of such
payment(s) as a satisfaction of Tenant's payment obligation (notwithstanding any
statement to the contrary on any correspondence accompanying such payment(s)
and/or note(s) written on any check).

            12.10. NON-WAIVER BY LANDLORD. The failure of Landlord to insist in
any one or more instances upon the strict performance of any one or more of the
agreements, terms, covenants, conditions or obligations of this Lease, or to
exercise any right, remedy or election herein contained, shall not be construed
as a waiver or relinquishment in the future of such performance or exercise, but
the same shall continue and remain in full force and effect with respect to any
subsequent breach, act or omission.

            12.11. PARTIAL PAYMENT. No payment by Tenant or receipt by Landlord
of a lesser amount than the correct minimum rent or additional rent due
hereunder shall be deemed to be other than a payment on account, nor shall any
endorsement or statement on any check or any letter accompanying any check or
payment be deemed to effect or evidence an accord and satisfaction, and Landlord
may accept such check or payment without prejudice to Landlord's right to
recover the balance or pursue any other remedy in this Lease or at law provided.

            12.12. OVERDUE PAYMENTS. If any payment required to be made by
Tenant to Landlord under this Lease shall not have been received by Landlord by
5:00 pm local time on the fifth (5th) day after the date such payment is due,
then (i) in addition to such payment, and in order to partially compensate
Landlord for the extra expense incurred in the handling of overdue payments,
Tenant shall pay Landlord a late fee equal to the greater of (a) five percent
(5%) of such overdue payment, or (b) two hundred fifty dollars ($250); and (ii)
such overdue payment shall bear interest, from the date such overdue payment was
due until it is paid, at the higher of (a) five percent (5%) above the highest
prime rate published in the Wall Street Journal, if available (and, if not
available, then such comparable substitute rate as may be selected by Landlord),
from time to time, and (b) the rate of eighteen percent (18%) per annum (or, if
lower, the highest legal rate); provided, however, that if on two (2) occasions
in any calendar year a payment required to be made by Tenant to Landlord shall
not have been received by Landlord by 5:00 pm local time on the date such
payment is due, then, and for the remainder of the Lease term, Tenant shall not
be entitled to the five (5) day grace period set forth above in this Section,
and the late fee shall be charged, and interest shall commence to accrue, if a
payment is not received by Landlord by 5:00 pm local time on the date such
payment is due. The late fee and interest set forth in this Section shall not
affect any other right or remedy available to Landlord as a result of a failure
by Tenant to make any payment as required under this Lease.

            12.13. CUMULATIVE REMEDIES. No right or remedy herein conferred upon
or reserved to Landlord is intended to be exclusive of any other right or remedy
herein or by law

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                      -36-

<PAGE>

provided, but each shall be cumulative and in addition to every other right or
remedy given herein or now or hereafter existing at law or in equity or by
statute.

      13. SUBORDINATION.

            13.1. GENERAL. This Lease is and shall be subject and subordinate to
all ground or underlying leases of the entire Research Building (or of the
entire Center) and to all mortgages, deeds of trust and similar security
documents which may now or hereafter be secured upon the Research Building (or
upon the Center), and to all renewals, modifications, consolidations,
replacements and extensions thereof. This clause shall be self-operative and no
further instrument of subordination shall be required by any lessor or
mortgagee, but in confirmation of such subordination, Tenant shall execute,
within ten (10) days after request, any certificate that Landlord may reasonably
require acknowledging such subordination. Notwithstanding the foregoing, the
party holding the instrument to which this Lease is subordinate shall have the
right to recognize and preserve this Lease in the event of any foreclosure sale
or possessory action, and in such case, this Lease shall continue in full force
and effect at the option of the party holding the superior lien and Tenant shall
attorn to such party and shall execute, acknowledge and deliver any instrument
that has for its purpose and effect the confirmation of such attornment. Tenant
shall send to any mortgagee or ground lessor of the Research Building designated
by Landlord a copy of any notice given by Tenant to Landlord alleging a material
breach by Landlord in its obligations under this Lease.

            13.2. RIGHTS OF MORTGAGEE. In the event of any act or omission of
Landlord which would give Tenant the right, immediately or after lapse of a
period of time, to cancel or terminate this Lease, or to claim a partial or
total eviction, Tenant shall not exercise such right (i) until it has given
written notice of such act or omission to the holder of each such mortgage and
ground lease whose name and address shall previously have been furnished to
Tenant in writing, and (ii) until a reasonable period for remedying such act or
omission by the holder of each such mortgage and ground lease shall have elapsed
following the giving of such notice (which reasonable period shall in no event
be less than the period to which Landlord would be entitled, under this Lease or
otherwise, after similar notice, to effect such remedy plus an additional period
of time of thirty (30) days for a monetary default, or the number of days
reasonably required for the holder of each such mortgage and ground lease to
obtain possession of the Research Building and to cure such default (but in no
event less than an additional 45 days period) for any other default). Nothing
herein shall obligate any such mortgagee to remedy any alleged default of
Landlord.

            13.3. MODIFICATIONS. If, in connection with obtaining, continuing or
renewing financing for which the Research Building, Center or the Demised
Premises or any interest therein represents collateral in whole or in part, a
banking, insurance or other lender shall request reasonable modifications of
this Lease as a condition of such financing, Tenant will not unreasonably
withhold, delay, condition or defer its consent thereto, provided that such
modifications do not increase the monetary obligations of Tenant hereunder,
change the business terms of this Lease or adversely affect to a material degree
Tenant's leasehold interest hereby created.

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

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<PAGE>

            13.4. SNDA. For the benefit of Tenant (and upon Tenant's request
therefor), Landlord shall use commercially reasonable efforts to obtain from its
future mortgagee, if any, a Subordination, Non-Disturbance and Attornment
Agreement (a "SNDA"), to be entered into between Landlord, Tenant and Landlord's
future mortgagee, under which, among other things, this Lease and the rights of
Tenant hereunder shall not be adversely affected or modified by foreclosure or
the exercise of any other right or remedy by the mortgagee so long as Tenant
shall not be in default under any of the provisions of this Lease beyond any
applicable period of grace, and under which Tenant shall attorn to and recognize
the mortgagee or any purchaser at foreclosure sale or other
successor-in-interest to Landlord as Tenant's landlord hereunder. Landlord also
agrees to use commercially reasonable efforts to obtain a SNDA from each
additional mortgagee. Each SNDA shall be in the form required by the lender.
Tenant's obligations under this Lease shall not be affected by Landlord's
failure to obtain a SNDA from its current or any future mortgagee. Tenant
covenants and agrees to execute and deliver to Landlord or to the lender a SNDA
within ten (10) days after a written request therefor.

      14. NOTICES. All notices and other communications hereunder, to be
effective, must be in writing (whether or not a writing is expressly required
hereby), and must be either (i) hand delivered, or (ii) sent by a recognized
national overnight courier service, fees prepaid, or (iii) sent by United States
registered or certified mail, return receipt requested, postage prepaid, or (iv)
sent by facsimile transmission (with a confirmation copy immediately to follow
by any of the methods of delivery set forth above); in all of the foregoing
cases to the following respective addresses:

            14.1. IF TO LANDLORD:

                  Radnor Properties-145 KOP, L.P.
                  c/o The Rubenstein Company, L.P.
                  4100 One Commerce Square
                  2005 Market Street
                  Philadelphia, Pennsylvania 19103
                  Attention: David B. Rubenstein
                             R. Bruce Balderson, Jr., Esq.
                  FAX: (215)563-4110

                  With a copy to:

                  MMBC Equity Holdings II, LP
                  c/o David L. Babson and Company Incorporated
                  1295 State Street
                  Springfield, MA 01111
                  Attention: Robert F. Little
                  FAX: (413)846-5065

                  Boston Capital Institutional Advisors, LLC
                  One Boston Place, Suite 2100
                  Boston, MA 02108

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                      -38-

<PAGE>

                  Attention: William H. Kremer, Managing Director
                  FAX: (617) 624-8399

                  Goodwin Procter LLP
                  Exchange Place
                  Boston, MA 02109
                  Attention: Lawrence R. Cahill, P.C.
                  FAX: (617)227-8591

            14.2. IF TO TENANT:

                  Centocor, Inc.
                  200 Great Valley Parkway
                  Malvern, PA 19355
                  Attention: Jill Tiracorda, P.E.
                  FAX: (610)240-8080

                  With a copy to:

                  Johnson & Johnson
                  One Johnson & Johnson Plaza
                  New Brunswick, New Jersey 08933
                  Attention: Office of General Counsel
                  FAX: (732)524-2788

or at such other address or to the attention of such other person as either
party may hereafter give the other for such purpose. Notices will be deemed to
have been given (a) when so delivered (by hand delivery or courier service), or
(b) three days after being so mailed (by registered or certified mail as
aforesaid).

      15. HOLDING OVER. Should Tenant continue to occupy the Demised Premises
after expiration of the Term of this Lease or any renewal or renewals thereof,
or after a forfeiture or other termination thereof, such tenancy shall (without
limitation on any of Landlord's rights or remedies therefor) be one at
sufferance from month to month at a minimum monthly rent equal to one hundred
twenty five percent (125%) for the first ninety days and one hundred fifty
percent (150%) thereafter of the greater of (i) the sum of minimum rent and
additional rent payable for the last month of the term of this Lease or, (ii)
the fair market rental value at the time of such holdover, and, in addition to
either of the foregoing, all other charges payable with respect to such last
month of this Lease and all damages suffered or incurred by Landlord as a result
of or arising from such holdover tenancy. Nothing contained herein shall grant
Tenant the right to holdover after the term of this Lease has expired.

      16. RESERVATIONS IN FAVOR OF LANDLORD. (i) All walls, windows and doors
bounding the Demised Premises (including exterior Research Building walls, core
corridor walls and doors and any core corridor entrance), except the inside
surfaces thereof, (ii) any terraces or roofs adjacent to the Demised Premises,
and (iii) any space in or adjacent to the Demised Premises

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                      -39-

<PAGE>

used for shafts, pipes, conduits, fan rooms, ducts, electric or other utilities,
sinks or other Research Building facilities, and the use thereof, as well as
reasonable access thereto through the Demised Premises for the purposes of
construction, operation, maintenance, decoration and repair, are reserved to
Landlord.

      17. COMPLETION OF IMPROVEMENTS; DELAY IN POSSESSION.

            17.1. INTENTIONALLY OMITTED.

            17.2. TENANT IMPROVEMENTS. Tenant, at Tenant's own cost, shall
furnish, install and otherwise provide and be responsible for all "Tenant
Improvements" identified on Exhibit "F", and Tenant shall perform, observe and
complete its obligations with respect to Tenant Improvements, all within the
time periods therefor and all as more completely set forth herein and in Exhibit
"F".

            17.3. ACCEPTANCE. Tenant represents that the Research Building,
Land, and the Demised Premises, the street or streets, sidewalks, parking areas,
curbs and access ways adjoining them, and the present uses and non-uses thereof,
have been examined by Tenant, and Tenant accepts them in the condition or state
in which they now are, or any of them now is, without relying on any
representation, covenant or warranty, express or implied, by Landlord. Tenant
specifically agrees to accept the Demised Premises in "AS-IS", "WHERE-IS"
condition, without any obligation on the part of Landlord to perform any
alterations, improvements, redecorating or other work therein except as
specifically provided in this Lease. The provisions of this Paragraph shall
survive the termination of this Lease.

            17.4. Intentionally Omitted.

      18. COMMUNICATION AND COMPUTER LINES. Tenant may install, maintain,
replace, remove or use any communications or computer wires, cables and related
devices (collectively the "Lines") at the Research Building in or serving the
Demised Premises, provided: (a) Tenant shall obtain Landlord's prior written
consent, use an experienced and qualified contractor approved in writing by
Landlord, and comply with all of the other provisions of Paragraph 6.7, (b)any
such installation, maintenance, replacement, removal or use shall comply with
all Governmental Requirements applicable thereto and good work practices
including, but not limited to, the national electrical codes and all
requirements of the National Fire Protection Agency and shall not interfere with
the use of any then existing Lines at the Research Building, (c) an acceptable
number of spare Lines and space for additional Lines shall be maintained for
existing and future occupants of the Research Building, as determined in
Landlord's reasonable opinion, (d) if Tenant at any time uses any equipment that
may create an electromagnetic field exceeding the normal insulation ratings of
ordinary twisted pair riser cable or cause radiation higher than normal
background radiation, the Lines therefor (including riser cables) shall be
appropriately insulated to prevent such excessive electromagnetic fields or
radiation, (e) as a condition to permitting the installation of new Lines,
Landlord may require that Tenant remove existing Lines located in or serving the
Demised Premises, (f) Tenant's rights shall be subject to the rights of any
regulated telephone company, and (g) Tenant shall pay all costs in connection
therewith, and Landlord reserves the right to require that Tenant remove any
Lines located in or serving the Demised Premises which are installed in
violation of these provisions, or which are at

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

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<PAGE>

any time in violation of any Governmental Requirements or represent a dangerous
or potentially dangerous condition (whether such Lines were installed by Tenant
or any other party), within three (3) days after written notice.

            18.1. LANDLORD RESERVATION. Landlord may (but shall not have the
obligation to): (i) install new Lines at the Research Building (ii) create
additional space for Lines at the Research Building, and (iii) reasonably
direct, monitor and/or supervise the installation, maintenance, replacement and
removal of, the allocation and periodic re-allocation of available space (if
any) for, and the allocation of excess capacity (if any) on, any Lines now or
hereafter installed at the Research Building by Landlord, Tenant or any other
party (but Landlord shall have no right to monitor or control the information
transmitted through such Lines). Such rights shall not be in limitation of other
rights that may be available to Landlord by Governmental Requirements or
otherwise. If Landlord exercises any such rights, Landlord may charge Tenant for
the costs attributable to Tenant, or may include those costs and all other costs
in Operating Expenses (including without limitation, costs for acquiring and
installing Lines and risers to accommodate new Lines and spare Lines, any
associated computerized system and software for maintaining records of Line
connections, and the fees of any consulting engineers and other experts);
provided, any capital expenditures included in Operating Expenses hereunder
shall be amortized (together with reasonable finance charges) over the useful
life of such item (but in no event longer than five years).

            18.2. REMOVAL OF LINES. Notwithstanding anything to the contrary
contained in Paragraph 6.4, Landlord reserves the right to require that Tenant
remove any or all Lines installed by or for Tenant, except if Tenant removes
substantially all of the existing (as of the date of this Lease) Lines installed
within or serving the Demised Premises, then Tenant shall not be required to
remove Tenant installed Lines upon termination of this Lease. Any Lines not
required to be removed pursuant to this Paragraph shall, at Landlord's option,
become the Property of Landlord (without payment by Landlord). If Tenant fails
to remove such Lines as required by Landlord, or violates any other provision of
this Paragraph, Landlord may, after twenty (20) days written notice to Tenant,
remove such Lines or remedy such other violation, at Tenant's expense (without
limiting Landlord's other remedies available under this Lease or applicable
Governmental Requirements). Tenant shall not, without the prior written consent
of Landlord in each instance, grant to any third party a security interest or
lien in or on the Lines, and any such security interest or lien granted without
Landlord's written consent shall be null and void. Except to the extent arising
from the intentional or negligent acts of Landlord or Landlord's agents or
employees, Landlord shall have no liability for damages arising from, and
Landlord does not warrant that the Tenant's use of any Lines will be free from
the following (collectively called "Line Problems"): (x) any eavesdropping or
wire-tapping by unauthorized parties, (y) any failure of any Lines to satisfy
Tenant's requirements, or (z) any shortages, failures, variations,
interruptions, disconnections, loss or damage caused by the installation,
maintenance, replacement, use or removal of Lines by or for other tenants or
occupants at the Research Building, by any failure of the environmental
conditions or the power supply for the Research Building to conform to any
requirements for the Lines or any associated equipment, or any other problems
associated with any Lines by any other cause. Under no circumstances shall any
Line Problems be deemed an actual or constructive eviction of Tenant, render
Landlord liable to Tenant for abatement of Rent, or relieve Tenant from
performance of Tenant's

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

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<PAGE>

obligations under this Lease. Landlord in no event shall be liable for damages
by reason of loss of profits, business interruption or other consequential
damage arising from any Line Problems.

            18.3. COMMUNICATION CONTRACTORS. Landlord has informed Tenant that
certain communication services may be offered to tenants of the Research
Building by an entity which may or may not be related to or under contract with
Landlord ("Supplier"). Tenant shall be permitted to contract with Supplier for
the provision of any or all of such services on such terms and conditions as
Tenant and Supplier may agree. Tenant shall also be permitted to obtain
communication services from any other reputable person or entity in the business
of providing the same (hereinafter referred to as "Separate Supplier"), provided
that Landlord shall not be required thereby to make any alterations in or to any
part of the Research Building or the use of any facilities or equipment of the
Research Building, and provided further that no such services provided by a
Separate Supplier, or any equipment or facilities used or to be used in
connection therewith, shall be incompatible in any respect with, or shall
interfere with or otherwise impair or adversely affect the operation,
reliability or quality of any Research Building Systems or any services,
equipment or facilities used or operated by Supplier or any tenant in the
Research Building. Tenant acknowledges and agrees that: (a) Landlord has made no
warranty or representation to Tenant with respect to the availability of any
such services, whether provided by Supplier or any Separate Supplier, or the
quality, reliability or suitability thereof; (b) neither Supplier nor any
Separate Supplier is acting as the agent or representative of Landlord in the
provision of such services, and Landlord shall have no liability or
responsibility for any failure or inadequacy of such services, or any equipment
or facilities used in the furnishing thereof, or any act or omission of Supplier
or any Separate Supplier or their agents, employees, representatives, officers
or contractors; (c) if Tenant so contracts for such services with Supplier or
Separate Supplier, Landlord shall have no responsibility or liability for the
installation, alteration, repair, maintenance, furnishing, operation, adjustment
or removal of any such services, equipment, or facilities; and (d) any contract
or other agreement between Tenant and Supplier or any Separate Supplier shall be
independent of this Lease, the obligations of Tenant hereunder, and the rights
of Landlord hereunder, and, without limiting the foregoing, no default or
failure of Supplier or any Separate Supplier with respect to any such contract
or agreement relating thereto, shall have any effect on this Lease or give to
Tenant any offset or defense to the full and timely performance of its
obligations hereunder, entitle Tenant to any abatement of rent or any other
payment required to be made by Tenant hereunder or constitute any actual or
constructive eviction of Tenant or otherwise give rise to any other claim of any
nature against Landlord. If Tenant does not contract for such communication
services with a Supplier or Separate Supplier, this subparagraph shall be deemed
of no force or effect under this Lease.

      19. LANDLORD'S RELIANCE. Within five (5) business days of a monetary Event
of Default, Tenant will submit to Landlord current non-confidential financial
information, in detail reasonably satisfactory to Landlord, in order for
Landlord to determine properly Tenant's then financial condition. In the event
of a sale or refinancing of the Research Building, Tenant shall cooperate with
Landlord in providing a potential lender or buyer with non-confidential
information as to the financial condition of Tenant. As a material inducement to
Landlord to enter into this Lease, Tenant (and each party executing this Lease
on behalf of Tenant individually) represents and warrants to Landlord that: (i)
Tenant and the party executing on behalf of Tenant are fully and properly
authorized to execute and enter into this Lease on behalf

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of Tenant and to deliver the same to Landlord; (ii) the execution, delivery and
full performance of this Lease by Tenant do not and shall not constitute a
violation of any contract, agreement, undertaking, judgment, law, decree,
governmental or court order or other restriction of any kind to which Tenant is
a party or by which Tenant may be bound; (iii) Tenant has executed this Lease
free from fraud, undue influence, duress, coercion or other defenses to the
execution of this Lease; (iv) this Lease constitutes a valid and binding
obligation of Tenant, enforceable against Tenant in accordance with its terms;
(v) each individual executing this Lease on behalf of Tenant is legally
competent, has attained the age of majority and has full capacity to enter into
this Lease; and (vi) if Tenant is a corporation, a partnership or a limited
liability company: (a) Tenant is duly organized, validly existing and in good
standing under the laws of the state of its organization and has full power and
authority to enter into this Lease, to perform its obligations under this Lease
in accordance with its terms, and to transact business in Pennsylvania; (b) the
execution of this Lease by the individual or individuals executing it on behalf
of Tenant, and the performance by Tenant of its obligations under this Lease,
have been duly authorized and approved by all necessary corporate, partnership
or limited liability company action, as the case may be; and (c) the execution,
delivery and performance of this Lease by Tenant is not in conflict with
Tenant's bylaws or articles of incorporation, agreement of partnership, limited
liability company operating agreement or certificate of formation or other
organization documents or charters, agreements, rules or regulations governing
Tenant's business as any of the foregoing may have been supplemented, modified,
amended, or altered in any manner.

      20. PRIOR AGREEMENTS; AMENDMENTS. This Lease constitutes the entire
agreement between the parties relating to the subject matter contained herein.
Neither party hereto has made any representations or promises except as
contained herein or in some further writing signed by the party making such
representation or promise, which, by its express terms, is intended to
supplement the terms hereof. Without limiting the foregoing, this Lease
supersedes all prior negotiations, agreements, informational brochures, letters,
promotional information, proposals, and other statements and materials made or
furnished by Landlord or its agents. No agreement hereinafter made shall be
effective to change, modify, discharge, waive obligations under, or effect an
abandonment of this Lease, in whole or in part, unless such agreement is in
writing and signed by the party against whom enforcement of the change,
modification, discharge, waiver or abandonment is sought. Notwithstanding the
foregoing, no warranty, representation, covenant, writing, document, instrument,
amendment, modification, agreement or like instrument shall be binding upon or
enforceable against Landlord unless executed by Landlord.

      21. CAPTIONS. The captions of the paragraphs and subparagraphs in this
Lease are inserted and included solely for convenience and shall not be
considered or given any effect in construing the provisions hereof.

      22. LANDLORD'S RIGHT TO CURE. Landlord may (but shall not be obligated
to), on five (5) business days' notice to Tenant (except that no notice or
opportunity to cure need be given in case of emergency or on account of a
default by Tenant which adversely affects the operation of the Research Building
or the use and enjoyment thereof by any other tenant(s) of the Research
Building), cure on behalf of Tenant any Event of Default hereunder by Tenant,
which has not been cured within any applicable cure period provided under
Paragraph 12.1 hereof, and the cost

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of such cure (including any attorney's fees incurred) shall be deemed additional
rent payable upon demand.

      23. ESTOPPEL STATEMENT. Tenant shall from time to time, within fifteen
(15) days after request by Landlord or any mortgagee, execute, acknowledge and
deliver to Landlord, or to any third party designated by Landlord, a statement
certifying that this Lease is unmodified and in full force and effect (or that
the same is in full force and effect as modified, listing any instruments of
modification), confirming the rents and other charges under this Lease and the
dates to which rent and other charges have been paid, and certifying whether or
not, to the best of Tenant's knowledge, Landlord is in default hereunder or
whether Tenant has any claims or demands against Landlord (and, if so, the
default, claim and/or demand shall be specified) and such other reasonable
information as Landlord shall require, in the form set forth in Exhibit "G"
hereto or such similar form as may be required by any subsequent mortgagee or
third party. To the extent such estoppel statement is not received from Tenant
in a timely manner in accordance with this Paragraph, Landlord shall be entitled
to furnish to any third party to whom such estoppel statement would have been
delivered Landlord's good faith statement to the effect requested from Tenant,
and Tenant shall be bound by, and deemed to have delivered, such Landlord's
estoppel statement with respect to this Lease. Any such estoppel statement may
be relied upon by Landlord, any mortgagees, auditors, insurance carriers and
prospective purchasers.

      24. BROKER. Tenant represents and warrants that it has not dealt with any
broker or agent in the negotiation for or the obtaining of this Lease, other
than The Rubenstein Brokerage Group, Inc. and Brite Realty Services, Inc.
("Brokers"), and agrees to indemnify, defend and hold Landlord harmless from any
and all cost or liability for compensation claimed by any such broker or agent,
other than Brokers, employed or engaged by it or claiming to have been employed
or engaged by it. Each of the Brokers is entitled to a leasing commission in
connection with the making of this Lease, and Landlord shall pay such commission
to each of the Brokers pursuant to a separate agreement between Landlord and
each of the respective Brokers.

      25. MISCELLANEOUS.

            25.1. CERTAIN INTERPRETATIONS. The word "Tenant" as used in this
Lease shall be construed to mean tenants in all cases whether there is more than
one tenant (and in such case the liability of such tenants shall be joint and
several), and the necessary grammatical changes required to make the provisions
hereof apply to corporations, partnerships or individuals, men or women, shall
in all cases be assumed as though in each case fully expressed. Each provision
hereof shall extend to and shall, as the case may require, bind and inure to the
benefit of Tenant and its successors and assigns, provided that this Lease shall
not inure to the benefit of any assignee or successor of Tenant except upon the
express written consent of Landlord as herein provided.

            25.2. PARTIAL INVALIDITY. If any of the provisions 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 or provisions to persons or circumstances other than those as to
whom or to which it is held invalid or

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unenforceable, shall not be affected thereby, and every provision of this Lease
shall be valid and enforceable to the fullest extent permitted by law.

            25.3. GOVERNING LAW. This Lease shall be governed in all respects by
the laws of the Commonwealth of Pennsylvania.

            25.4. FORCE MAJEURE. If Landlord shall be delayed in the performance
or unable to perform any of Landlord's obligations under this Lease because of a
"force majeure" event (which shall mean any event beyond the reasonable control
of Landlord including, without limitation, labor disputes, civil commotion, war,
war-like operations, invasion, rebellion, hostilities, military power, sabotage,
governmental regulations or controls, fire or other casualty, inability to
obtain material or services, inclement weather or other act of God), then, in
any such case, Landlord shall not be subject to any liability to Tenant.
Landlord's delay in performance or failure to perform under this Lease as a
result of any force majeure event shall not affect the validity of this Lease or
any obligation of Tenant hereunder.

            25.5. LIGHT AND AIR. This Lease does not grant any legal rights to
"light and/or air" outside the Demised Premises nor any particular view or
cityscape visible from the Demised Premises.

            25.6. RECORDING. Neither this Lease nor any memorandum of lease or
short form lease shall be recorded by Tenant and Tenant shall remove immediately
upon request by Landlord any improperly recorded copy of this Lease or
memorandum of Lease.

      26. QUIET ENJOYMENT. Upon payment by Tenant of the rent and other sums
provided herein and Tenant's observance and performance of the covenants, terms
and conditions of this Lease to be observed and performed by Tenant, Tenant
shall peaceably hold and quietly enjoy the Demised Premises for the term of this
Lease without hindrance or obstruction by Landlord or any other person claiming
by, through or under Landlord, subject to the terms and conditions of this
Lease, and to any mortgage or ground lease which is superior to this Lease.

      27. CONFIDENTIALITY. TENANT AND LANDLORD ACKNOWLEDGE AND AGREE THAT THE
TERMS OF THIS LEASE AND THE NEGOTIATIONS WHICH LED TO THE EXECUTION OF THIS
LEASE ARE CONFIDENTIAL IN NATURE. TENANT AND LANDLORD COVENANT THAT, EXCEPT AS
MAY BE REQUIRED BY LAW OR AS REQUIRED TO CONDUCT THEIR BUSINESS OR AS REQUIRED
BY ANY LENDER IN CONNECTION WITH ANY CURRENT OR PROPOSED FINANCING FOR TENANT OR
LANDLORD, NEITHER TENANT NOR LANDLORD SHALL COMMUNICATE THE TERMS OR ANY OTHER
ASPECT OF THIS TRANSACTION WITH, AND WILL NOT DELIVER ALL OR ANY PORTION OF THIS
LEASE TO, ANY PERSON OR ENTITY OTHER THAN TO THE OTHER PARTY.

      28. MONUMENT SIGN. Provided Landlord obtains, all necessary governmental
approval(s), Landlord shall install one (1) multi-tenant monument sign (the
"Monument Sign"). Landlord shall be solely responsible and shall pay for all
costs and expenses of the initial design, construction and installation of the
Monument Sign. Tenant shall pay Tenant's pro-rata share of the initial design,
construction and installation and ongoing maintenance charges of the

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Monument Sign. At the request of Tenant, Landlord shall install, at Landlord's
sole cost and expense, one (1) Building Standard sign on the Monument Sign (the
"Sign") provided: Landlord approves the design, location and size of the Sign.
At the option of Landlord and upon the earlier to occur of either (i) the
expiration or sooner termination of the Lease, or (ii) the date that the Demised
Premises should consist of less than 80,000 RSF (whether due to a Transfer,
recapture or otherwise), Tenant shall, at Tenant's sole cost and expense, remove
the Sign and shall repair all damage caused by such removal.

      29. RIGHT OF FIRST REFUSAL TO PURCHASE.

            29.1. GRANT. Landlord hereby grants to Tenant a right of first
refusal (the "Right of First Refusal") to purchase all (but not less than all)
of the Center, all fixtures, equipment and other structures and improvements
owned by Landlord and then existing on or within the Land or the Center and used
by the Landlord in connection with the operation thereof, (collectively, the
"Property"), all on and subject to the terms and conditions hereinafter set
forth.

            29.2. OFFER TO PURCHASE.

                  (A) In the event Landlord shall receive a bona-fide written
offer (an "Offer") to purchase the Property (including, without limitation an
offer to purchase the Property only as well as an offer to purchase the Property
as part of a larger assembly of real estate)[the property identified in any such
offer is referred to as the "Subject Property"], from a third-party that does
not intend to use and occupy the Subject Property for its own business purposes
(any such offerer is referred to as an "Investor"), which Offer Landlord wishes
to accept, then Landlord shall submit written notice of such Offer (together
with a copy thereof) to Tenant ("Landlord's Offer Notice").

                  (B) In the event Landlord shall receive an Offer from a
third-party that intends to use and occupy all or part of the Subject Property
(or that desires to accommodate, through a purchase, an entity that specifically
desires to use and occupy all or part of the Subject Property [any such offerer
is referred to as a "User"]), which Offer Landlord wishes to accept, then
Landlord shall submit a written Landlord's Offer Notice with respect to such
Offer (together with a copy thereof) to Tenant.

            29.3. EXERCISE. Pursuant to the Right of First Refusal, Tenant shall
have the option to purchase the Subject Property on the terms (including,
without limitation, purchase price set forth in the Offer) set forth in the
Landlord's Offer Notice by written notice to Landlord (the "Tenant's Acceptance
Notice"), which Tenant's Acceptance Notice must be received by Landlord within
fifteen (15) days after Tenant's receipt of the Landlord's Offer Notice, on and
subject to the following terms and conditions: (i) at the time of exercising the
Right of First Refusal, Tenant's financial condition, in Landlord's reasonable
discretion, shall be sufficient to enable Tenant to fulfill all of the financial
obligations contained in Landlord's Offer Notice (evidence of which Tenant shall
submit to Landlord together with or prior to Tenant's Acceptance Notice); and
(ii) at the time of any Landlord's Offer Notice and Landlord's receipt of any
Tenant's Acceptance Notice, this Lease shall be in full force and effect and
there shall exist no Event of Default or event after which, the giving of
notice, the passage of time, or both, would (or at Landlord's option could)
constitute an Event of Default.

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            29.4. AGREEMENT OF PURCHASE AND SALE. In the event the Right of
First Refusal is effectively exercised as aforesaid, then Landlord and Tenant
shall promptly thereafter (and in any event within thirty (30) days) execute an
Agreement of Purchase and Sale upon the terms and conditions set forth in the
Offer to the extent such terms and conditions do not conflict with this
Paragraph in which event the terms and conditions of this Paragraph shall
control unless otherwise specifically agreed to, in writing, by Landlord and
Tenant. The Agreement of Purchase and Sale shall provide that (i) any term or
condition in the Offer relating to this Lease or within the control of Tenant
(including, without limitation, any condition requiring the execution of an
estoppel certificate and/or a subordination and attornment agreement by Tenant)
shall automatically be deemed to have been satisfied; (ii) Tenant shall be
required to post a non-refundable deposit in an amount of not less than ten
percent (10%) of the purchase price at the time of Tenant's execution of the
Agreement of Purchase and Sale; (iii) the closing (the "Closing") thereunder
shall take place at 10:00 A.M. on the forty fifth (45th) consecutive day
following Landlord's receipt of the Tenant's Acceptance Notice, or if such a day
is not a business day then on the next succeeding day which is a business day;
Closing shall be held at the office of Landlord's affiliate, The Rubenstein
Company, L.P., 4100 One Commerce Square, 2005 Market Street, Philadelphia,
Pennsylvania 19103-7041, or on such other date or at such other time or place as
Landlord and Tenant may mutually agree; (iv) at Closing, Tenant shall pay the
purchase price and all rent due under this Lease applicable to the period prior
and up to the Closing date, Tenant shall accept title to the Subject Property
subject to all easements, covenants, conditions and encumbrances (other than
monetary liens) existing on the date of this Lease) and Landlord and Tenant
shall each execute and deliver (as applicable) such documents and instruments,
and make such prorations, and pay such expenses (and shall split equally any
realty transfer taxes) as may be required or reasonably requested by either
party to effect or assure the simultaneous, complete and effective transfer,
assignment and conveyance to, and assumption by, Tenant of all of Landlord's
right, title and interest in and to the Subject Property. Furthermore, except as
specifically set forth in the Offer (but subject to clause (i) of this
subsection above), the Subject Property shall be sold and conveyed in an "AS
IS-WHERE IS" condition, without any express or implied warranty whatsoever as to
the condition thereof, fitness for a particular purpose or otherwise. In the
event Landlord and Tenant shall fail, within such thirty (30) day period, to
execute an Agreement of Purchase and Sale upon the terms and conditions set
forth above, then Tenant shall be deemed to have failed to have effectively
exercised the Right of First Refusal.

            29.5. FAILURE TO EFFECTIVELY EXERCISE. In the event Tenant fails to
effectively exercise the Right of First Refusal as aforesaid, then, for a period
of one (1) year after the last day Landlord could have received a Tenant's
Acceptance Notice pursuant to an effective exercise of the Right of First
Refusal, Landlord shall be free to sell the Subject Property (or any substantial
part thereof) to any third party on substantially the terms and conditions
contained in the Offer and upon any such sale, the Right of First Refusal shall
become null and void.

            29.6. SPECIAL PROVISIONS RELATING TO AN OFFER FROM A USER. In the
event Tenant fails to effectively exercise the Right of First Refusal as
aforesaid after receipt of a Landlord's Offer Notice with respect to an Offer
from a User, then upon closing of the sale to the User (or its assignee or
nominee or other User), this Lease shall be deemed to have been automatically
and irrevocably amended as follows: The landlord under this Lease shall have the

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option to terminate this Lease effective as of March 31, 2007 or if the Initial
Renewal Option has been effectively exercised for less than thirty-six (36)
months prior to receipt of Landlord's Offer Notice, then at the end of the
Designated Renewal Term, by giving Tenant not less than eighteen (18) months
prior written notice of the exercise of such termination option. The Lease shall
not be amended and landlord under this Lease shall have no option to terminate
if (i) tenant has effectively exercised its Initial Renewal Option for a
Designated Renewal Term of thirty-six (36) months or longer (pursuant to Section
30 of this Lease) prior to or within thirty (30) days after receiving Landlord's
Offer Notice or (ii) if Tenant has effectively exercised its Initial Renewal
Option for a Designated Renewal Term of thirty six (36) months or greater prior
to Landlord's Offer Notice then Tenant may exercise its second Renewal Option
for an identical Designated Renewal Term within thirty (30) days after
receiving Landlord's Offer Notice.

            29.7. MISCELLANEOUS. If Landlord and Tenant have executed the
Purchase and Sale Agreement and Tenant defaults in its obligation to proceed to
and consummate Closing, then Landlord shall have the following further rights:
(i) to retain or receive the deposit (whether or not then paid) as liquidated
damages (and not as a penalty) for such default and (ii) the Right of First
Refusal shall be null and void. Notwithstanding anything to the contrary
contained herein, the Right of First Refusal will not be triggered by the
disposition of the Center, or any part thereof, at sheriff's sale following
foreclosure of any mortgage encumbering the Center or the transfer of the
Center, or any part thereof, by deed in lieu of foreclosure. Landlord and Tenant
agree that all time periods and deadlines contained in this Right of First
Refusal are of the essence.

      30. RENEWAL OPTION.

            30.1. GRANT OF OPTION. Tenant is hereby granted the right and option
(the "Renewal Option") to extend the term of the Lease for one (1) additional
period of between eighteen (18) months and five (5) years, such renewal term
(the "Renewal Term") to commence on April 1, 2007 and to expire on the last day
of the Designated Renewal Term (as defined below), provided that:

                  (A) At the time the Tenant's Unconditional Renewal Notice (as
defined below) is received by Landlord and at the time the Renewal Term
commences, the Lease shall be in full force and effect and there shall exist no
Event of Default by Tenant or event which except for the passage of time, the
giving of notice or both, would constitute a default by Tenant;

                  (B) Tenants Unconditional Renewal Notice shall specifically
state that Tenant grants the warrants of attorney to Landlord to confess
judgment against it and shall restate in its entirety Paragraph 12.7 of the
Lease relating to such matters;

                  (C) The Renewal Option, when effectively exercised, shall
apply to the entire then-current Demised Premises; and

                  (D) The Renewal Option is personal to Tenant and may only be
exercised by Tenant and not by any assignee of the Lease or subtenant of all or
any portion of the Demised Premises (except an Affiliate), whether or not
Landlord has consented to such assignment or

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subletting. The Renewal Option may not be exercised if Tenant has assigned this
Lease or subleased more than fifty percent (50%) of the Demised Premises
(excluding an Affiliate).

            30.2. PROCEDURE. If Tenant wishes to exercise the Renewal Option,
Tenant shall follow the following procedure:

                  (A) Tenant shall give written notice ("Tenant's Unconditional
Renewal Notice") to Landlord on or before March 31, 2005, stating that Tenant
is exercising the Renewal Option and further stating the exact "Designated
Renewal Term" which shall be between eighteen (18) months and five (5) years.

                  (B) The minimum annual rental rates applicable to the Renewal
Term shall be a continuing three percent (3%) per annum increase over the
previous annual minimum rent starting with the last year of the Lease term.
Tenant shall not be entitled to any improvement or construction allowance.

            30.3. TERMS OF OPTION. If the Renewal Option is effectively
exercised, all of the terms and conditions contained in this Lease shall
continue to apply during the Renewal Term, except that:

                  (A) There shall be no further right of renewal beyond the one
(1) Renewal Term, provided that if the Designated Renewal Term is thirty six
(36) months or greater then Tenant shall have an additional Renewal Option for
the identical Designated Renewal Term on the same terms and conditions as this
Paragraph 30 except that (i) the minimum annual rental rates applicable to the
second Renewal Term shall be a continuing three percent (3%) per annum increase
over the previous annual minimum rent starting with the last year of the initial
Renewal Term, and (ii) Tenant's Unconditional Notice shall be given at least
twenty four (24) months prior to the expiration of the initial Renewal Term. By
way of illustration, if the Designated Renewal Term for the initial Renewal Term
is 42 months, then the Designated Renewal Term for the additional Renewal Option
is set at 42 months;

                  (B) There shall be no rent abatements, construction
allowances, or other concessions for or with respect to the Renewal Term; and

                  (C) The annual minimum rent during the Renewal Term shall be
as set forth above, and all annual minimum rent and all additional rent for and
during the Renewal Term shall be paid in the manner and at the times required by
the Lease.

                  (D) In no event shall there be a further right of renewal
beyond the second (2) renewal term.

            30.4. FAILURE TO EXERCISE. In the event Tenant fails to provide to
Landlord Tenant's Unconditional Renewal in the manner and within the applicable
time periods set forth herein, this Renewal Option shall automatically and
immediately terminate and Tenant shall have no other Renewal Option. In such
event, the Renewal Option shall be of no force or effect and Landlord shall be
free to lease the Demised Premises to any other person or entity, on whatever
business terms Landlord may choose.

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            30.5. TIME OF THE ESSENCE. Landlord and Tenant agree that all time
periods and deadlines contained in this Renewal Option are of the essence.

      31. LANDLORD'S DEFAULT. Landlord shall not be deemed to be in default
under this Lease unless Landlord shall fail to comply with any term, provision
or covenant in this Lease on the part of Landlord to be performed within thirty
(30) days after Landlord's receipt of Tenant's written notice thereof; provided,
however, that if the failure cannot reasonably be cured within such thirty (30)
day period, Landlord shall not be in default if Landlord commences to cure the
failure within such thirty (30) day period and thereafter diligently and in good
faith proceeds to cure the failure until completion.

      32. TENANT'S RIGHT OF FIRST OFFER. Tenant is hereby granted the right and
option (the "First Offer Option") to lease any full floor of the Research
Building or other office buildings in the Center (the "First Offer Space") (i)
then available for lease (ii) not leased or subject to any renewal, expansion,
or other option heretofore or hereafter given or granted and (iii) not part of a
first generation lease. The First Offer Option as aforesaid is hereby granted to
Tenant all on and subject to the following terms and conditions:

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            32.1. LANDLORD'S RFO NOTICE. If at any time after the First Offer
Space is initially leased and ending on the twenty-forth (24th) month prior to
the expiration date of this Lease (the "First Offer Period"), Landlord shall
determine that any First Offer Space shall become available during First Offer
Period, Landlord shall notify Tenant, in writing, of such availability of the
First Offer Space ("Landlord's RFO Notice"). Landlord's RFO Notice shall
identify the applicable First Offer Space (to include the location(s) and number
of rentable square feet) and shall contain the proposed business terms of a
lease amendment between Landlord and Tenant in respect of such space, which
business terms shall include: (i) the commencement date (the "First Offer Space
Commencement Date") and the expiration date (the "First Offer Space Expiration
Date"), which First Offer Space Expiration Date shall be the later of (i)
expiration date of this Lease (ii) sixty months (60) months after the First
Offer Space Commencement Date, (ii) rental rates and other business terms, which
shall be based on Landlord's then offered rental rates and other business terms,
(iii) provisions relating to additional rent (including Tenant's Share of Taxes
and Tenant's Share of Operating Expenses), and (iv) provisions relating to the
tenant improvement allowance, which shall be based on Landlord's then offered
tenant improvement allowance, adjusted for the term of the Lease with respect to
such First Offer Space.

            32.2. DEFINITION OF "AVAILABLE". For the specific purposes of this
Section, First Offer Space shall be considered "available" only if, in
Landlord's sole judgment, such space is not or will not be leased, or subject to
lease, for any part of the period commencing on the First Offer Commencement
Date; provided, however, that (i) Landlord may permit any then-existing tenant
to renew or extend its lease (either by the execution of a new lease or by an
amendment to its existing lease), whether or not such lease contains an option
to do so, and the space subject to any such lease shall not be considered
"available"; and (ii) space recaptured by Landlord from a tenant as a result of
Landlord exercising its right to do so upon receiving a request to sublease
shall not be considered "available".

            32.3. EXERCISE. A First Offer Option must be exercised on and
subject to the following terms and conditions: (i) a First Offer Option must be
exercised by Tenant, if at all, by written notice from Tenant to Landlord given
not later than fifteen (15) business days following the date of Tenant's receipt
of a Landlord's RFO Notice if the First Offer Commencement Date is less than six
(6) months from the Landlord's RFO Notice and not later than thirty (30)
calendar days following the date of Tenant's receipt of a Landlord's RFO Notice
if the First Offer Commencement Date is greater than six (6) months from the
Landlord's RFO Notice; (ii) all First Offer Space(s) identified in Landlord's
RFO Notice must be leased, by Tenant except if the First Offer Space(s) contain
greater than 45,000 rsf, then Tenant shall be required to lease at least 45,000
rsf in full floor increments and (iii) at the time of exercising any First Offer
Option, this Lease shall be in full force and effect and no Event of Default
(after the expiration of any applicable notice and cure period) under the Lease
shall exist on the date that Tenant exercises the First Offer Option; provided,
however, that if on the date that Tenant exercises the First Offer Option, an
event which, with the passage of time, the giving of notice or both, would
constitute an Event of Default shall have occurred, Tenant's failure to cure
such event within the applicable cure period under the Lease shall, at
Landlord's election, render Tenant's exercise of the First Offer Option null and
void. Tenant's exercise of the First Offer Option shall constitute Tenant's
agreement with all of the terms and conditions of Landlord's RFO Notice unless
Landlord and

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                      -51-

<PAGE>

Tenant agree otherwise in writing. Time is of the essence with respect to
Tenant's exercise of its First Offer Option.

            32.4. LEASE TERMS. In the event a First Offer Option is effectively
exercised, all terms and conditions contained in the Lease shall continue to
apply in respect of the First Offer Space so taken, effective as of the First
Offer Space Commencement Date, on and subject to (and expressly including) all
of the terms and provisions set forth in the applicable Landlord's RFO Notice.
All First Offer Space that is taken, in accordance with the foregoing provisions
of this Section, shall become part of the Demised Premises and included as such
for any purposes of the Lease. If Tenant effectively exercises its First Offer
Option, then Landlord and Tenant shall promptly thereafter execute a supplement
to this Lease confirming such exercise and reflecting the terms and conditions
set forth herein and in the Landlord's RFO Notice.

            32.5. FAILURE TO EXERCISE. In the event Tenant fails to exercise a
First Offer Option in the manner and within the applicable time period therefor
set forth herein, then the Right of First Offer with respect to that space so
offered by Landlord shall immediately terminate and Tenant shall have no other
Right of First Offer with respect to such space. Upon Tenant's failure to
exercise a right of First Offer, Landlord shall be free to lease such First
Offer Space to any other person or entity, on such terms as Landlord may choose.

            IN WITNESS WHEREOF, intending to be legally bound hereby, the
parties hereto have caused this Radnor Technology and Research Center Lease to
be executed by their duly authorized representatives the day and year first
above written.

WITNESS:                        LANDLORD:

                                RADNOR PROPERTIES-145 KOP, L.P.,

                                By: Radnor GP-145 KOP, L.L.C.
                                        General Partner
/s/ [ILLEGIBLE]                          By: /s/ [ILLEGIBLE]
-----------------                            --------------------------
                                             Authorized Signature

WITNESS:                        TENANT:

                                CENTOCOR, INC.

/s/ JILL TIRACORDA              By: /s/ RICHARD A. BIERLY
-------------------                 -------------------------------
Name: JILL TIRACORDA                Name: RICHARD A. BIERLY
                                    Title: VICE PRESIDENT, FINANCE

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                      -52-

<PAGE>

                         INDEX OF CERTAIN DEFINED TERMS

<TABLE>
<CAPTION>
TERM                                                                           PAGE
----                                                                           ----
<S>                                                                            <C>
"Accelerated Rent Component"..............................................       33
"Affiliate"...............................................................       26
"Automatic Approval Notice"...............................................       25
"Brokers".................................................................       44
"Center"..................................................................        2
"Commencement Date".......................................................        3
"Declaration".............................................................        9
"Demised Premises"........................................................        1
"Effective Date"..........................................................       26
"Event of Default"........................................................       32
"Expense Statement".......................................................       10
"Final Adjustment Amount".................................................       10
"force majeure"...........................................................       45
"Governmental Requirements"...............................................        8
"Landlord"................................................................        1
"Lease"...................................................................        1
"Line Problems"...........................................................       41
"Lines"...................................................................       40
"Operating Expenses"......................................................        5
"Other Center Buildings"..................................................        9
"Renewal Option"..........................................................       48
"Renewal Term"............................................................       48
"Research Building".......................................................        1
"Separate Supplier".......................................................       42
"SNDA"....................................................................       38
"Supplier"................................................................       42
"Surety"..................................................................       32
"Taxes"...................................................................        5
"Tenant Improvements".....................................................       40
</TABLE>

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                    Index-1
<PAGE>

<TABLE>
<S>                                                                             <C>
"Tenant"...................................................................       1
"Tenant's Conditional Renewal Notice"......................................      49
"Tenant's Estimated Share".................................................       9
"Tenant's Proportionate Share".............................................       9
"Tenant's Share of Taxes and Operating Expenses"...........................       9
"Transfer Space"...........................................................      25
"Transfer".................................................................      24
"Waste"....................................................................      23
"available"................................................................      51
"Business Hours"...........................................................      11
"Central Plant"............................................................      14
"Designated Renewal Term"..................................................      49
"First Offer Option".......................................................      50
"First Offer Period".......................................................      51
"First Offer Space Commencement Date"......................................      51
"First Offer Space Expiration Date"........................................      51
"First Offer Space"........................................................      50
"Land".....................................................................       1
"Landlord's RFO Notice"....................................................      51
"Non-Reserved Spaces"......................................................       2
Minor Improvements.........................................................      21
</TABLE>

(C) 2001 The Rubenstein Company, L.P. All Rights Reserved.

                                    Index-2<PAGE>

                                                                   EXHIBIT 10.24

                            FIRST AMENDMENT TO RADNOR
                      TECHNOLOGY AND RESEARCH CENTER LEASE

      THIS FIRST AMENDMENT TO LEASE (the "Amendment") is made this 21st day of
June, 2002 by and between RADNOR PROPERTIES-145 KOP, L.P., a Delaware limited
partnership (hereinafter called "Landlord"), and CENTOCOR, INC., a Pennsylvania
corporation (hereinafter called "Tenant").

                                   BACKGROUND

      A.    Landlord entered into that certain Radnor Technology and Research
Center Lease dated March 8, 2002 (the "Lease"), whereby Landlord leased to
Tenant and Tenant rented from Landlord the space containing 135,125 rentable
square feet (the "Demised Premises") located on the court level and third (3rd)
and fourth (4th) floors of the research building (the "Research Building") which
is located within the Radnor Technology and Research Center (the "Center"), at
145 King of Prussia Road, Radnor Township, Delaware County, Pennsylvania 19087.

      B.    Tenant desires to expand the amount of space it is leasing in the
Center to include the space more particularly delineated on the site plan
attached hereto as Exhibit "A" and made a part hereof containing 1,344 rentable
square feet (the "Storage Building"), located in a one (1) story building which
shall be leased entirely by Tenant. Landlord is willing to lease the Storage
Building to Tenant, and otherwise accommodate Tenant all on and subject to the
terms set forth herein.

      C.    As of the date hereof, the Storage Building shall constitute a part
of the "Demised Premises" under the Lease and, unless expressly set forth herein
to the contrary, all of the terms and conditions set forth in the Lease shall
apply to the Storage Building. Additionally, with respect to the Storage
Building only, the term "Storage Building" (as defined above) shall replace the
term "Research Building" in the Lease, where applicable.

                                      TERMS

      NOW, THEREFORE, Landlord and Tenant, in consideration of the mutual
promises contained herein and for other good and valuable consideration, the
receipt and adequacy of which are hereby acknowledged, and intending to be
legally bound, agree as follows:

      1 . STORAGE BUILDING. Landlord, for the term set forth in the Lease,
leases to Tenant, and Tenant rents from Landlord, all of the space located in
the Storage Building, on the following terms and conditions:

            1.1. The Storage Building shall be used by Tenant only for the
temporary storage of chemicals and materials that Tenant uses or creates as part
of its business that is conducted in the Research Building. Tenant agrees that,
upon Landlord's sixty (60) days' written notice to Tenant, Landlord shall have
the right to recapture up to one-third (1/3) of the

(C)2001 The Rubenstein Company, L.P. All Rights Reserved.

<PAGE>

rentable square footage of the Storage Building, in the location identified on
the plan attached hereto as Exhibit "B", so that Landlord can lease space in the
Storage Building to other tenants of the Center. In the event of such recapture,
the minimum rent payable pursuant to Paragraph 1.2 hereof, the electrical
services charge payable pursuant to Paragraph 1.5 hereof, and the Operating
Expenses and Taxes charge payable pursuant to Paragraph 1.9 hereof shall all be
proportionately reduced to reflect the reduction in rentable square footage
leased by Tenant.

            1.2. Minimum rent for the Storage Building shall commence on July
1,2002 and accrue during the term as follows:

<TABLE>
<CAPTION>
                                                        ANNUAL MINIMUM       MONTHLY
      AGREEMENT PERIOD                      RATE            RENT           MINIMUM RENT
---------------------------------        ----------    ---------------    ------------
<S>                                      <C>           <C>               <C>
July 1,  2002 - March 31, 2003           $   15.00     $   20,160.00     $   1,680.00
April 1, 2003 - March 31, 2004           $   15.45     $   20,764.80     $   1,730.40
April 1, 2004 - March 31, 2005           $   15.90     $   21,369.60     $   1,780.80
April 1, 2005 - March 31, 2006           $   16.35     $   21,974.40     $   1,831.20
April 1, 2006 - March 31, 2007           $   16.80     $   22,579.20     $   1,881.60
</TABLE>

Minimum rent shall be payable during the term hereof, in advance, in the monthly
installments as set forth above, the first installment to be payable upon the
execution of this Amendment and subsequent installments to be payable on the
first day of each successive month of the term hereof following the first month
of such term.

            1.3. The storage, removal and disposal of materials from the Storage
Building shall be subject to the rules and regulations and other requirements
promulgated by Landlord for the health, safety and well-being of the Storage
Building and the Center, including without limitation those set forth in
Paragraph 6.11 of the Lease. Tenant shall keep the Storage Building and all
improvements, installations and systems therein in good order and condition.
Landlord shall have no liability to Tenant for any loss, claims or damage
incurred by Tenant in the Storage Building, whether or not occasioned by the
negligence of Landlord, its agents, servants, employees invitees or visitors.

            1.4. Landlord shall not be required to maintain, repair or provide
any services to the Storage Building other than gas, electric and domestic water
and sewer in order to provide heat and lighting in accordance with the then
current heat and lighting conditions in the Storage Building.

            1.5. So long as Tenant does not use the cold box located in the
Storage Building, Tenant shall pay Two Dollars ($2.00) per rentable square foot
of the Storage Building for electrical services used in the Storage Building. If
Tenant does use the cold box located in the Storage Building, Tenant shall
install, at Tenant's sole cost and expense, a separate meter to measure such
electrical services and, in lieu of such Two Dollars ($2.00) per rentable square
foot charge, Tenant will pay for all such electrical services as measured by
such meter.

            1.6. Tenant shall be responsible for any and all loss or damage to
Tenant's property in the Storage Building, by fire or other casualty, ordinary
wear and tear, or from any

(C)2001 The Rubenstein Company, L.P. All Rights Reserved.

                                       2
<PAGE>

other cause or circumstance that may occur.

            1.7. Tenant acknowledges that it has accepted the Storage Building
in its "AS IS" condition. Except as expressly set forth in this Amendment,
Landlord shall have no obligation to provide cleaning services or other services
to the Storage Building.

            1.8. Upon the termination or earlier expiration of the Lease, Tenant
shall remove Tenant's goods and effects and those of any other person claiming
under Tenant, and quit and deliver up the Storage Building to Landlord peaceably
and quietly, BROOM CLEAN, and in as good order and condition as at the inception
of the term, reasonable use and wear excepted, and in accordance with the
standards set forth in Paragraphs 6.11 and 6.12 of the Lease.

            1.9. In addition to the charges payable by Tenant pursuant to
Paragraph 1.5 above, Tenant shall pay Four Dollars ($4.00) per rentable square
foot of the Storage Building for Operating Expenses (as defined in the Lease)
and Taxes (as defined in the Lease) which shall be increased by three percent
(3%) per calendar year of the term hereof.

            1.10. Paragraph 5 of the Lease shall not apply to the Storage
Building.

      2. ADDRESS FOR PAYMENT. In Paragraph 3.2 of the Lease, the address "c/o
The Rubenstein Company, L.P., 4100 One Commerce Square, 2005 Market Street,
Philadelphia, Pennsylvania 19103" shall be deleted and the address "P.O. Box
8000, Department 175, Buffalo, New York 14267" shall be inserted in its place.

      3. CONFESSION OF JUDGMENT. Tenant hereby grants the warrants of attorney
to Landlord to confess judgment against Tenant as set forth in Paragraph 12.7 of
the Lease, all of the terms and conditions of which are incorporated herein by
reference. The parties further acknowledge the effectiveness of such confession
of judgment as if fully set forth herein.

      4. DEFINITIONS. For purposes of this Amendment, capitalized terms shall
have the meanings ascribed to them in the Lease unless otherwise defined herein.

      5. NO DEFAULT. Tenant represents, warrants and covenants that to the best
of Tenant's knowledge, no Event of Default has occurred under the Lease and no
event has occurred which, with the passage of time or the giving of notice, or
both, would constitute a default by either Landlord or Tenant thereunder.

      6. CROSS DEFAULT. An Event of Default by Tenant under the Lease shall, at
the option of Landlord, constitute an Event of Default by Tenant under the
leases between Tenant and Landlord and/or Landlord's affiliates and an Event of
Default under Tenant's other leases shall be an Event of Default under the
Lease.

      7. EFFECT OF AMENDMENT. Except as modified by this Amendment, the Lease
and all the covenants, agreements, terms, provisions and conditions thereof
shall remain in full force and effect and are hereby ratified and affirmed. The
covenants, agreements, terms, provisions and conditions contained in this
Amendment shall bind and inure to the benefit of the parties hereto and their
respective successors and, except as otherwise provided in the Lease, their
respective

(C)2001 The Rubenstein Company, L.P. All Rights Reserved.

                                       3
<PAGE>

assigns. In the event of any conflict between the terms contained in this
Amendment and the Lease with respect to the Storage Building only, the terms
herein contained shall supersede and control the obligations and liabilities of
the parties.

      8. MISCELLANEOUS. This Amendment becomes effective only upon execution and
delivery hereof by Landlord and Tenant.

            IN WITNESS WHEREOF, intending to be legally bound hereby, the
parties hereto have caused this Amendment to be executed by their duly
authorized representatives the day and year first above written.

WITNESS:                                 LANDLORD:

                                         RADNOR PROPERTIES-145 KOP, L.P.,

                                         By: Radnor GP-145 KOP, L.L.C.
                                               General Partner

/s/ [ILLEGIBLE]                          By: /s/ [ILLEGIBLE]
----------------------                       ------------------------------
                                             Authorized Signature

WITNESS:                                 TENANT:

                                         CENTOCOR, INC.

      /s/ JILL TIRACORDA                 By: /s/ RICHARD A. BIERLY
      -------------------                   --------------------------------
Name: Jill Tiracorda                       Name: Richard A. Bierly
                                           Title: VP FINANCE
                                                  6/19/02

(C)2001 The Rubenstein Company, L.P. All Rights Reserved.

                                       4

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