<PAGE>   1
                                                                   Exhibit 10.13


                 PLYMOUTH MEETING EXECUTIVE CAMPUS OFFICE LEASE

                                    BETWEEN

                           PLYMOUTH CAMPUS ASSOCIATES
                      (a Pennsylvania limited partnership)

                                  AS LANDLORD

                                     -AND-


                         MAGAININ PHARMACEUTICALS, INC.
                            (a Delaware corporation)

                                   AS TENANT

                            DATED: JANUARY 16, 1998


                                   PREMISES:

                           5,077 RENTABLE SQUARE FEET
                            SECOND FLOOR - SUITE 270
                       PLYMOUTH MEETING EXECUTIVE CAMPUS
                      PLYMOUTH MEETING, PENNSYLVANIA 19462
<PAGE>   2
                 PLYMOUTH MEETING EXECUTIVE CAMPUS OFFICE LEASE

                               TABLE OF CONTENTS

PARAGRAPH                                                                   PAGE


1.    DEMISED PREMISES: USE .............................................    -1-

      1.1     LETTING AND DEMISED PREMISES: USE .........................    -1-
      1.2     CAMPUS ....................................................    -1-
      1.3     COMMON FACILITIES .........................................    -1-
      1.4     RENTABLE SQUARE FEET ......................................    -1-

2.    TERM: COMMENCEMENT ................................................    -2-

      2.1     DURATION ..................................................    -2-
      2.2     SUBSTANTIAL COMPLETION ....................................    -2-
      2.3     CONFIRMATION ..............................................    -2-
      2.4     ACCEPTANCE OF WORK ........................................    -2-

3.    MINIMUM RENT: INCREASES IN MINIMUM RENT: SECURITY DEPOSIT .........    -2-

      3.1     AMOUNT AND PAYMENT ........................................    -2-
      3.2     PARTIAL MONTH .............................................    -2-
      3.3     ADDRESS FOR PAYMENT .......................................    -3-
      3.4     NON-WAIVER OF RIGHTS ......................................    -3-
      3.5     ADDITIONAL SUMS DUE: NO SET-OFF ...........................    -3-
      3.6     PERSONAL PROPERTY AND OTHER TAXES .........................    -3-
      3.7     MINIMUM RENT INCREASES ....................................    -3-
      3.8     SECURITY DEPOSIT ..........................................    -3-

4.    INCREASES IN TAXES AND OPERATING EXPENSES .........................    -4-

      4.1     DEFINITIONS ...............................................    -4-
      4.2     GENERAL ALLOCATION PROCEDURES .............................    -7-
      4.3     TENANT'S SHARE OF TAXES AND OPERATING EXPENSES ............    -8-
      4.4     DISPUTES ..................................................    -9-
      4.5     SURVIVAL ..................................................    -9-

5.    SERVICES ..........................................................    -9-

      5.1     HVAC AND ELECTRICITY ......................................    -9-
      5.2     WATER AND SEWER ...........................................   -11-
      5.3     ELEVATOR: ACCESS ..........................................   -11-
      5.4     JANITORIAL ................................................   -11-
      5.5     SECURITY ..................................................   -12-
      5.6     REPAIRS ...................................................   -12-
      5.7     SYSTEM CHANGES ............................................   -12-


                                      -i-
<PAGE>   3
      5.8     DIRECTORY .................................................   -13-
      5.9     LIMITATION REGARDING SERVICES .............................   -13-

6.    CARE OF DEMISED PREMISES ..........................................   -13-

      6.1     INSURANCE AND GOVERNMENTAL REQUIREMENTS ...................   -13-
      6.2     ACCESS ....................................................   -14-
      6.3     CONDITION .................................................   -14-
      6.4     SURRENDER .................................................   -14-
      6.5     SIGNS .....................................................   -14-
      6.6     CARE; INSURANCE ...........................................   -15-
      6.7     ALTERATIONS; ADDITIONS ....................................   -15-
      6.8     MECHANICS' LIENS ..........................................   -15-
      6.9     VENDING MACHINES ..........................................   -15-
      6.10    RULES AND REGULATIONS .....................................   -15-
      6.11    ENVIRONMENTAL COMPLIANCE ..................................   -16-

7.    SUBLETTING AND ASSIGNING ..........................................   -17-

      7.1     GENERAL RESTRICTIONS ......................................   -17-
      7.2     DEFINITIONS ...............................................   -18-
      7.3     PROCEDURES FOR APPROVAL OF TRANSFER .......................   -18-
      7.4     RECAPTURE .................................................   -19-
      7.5     CONDITIONS ................................................   -19-
      7.6     SPECIAL CONDITIONS FOR TRANSFERS TO AFFILIATES OF TENANT ..   -19-

8.    FIRE OR OTHER CASUALTY ............................................   -20-

9.    REGARDING INSURANCE AND LIABILITY .................................   -20-

      9.1     DAMAGE IN GENERAL .........................................   -20-
      9.2     INDEMNITY .................................................   -20-
      9.3     TENANT'S INSURANCE ........................................   -21-
      9.4     WAIVER OF SUBROGATION .....................................   -22-
      9.5     LIMITATION ON PERSONAL LIABILITY ..........................   -22-
      9.6     SUCCESSORS IN INTREST TO LANDLORD, MORTGAGEES .............   -22-
      9.7.    SURVIVAL ..................................................   -23-

10.   EMINENT DOMAIN ....................................................   -23-

11.   INSOLVENCY ........................................................   -23-

12.   DEFAULT ...........................................................   -24-

      12.1    EVENTS OF DEFAULT .........................................   -24-
      12.2    ACCELERATED RENT COMPONENT ................................   -24-
      12.3    RE-ENTRY ..................................................   -25-


                                      -ii-
<PAGE>   4
     12.4     CONTINUING LIABILITY ......................................   -25-
     12.5     CREDIT ....................................................   -26-
     12.6     NO DUTY TO RELET ..........................................   -26-
     12.7     CONFESSION OF JUDGMENT ....................................   -26-
     12.8     BANKRUPTCY ................................................   -27-
     12.9     WAIVER OF DEFECTS .........................................   -27-
     12.10    NON-WAIVER BY LANDLORD ....................................   -28-
     12.11    PARTIAL PAYMENT ...........................................   -28-
     12.12    OVERDUE PAYMENTS ..........................................   -28-
     12.13    CUMULATIVE REMEDIES .......................................   -28-

13.  SUBORDINATION ......................................................   -28-

     13.1     GENERAL ...................................................   -28-
     13.2     RIGHTS OF MORTGAGEE .......................................   -29-
     13.3     MODIFICATIONS .............................................   -29-

14.  NOTICES ............................................................   -29-

     14.1     IF TO LANDLORD ............................................   -29-
     14.2     IF TO TENANT ..............................................   -30-

15.  HOLDING OVER .......................................................   -30-

16.  RESERVATIONS IN FAVOR OF LANDLORD ..................................   -30-

17.  COMPLETION OF IMPROVEMENTS: DELAY IN POSSESSION ....................   -30-

     17.1     LANDLORD IMPROVEMENTS .....................................   -31-
     17.2     TENANT IMPROVEMENTS .......................................   -31-
     17.3     PERFORMANCE OF LANDLORD AND TENANT IMPROVEMENTS ...........   -31-
     17.4     ACCEPTANCE ................................................   -31-
     17.5     DELAY IN POSSESSION .......................................   -31-

18.  COMMUNICATION AND COMPUTER LINES ...................................   -31-

     18.1     LANDLORD RESERVATION ......................................   -32-
     18.2     REMOVAL OF LINES ..........................................   -32-
     18.3     COMMUNICATION CONTRACTORS .................................   -33-

19.  LANDLORD'S RELIANCE ................................................   -34-

20.  PRIOR AGREEMENTS; AMENDMENTS .......................................   -34-

21.  CAPTIONS ...........................................................   -35-

22.  LANDLORD'S RIGHT TO CURE ...........................................   -35-


                                     -iii-
<PAGE>   5
       23.     ESTOPPEL STATEMENT ........................................  -35-

       24.     RELOCATION OF TENANT ......................................  -35-

       25.     BROKER ....................................................  -36-

       26.     MISCELLANEOUS .............................................  -36-
               26.1.   CERTAIN INTERPRETATIONS ...........................  -36-
               26.2.   PARTIAL INVALIDITY ................................  -36-
               26.3.   GOVERNING LAW .....................................  -36-
               26.4.   LIGHT AND AIR .....................................  -37-
               26.5.   RECORDING .........................................  -37-

       27.     QUIET ENJOYMENT ...........................................  -37-

       28.     CONFIDENTIALITY ...........................................  -37-

                      ====================================

                               SCHEDULE OF EXHIBITS

      Exhibit                  Contents                         Page Nos.
      -------                  --------                         ---------

        A             FLOOR PLAN OF THE DEMISED PREMISES        A-1 only

        B             SITE PLAN                                 B-1 only

        C             CONFIRMATION OF LEASE TERM                C-1 through C-2

        D             JANITORIAL SERVICES                       D-1 through D-3

        E             RULES AND REGULATIONS                     E-1 through E-5

        F             INTENTIONALLY DELETED

        G             INTENTIONALLY DELETED

        H             ESTOPPEL CERTIFICATE                      H-1 through H-5


                                      -iv-
<PAGE>   6
                        PLYMOUTH MEETING EXECUTIVE CAMPUS
                                  OFFICE LEASE

          THIS OFFICE LEASE (the "Lease") is made this 16 day of January, 1998,
by and between PLYMOUTH CAMPUS ASSOCIATES, a Pennsylvania limited partnership
(hereinafter called "Landlord"), and MAGAININ PHARMACEUTICALS, INC., a Delaware
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
5,077 rentable square feet, located on the second floor of the office building
(hereinafter referred to as the "Building") known as Building No. 620 of
Plymouth Meeting Executive Campus, or such other name as Landlord may from time
to time designate, with an address of 620 West Germantown Pike, Plymouth
Township, Montgomery County, Pennsylvania 19462, located as shown on the Site
Plan attached hereto as Exhibit "B", to be used by Tenant only for general
office purposes and associated incidental uses and for no other purpose without
the prior written consent of Landlord.

            1.2. CAMPUS. Plymouth Meeting Executive Campus consists of
approximately 21.854 acres of ground and certain buildings and other
improvements thereon (including four separate office buildings, of which the
Building is one, and related amenities), all located at or about Germantown Pike
and Hickory Road, in Plymouth Township, Montgomery County, Pennsylvania (the
"Campus"). 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 Campus consists.

            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, access
roads, parking areas and other outdoor areas within the Campus, 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, regulations, limitations and requirements 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 Campus.

            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


                                      -1-
<PAGE>   7
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, Tenant's construction
allowance, if any, and other items which are based upon the computation of 
square footage.

      2.    TERM: COMMENCEMENT.

            2.1. DURATION. The term of this Lease shall commence (the
"Commencement Date") on February 1, 1998. Unless extended or sooner terminated
as herein provided, the initial term of this Lease shall continue until, and
shall expire on January 31, 2001.

            2.2. SUBSTANTIAL COMPLETION. INTENTIONALLY DELETED

            2.3. CONFIRMATION. INTENTIONALLY DELETED

            2.4. ACCEPTANCE OF WORK. INTENTIONALLY DELETED

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

            3.1. AMOUNT AND PAYMENT. Minimum rent for the Demised Premises shall
accrue during the term as follows:

<TABLE>
<CAPTION>
 FROM              TO               RATE           MONTHLY          ANNUALLY
<S>                <C>              <C>            <C>              <C>        
 Commencement      01/31/99         $21.00         $8,884.75        $106,617.00
 Date

 02/01/99          01/31/00         $22.50         $9,519.38        $114,232.56

 02/01/00          01/31/01         $23.50         $9,942.46        $119,309.52
</TABLE>

Minimum rent shall be payable during the term hereof, in advance, in the monthly
installments as set forth above, without demand, offset, abatement, diminution
or reduction. 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. PARTIAL MONTH. If the term of this Lease begins on a day other
than the first day of a month, rent from such day until the first day of the
following month shall be prorated (at the rate of one-thirtieth (1/30) of the
fixed monthly rental for each day) and shall be payable, in arrears, on the
first day of the first full calendar month of the term hereof (and, in such
event, the


                                      -2-
<PAGE>   8
installment of rent paid at execution hereof shall be applied to the rent due
for the first full calendar month of the term hereof).

            3.3. ADDRESS FOR PAYMENT. All rent and other sums due to Landlord
hereunder shall be payable to Plymouth Campus Associates, c/o The Rubenstein
Company, 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.

            3.4. 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.

            3.5. 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.

            3.6. 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 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 personal
property of Tenant.

            3.7. MINIMUM RENT INCREASES. INTENTIONALLY DELETED

            3.8. SECURITY DEPOSIT. As additional security for the full and
prompt performance by Tenant of the terms and covenants of this Lease, Tenant
has deposited with the Landlord the sum of Nine Thousand Nine Hundred Forty Two
Dollars and 00/100 ($9,942.00), (the "Security Deposit") which shall not
constitute rent for any month (unless so applied by Landlord on account of
Tenants default). Tenant shall, upon demand, restore any portion of the Security
Deposit which may be applied by Landlord to the cure of any default by Tenant
hereunder. To the extent that


                                       -3-
<PAGE>   9
Landlord has not applied the Security Deposit on account of a default, the
Security Deposit shall be returned (without interest) to Tenant promptly after
the expiration of this Lease. Until returned to Tenant after the expiration of
the Lease and the full performance of Tenant hereunder, the Security Deposit
shall remain the Property of Landlord.

      4.    INCREASES IN TAXES AND OPERATING EXPENSES.

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

                 (i)  "TAXES" shall mean all real estate taxes and assessments
of whatever kind, general or special, ordinary or extraordinary, foreseen or
unforeseen, imposed upon the Building or with respect to the ownership of the
Building and the Campus and the parcel of land on which the Building and the
Campus are located, and any existing or future improvements to the Building or
the Campus or to the parcel of land on which the Building or the Campus 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.

                  (ii) (l) "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 ownership,
operation, maintenance, repair, replacement and management of the Building and
the Campus (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 Building and the Campus and any security personnel
for the Building and the Campus, 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
Building and related facilities and amenities in the Campus; (C) costs of
materials, supplies and equipment (including trucks) used in connection with the
operation, security, maintenance, cleaning, repair and replacement of the
Building and related facilities and amenities in the Campus; (D) costs of
electricity, steam, water, sewer, fuel and other utilities used at the Building
or the Campus, together with the cost of providing the services specified in
Paragraph 5


                                       -4-
<PAGE>   10
hereof, to the extent such utilities and/or services are not separately
chargeable to an occupant of the Building or an occupant elsewhere in the
campus; (E) cost of insurance for public and general liability insurance and
insurance relating to the Building and the Campus, 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 Building or elsewhere in the Campus because of extra
risk which are reimbursed to Landlord by such other occupants; (F) costs of
tools, supplies and services; (G) costs of "Essential Capital Improvements", as
defined in and to the extent permitted pursuant to subparagraph 4.1(ii)(3)
below; (H) costs of alterations and improvements to the Building or the Campus
made pursuant to any Governmental Requirements (as defined in subparagraph
4.1(iii) below) which are not capital in nature (except to the extent permitted
by subparagraph 4.1(ii)(3) below), and which are not the obligation of Tenant or
any other occupant of the Building or elsewhere in the Campus; (I) legal and
accounting fees and disbursements necessarily incurred in connection with the
ownership, maintenance and operation of the Building and the Campus, and the
preparation, determination and certification of bills for Taxes and Operating
Expenses pursuant to this and other leases at the Building and the Campus; (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 Building and the
Campus (including seasonal decorations); (L) management fees payable to the
managing agent for the Building and the Campus (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 submarket within which the Campus is located); (M) the cost
of telephone service, postage, office supplies, maintenance and repair of office
equipment and similar costs related to operation of the Building's and the
Campus's management and superintendents offices; (N) the cost of licenses,
permits and similar fees and charges related to operation, maintenance, repair
and replacement of the Building and the Campus, 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
office building would be construed as an operating expense. Operating Expenses
(including such as are stated above which relate or are applicable to the
Campus) 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 resurfacing, 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 Campus, all as payable in respect of or
allocable to the 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 Building; (b) wages or salaries paid to executive personnel
of Landlord not providing full-time service at the Campus; (c) the cost of any
new item (not replacement or upgrading of an existing item) which, by


                                      -5-
<PAGE>   11
standard accounting principles, should be capitalized (except as provided above
or in subparagraph 4.1(ii)(3) below); (d) any charge for depreciation or
interest paid or incurred by Landlord; (e) leasing commissions; (f) Taxes; (g)
any charge for Landlord's income tax, excess profit taxes, franchise taxes or
similar taxes on Landlord's business; or (h) legal fees for the negotiation or
enforcement of leases. 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 Landlord had in fact performed the work or service at its expense.
The costs of electric consumption and water, sewer and other utility services to
the Demised Premises (including, without limitation, for HVAC usage) are not
included as Operating Expenses of the Building and shall be paid for by Tenant
separately in accordance with Paragraph 5 of this Lease. Notwithstanding the
foregoing, in the event the Landlord now, or in the future, employs oil or gas
to partially fuel the HVAC at the Building, the cost of such oil or gas shall be
included in Operating Expenses.

            (2) In determining Operating Expenses for any year, if less than 95%
of the rentable square feet of the 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 95% throughout such year. In
no event shall the total of Taxes and Operating Expenses for any year be deemed
to be less than the Base Amount for Taxes and Operating Expenses.

            (3) In the event Landlord shall make a capital expenditure for an
"Essential Capital Improvement", as hereinafter defined in this subsection(3),
during any year, the annual amortization of such expenditure (determined by
dividing the amount of the expenditure by the useful life of the improvement,
but in no event longer than five 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. As used herein, an "Essential
Capital Improvement" means any of the following: (A) a labor saving device,
energy saving device or other installation, improvement, upgrading or
replacement which reduces or is intended to reduce Operating Expenses as
referred to above, whether or not voluntary or a Government Requirement; or (B)
an installation, improvement, alteration or removal of any improvements
including architectural or communication barriers which are made to the Building
by reason of any Governmental Requirement whether or not such improvements are
structural in nature and whether or not such Governmental Requirement either
existed or was required of the Landlord on the date of execution of this Lease,
if such Governmental Requirement is or will be applicable generally to similar
suburban office buildings in the vicinity of Plymouth Township, or (C) an
installation or improvement which directly enhances the safety of occupants or
tenants in the Building generally, whether or not voluntary or a Governmental
Requirement (as, for example, but without limitation, for general safety, fire
safety or security).


                                       -6-
<PAGE>   12
            (iii) "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 Building (including, without limitation, the Demised Premises) including,
but not limited to, requirements under applicable Plymouth Township building,
zoning and fire codes and federal, state and local requirements and regulations
governing accessibility by persons with physical disabilities.

            (iv)  "BASE AMOUNT FOR TAXES AND OPERATING EXPENSES" shall mean the
total of Taxes and Operating Expenses allocable and attributable to calendar
year 1998 for the Building. The Base Amount for Operating Expenses shall be
calculated on the basis of the Building being 95% occupied in accordance with
Paragraph 4.1(ii)(2) hereof. The Base Amount for Taxes and Operating Expenses
shall be adjusted for the calendar year above stated to adjust for average and
reasonable allowances for on-going repairs and maintenance and to exclude from
the Base Amount extraordinary items of Taxes and/or Operating Expenses incurred
in such calendar year.

            (v)   "TENANT'S PROPORTIONATE SHARE" shall be five and 6305/10000
percent (5.6305%). 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 Building.

            (vi)  "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, if any, by which the total of Taxes and
Operating Expenses for such calendar year exceeds the Base Amount for Taxes and
Operating Expenses.

            (vii) "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, if any, by which Landlord's good faith estimate of the total of
Taxes and Operating Expenses for such calendar year exceeds the Base Amount for
Taxes and Operating Expenses.

            (viii) "DECLARATION" shall mean the Declaration of Plymouth Meeting
Executive Campus 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 Campus) and placed of
record, submitting the Campus 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:

            (i)   To the extent practicable and known exactly, all Taxes and
Operating Expenses will be accounted for and attributed separately for the
Building and for the three other office buildings which presently comprise the
Campus (the "Other Campus Buildings"). To the extent allocations of an item of
Taxes or Operating Expenses in accordance with the foregoing


                                      -7 -
<PAGE>   13
sentence is not practicable and known exactly, allocations will be made between
and among the Building and the Other Campus Buildings proportionately among all
thereof (based upon the respective square footage of each), or equally among all
thereof, or in such other proportions as may reasonably be determined by
Landlord in the exercise of prudent management practices.

                  (ii) Notwithstanding the foregoing, and to the extent deemed
reasonable by Landlord, all common area and other charge under and as permitted
by the Declaration will be charged and allocated among the Building, the Other
Campus 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.

                  (i) 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.

                  (ii) 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.

                  (iii) Landlord shall furnish to Tenant, on or before April 30
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 Base Amount for Taxes and
Operating Expenses; (C) the Tenant's Proportionate Share; (D) the Tenant's Share
of Taxes and Operating Expenses; (E) the Tenant's Estimated Share; and (F) 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 ten [10] 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


                                      -8-
<PAGE>   14
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 calender 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 in detail 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 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 ten (10)
business 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.

            5.1. HVAC AND ELECTRICITY. Landlord shall furnish (a) heat,
ventilation and air conditioning (including the labor, maintenance and equipment
necessary to provide the same), (b) electricity and other utilities needed to
operate such systems and (c) electricity for lighting and general power for
office use, each of the foregoing to be paid for by Tenant as follows:

                  (i) Standard Usage: Business Hours. Tenant shall pay its pro
rata share (based upon Tenant's Proportionate Share, but subject to the last
sentence of this subparagraph) of the cost to the Building (including applicable
sales or use taxes) for the foregoing services during "Business Hours" (as
hereinafter defined) and for "Building Standard Consumption" (as hereinafter
defined). Such payment shall be made by Tenant within ten (10) days after
submission by Landlord of a statement to Tenant setting forth the amount due.
"Business Hours" shall mean Monday through Friday from 8:00 a.m. to 6:00 p.m.
and on Saturday from 8:00 a.m. to 1:00 p.m., Holidays (defined below) excepted.
New Year's Day, Memorial Day, Independence Day, Labor Day, Thanksgiving,
Christmas, or any day set aside to celebrate such holidays are "Holidays" under
this Lease. "Building Standard Consumption" shall mean the consumption
necessary, in Landlord's reasonable


                                      -9-
<PAGE>   15
judgement, for use and comfortable occupancy of the Demised Premises when
occupied by the density of people for which the building standard system was
designed with occupants using Standard Office Equipment. "Standard Office
Equipment" shall mean all office equipment normally found in an office facility
but shall not include computer and communication systems, telephone switches and
conference or training rooms (or items similar thereto) which require Additional
Electric Equipment, as hereinafter defined in Paragraph 5.1(v) below, or
additional air conditioning service or systems. In determining Tenant's pro rata
share for the foregoing services for any period, the cost for the foregoing
services shall be deemed for such period to be an amount equal to the like
expenses which Landlord reasonably determines would normally be incurred had the
Building been fully occupied throughout such period.

                  (ii) Non-Standard Usage; After-Hours. Tenant shall pay the
cost of supplying the Demised Premises with the foregoing services at times
outside of Business Hours or in amounts in excess of Building Standard
Consumption, at such rates as Landlord shall specify from time to time to cover
all of the estimated costs and expenses incurred by Landlord in connection with
supplying the Demised Premises with such service, including without limitation
the costs of labor and utilities associated with such service and including
applicable sales or use taxes thereon, such amounts to be paid by Tenant within
ten (10) days after submission by Landlord of a statement to Tenant setting
forth the amount due. With respect to heat, ventilation and air conditioning
required by Tenant outside of Business Hours, Tenant shall notify Landlord by
12:00 noon on the day such after-hours use is desired, except if such use is
desired for a weekend, in which event Tenant shall notify Landlord no later than
12:00 noon on the Friday immediately preceding such weekend.

                  (iii) Separate Metering; Survey. Landlord reserves the right,
at Tenant's sole cost, to determine Tenant's charge for electrical usage by
separate meter or electrical engineering survey. At any time after the
installation of separate metering for the Demised Premises (or any part
thereof), or the completion of such survey, Landlord shall furnish to Tenant a
statement setting forth the amount due for Tenant's electric usage (or the part
thereof that is so metered or subject to such survey), and the total amount set
forth in such statement shall be due and payable by Tenant within ten (10) days
after submission to Tenant by Landlord of such statement. In such case, Tenant
shall pay for such consumption based upon the average KWH rate paid by Landlord.

                  (iv) System Failure. Landlord shall not be responsible for any
failure or inadequacy of the air conditioning 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 which exceed
the maximum wattage per square foot contemplated by, or generate more heat than
anticipated in, the design of the Demised Premises (as such design standards may
be set forth in Exhibit "F" attached hereto or otherwise established by Landlord
if not so set forth).

                  (v) Additional Electrical Equipment. Tenant will not install
or use electrically-operated equipment in excess of the design capacity of the
Demised Premises (as such


                                      -10-
<PAGE>   16
design standards may be set forth in Exhibit "F" attached hereto or otherwise
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 office operation without first
obtaining the prior written consent of the Landlord. Landlord may condition any
consent required under this Paragraph 5.1(v) 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 5.1 (ii) or (iii) above. Landlord shall replace, when and as
requested by Tenant (the cost of which replacement light bulbs and tubes, and
ballasts, plus the labor cost for such replacement, to be chargeable to Tenant)
light bulbs and tubes, and ballasts, within the Demised Premises which are
Building standard (but at Landlord's option such undertaking of Landlord shall
not include bulbs or tubes for any non-Building standard lighting, high hats, or
other specialty lighting of Tenant, which shall be and remain the responsibility
of Tenant).

                  (vi) 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. Furnish the Building with water (i) for drinking,
lavatory, toilet and sanitary sewer purposes drawn through fixtures installed by
Landlord, and (ii) necessary for the operation of the Building's fire safety
devices. 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 attributable to
the Demised Premises, and the total amount set forth in such statement shall be
due and payable by Tenant within ten (10) days after submission thereto by
Landlord of such statement.

         5.3. ELEVATOR: ACCESS. Provide passenger elevator service to the
Demised Premises during all working days (Saturday, Sunday and Holidays
excepted) from 8:00 a.m. to 6:00 p.m., with one elevator subject to call at all
other times. 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 Building. Elevator services for freight shall be
supplied in common with service to other tenants and for other Building
requirements at reasonable times during Business Hours 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 Building or other
tenants. Freight elevator service outside of Business Hours shall be provided to
Tenant upon reasonable written advance notice, at charges equal to Landlord's
estimated cost for providing such service from time to time, which shall be
payable by Tenant to Landlord not later than ten (10) days after Landlord's bill
therefor.

         5.4. JANITORIAL. Provide janitorial service to the Demised Premises as
specified


                                      -11-
<PAGE>   17
on Exhibit "D" annexed hereto. Any and all additional or specialized janitorial
or trash removal service desired by Tenant (i) shall be contracted for by Tenant
directly with Landlord's janitorial agent and the cost and payment thereof shall
be and remain the sole responsibility of Tenant, or (ii) at the option of
Landlord, shall be contracted for by Landlord and paid for by Tenant to Landlord
within ten (10) days after the submission by Landlord of a statement to Tenant
setting forth the amount due. If Landlord shall from time to time reasonably
determine that the use of any cleaning service in the Demised Premises,
including without limitation, removal of refuse and rubbish from the Demised
Premises, is in an amount greater than usually attendant upon the use of such
Demised Premises as offices, the reasonable cost of such additional cleaning
services shall be paid by Tenant to Landlord as additional rent, on demand.

         5.5. SECURITY. Landlord provides a security card or code type access
systems for Tenant's convenience. Tenant and Tenant's employees, as well as
other tenants of the Building, will have access to the Building using such
access system. Landlord makes no representation that the access system or any
future system employed at the Building to monitor access to the Building outside
of standard business hours will prevent unauthorized access to the 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 Building or the Campus. Tenant further
acknowledges that Landlord may (but shall have no obligation to) alter current
security measures in the 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. 

         5.6. REPAIRS. Make (i) all structural repairs to the Building, (ii) all
repairs to the exterior windows and glass and all repairs to the common areas of
the Building and (iii) all repairs which may be needed to the mechanical,
electrical and plumbing systems in the Demised Premises, excluding repairs to
(or replacement of) any non-building standard fixtures or other improvements in
the Demised Premises installed by Tenant or made by or at the request of Tenant
and requiring unusual or special maintenance. 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 Landlord shall have actually recovered such cost through insurance
proceeds.

         5.7. 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 Building; nor
install any plumbing fixtures in the Demised Premises; nor use in excess of
normal office use any of the utilities, the common areas of the Building, the
janitorial or trash removal services, or any other services or portions of the
Building without the prior written consent of the Landlord, and in the event
such consent is granted, the cost of any such


                                      -12-
<PAGE>   18
installation, replacements, changes, additions or excessive use shall be paid
for by Tenant, in advance in the case of any installations replacements and
additions, and promptly upon being billed therefor in the case of charges in
excessive use.

         5.8. DIRECTORY. Landlord shall maintain a directory of office tenants
in the lobby area of the 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.

         5.9. 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
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 good faith deems advisable, or by reason of difficulty in securing proper
supplies of fuel, steam, water, electricity, 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 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 Building systems or services arising out of
the causes set forth in this Paragraph.

     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 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.


                                      -13-
<PAGE>   19
         6.2. ACCESS. Tenant shall give Landlord, its agents and employees,
access to the Demised Premises at all reasonable times upon reasonable prior
verbal or written notice from Landlord, and at any time in the case of an
emergency, 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 Building or any part
thereof; and (ii) upon reasonable notice, to show the Demised Premises to
prospective mortgagees and purchasers and to prospective tenants. 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 Building or to
any appurtenance or any equipment therein.

         6.3. CONDITION. 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,
and Tenant shall commit no waste in the Demised Premises. 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 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.

         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 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
Building, or on the outside of the Demised Premises or on the exterior doors,
windows or walls of the Demised


                                      -14-
<PAGE>   20
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 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. Tenant shall not make any alteration of or
addition to the Demised Premises without the prior written approval of Landlord
(except for work of a decorative nature). Such approval shall not be
unreasonably withheld for nonstructural interior alteration, provided that (i)
no 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) shall, upon installation, become and remain the property of Landlord.
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, upon termination of the term hereof, shall be removed 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.

         6.8. MECHANICS' LIENS. Tenant, within ten (10) days after notice from
Landlord, (i) shall discharge (by bonding or otherwise) any mechanics' lien 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 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 Building.


                                      -15-
<PAGE>   21
         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 Building, or permit Tenant's
employees, agents, contractors, and other occupants of the Demised Premises to
engage in such activities upon or about the 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 (or such other business or activity
expressly permitted to be undertaken in the Demised Premises pursuant to the
terms of this Lease), provided: (a) such substance 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 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) if any
applicable Governmental Requirements or Landlord's trash removal contractor
requires that any such substances be disposed of separately from ordinary trash,
Tenant shall make arrangements at Tenant's expense for such disposal 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 and lawfully removed from the Building upon expiration
or earlier termination of this Lease.

         (i) 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 Building, (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 therefor 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 Comprehensive
Environmental Response, Compensation and Liability Act. 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


                                      -16-
<PAGE>   22
"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 an
MSDS.

                  (ii) 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 Building 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 Building and
clean or replace any affected property at the Building (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 Building and such release, discharge,
or disposal is not caused 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.

     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
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 Building or the tenancy at the Building in
Landlord's reasonable opinion, or conflicts with exclusive use rights granted to
another tenant of the Building; (2) 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 permitted under this Lease; or
(3) if the document creating the Transfer is not reasonably acceptable to
Landlord; or (4) the nature of the fixtures and improvements to be performed or
installed are not consistent with general office use and the terms of this
Lease; or (5) 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 Building; or (6) if the proposed user is a governmental or
quasi-governmental agency; or (7) if the proposed transferee will be using or
if Landlord has


                                      -17-
<PAGE>   23
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 office
operations in compliance with applicable Governmental Requirements; or (8) 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 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 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 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. DEFINITIONS. For purposes hereof, an Transfer shall include any
direct or indirect transfer of fifty percent (50%) or more of the voting stock
of a corporate Tenant, or fifty percent (50%) or more of the interests in
partnership profits of a partnership Tenant in any single or related series of
transactions.

         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 assignee or subtenant, 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 twenty (20) 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 that Landlord's failure to respond or request additional
information from Tenant within an additional ten (10) business days shall be
deemed an approval. 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


                                      -18-

<PAGE>   24
to the Transfer. If Landlord requests additional information, Landlord shall
respond within ten (10) business days after receipt of all requested
information, and Landlord's failure to do so shall be deemed a consent to the
Transfer. If Landlord consents to any such Transfer, such consent shall be given
on Landlord's form of consent, which shall be executed by Tenant and the
assignee or subtenant of Tenant. It shall nevertheless be a condition to the
deemed effectiveness thereof that Landlord be furnished a fully executed copy of
the Transfer, in form and substance approved by Landlord. 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 twenty (20) 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 as of the date which is thirty (30) days after Landlord's election
to recapture (the "Effective Date") the Transfer Space and as of the Effective
Date 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 seventy-five (75%) 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,
(iv) or an entity which is the surviving entity in a merger pursuant to state
corporation or partnership law with the Tenant. The effectiveness of such
Transfer to an Affiliate of Tenant shall nevertheless be conditioned on the
following: (a) Landlord receiving a fully


                                      -19-

<PAGE>   25
]
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), and
(c) a written acknowledgement by Tenant evidencing that Tenant is not released
from its obligations under this Lease.

      8. FIRE OR OTHER CASUALTY. In case of damage to the Demised Premises or
those portions of the 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". Landlord shall not, however, be obligated to repair, restore, or
rebuild any of Tenant's property or any alterations or additions made by 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 Building
generally and shall be so extensive that Landlord shall decide, at its sole
discretion, not to repair or rebuild the 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 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. Notwithstanding the
foregoing, in the event Landlord does not repair or rebuild the Demised Premises
and the Building to a condition such that Tenant may operate its business in a
manner substantially similar to that which existed prior to the date of the
casualty within two hundred (200) days of the date of the casualty, then Tenant
shall be permitted, upon ten days notice to Landlord, to terminate this Lease
and neither party shall thereafter have any further obligation to the other.

      9. REGARDING INSURANCE AND LIABILITY.

            9.1. DAMAGE IN GENERAL. Tenant agrees that Landlord and its Building
manager and their respective partners, officers, employees and agents 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
gross negligence or willful misconduct of Landlord, its Building manager, or
their partners, officers, employees or agents, and Landlord and its Building
manager and their partners, officers or employees shall not be liable to Tenant
for any such damage or loss whether or not the result of their gross negligence
or willful misconduct to the extent Tenant is compensated therefor by Tenant's


                                      -20-

<PAGE>   26

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. Tenant shall defend, indemnify and save harmless
Landlord 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:

                  (i) 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;

                  (ii) 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;

                  (iii) 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 gross negligence or willful misconduct of Landlord, its employees
or agents; and

                  (iv) 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.

            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
Tenants use thereof, comprehensive public liability insurance, naming Landlord
and Landlord's agent as an additional insured, covering injury to persons in
amounts at least equal to $2,000,000.00 per person and $2,000,000.00 per
accident, and damage to property of at least $500,000.00. 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 satisfactory 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, 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


                                      -21-

<PAGE>   27

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. 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 Building, to the extent that such loss or
damage is recovered under an insurance policy or policies and to the extent such
policy or policies contain provisions permitting such waiver of claims. Each
party agrees to request its insurers to issue policies containing such
provisions and if any extra premium is payable therefor, the party which would
benefit from the provision shall have the option to pay such additional premium
in order to obtain such benefit.

            9.5. 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 Building; 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, subsidiary or partner of
Landlord or 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.

            9.6. SUCCESSORS IN INTEREST TO LANDLORD, MORTGAGEES. The term
"Landlord" as used in this Lease means the fee owner of the Building, or, if
different, the party holding and exercising the right, as against all others
(except space tenants of the Building) to possession of the entire 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 Building and Land, 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


                                      -22-

<PAGE>   28
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.

            9.7. 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 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. 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 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 13 of this Lease for events of default hereunder: (i)
the commencement of levy, execution or attachment proceedings against 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).


                                      -23-

<PAGE>   29


      12. DEFAULT.

            12.1. EVENTS OF DEFAULT. If Tenant shall fail to take possession of
the Demised Premises on the Commencement Date, or 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 fifteen (15) 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 or manifests an
intention not to take actual, bona-fide occupancy of the Demised Premises, or if
Tenant vacates or abandons the Demised Premises during the term hereof or
removes or manifests an intention to remove any of Tenant's goods or property
therefrom other than in the ordinary and usual course of Tenant's business, 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
suretyship 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.

                  (i) 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 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

                  (ii) 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:

                  (i) 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;


                                      -24-

<PAGE>   30

                  (ii) 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

                  (iii) 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 therefrom. 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.

            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:

                  (i) 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.


                                      -25-

<PAGE>   31
                  (ii) 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
Building or otherwise.

            12.7. CONFESSION OF JUDGMENT. LANDLORD SHALL HAVE THE FOLLOWING
RIGHTS TO CONFESS JUDGMENT AGAINST TENANT AND ALL PERSONS CLAIMING THROUGH
TENANT, FOR POSSESSION OF THE DEMISED PREMISES:

                  (i) WHEN THIS LEASE SHALL BE TERMINATED BY REASON OF A DEFAULT
BY TENANT OR ANY OTHER REASON WHATSOEVER, 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 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
DEFAULT OR DEFAULTS, OR AFTER EXPIRATION OF


                                      -26-

<PAGE>   32

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.

                  (ii) 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.

                  (iii) Tenant expressly agrees, to the extent not prohibited by
law, that any judgment, order or decree entered against it by or in any court or
magistrate by virtue of the powers of attorney contained in this Lease shall be
final, and that Tenant will not take an appeal, certiorari, writ of error,
exception or objection to the same, or file a motion or rule to strike off or
open or to stay execution of the same, and releases to Landlord and to any and
all attorneys who may appear for Tenant all errors in such proceedings and all
liability therefor.

                  (iv) 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.

                  (vi) Tenant acknowledges that it has been represented by
counsel in connection with the negotiation of this Lease, the 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 am to be proved.

            12.9. WAIVER OF DEFECTS. Tenant hereby waives all errors and defects
of a procedural nature in any proceedings brought against it by Landlord under
this Lease. Tenant further 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


                                      -27-

<PAGE>   33

be sufficient in any case where a longer period may be statutorily specified.

            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 rent or any other sum due from Tenant to
Landlord shall be overdue for more than five (5) days, it shall thereafter,
until paid, bear interest at the higher of (i) five percent (5%) above the 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 (ii) the rate of eighteen percent (18%) per annum (or, if lower,
the highest legal rate).

            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 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 Building (or of the entire Campus)
and to all mortgages, deeds of trust and similar security documents which may
now or hereafter be secured upon the Building (or upon the Campus), 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. If Landlord shall so
request, Tenant shall send to any mortgagee or ground lessor of the Building
designated by Landlord, a copy of any notice given by


                                      -28-

<PAGE>   34

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 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 for any other default, the number of days reasonably
required for the holder of each such mortgage and ground lease to obtain
possession of the Building and to cure such default (but in no event less than
an additional thirty (30) day period)).

            13.3. MODIFICATIONS. If, in connection with obtaining, continuing or
renewing financing for which the Building, Land 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 or adversely affect to a
material degree Tenant's leasehold interest hereby created.

      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 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:

                  Plymouth Campus Associates
                  c/o The Rubenstein Company
                  4100 One Commerce Square
                  2005 Market Street
                  Philadelphia, Pennsylvania 19103
                  Attention: Mark E. Rubenstein
                  FAX: (215) 563-4110

            14.2. IF TO TENANT:

                  Prior to the Commencement Date:


                                      -29-

<PAGE>   35
                        Michael Dougherty
                        Magainin Pharmaceutical
                        5110 Campus Drive
                        Plymouth Meeting, PA 19462

                        Following the Commencement Date:

                        Michael Dougherty
                        Magainin Pharmaceutical
                        Plymouth Meeting Executive Campus, Suite 270
                        620 West Germantown Pike
                        Plymouth Meeting, Pennsylvania 19462

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, courier service or
facsimile transmission as aforesaid), 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
fifty percent (150%) 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 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 used for shafts, pipes,
conduits, fan rooms, ducts, electric or other utilities, sinks or other Building
facilities, and the use thereof, as well as reasonable access thereto through
the Demised Premises for the purposes of operation, maintenance, decoration and
repair, are reserved to Landlord.

        17.     COMPLETION OF IMPROVEMENTS: DELAY IN POSSESSION.

                17.1. LANDLORD IMPROVEMENTS. As a general matter, the Demised
Premises will be delivered to Tenant at the Commencement Date in its present "AS
IS/WHERE IS" condition, subject, nevertheless, to any further or additional wear
and tear between the date hereof and the Commencement Date, and further subject
nevertheless to the remaining provisions of this Paragraph




                                      -30-
<PAGE>   36
17. Landlord, at Landlord's own cost, shall furnish, install and otherwise
provide and be responsible for the installation of the following: (a) the
construction of a Demising Wall between the Demised Premises and the adjacent
space, (b) clean and shampoo the carpeting in the Demised Premises, and (c)
install a sink in the Demised Premises at the location requested by Tenant.

                17.2. TENANT IMPROVEMENTS.  INTENTIONALLY DELETED

                17.3. PERFORMANCE OF LANDLORD AND TENANT IMPROVEMENTS.
INTENTIONALLY DELETED

                17.4. ACCEPTANCE. Tenant represents that the 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, except as may be
expressly contained herein with respect to Landlord Improvements to be
constructed in the Demised Premises. Tenant's occupancy of the Demised Premises
shall constitute acceptance of the Landlord Improvements, as set forth in this
paragraph. The provisions of this paragraph shall survive the termination of
this Lease.

                17.5. DELAY IN POSSESSION. If Landlord shall be unable to
deliver possession of the Demised Premises to Tenant on the date specified for
commencement of the term hereof (i) because a certificate of occupancy has not
been procured, or (ii) because of the holding over or retention of possession of
any tenant or occupant, or (iii) if repairs, improvements or decoration of the
Demised Premises, or of the Building, are not completed, or (iv) because of the
operation of a "force majeure" (which shall mean any delay in performance
hereunder caused by any event beyond the 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 or
acts of God), or (v) for any other reason, then in any such case Landlord shall
not be subject to any liability to Tenant. Under such circumstances, except for
delays resulting from actions or omissions by Tenant, the rent reserved and
covenanted to be paid herein shall not commence until possession of the Demised
Premises is given or the Demised Premises are available for occupancy by Tenant,
and no such failure to give possession shall in any other respect affect the
validity of this Lease or any obligation of the Tenant hereunder (except as to
the date of commencement of accrual of rent).

        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 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




                                      -31-
<PAGE>   37
and all requirements of the National Fire Protection Agency and shall not
interfere with the use of any then existing Lines at the Building, (c) an
acceptable number of spare Lines and space for additional Lines shall be
maintained for existing and future occupants of the 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 will 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 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 Building (ii) create additional
space for Lines at the 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 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 within or serving the Demised
Premises upon termination of this Lease, provided Landlord notifies Tenant prior
to or within thirty (30) days following such termination. 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 Lease, and any such




                                      -32-
<PAGE>   38
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 Building, by any failure of
the environmental conditions or the power supply for the 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 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 office and communication services may be offered to tenants of the
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 office
and 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 Building or the use of any facilities or equipment of the
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 Building Systems or any services, equipment or facilities used or operated
by Supplier or any tenant in the 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




                                      -33-
<PAGE>   39
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 rim to any other claim of
any nature against Landlord. If Tenant does not contract for such office and
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. Landlord has executed the Lease in reliance
upon certain financial information which his been submitted by Tenant to
Landlord prior to the execution of the Lease (the "Financial Information"). From
time to time, upon five (5) days written request by Landlord, Tenant will submit
to Landlord current financial information, in detail reasonably satisfactory to
Landlord, in order for Landlord to determine properly Tenant's then financial
condition. 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) the Financial Information is
complete, true and correct and a presents a fair representation of Tenant's
financial condition at the time of signing of this Lease, (ii) Tenant and the
party executing on behalf of Tenant are fully and properly authorized to execute
and enter into this Lease on behalf Tenant and to deliver the same to Landlord;
(iii) 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; (iv) Tenant has executed this Lease free from fraud, undue influence,
duress, coercion or other defenses to the execution of this Lease; (v) this
Lease constitutes a valid and binding obligation of Tenant, enforceable against
Tenant in accordance with its terms; (vi) 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 (vii) if Tenant is a corporation
or a partnership (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 or Partnership
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, or other 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




                                      -34-
<PAGE>   40
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) days' notice to Tenant (except that no notice need be given in
case of emergency), cure on behalf of Tenant any default hereunder by Tenant,
and the cost 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 ten (10)
days after request by Landlord, 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. Relocation of Tenant. Landlord, at its sole expense, upon not less
than sixty (60) days prior written notice to Tenant (the "Relocation Notice"),
may require Tenant to relocate from the Demised Premises to other premises of
comparable size within the Campus in order to permit Landlord to consolidate the
Demised Premises with other adjoining space leased or to be leased to another
tenant in or coming into the Building; provided, however, that in the event of
delivery of any such Relocation Notice, Tenant, by written notice to Landlord
given not later than thirty (30) days following Tenant's receipt of the
Relocation Notice, may elect not to relocate to such other premises, and in lieu
thereof, may terminate this Lease and Tenant shall thereafter vacate the Demised
Premises no later than thirty (30) days after the expiration of such thirty (30)
day period. In the event of any such relocation, Landlord shall: (i) pay all the
expenses of preparing




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<PAGE>   41
and decorating the new premises so that such premises will be substantially
similar to the Demised Premises; (ii) pay the expense of moving Tenant's
furniture, furnishings, equipment, files and other personal property to the new
premises; and (iii) pay the reasonable costs of replacing existing stocks of
Tenant's letterhead, envelopes, billing statements and other stationary having
Tenant's address thereon. Use and occupancy by Tenant of the new premises shall
be under and pursuant to the same terms, conditions and provisions of this Lease
and Tenant shall execute any and all amendments to this Lease as Landlord shall
deem necessary to effectuate the provisions of this Paragraph.

       25. 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 Jackson-Cross Company ("Agent"), 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 Agent, employed or engaged by it or
claiming to have been employed or engaged by it. Agent is entitled to a leasing
commission in connection with the making of this Lease, and Landlord shall pay
such commission to Agent pursuant to a separate agreement between Landlord and
Agent.

       26. MISCELLANEOUS.

               26.1. 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.

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

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

               26.4. LIGHT AND AIR. This Lease does no grant any legal rights to
"light and/or air" outside the Demised Premises nor any particular view or
cityscape visible from the Demised Premises.




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<PAGE>   42
               26.5. 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.

      27. 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.

      28. CONFIDENTIALITY. TENANT ACKNOWLEDGES AND AGREES THAT THE TERMS OF THIS
LEASE AND THE NEGOTIATIONS WHICH LED TO THE EXECUTION OF THIS LEASE ARE
CONFIDENTIAL IN NATURE. TENANT COVENANTS THAT, EXCEPT AS MAY BE REQUIRED BY LAW
OR BY ANY LENDER IN CONNECTION WITH CURRENT OR PROPOSED FINANCING FOR TENANT,
TENANT SHALL NOT 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 LANDLORD.




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<PAGE>   43
          IN WITNESS WHEREOF, intending to be legally bound hereby, the parties
hereto have caused this Lease to be executed by their duly authorized
representatives the day and year first above written.


WITNESS:                           LANDLORD:
                                   
                                   PLYMOUTH CAMPUS ASSOCIATES
                                   
                                   BY: The Rubenstein Company, L.P.
                                         General Partner
                                   
                                   
                                   
/s/ XXX                            By: /s/ XX
--------------------                  ------------------------------------------
                                   Authorized Signature
                                   
WITNESS:                           TENANT:
                                   
                                   MAGAININ PHARMACEUTICALS INC
                                   
                                   
/s/ Barbara L. Lehman              By: /s/ M.R. Dougherty
---------------------                 ------------------------------------------
                                   Authorized Signature  M.R. Dougherty EVP, CFO
                            


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