LEASE AGREEMENT

                                     BETWEEN

                    MARYLAND ECONOMIC DEVELOPMENT CORPORATION

                                       AND

                           HUMAN GENOME SCIENCES, INC.

                             DATED DECEMBER 1, 1997


<PAGE>



                                TABLE OF CONTENTS
                                -----------------
<TABLE>
<CAPTION>
                                                                                      Page
                                                                                      ----
<S>                                                                                   <C>
1.       Demise of Leased Premises....................................................  1
2.       Certain Definitions..........................................................  2
3.       Title........................................................................ 10
4.       Plans and Specifications; Construction....................................... 11
5.       Use of Leased Premises....................................................... 11
6.       Term; Purchase Option........................................................ 12
7.       Rent......................................................................... 17
8.       Net Lease; Non-Terminability................................................. 20
9.       Payment of Impositions; Compliance with Law and Restrictive Covenants........ 21
10.      Liens; Recording and Title; Easements........................................ 22
11.      Indemnification.............................................................. 22
12.      Tenant's Equipment; Building Equipment; Maintenance and Repair............... 23
13.      Alterations.................................................................. 25
14.      Condemnation................................................................. 27
15.      Insurance.................................................................... 28
16.      Casualty and Restoration..................................................... 31
17.      Assignment and Subletting.................................................... 33
18.      Permitted Contests........................................................... 35
19.      Default Provisions........................................................... 36
20.      Additional Rights of Landlord................................................ 40
21.      Inspection................................................................... 41
22.      Notices, Demands and Other Instruments....................................... 42
23.      Estoppel Certificates........................................................ 42
24.      No Merger.................................................................... 43
25.      Representations and Warranties of Tenant..................................... 43
26.      Affirmative Covenants of Tenant.............................................. 45
27.      Negative Covenants of Tenant................................................. 51
28.      Non-Recourse................................................................. 52
29.      Separability................................................................. 52
30.      Subordination................................................................ 53
31.      Binding Effect............................................................... 54
32.      Heading...................................................................... 54
33.      Environmental Matters........................................................ 54
34.      Quiet Enjoyment.............................................................. 59
35.      Miscellaneous................................................................ 59

</TABLE>


<PAGE>

LIST OF EXHIBITS

EXHIBIT A       Description of Land
EXHIBIT B       List of Construction Contracts
EXHIBIT C       List of Tenant's Equipment
EXHIBIT D       Schedule of Option Purchase Prices
EXHIBIT E       Notice and Payment Addresses


                                       2
<PAGE>


                                 LEASE AGREEMENT

         THIS LEASE  AGREEMENT (this "Lease") is made as of December 1, 1997, by
and  between  MARYLAND  ECONOMIC  DEVELOPMENT  CORPORATION,  a body  politic and
corporate and an instrumentality of the State of Maryland ("Landlord") and HUMAN
GENOME SCIENCES, INC., a Delaware corporation ("Tenant").

                                    RECITALS

         A.  Landlord,  at the request of Tenant,  has acquired from  Montgomery
County,  Maryland a certain parcel of land located at the Johns Hopkins  Belward
Research Campus in Montgomery County,  Maryland,  more particularly described on
Exhibit A attached hereto and made a part hereof (the "Land") as further defined
in Paragraph 1 below). ---------

         B. Landlord is acquiring the Land at the request of Tenant for the sole
purposes  of  (a)   constructing   on  the  Land,  a  process   development  and
manufacturing plant consisting of approximately 80,000 square feet in accordance
with plans and  specifications  to be approved by Landlord  and Tenant,  and (b)
leasing the Leased Premises (hereinafter defined) to Tenant.

         C.  The  parties  desire  to  enter  into  this  Lease  defining  their
respective rights,  duties,  obligations and liabilities  relating to the Leased
Premises.

                                   AGREEMENTS

         NOW,  THEREFORE,  in consideration of the mutual promises and covenants
contained  herein,  and other good and valuable  consideration,  the receipt and
sufficiency  of which  are  hereby  acknowledged,  Landlord  and  Tenant  hereby
covenant and agree as follows:

         A.  Demise  of  Leased  Premises.  In  consideration  of the  rents and
covenants  herein  stipulated to be paid and performed,  Landlord hereby demises
and lets to Tenant,  and  Tenant  hereby  demises  and lets from  Landlord,  the
premises  (collectively,  the "Leased Premises") consisting of (i) the parcel of
land  described in Exhibit A hereto,  together  with the  easements,  rights and
appurtenances  thereunto belonging or appertaining  (collectively,  the "Land"),
(ii) the buildings,  structures and other  improvements to be constructed on the
Land  pursuant  to  Paragraph  4 hereof  (the  "Improvements"),  and  (iii)  the
equipment and fixtures to be installed in the Improvements which are integral to
the  occupancy  of the  Leased  Premises  as a  "tenantable  shell"  (e.g.,  all
elevators,  escalators,  shades, awnings, floor coverings,  screens, landscaping
and security systems and building code required



<PAGE>

plumbing, heating, electrical, ventilation and fire-extinguishing equipment) and
financed  with  proceeds of the Bonds  (hereinafter  defined) or the State Loans
(hereinafter  defined) as evidenced  through the requisitions  from the Facility
Fund  (hereinafter  defined)  and the  requisitions  for the  State  Loans  (the
"Building   Equipment"),   but  excluding   therefrom  the  Tenant's   Equipment
(hereinafter defined).

         2. Certain Definitions.  The following terms shall have the definitions
provided below.  Unless specifically  provided  otherwise,  all accounting terms
have the definitions given them in accordance with GAAP (hereinafter defined) as
applied to the applicable Person on a consistent basis by its accountants in the
preparation of its previous annual financial statements.
 
         Act of  Bankruptcy  means with  respect to any Person,  the filing of a
petition in  bankruptcy  under the  Bankruptcy  Code, or the  commencement  of a
proceeding under any other applicable law concerning insolvency,  reorganization
or bankruptcy, by or against such Person as debtor.

         Accumulated   Funding   Deficiency   means  an   "accumulated   funding
deficiency" as defined in Section 302 of ERISA or Section 412(a) of the Code.

         Additional Rent means Additional Rent as defined in Paragraph 7.

         Affiliate means: (a) any Person in which Tenant legally or beneficially
owns or  holds,  directly  or  indirectly,  any  capital  stock or other  equity
interest;  (b) any Person that is a partnership in which Tenant is a partner, or
a joint  venturer in which  Tenant is a joint  venturer  or a limited  liability
company of which Tenant is a managing member; (c) any Person that is a director,
officer,  employee,  stockholder (legally or beneficially) or other affiliate of
any of the  foregoing  or of  Tenant;  and  (d)  any  Person  that  directly  or
indirectly  controls,  is under the control of, or is under common control with,
Tenant,  including,  without limitation,  any Person that directly or indirectly
has the right or power to direct the  management  or  policies of Tenant and any
Person whose  management or policies Tenant directly or indirectly has the right
or power to direct.

         Alterations  means  all  changes,   additions   (including   additional
Improvements  on  the  Land),  improvements  or  repairs  to,  all  alterations,
reconstructions,  renewals or removals of and all  substitutions or replacements
for  any of  the  Improvements,  both  interior  and  exterior,  structural  and
non-structural, and ordinary and extraordinary.




                                       2
<PAGE>

         Assignments means, collectively, the Bond Assignment and the State Loan
Assignment.

         Bank means The First  National  Bank of  Maryland,  a national  banking
association, its successors and assigns.

         Bankruptcy  Code means Title 11 of the United  States Code, as amended,
and all rules and regulations promulgated pursuant thereto.

         Basic Rent means Basic Rent as defined in Paragraph 7.

         Basic Rent Payment Date means any date on which an installment of Basic
Rent is due pursuant to Paragraph 7 hereof.

         Beneficiaries  mean,  collectively,  the Bond Beneficiary and the State
Loan Beneficiary.

         Bond Assignment means the Assignment, Subordination and Non-Disturbance
Agreement by and among Landlord,  the Tenant and the Bank,  dated as of December
1, 1997, together with all amendments thereto and modifications thereof.

         Bond  Beneficiary  means,  collectively,  MIDFA, the Bank and any other
Credit Facility Provider, as Beneficiary under the Bond Deed of Trust.

         Bond Deed of Trust  means  the Deed of Trust  dated as of  December  1,
1997,  encumbering  the Leased  Premises,  from  Landlord to certain  individual
trustees for the benefit of the Bond  Beneficiary,  together with all amendments
thereto and modifications thereof.

         Bond Documents has the meaning given to such term in the Indenture.

         Bond  Purchase  Drawing  has the  meaning  given  to  such  term in the
Indenture.

         Bonds means the $23,000,000  Taxable  Variable Rate  Demand/Fixed  Rate
Revenue Bonds (Human Genome Sciences,  Inc. Facility),  1997 Issue, being issued
by the  Landlord  to  finance a  portion  of the  costs of the  acquisition  and
construction of the Leased Premises.

         Building  Equipment  means the  Building  Equipment  as  defined in the
Recitals to this Lease.



                                       3
<PAGE>

         Closing Date means the date on which fully  executed and  authenticated
Bonds are issued and initially delivered.

         Code  means  the  Internal  Revenue  Code of  1986,  or any  applicable
predecessor statutory provision.  Each reference to a section of the Code herein
shall be deemed to include the United States  Treasury  Regulations in effect or
proposed from time to time with respect thereto.

         Collateral Pledge Agreement means the Collateral Pledge Agreement dated
as of December 1, 1997 from Tenant to  Landlord,  together  with all  amendments
thereto and modifications thereof.

         Commonly  Controlled Entity means any trade or business (whether or not
incorporated) which is a member of a "controlled group of corporations" (as such
phrase  is used and  defined  in  Section  414(b) of the Code) or which is under
"common  control"  (as such phrase is used and defined in Section  414(c) of the
Code), and of which Tenant or any Subsidiary of Tenant is a part.

         Construction  Contracts  means  those  certain  Construction  Contracts
between  Contractors  and Landlord  listed on Exhibit B hereto (which  Exhibit B
shall be updated from time to time if and when new  construction  contracts  are
entered into with Tenant's written consent).

         Contractors means the contractors named in the Construction Contracts.

         Credit  Facility  Agreement  has the meaning  given to such term in the
Indenture.  The  initial  Credit  Facility  Agreement  is the  Letter  of Credit
Agreement.

         Credit  Facility  Documents  has the meaning  given to such term in the
Indenture.  The  initial  Credit  Facility  Documents  are the  Letter of Credit
Documents.

         Credit  Facility  Provider  has the  meaning  given to such term in the
Indenture. The initial Credit Facility Provider is the Bank.

         Deeds of Trust  means,  collectively,  the Bond  Deed of Trust  and the
State Loan Deed of Trust.

         Default Rate means the Default Rate as defined in Paragraph 7(e).

         Encumbrances means Encumbrances as defined in Paragraph 30.



                                       4
<PAGE>

         ERISA means the Employee  Retirement  Income  Security Act of 1974,  as
amended, and all Laws promulgated pursuant thereto or in connection therewith.

         Event of Default means an Event of Default as defined in Paragraph 19.

         Facility Fund means the "Facility Fund", as such term is defined in the
Indenture.

         GAAP  means  generally  accepted  accounting  principles  in the United
States of  America in effect  from time to time,  consistently  applied.  In the
event of a change in GAAP affecting the covenants  contained in Paragraphs 26 or
27 of this Lease or definitions  contained in Paragraph 2 of this Lease relating
to such covenants,  such covenants and definitions  shall continue to be applied
as though such change in GAAP had not occurred  unless and until  Landlord,  the
Credit Facility Provider,  MIDFA, the State and Tenant shall agree in writing to
amend or adjust such covenants or definitions as deemed necessary as a result of
such change in GAAP.

         Hedge means any  interest  rate swap or similar  hedge  arrangement  in
existence  at any  time or from  time to time  between  Landlord  and the  Hedge
Counterparty.

         Hedge  Agreement  means any  agreement  between  Landlord and the Hedge
Counterparty  in  existence  at any  time or  from  time to  time,  executed  in
connection with the Hedge, including (without limitation) the Swap Agreement (as
defined in the Letter of Credit Agreement), together with all amendments thereto
and modifications thereof.

         Hedge Counterparty means any Person, in its capacity as counterparty to
the Hedge Agreement,  with which Landlord has entered the Hedge or may hereafter
at any time or from  time to time  enter  into  the  Hedge,  including  (without
limitation) the Bank and any other Credit Facility Provider.

         Hedge Documents means, collectively,  the Hedge Agreement and all other
documents in existence at any time or from time to time,  executed and delivered
to evidence, secure, or in connection with, the Hedge.

         Impositions means all taxes, including,  without limitation,  sales and
use taxes (but excluding,  except as hereinafter  provided,  income,  franchise,
profits and gross receipt taxes),  assessments  (including,  without limitation,
all  assessments for public  improvements  or benefits),  water and sewer rents,
rates and



                                       5
<PAGE>

charges,  excises,  levies, license fees, permit fees, inspection fees and other
authorization fees and other charges or costs of any nature whatsoever,  in each
case  whether  general  or  special,  ordinary  or  extraordinary,  foreseen  or
unforeseen,  of every character  (including all interest and penalties thereon),
which at any time  during  or in  respect  of the term  hereof  may be  assessed
against,  levied  upon,  confirmed or imposed on, or in respect of, or be a lien
upon  (a) the  Leased  Premises  or any part  thereof  or any  estate,  right or
interest therein, (b) any occupancy, use or possession of, or activity conducted
on, the Leased  Premises or any part  thereof,  (c) any Basic Rent or Additional
Rent or other sum reserved or payable by Tenant hereunder,  or (d) this Lease or
Landlord. Notwithstanding the foregoing provisions, the term "Impositions" shall
exclude (i) franchise,  capital stock or similar taxes,  if any, of Landlord and
assessments,  levies and liens arising therefrom; (ii) transfer, income, profits
or other taxes,  if any, of Landlord,  determined on the basis of its net income
or net revenues,  and  assessments,  levies and liens arising  therefrom;  (iii)
excise,  gross  receipts or gross income taxes imposed upon or measured by Basic
Rent,  Additional  Rent or other sums payable by Tenant  pursuant to this Lease,
unless the taxes  referred  to in clauses (i) and (ii) above are in lieu of or a
substitute  for any other tax or  assessment  upon or with respect to the Leased
Premises or any increases therein which, if such other tax or assessment were in
effect, would be payable by Tenant.

         Improvements means Improvements as defined in Paragraph 1.

         Indenture  means  the  Trust  Indenture  dated as of  December  1, 1997
between  Landlord  and the Trustee,  together  with all  amendments  thereto and
modifications thereof.

         Insurance  and  Award  Trustee  has the  meaning  given to that term in
Paragraph 15.

         Land means that parcel of land described in Exhibit A attached  hereto,
together with the easements,  rights and  appurtenances  thereunto  belonging or
appertaining.

         Landlord  means  Maryland  Economic  Development  Corporation,  a  body
politic and corporate and a public instrumentality of the State of Maryland.

         Landlord's Bond Obligations  means the "Issuer's Bond  Obligations," as
such term is defined in the Indenture.



                                       6
<PAGE>

         Landlord's  Credit  Facility  Obligations  means the  "Issuer's  Credit
Facility Obligations", as such term is defined in the Indenture.

         Landlord's  State  Loan  Obligations  means all of  Landlord's  limited
obligations  to the State pursuant to the terms and conditions of the State Loan
Documents.

         Law means the  Constitution  of the  United  States and of the State of
Maryland and any statute or rule of law of the United States and of the State of
Maryland.

         Lease Documents has the meaning given to such term in Paragraph 25.

         Leased  Premises  means the Land,  the  Improvements  and the  Building
Equipment.

         Legal Requirements means all laws, statutes,  codes, acts,  ordinances,
orders, judgments, decrees, injunctions, rules, regulations,  permits, licenses,
authorizations,  directions,  requirements  and agreements with all governments,
departments,  commissions, boards, courts, authorities,  agencies, officials and
officers, foreseen or unforeseen, ordinary or extraordinary, which now or at any
time hereafter may be applicable to the use, occupancy, possession, maintenance,
alteration, repair or reconstruction of any of the Leased Premises.

         Letter of Credit  means that  certain  Letter of Credit to be issued by
the Bank in the  original  stated  amount  of  $23,378,083  for the  account  of
Landlord  as  security  for the  Bonds,  as the same  may  from  time to time be
modified, amended, supplemented, renewed or replaced.

         Letter  of  Credit  Agreement  means  that  certain  Letter  of  Credit
Agreement  between the Bank and  Landlord  dated as of December 1, 1997,  as the
same  may from  time to time be  modified,  amended,  supplemented,  renewed  or
replaced.

         Letter of Credit  Documents  has the meaning  given to such term in the
Letter of Credit Agreement.

         LIBOR Rate means the fluctuating annual rate of interest which shall at
all times equal the interest rate which the Credit Facility  Provider  announces
and  declares  from time to time to be its one month  London  Interbank  Offered
Rate, adjusted for any Federal Reserve Board requirements  imposed on the Credit
Facility  Provider from time to time. All interest at the LIBOR Rate or computed
thereon  shall be  calculated  on the basis of a 360-day year factor  applied to
actual days  elapsed and shall be adjusted on any date on which a change  occurs
in the LIBOR Rate.



                                       7
<PAGE>

         MIDFA means the Maryland Industrial Development Financing Authority.

         MIDFA Insurance  Agreement  means the Insurance  Agreement of even date
herewith by and among MIDFA, the Bank and Landlord, together with all amendments
thereto and modifications thereof.

         Multiemployer  Plan means a multiemployer plan (as defined in ERISA) to
which Tenant, or any Commonly  Controlled Entity, as appropriate,  has or had an
obligation to contribute.

         Net Award has the meaning given to such term in Paragraph 14.

         Net Proceeds has the meaning given to such term in Paragraph 15.

         Paying Agent has the meaning given to such term in the Indenture.

         Permitted  Equipment Lien means any  encumbrance or other lien upon, or
security  interest in, or any  equipment  lease of, any Tenant's  Equipment,  or
interest  therein,  provided that the acquisition to which any such encumbrance,
lien, security interest or lease relates shall not result in a default under any
other provisions of this Lease.

         Permitted Use means the Permitted Use as defined in Paragraph 5.

         Person  means  any  natural  person,  firm,  association,  corporation,
company, trust, partnership, public body or other entity.

         Plan means any pension,  profit sharing,  savings, stock bonus or other
deferred  compensation  plan which is intended to qualify under Code '401 and is
subject to the requirements of ERISA, together with any related trusts.

         Plans means the Plans and  Specifications  for the  Improvements  which
have been approved,  and which will be approved from time to time, in writing by
Landlord and Tenant,  as the same may be modified or amended in accordance  with
Paragraph 4.

         Prohibited  Transaction means a "prohibited  transaction" as defined in
Section 406 of ERISA or Section 4975 of the Code.

         Rating Agency means any rating agency which at any time or from time to
times provides or furnishes a rating with respect to the Bonds.



                                       8
<PAGE>

         Registrar has the meaning given to such term in the Indenture.

         Remarketing Agent has the meaning given to such term in the Indenture.

         Remarketing  Agreement means the "Placement and Remarketing  Agreement"
as such term is defined in the Indenture.

         Rent  Commencement  Date means the Rent Commencement Date as defined in
Paragraph 7(a).

         Reportable  Event means a "reportable  event" as defined by Title IV of
ERISA.

         Restrictive Covenants means the covenants and restrictions set forth in
(a)  the  Declaration  of  Covenants,  Easements  and  Restrictions  (Protective
Covenants)  made  the  24th  day  of  September,  1997,  by  The  Johns  Hopkins
University,  and recorded among the Land Records of Montgomery County, Maryland,
in Liber  15181 at folio  074,  and (b) The  Johns  Hopkins  University  Belward
Research Campus Declaration of Covenants, Conditions, Easements and Restrictions
made the 24th day of  September,  1997,  by The Johns  Hopkins  University,  and
recorded among the Land Records of Montgomery County,  Maryland,  in Liber 15181
at folio 084.

         Scheduled  Completion  Date means December 30, 1999,  regardless of the
actual date the Improvements are completed.

         State  means  the  State  of  Maryland,  acting  through  the  Maryland
Department  of Business and Economic  Development  and any other  department  or
agency of the State of Maryland which makes any of the State Loans to Landlord.

         State Loans means, collectively,  the following loans to be made by the
State to  Landlord  for the  purpose of  financing a portion of the costs of the
acquisition and construction of the Leased Premises:

               (a)  Loan  in  the  principal  amount  of  $2,000,000,  from  the
                    Maryland  Department  of Business and  Economic  Development
                    under the Maryland Industrial Land Act;

               (b)  Loan in the  principal  amount  of  $3,000,000,  made by the
                    Maryland  Department  of Business and  Economic  Development
                    from the Maryland  Industrial and  Commercial  Redevelopment
                    Fund; and



                                       9
<PAGE>

               (c)  Loan in the  principal  amount  of  $2,000,000,  made by the
                    Maryland  Department  of Business and  Economic  Development
                    from the Maryland Economic Development Opportunities Program
                    Fund.

         State  Loan  Assignment   means  the  Assignment,   Subordination   and
Non-Disturbance Agreement by and among Landlord, the Tenant and the State, dated
December  31,  1997,  together  with all  amendments  thereto and  modifications
thereof.

         State Loan Beneficiary means the Beneficiary as such term in defined in
the State Loan Deed of Trust.

         State Loan Deed of Trust means the Second Deed of Trust dated  December
31, 1997,  encumbering the Leased Premises,  from Landlord to certain individual
trustees  for the  benefit  of the State  Loan  Beneficiary,  together  with all
amendments thereto and modifications thereof.

         State  Loan  Documents  means,  collectively,  any  and  all  documents
executed  and  delivered  by  Landlord as  evidence  of, as security  for, or in
connection with, the State Loans,  including (without limitation) the State Loan
Deed of Trust and the State Loan Assignment.

         Subsidiary  means,  with  respect to any Person,  any present or future
corporation at least a majority of whose  outstanding  Voting Stock shall at the
time be owned by such Person or by one or more  Subsidiaries of such Person,  or
by such Person and one or more Subsidiaries of such Person.

         Substantial  Completion means the date on which the Improvements are in
such  condition  that Tenant may commence its final fit out of the  Improvements
and move in and a Certificate of Occupancy of a tenantable shell either has been
issued or would be issued except for work to be performed by Tenant.

         Tenant's Equipment means that certain equipment  described on Exhibit C
attached  hereto  (as such  Exhibit  C may from time to time be  updated  by the
Tenant to include equipment to be used for the Permitted Use), together with all
replacements  thereof.  It is anticipated that some or all of Tenant's Equipment
will be leased by Tenant.

         Term means the Term as defined in Paragraph 6.

         Trustee means FMB Trust Company,  National Association,  its successors
and assigns.


                                       10
<PAGE>

         Voting  Stock  means  the  shares of any  class of  capital  stock of a
corporation  having  ordinary  voting power to elect the directors,  managers or
trustees thereof  (irrespective of whether or not at the time stock of any class
or classes of such  corporation  shall have or might have voting power by reason
of the happening of any contingencies).

         3.       Title.
                  (a) The Leased Premises are demised and let subject to (i) the
Deeds of Trust and any Encumbrances  executed in connection therewith and all of
the terms and  provisions  thereof,  including but not limited to the provisions
governing  disbursement of insurance proceeds and condemnation  awards, (ii) the
existing  state of the  title of the Land as of the date  hereof  and any  other
exceptions  or  encumbrances  of  record  as of the date  hereof  and any  other
restrictions,  exceptions and  Encumbrances  entered into subsequent to the date
hereof with Tenant's  knowledge and written consent,  which consent shall not be
unreasonably  withheld or delayed  provided  Tenant's  rights  hereunder are not
adversely  affected in a material manner (including  Tenant's option to purchase
the Leased Premises as hereinafter provided),  (iii) any state of facts which an
accurate  survey or physical  inspection of the Leased  Premises might show, and
(iv) the condition of the Leased  Premises,  as of the Rent  Commencement  Date,
without  representation  or  warranty by  Landlord,  and  without  liability  or
obligation of Landlord for patent or latent defects  (except that Landlord shall
assign the  benefit of all  warranties  written and implied to Tenant and Tenant
shall be a third party  beneficiary of such  warranties  under the  Construction
Contracts).

          (b)  Tenant has made its own investigation as to the existing state of
               the  title  of the Land  and has  made  arrangements  for its own
               survey.

         4.    Plans and Specifications; Construction.

          (a)  Landlord will cause the  Improvements  to be  constructed  on the
               Land in  accordance  with the Plans by the execution and delivery
               of the Construction Contracts. Landlord has entered into, or will
               enter  into,  the  Construction  Contracts  listed  on  Exhibit B
               attached hereto.

          (b)  Landlord will not agree to any modifications of the Plans without
               Tenant's consent thereto, and any modifications to the Plans will
               be made and approved in accordance  with the  requirements of



                                       11
<PAGE>

               the Bond Documents,  the Credit Facility  Documents and the State
               Loan Documents.

          (c)  Any change orders with respect to the Construction Contracts will
               be entered into and approved in accordance with the  requirements
               of the Bond  Documents,  the Credit  Facility  Documents  and the
               State Loan Documents.

          (d)  Landlord may enter into additional  Construction  Contracts.  All
               such  Construction  Contracts  are subject to Tenant's  approval,
               which approval will not be unreasonably  withheld or delayed, and
               must be approved by the Credit Facility Provider and the State.

         5.       Use of Leased Premises.

                  Tenant  shall  occupy  and use the Leased  Premises  only as a
biological   research,   product   development  and  manufacturing  and  related
administrative  use facility  (the  "Permitted  Use"),  or for such other lawful
purpose as may be approved by Landlord, the Credit Facility Provider,  MIDFA and
the State in their sole  discretion  (except that Landlord,  the Credit Facility
Provider,  MIDFA  and the  State  will  not  unreasonably  withhold  consent  to
additional uses which are related to the Permitted Use),  subject,  in addition,
to  the  terms  and  provisions  of  any  covenants,  easements,  conditions  or
restrictions  of record now or hereafter  recorded  with the written  consent of
Tenant,  including  but not  limited  to the Deeds of Trust and the  Restrictive
Covenants,  and for no other  purpose.  Tenant  shall  not  abandon  the  Leased
Premises. Tenant shall not permit any unlawful occupation,  business or trade to
be  conducted  on any of the  Leased  Premises  or any  use to be  made  thereof
contrary to  applicable  Legal  Requirements.  Tenant shall not use or occupy or
permit  any of the  Leased  Premises  to be used or  occupied,  nor do or permit
anything to be done in or on any of the Leased Premises, in a manner which would
or might (i) make void or voidable any  insurance  then in force with respect to
any of the Leased Premises,  (ii) make it difficult or impossible to obtain fire
or other  insurance which Tenant is required to furnish  hereunder,  (iii) cause
structural  injury to any of the  Improvements,  or (iv)  constitute a public or
private nuisance or waste.



                                       12
<PAGE>

         6.       Term; Purchase Option.

                  (a) This Lease shall be  effective  from and after the date of
its execution and delivery by Landlord and Tenant, December 31, 1997. Subject to
the terms,  covenants,  agreements and conditions contained herein, Tenant shall
have and hold the Leased Premises for a term (the "Term") commencing on the Rent
Commencement  Date and ending at midnight on January 1, 2019. From the effective
date of this Lease, as set forth above,  to and including the Rent  Commencement
Date,  Tenant shall have the right to enter the Leased  Premises for the purpose
of performing,  or causing to be performed,  "tenant  improvement  work" for the
purpose of installing,  or causing to be installed,  Tenant's  Equipment and for
the purpose of monitoring the construction of the Improvements.

                  Landlord shall have the right during the last twelve months of
the Term of this Lease to (i) advertise the  availability of the Leased Premises
for sale or for reletting and to erect upon the Leased Premises signs indicating
such availability  (provided that such signs do not unreasonably  interfere with
the use of the Leased Premises by Tenant),  and (ii) show the Leased Premises to
prospective  purchasers  or tenants at such  reasonable  times and on reasonable
prior notice during  normal  business  hours as Landlord may select,  subject to
Tenant's customary access restrictions.

                  (b) Provided  that,  at the time of exercise of the  following
purchase  option  and at the  time of  closing  of the  purchase  of the  Leased
Premises  pursuant to such option,  (i) no Event of Default or event which, with
the giving of notice or the lapse of time, or both, would constitute an Event of
Default  which would  entitle  Landlord to terminate  this Lease or evict Tenant
from possession of the Leased Premises,  shall exist, (ii) all payments of Basic
Rent and  Additional  Rent shall have been paid through the date of the exercise
of such purchase option,  and (iii) this Lease shall be in full force and effect
(unless this Lease in not in full force and effect due to  Landlord's  default),
then  Tenant  shall  have the right and  option,  by giving  notice as set forth
below, to acquire the Leased  Premises from Landlord as provided  below.  Tenant
may not exercise such  purchase  option during any period in which the Bonds are
not subject to redemption  pursuant to Section  3.1(c) or Section  3.1(e) of the
Indenture,  unless the Bonds are to remain outstanding after the closing of such
purchase option.

                  From and after  the date  which is five  years  after the Rent
Commencement Date, Tenant may exercise such purchase option by written notice to
Landlord,  with a copy of such  written  notice


                                       13
<PAGE>

to MIDFA,  the State and the Credit  Facility  Provider;  provided  that, in the
event that  Landlord is in default under the  provisions of the Bond  Documents,
the Credit  Facility  Documents or the State Loan  Documents and such default is
not the result of an Event of Default under this Lease, Tenant may also exercise
such purchase option during such five year period by written notice to Landlord,
with a copy of such written notice to MIDFA,  the State and the Credit  Facility
Provider.  If Tenant  exercises  such  purchase  option by giving  such  written
notice,  and (i) the Bonds have been  previously  redeemed,  the closing of such
purchase option shall occur no later than the 90th day following such notice (or
the next business day if such 90th day is not a business day), or (ii) the Bonds
then bear interest at a variable rate, the closing of such purchase option shall
occur no later than the 180th day  following  such notice (or the next  business
day if the  180th day is not a  business  day),  or (iii)  the  Bonds  then bear
interest at a fixed rate,  the closing of such  purchase  option  shall occur no
later  than the later of (A) the  first  day on which the Bonds may be  redeemed
pursuant to Section  3.1(e) of the  Indenture,  and (B) the 180th day  following
such notice (or the next  business day if the 180th day is not a business  day),
PROVIDED  THAT,  in the case of (ii) or (iii)  above,  unless  the  Bonds are to
remain  outstanding  after the closing of such purchase  option,  the closing of
such  purchase  option  shall not take place  unless  all Bonds  shall have been
redeemed on or before the date of the closing of such purchase option.

                  Not later  than 50 days  prior to the date of the  closing  of
such purchase  option,  Tenant shall pay to Landlord,  in immediately  available
funds, the sum of the following (the "Basic Purchase Price"), which sum shall be
held,  in trust,  by  Landlord  and used by  Landlord  solely  for the  purposes
hereinafter set forth:

                           (A) the applicable option purchase price set forth on
         the Schedule of Option Purchase Prices attached hereto as Exhibit D and
         made a part hereof, plus

                           (B) if Tenant exercises such purchase option during a
         period in which the Bonds bear  interest at a fixed rate,  an amount of
         money equal to any redemption  premium  payable upon  redemption of the
         Bonds on the next  optional  redemption  date as set  forth in  Section
         3.1(e) of the  Indenture,  unless  the Bonds are to remain  outstanding
         after the closing of such purchase option.

Any portion of the Basic  Purchase  Price which is not paid to the  Trustee,  as
provided below,  will be held by Landlord,  in trust,  upon terms and conditions
mutually  acceptable to Landlord and



                                       14
<PAGE>

Tenant, in an interest bearing account at a commercial bank mutually  acceptable
to Landlord and Tenant, pending the closing of such purchase option.

                  Upon receipt by Landlord of the Basic Purchase Price, Landlord
shall  pay to the  Trustee  from  the  Basic  Purchase  Price,  to be held in an
irrevocable  escrow for the redemption of the Bonds,  in  immediately  available
funds, an amount  sufficient,  when added to moneys then held by the Trustee and
available for the redemption of Bonds, to redeem all of the Bonds in full on the
next date on which  the Bonds may be  redeemed  pursuant  to  Section  3.1(c) or
3.1(e) of the Indenture,  unless the Bonds are to remain  outstanding  after the
closing of such purchase option.

                  In addition,  at the closing of such purchase  option,  Tenant
shall pay to Landlord, in immediately available funds, the sum of the following:

                           (A) all Basic Rent and  Additional  Rent  through the
         date of the closing of such purchase option, plus

                           (B)  all  actual   third  party  costs  and  expenses
         (including  reasonable  attorneys  fees  and  expenses)  of the  Credit
         Facility Provider,  Landlord, MIDFA and the State (excluding Landlord's
         internal overhead) incurred in connection with such purchase, including
         (without  limitation) any costs incurred by Landlord in connection with
         "unwinding" the Hedge, but deducting any benefits  accruing to Landlord
         in connection with "unwinding" the Hedge, plus

                           (C) all transfer  and  recordation  taxes,  brokerage
         fees, if any, and other costs and expenses  required or necessary to be
         paid in  connection  with the  transfer  of the  Leased  Premises  from
         Landlord to Tenant.

                  At the closing of such  purchase  option,  Landlord will use a
portion of the Basic Purchase Price received by Landlord to pay the  outstanding
principal  balance  and all  accrued  and unpaid  interest  on the State  Loans;
provided,  however,  that in the event that, in connection  with the purchase of
the Leased Premises by Tenant pursuant to such purchase  option,  Tenant assumes
all of the  obligations  of Landlord under the State Loan Documents with respect
to the State Loans, the Basic Purchase Price will be reduced by the total amount
of the State  Loans  then  outstanding  which are so assumed by Tenant as of the
date of the closing of such purchase option.

                  If, at the time Tenant exercises such purchase option,  any of
the Bonds  shall have been  redeemed or paid prior to 



                                       15
<PAGE>

maturity  or any  portion of the  principal  of the State  Loans shall have been
prepaid  prior to  maturity,  the Basic  Purchase  Price  shall be reduced by an
amount equal to the total amount of Bonds so redeemed or paid and the portion of
the principal of the State Loans so prepaid.

                  If, at the time Tenant exercises such purchase  option,  there
shall be on deposit  with the Trustee  any moneys  which are  available  for the
redemption  of the Bonds  upon the  closing  of such  purchase  option,  and the
outstanding  Bonds are to be redeemed upon the closing of such purchase  option,
the Basic  Purchase  Price shall be reduced by an amount  equal to the amount of
moneys so on deposit with the Trustee.

                  Upon  Tenant's  exercise of such purchase  option,  Tenant may
advise Landlord that Tenant will purchase the Leased  Premises  pursuant to such
purchase  option,  subject  to  the  Bond  Documents  and  the  Credit  Facility
Documents, and that Tenant either will assume all of the obligations of Landlord
under  the  Bond  Documents  and  the  Credit  Facility  Documents  or,  in  the
alternative,  pay the portion of the Basic  Purchase Price  attributable  to the
outstanding  Bonds by the  delivery of a loan  agreement,  or similar  document,
evidencing  Tenant's  agreement to pay Landlord  amounts which are sufficient to
enable Landlord to pay its monetary obligations under the Bond Documents and the
Credit Facility  Documents,  in which event (i) the Basic Purchase Price will be
reduced by the principal amount of the Bonds which would have been redeemed upon
the  closing of such  purchase  option,  (ii) at or prior to the closing of such
purchase  option,  Tenant and Landlord will execute and deliver such  documents,
and take such actions,  as Landlord,  the Credit Facility Provider and MIDFA may
require,  in their sole  discretion,  to provide for the assumption by Tenant of
Landlord's  obligations  under  the  Bond  Documents  and  the  Credit  Facility
Documents,  and (iii) the Bonds will not be redeemed but will remain outstanding
after the closing of such purchase option.

                  At the closing of such purchase  option,  Landlord  shall pay,
from the moneys paid to Landlord by Tenant as set forth above, (1) to the State,
in immediately  available  funds,  an amount  sufficient to pay the  outstanding
principal of and accrued and unpaid interest on the State Loans,  unless, and to
the extent that,  Tenant shall have assumed all of the  obligations  of Landlord
under the State Loan  Documents  as set forth  above,  (2) to the  Trustee,  the
Paying Agent,  the Registrar,  the  Remarketing  Agent,  the Rating Agency,  the
Credit  Facility  Provider,  MIDFA,  the State and the Hedge  Counterparty,  all
accrued fees, costs and expenses then payable to the Trustee,  the Paying Agent,
the Registrar,  the Remarketing  Agent,  the Rating Agency,  the Credit Facility
Provider,  MIDFA,  the  State  and the  Hedge  Counterparty,  (3) to the



                                       16
<PAGE>

Credit Facility Provider,  MIDFA and the State, all actual third party costs and
expenses (including  reasonable attorneys fees and expenses) incurred by them in
connection  with  such  purchase  of the  Leased  Premises  by  Tenant  and,  if
applicable,  in connection  with the assumption by Tenant of the  obligations of
Landlord  under the State  Loan  Documents,  the Bond  Documents  and the Credit
Facility Documents.

                  In  consideration  of the payment by Tenant to Landlord of the
Basic Purchase  Price and the other amounts of money set forth above,  Landlord,
by special warranty deed, will transfer its interest in the Leased Premises,  as
well as incidental personal property relating to the Leased Premises,  to Tenant
as of the date of the closing of such purchase option, free of all Encumbrances,
other  than  (1)  Encumbrances  in  existence  on the  date of this  Lease,  (2)
Encumbrances  assumed by Tenant,  (3) Encumbrances  approved by Tenant,  (4) the
State Loan  Documents in the event that in  connection  with the purchase of the
Leased Premises by Tenant pursuant to such Purchase Option Tenant assumes all of
Landlord's  obligations  under  the  State  Loan  Documents,  and (5)  the  Bond
Documents and the Credit Facility Documents in the event that in connection with
the purchase of the Leased  Premises by Tenant  pursuant to such purchase option
Tenant  assumes all of Landlord's  obligations  under the Bond Documents and the
Credit Facility Documents;  and Landlord will assign to Tenant all contracts and
warranties (to the extent  assignable)  relating to the Leased  Premises  and/or
incidental to any and all personal property relating to the Leased Premises.

                  Notwithstanding  any other  provision of this Lease,  Landlord
will not  accept  the Basic  Purchase  Price and the other  amounts of money set
forth above, and will not close such purchase  option,  unless the amount of the
Basic Purchase  Price is sufficient to enable  Landlord to (1) redeem all of the
Bonds at the then applicable redemption price, and to pay all of Landlord's Bond
Obligations and Landlord's Credit Facility Obligations in connection  therewith,
unless,  in  connection  with the  purchase  of the  Leased  Premises  by Tenant
pursuant to such  purchase  option,  Tenant  assumes all of the  obligations  of
Landlord under the Bond Documents and the Credit Facility Documents,  or, in the
alternative,  delivers a loan agreement,  or similar  document,  in payment of a
portion of the Basic Purchase Price as set forth above, and (2) to prepay all of
the State Loans in full,  including all accrued and unpaid interest thereon, and
to pay all of the Landlord's  State Loan  Obligations  in connection  therewith,
unless,  and to the extent that, in  connection  with the purchase of the Leased
Premises by Tenant pursuant to such purchase  option,  Tenant assumes all of the
obligations of Landlord under the State Loan Documents.



                                       17
<PAGE>

                  Concurrently   with  the  closing  of  such  purchase  option,
Landlord shall cause the Bond Deed of Trust (if not previously  satisfied) to be
released  upon the  payment by  Landlord to the Trustee of the amounts set forth
above, unless Tenant shall have assumed all of the obligations of Landlord under
the Bond  Documents  and the Credit  Facility  Documents as set forth above,  in
which event the Bond Deed of Trust will not be so released;  and Landlord  shall
cause the State Loan Deed of Trust (if not previously  satisfied) to be released
upon the payment by Landlord to the State of the amounts set forth above, unless
Tenant shall have  assumed all of the  obligations  of Landlord  under the State
Loan Documents as set forth above, or, in the alternative,  shall have delivered
a loan  agreement,  or  similar  document,  in payment of a portion of the Basic
Purchase  Price, as set forth above, in which event the State Loan Deed of Trust
will not be so released.

                  Upon the  closing of such  purchase  option and the payment of
all amounts set forth above,  Tenant shall be released of all of its obligations
under this Lease; provided, however that any and all obligations and liabilities
of  Tenant  under  this  Lease  that  survive  the Term of this  Lease  (such as
indemnification obligations) shall survive the closing of such purchase option.

                  (c) In the event Tenant  exercises  its option to purchase the
Leased Premises from Landlord as set forth above, but fails to close as and when
required as set forth above,  such failure shall  constitute an Event of Default
under this Lease.

         7.       Rent.

                  (a) As used herein,  the term "Rent  Commencement  Date" means
the earlier to occur of (i) the first day of the first month  following the date
on which Tenant gives  written  notice to Landlord,  with a copy of such written
notice to the  Credit  Facility  Provider,  the State and MIDFA,  that  Tenant's
beneficial use of the Leased Premises has begun, and (ii) January 1, 1999.



                                       18
<PAGE>

                  (b) Tenant  covenants to pay to Landlord,  on the first day of
each and every calendar month,  beginning on the Rent  Commencement  Date, basic
rent in the amount of $186,376.00 per month,  subject to adjustment as set forth
in subparagraph (c) below (such basic rent, as so adjusted from time to time, is
hereinafter  referred  to as "Basic  Rent").  Basic  Rent  shall be  payable  to
Landlord by separate check or wire transfer at Landlord's  payment addresses set
forth in Exhibit E attached hereto and made a part hereof or at such other place
or bank account within the continental  United States or to such other Person as
Landlord from time to time may  designate to Tenant in writing,  in lawful money
of the United States of America.

                  (c) Landlord and Tenant  acknowledge  and agree that the Basic
Rent has been  determined  based upon a number of  factors,  which  include  the
amount of debt  service  payable by Landlord  with  respect to the Bonds and the
State Loans and other costs which may fluctuate from time to time.  Accordingly,
the Basic Rent shall be  adjusted  from time to time by  Landlord  and Tenant to
reflect (i) any  redemption of the Bonds prior to maturity and any prepayment of
any of the State Loans prior to maturity,  and (ii) the  expiration of the Hedge
or any default by the Hedge  Counterparty  in the performance of its obligations
under the Hedge Documents.

                  (d) Tenant covenants to pay and discharge, as additional rent,
the following (collectively, the "Additional Rent"):

                           (i) the amount of any cost or expense  required to be
         paid by Landlord with respect to or in connection with the acquisition,
         construction and financing of the Improvements and the ownership of the
         Leased  Premises  and the  leasing  of the Leased  Premises  to Tenant,
         including (without  limitation),  consultants'  fees,  accounting fees,
         legal fees and other expenses relating to any litigation  involving the
         Leased  Premises  (except  to the extent  that  Landlord  is  otherwise
         indemnified  therefor  pursuant to another  provision  of this  Lease),
         costs of maintenance, upkeep and repair of the Leased Premises paid for
         by Landlord, costs of permits, charges by governmental authorities, and
         amounts paid  pursuant to any  declaration  or covenants  including the
         Restrictive Covenants, and all indemnification  obligations of Landlord
         to any  Person  or  Persons  resulting  from  or  growing  out of  such
         acquisition,  construction,  financing,  ownership and leasing, and any
         sales taxes, plus

                           (ii) all fees and amounts  payable by Landlord to any
         Person or Persons in connection with the acquisition,  construction and
         financing  of the  Improvements,  including  (without  limitation)  all
         credit facility fees,  remarketing



                                       19
<PAGE>

         fees, insurance premiums payable to MIDFA, common area maintenance fees
         or rents or other similar  charges  relating to the  maintenance of the
         Leased  Premises  or any roads or  otherimprovements  related  thereto,
         monthly deposits on account of Impositions and insurance  premiums,  in
         the event that  Landlord is required to make such  monthly  deposits on
         account of Impositions and insurance premiums, and amounts representing
         increases in fees payable to the Rating Agency or to the Trustee or the
         Registrar or the Paying Agent pursuant to the Indenture or increases in
         the  negotiation  fee  payable to the  Credit  Facility  Provider,  and
         amounts  representing changes in costs resulting from any conversion of
         the interest  rate payable on the Bonds from a variable  rate to one or
         more fixed  rates or from one or more fixed  rates to one or more other
         fixed rates or to a variable rate, plus

                           (iii) to the extent not paid on the Closing Date from
         the  proceeds of the Bonds,  the amounts  determined  by Landlord to be
         sufficient to enable  Landlord to make  payments of all other  monetary
         obligations of Landlord under the Bond  Documents,  the Credit Facility
         Documents, the State Loan Documents and the Hedge Documents.

Landlord,  as  promptly  as  practicable  after  obtaining  knowledge  that  any
Additional Rent will be payable under this Lease, will advise Tenant, by written
notice,  of the amount of any Additional Rent payable  hereunder and the date on
which any Additional  Rent is due and payable by Tenant in order for Landlord to
meet its  obligations  with  respect to payments  by Landlord to other  Persons.
Additional  Rent  shall be paid to  Landlord's  payment  addresses  set forth in
Exhibit  E  attached  hereto.  In the event of any  failure  by Tenant to pay or
discharge  any  Additional  Rent,  Landlord  shall have all  rights,  powers and
remedies  provided  herein or by Law in the case of  non-payment  of Basic Rent.
Unless otherwise  provided herein,  all payments of Additional Rent shall be due
on the date  specified by Landlord in such  written  notice as the date on which
such Additional Rent is due and payable.

         (e) In the event that any payment of Basic Rent or  Additional  Rent is
not made within 15 days after the date on which the same is due and payable, any
such payment in default and the entire  unpaid  balance of all amounts  owing to
Landlord shall bear  interest,  from the date on which the payment was due until
such payment in default is paid in full, at the fluctuating rate which is at all
times  equal to the LIBOR  Rate  plus 3% per  annum  (the  ADefault  Rate@).  In
addition,  Tenant  shall pay (i) a late  charge  equal to 2% of the  payment  in
default  as set forth  above  (except  for any  payment  with  respect to a Bond
Purchase Principal Drawing,



                                       20
<PAGE>

as defined in the  Indenture)  which is made more than 15 days after the date on
which the same is due and payable,  and (ii) all costs of collection,  including
attorneys=  fees,  if  collection  of amounts  due to Landlord is referred to an
attorney after default by Tenant.

         8.       Net Lease; Non-Terminability.

                  (a) This is a net lease,  and Basic Rent,  Additional Rent and
all other  sums  payable  by Tenant  shall be paid  without  notice  (except  as
specifically provided herein) or demand.

                  (b) Except as expressly  provided in this Lease,  Tenant shall
not be entitled to any set-off, counterclaim, recoupment, abatement, suspension,
deferment,  diminution,  deduction,  reduction or defense of or to Basic Rent or
Additional  Rent or any other sums  payable  hereunder  and the  obligations  of
Tenant under this Lease shall not be  affected,  for any reason,  including  the
following: (i) any damage to or the destruction of all or any part of the Leased
Premises  from  whatever  cause,  (ii) the taking of the Leased  Premises or any
portion thereof or interest  therein by  condemnation,  requisition or otherwise
for any reason, (iii) the prohibition, limitation or restriction of Tenant's use
of all or any part of the Leased Premises,  or any  interference  with such use,
(iv) any title defect or  encumbrance,  or any eviction from the Leased Premises
by paramount  title or otherwise,  (v) Tenant's  acquisition or ownership of any
interest in all or any part of the Leased Premises otherwise than pursuant to an
express  provision  of this  Lease,  (vi) any failure on the part of Landlord to
observe any provision of this Lease,  or any default by Landlord under any other
agreement  to which  Landlord  and Tenant may be parties,  (vii) any claim which
Tenant has or might have  against  Landlord,  or (viii) any other cause  whether
similar  or  dissimilar  to the  foregoing,  any  present  or future  Law to the
contrary notwithstanding except by agreement by and among Landlord,  Tenant, the
State  and  the  Bank.  It is the  intention  of the  parties  hereto  that  the
obligations of Tenant hereunder shall be separate and independent  covenants and
agreements,  that Basic  Rent,  Additional  Rent and all other  sums  payable by
Tenant  hereunder  shall continue to and be payable in all events,  and that the
obligations  of  Tenant   hereunder  shall  continue   unaffected,   unless  the
requirement to pay or perform the same shall have been terminated pursuant to an
express provision of this Lease.

               (c) Tenant agrees that it will remain  obligated under this Lease
in accordance with its terms, and that it will not take any action to terminate,
rescind or avoid this Lease or abate the rent required  hereby,  notwithstanding
(i)  the  bankruptcy,  insolvency,  reorganization,  composition,  readjustment,
liquidation,  dissolution,  winding-up or other proceeding affecting



                                       21
<PAGE>

Landlord or any  assignee of  Landlord  in any such  proceeding  or/and (ii) any
other action (including rejection) with respect to this Lease which may be taken
by any trustee or  receiver  of  Landlord or of any  assignee of Landlord in any
such proceeding or by any court in any such proceeding;  and, in any such event,
so long as Tenant pays and  performs its  obligations  under this Lease and does
not take any action to terminate,  rescind or avoid this Lease or abate the rent
required hereby, Tenant shall be entitled to the benefits of Tenant set forth in
this Lease.

                  (d) Except as otherwise provided in this Lease,  Tenant waives
all rights which may now or hereafter be conferred by law (i) to quit, terminate
or  surrender  this Lease or (ii) to any  abatement,  suspension,  deferment  or
reduction of Basic Rent,  Additional  Rent or any other sums payable  under this
Lease,  except  as  expressly  approved  by the State  and the  Credit  Facility
Provider or as otherwise expressly provided herein.

                  (e) Subject to Paragraph 35(f), Tenant and Landlord agree that
the  State  and the  Credit  Facility  Provider  are and  shall  be  third-party
beneficiaries of this Lease and that, as such, the State and the Credit Facility
Provider  shall  have the right to pursue any right,  remedy or  performance  to
which Landlord shall be entitled  pursuant hereto  notwithstanding  that but for
the  provisions  of this  subparagraph  (e),  the State and the Credit  Facility
Provider  may not have had the  right  to  pursue  any  such  right,  remedy  or
performance.



                                       22
<PAGE>

         9.  Payment  of  Impositions;   Compliance  with  Law  and  Restrictive
Covenants.

                  (a)  Subject to the  provisions  of  Paragraph  18 relating to
contests, Tenant shall pay all Impositions before any fine, penalty, interest or
cost may be added for non-payment.  Tenant agrees to furnish to Landlord, within
30 days after written demand  therefor,  proof of the payment of all Impositions
payable  by Tenant  as  provided  in this  Paragraph  9. In the  event  that any
Imposition  becomes due and payable  during the Term and may be legally  paid in
installments,   Tenant  shall  have  the  option  to  pay  such   Imposition  in
installments;  and in  such  event,  Tenant  shall  be  liable  only  for  those
installments  which  become due and payable  during the Term,  with  appropriate
proration  in  the  case  of  fractional   years.  Any  Impositions   which  are
attributable in part to the Term and in part to a period  preceding or following
the Term, as the case may be, shall be equitably  apportioned  between  Landlord
and Tenant. If Landlord is required pursuant to the Bond Documents or the Credit
Facility  Documents  or the State Loan  Documents  to make  monthly  deposits on
account of Impositions and insurance  premiums,  and Landlord  informs Tenant in
writing  thereof  specifying the amount of such deposits,  Tenant shall pay such
monthly  deposits to  Landlord,  as  Additional  Rent  hereunder  as provided in
Paragraph 7 (d).

                  (b) Tenant shall promptly comply with and conform to all Legal
Requirements concerning the use, occupancy and conditions of the Leased Premises
and all machinery, equipment, furnishings, fixtures and improvements therein. If
any such Legal Requirement requires an occupancy or use permit, license, special
exception,  or other local, state or federal agency  certification,  then Tenant
shall promptly obtain and keep current the same.

                  (c) Tenant shall comply with all of the Restrictive Covenants.



                                       23
<PAGE>

         10.      Liens; Recording and Title; Easements.

                  (a) Tenant will not, directly or indirectly,  create or permit
to remain,  and will promptly  discharge,  at its expense,  any mortgage,  lien,
encumbrance  or  charge  on,  pledge  of,  or  conditional  sale or other  title
retention  agreement with respect to, the Leased Premises or any part thereof or
Tenant's  interest therein or Basic Rent,  Additional Rent or other sums payable
by Tenant under this Lease, other than Permitted  Equipment Liens. The existence
of any mechanic's, laborer's, materialman's, supplier's or vendor's lien, or any
right in respect thereof,  shall not constitute a violation of this Paragraph 10
if  payment is not yet due upon the  contract  or for the goods or  services  in
respect  of which any such lien has  arisen so long as such  payment  is made or
bonded off within 30 days after the later to occur of the completion of the work
which gave rise to the imposition of said liens or the rendering of the invoice,
statement or demand for such payment.  Nothing  contained in this Lease shall be
construed  as  constituting  the consent or request of  Landlord,  expressed  or
implied, of any contractor,  subcontractor, laborer, materialman or vendor to or
for the  performance  of any  labor  or  services  or  other  furnishing  of any
materials for any construction, alteration, addition, repair or demolition of or
to the Leased Premises or any part thereof.

                  (b) At Tenant's request and at Tenant's sole cost and expense,
Landlord and Tenant will execute and deliver a  memorandum  evidencing  Tenant's
option to purchase set forth in Paragraph 6, and shall cause such  memorandum to
be  recorded,  filed or  registered  in such manner and in such places as may be
required  by any  present or future Law in order to publish  notices and protect
the validity of such option to purchase.

                  (c)  Subject  to the terms and  conditions  of  Paragraph  30,
Landlord shall have the right to encumber the Leased Premises, provided that any
such  encumbrance  (except  for the  Deeds of Trust and  other  Credit  Facility
Documents and State Loan Documents) shall be made expressly  subject to Tenant's
rights under this Lease including the purchase option.

         11.  Indemnification.  Tenant shall pay,  protect,  indemnify  and save
harmless  Landlord from and against any and all  liabilities,  losses,  damages,
costs,  expenses  (including  all  reasonable  attorneys'  fees  and  expenses),
penalties,  causes of action, suits, claims,  demands or judgments of any nature
whatsoever  arising  from (i) any  injury to, or the death of, any person or any
damage to property on the Leased Premises or upon adjoining  sidewalks,  streets
or ways, if caused by the negligence of Tenant or its agents or employees, or in
any manner growing out of or connected with the use,  failure of use,  condition
or



                                       24
<PAGE>

occupancy  of the Leased  Premises  or any part  thereof or  resulting  from the
condition  thereof,  (ii) any violation by Tenant of any covenant,  agreement or
condition of this Lease,  and (iii) any  violation by Tenant of the terms of any
contract or agreement  to which  Tenant is a party and which  affects the Leased
Premises;  provided, however, that if any such liability, loss, damage, penalty,
cost or expense,  cause of action,  suit, claim, demand or judgment results from
the  negligence  of  Landlord,  its agents or  employees,  or if any such act or
omission is  determined  to be a failure by Landlord to observe any provision of
this Lease (if observance is required of Landlord),  the foregoing  indemnity by
Tenant shall apply with respect to Landlord  only to the extent of the insurance
coverage  maintained  (or  required  to be  maintained,  if  greater)  by Tenant
pursuant to the provisions of Paragraph 15 of this Lease.  In case any action or
proceeding  is brought  against  Landlord  by reason of any such  claim,  Tenant
covenants,  upon  notice  from  Landlord,  to resist or  defend  such  action or
proceeding by counsel reasonably  satisfactory to Landlord,  and, at the expense
of Tenant,  Landlord will  cooperate and assist in the defense of such action or
proceeding if reasonably requested so to do by Tenant.

         Tenant also shall pay,  protect,  indemnify and save harmless  Landlord
for all amounts,  liabilities,  indemnities and obligations which Tenant assumes
or agrees to pay or discharge pursuant to this Lease, as well as any payments or
indemnification  made or  required  to be  made by  Landlord  under  the  Credit
Facility  Documents,  the Bond Documents,  the State Loan Documents or the Hedge
Documents as a result of Tenant's default  hereunder,  together with every fine,
penalty,  interest  and cost which may be added for  nonpayment  or late payment
thereof.

         The  obligation  of Tenant under this  Paragraph  11 shall  survive any
termination of this Lease as to any right of indemnity  which shall have accrued
prior to such termination.



                                       25
<PAGE>

         12. Tenant's Equipment; Building Equipment; Maintenance and Repair.

         (a) Tenant,  at its expense,  shall install all specialized  machinery,
apparatus and equipment which Tenant, in its sole and absolute discretion, deems
necessary  to  permit  the  Leased  Premises  to be used for the  Permitted  Use
including,  without  limitation,  the Tenant's Equipment  described on Exhibit C
attached hereto.  All Tenant's Equipment shall remain the property of the lessor
thereof or the  property  of the  Tenant,  as  applicable,  notwithstanding  its
attachment  to the  Leased  Premises.  At the  expiration  of the  Term,  all of
Tenant's  Equipment  shall  remain the  property  of the  lessor  thereof or the
property of the Tenant (as  applicable) and shall be removed by Tenant or lessor
in accordance with subparagraph (c) below.

               (b) Tenant, at its sole cost and expense,  will keep and maintain
the Leased Premises,  including any altered, rebuilt,  additional or substituted
buildings,  structures  and  parts  of the  Improvements,  in  good  repair  and
appearance,  except  for  ordinary  wear  and  tear,  and will  with  reasonable
promptness make all structural and nonstructural,  foreseen and unforeseen,  and
ordinary  and  extraordinary  changes and repairs of every kind and nature which
may be required to be made upon or in connection with the Leased  Premises,  the
Building  Equipment,  or any part  thereof;  in order to keep and  maintain  the
Leased  Premises and the Building  Equipment in such good repair and appearance.
All repairs, replacements and renewals shall be at least equal in quality to the
original work and all  replacements  shall have a value and useful life at least
equal to the  value  and  remaining  estimated  useful  life of the  item  being
replaced,  and be suitable for a use which is the same or similar to that of the
item being  replaced.  Landlord  shall not be  required to  maintain,  repair or
rebuild,  or to  make  any  Alteration  to the  Leased  Premises,  the  Building
Equipment,  or Tenant's  Equipment,  or any part  thereof,  whether  ordinary or
extraordinary,  structural  or  non-structural,  foreseen or  unforeseen,  or to
maintain the Leased Premises, the Building Equipment,  or Tenant's Equipment, or
any part thereof,  in any way, and Tenant hereby  expressly  waives the right to
make  repairs at the  expense of  Landlord,  notwithstanding  the fact that such
right may be provided for in any Law in effect at the time of the  execution and
delivery of this Lease or which may thereafter be enacted.

               Notwithstanding anything herein to the contrary, Tenant shall not
be  required to replace any  Building  Equipment  during the last 3 years of the
Term, but Tenant, at Tenant's expense, shall keep all Building Equipment in good
working condition throughout the Term.



                                       26
<PAGE>

               (c) Upon the  expiration  or earlier  termination  of this Lease,
Tenant shall surrender the Leased  Premises in good  condition,  reasonable wear
and tear and damage by casualty  excepted,  with all Building  Equipment in good
working condition,  and all Tenant's  Equipment removed.  Any Tenant's Equipment
required  to be  removed  but not  removed  by Tenant  within 30 days  after the
expiration or earlier termination of this Lease shall be considered abandoned by
Tenant and may be  appropriated,  sold,  destroyed or  otherwise  disposed of by
Landlord  without first giving notice thereof and without  obligation to account
therefor  to either  Tenant or any  lessor of such  Tenant's  Equipment.  Tenant
agrees to pay all costs and expenses incurred in removing, storing and disposing
of  Tenant's  Equipment  required to be removed but not  removed.  Tenant  shall
repair (i.e., replace, restore or repair to a sightly and usable condition),  at
its  expense,  any damage to the Leased  Premises  caused by removal of Tenant's
Equipment,  whether effected by Landlord,  Tenant, or Tenant's lessor.  Landlord
shall not be responsible for any loss or damage to Tenant's  Equipment under any
circumstances. The provisions of this subparagraph (c) are not applicable in the
event that Tenant purchases the Leased Premises as provided in Paragraph 6.

               Notwithstanding anything herein to the contrary, Tenant shall not
be  required to replace any  Building  Equipment  during the last 3 years of the
Term, but Tenant, at Tenant's expense, shall keep all Building Equipment in good
working condition throughout the Term.

               (d)  Landlord  shall,  from  time to time upon  Tenant's  written
request,  execute  appropriate  documents for the benefit of Tenant's lenders or
equipment lessors  confirming the provisions of this Paragraph 12 and containing
such further undertakings of Landlord concerning the right of any such lender or
lessor to enter the Leased Premises following  termination of this Lease for the
purpose of exercising  its rights with respect to the  collateral of such lender
or lessor,  including removing the same, provided such further  undertakings are
on  commercially  reasonable  terms and  conditions  and require  such lender or
lessor to repair  any  damage to the Leased  Premises  caused by the  removal of
Tenant's Equipment.



                                       27
<PAGE>

         13.      Alterations.

                  (a) So long as no Event of  Default or event  which,  with the
giving of  notice,  the lapse of time,  or both,  would  constitute  an Event of
Default shall have occurred and be continuing,  Tenant may, at its expense, make
Alterations,  subject to the advance  written consent of Landlord and subject to
the Deeds of Trust  provided that the consent of Landlord  shall not be required
for non-structural Alterations which do not involve the exterior of the building
or changes in utilities,  electrical,  mechanical or other existing  systems and
which as in each separate  Alteration do not exceed  $500,000 in cost.  Landlord
agrees not to withhold,  delay or condition  its consent  provided  that (i) all
such Alterations,  construction and  installations  shall be performed in a good
and  workmanlike   manner;   (ii)  all  such   Alterations,   construction   and
installations  shall be  expeditiously  completed in  compliance  with all Legal
Requirements;  (iii)  all work  done in  connection  with any such  Alterations,
construction or installation shall comply with the requirements of any insurance
policy required to be maintained by Tenant hereunder; (iv) Tenant shall promptly
pay all costs and expenses of any such Alteration,  construction or installation
and shall discharge all liens filed against any of the Leased Premises  arising,
out of the same;  (v) Tenant shall  procure and pay for all permits and licenses
required in connection with any such  Alteration,  construction or installation;
(vi) all such Alterations, construction and installations (except as provided in
subparagraph 13(c) below) shall be the property of Landlord and shall be subject
to this Lease; (vii) the design of any Alterations  visible from the exterior of
the Leased  Premises  shall comply with the terms of the  Restrictive  Covenants
(including  obtaining any consents required  thereunder);  (viii) the contractor
performing such alterations shall be reputable,  licensed and insured and shall,
if required by Landlord,  be required to obtain  performance  and payment bonds;
and (ix) Landlord shall incur no expense or cost  whatsoever in connection  with
such  Alterations,   including  without  limitation,  costs  for  reviewing  and
approving  plans,  additional  common area  maintenance  fees, tap fees or other
utility  fees,  and costs  incurred by Landlord in obtaining the approval of the
Credit Facility Provider and the State.  Landlord may require, as a condition to
its consent to any Alterations,  reasonable appropriate payments, assurances and
undertakings  from  Tenant to ensure  that all such  conditions  are  satisfied.
Notwithstanding  the  foregoing,  it shall not be  unreasonable  for Landlord to
withhold  its  consent,   or  to  condition  its  consent,   if  either  of  the
Beneficiaries  withholds its consent to any of the  foregoing,  or requires that
certain conditions or requirements be satisfied or observed.

               (b) In the event that any  Alterations  shall  encroach



                                       28
<PAGE>

upon any property,  street or  right-of-way  adjoining or adjacent to the Leased
Premises,  or shall  violate  the  agreements  or  conditions  contained  in any
restrictive covenant affecting the Leased Premises or any part thereof, or shall
hinder or obstruct any easement or right-of-way to which the Leased Premises are
subject  or shall  impair  the  rights of  others  under  any such  easement  or
right-of-way,  then promptly after written  request of Landlord or of any Person
affected  by  any  such  encroachment,   violation,  hindrance,  obstruction  or
impairment,  Tenant shall, at its expense, either (i) obtain valid and effective
waivers or settlements  of all claims,  liabilities  and damages  resulting from
each such encroachment, violation, hindrance, obstruction or impairment, whether
the same shall affect  Landlord,  Tenant or both, or (ii) take such other action
as shall be necessary to remove such  encroachments,  hindrances or obstructions
and to end such violations or impairments.

               (c) All Tenant improvements that can be removed without damage to
the structural  integrity of the Leased Premises or the normal  functions of the
Leased  Premises or that are not necessary for the normal use of a building as a
tenantable shell building,  and which were not financed with the proceeds of the
Bonds or the State  Loans,  shall,  on  termination  of this  Lease,  become the
property of the Tenant.

         14.   Condemnation.

               (a)  Tenant,   immediately   upon  obtaining   knowledge  of  the
institution of any proceeding for any condemnation of the Leased Premises, shall
notify  Landlord  thereof and  Landlord  shall be entitled to  participate  with
Tenant  in any  condemnation  proceeding  at  Tenant's  expense.  Tenant  hereby
irrevocably  assigns to Landlord any condemnation award or condemnation  payment
to which Tenant may be or become  entitled  (except as set forth in subparagraph
(b) below) by reason of any taking of the Leased  Premises or any part  thereof,
in or by condemnation or other eminent domain  proceedings  pursuant to any Law,
or by reason of the temporary  requisition of the use or occupancy of the Leased
Premises or any part thereof, by any governmental authority,  civil or military,
whether  the same shall be paid or payable  in  respect  of  Tenant's  leasehold
interest hereunder or otherwise. The proceeds of the condemnation award shall be
made  available for  restoration  if permitted by the Deeds of Trust and if this
Lease  is not  terminated.  As used  herein,  the term  "Net  Award"  means  any
condemnation award received by Landlord,  less Landlord's  expenses and Tenant's
expenses, if any, in collecting same.

               (b) The  foregoing  notwithstanding,  nothing in this Lease shall
impair  Tenant's  right to any award or payment on  account  of  Tenant's  trade
fixtures, Tenant's Equipment, and other



                                       29
<PAGE>

tangible property, moving expenses, loss of business and the like, if available,
to the  extent  Tenant  shall  have a right to make a  separate  claim  therefor
against the appropriate  governmental authority,  but in no event shall any such
separate  claim be based upon the value of  Tenant's  leasehold  interest in the
Leased  Premises  or result in a reduction  of the award or payment  which would
have been payable to Landlord absent such separate claim by Tenant.

               (c) If there  shall be taken  by  condemnation  or other  eminent
domain  proceedings  pursuant  to any Law,  general or  special,  (i) the entire
Leased Premises or (ii) any substantial  portion of the Leased Premises which is
sufficient to render the remaining portion thereof,  in the reasonable  judgment
of Landlord or Tenant,  unsuitable  for  restoration  for the  continued use and
occupancy of Tenant's business,  or (iii) if the Credit Facility Provider or the
State  shall  retain  any Net  Award  pursuant  to the  Deeds of Trust (it being
recognized that as a result thereof,  either of the  Beneficiaries may refuse to
allow the award to be disbursed for restoration under certain circumstances,  as
provided in the Deeds of Trust),  then  Landlord and Tenant may each,  not later
than 90 days after any such taking, give notice to the other of its intention to
terminate  this Lease on any Basic Rent Payment  Date  specified in such notice,
which date shall not be prior to the date of the  vesting of title to the Leased
Premises or portion thereof in the condemning  authority.  In the event Landlord
elects to  terminate  this Lease in the case of (ii) or (iii)  above,  if Tenant
elects to provide funds which,  together with the Net Award,  are  sufficient to
restore the Leased  Premises and pay Basic Rent and Additional  Rent during such
restoration and provides  evidence  satisfactory to Landlord,  the State and the
Credit Facility Provider (in the Credit Facility Provider's and the State's sole
and  absolute  subjective  judgment)  of its  ability to do so within 30 days of
Landlord's election,  Landlord's election to terminate shall be rescinded,  this
Lease shall continue in full force and effect  pursuant to subsection (d) below,
and  restoration  of the  Leased  Premises  shall  proceed  in  accordance  with
Paragraph 16(b). In the event either Landlord or Tenant elects to terminate this
Lease under the provisions of this Paragraph  14(c),  Landlord shall be entitled
to recover  from  Tenant,  and Tenant will pay to  Landlord,  on or prior to the
effective  date of  termination,  an amount equal to the Basic Rent,  Additional
Rent and other sums  which are then due and  payable  to the  effective  date of
termination; provided that in the event of such termination, Tenant may exercise
its  purchase  option  under  Paragraph  6(b)  within  20 days  after  notice of
termination.

               (d) If a portion of the Leased  Premises  shall be taken in or by
condemnation or other eminent domain proceedings pursuant to any Law, general or
special,  which does not result in a



                                       30
<PAGE>

termination  of this  Lease,  then this Lease  shall  continue in full force and
effect,  and there shall be no abatement or reduction of rent payable hereunder,
except to the extent that any  portion of the Net Award is used to redeem  Bonds
or to prepay the State Loans prior to maturity. Unless Tenant immediately elects
to  exercise  its  purchase  option  under  Paragraph  6 above,  subject  to the
provisions of the Deeds of Trust,  the Net Award of such  condemnation  shall be
paid to Landlord and,  promptly after such  condemnation and payment to Landlord
of the Net  Award,  Landlord  shall make the Net Award  available  to Tenant for
restoration, in accordance with Paragraph 16.

               (e) For the purposes of this Lease,  all amounts payable pursuant
to any agreement with any condemning authority which has been made in settlement
of or under  threat  of any  condemnation  or other  eminent  domain  proceeding
affecting  the Leased  Premises  shall be deemed to  constitute an award made in
such proceeding.

         15.   Insurance.

               (a) Tenant will maintain at its expense (i) such fire,  casualty,
extended  coverage  and all risk  insurance  on the  Improvements  and  Building
Equipment  as is required to be  maintained  by Landlord,  as Grantor  under the
Deeds of Trust,  provided that the amount of any casualty  insurance shall be in
no event less than the actual replacement value of the Improvements and Building
Equipment,  less footings,  foundations and other non-insurable  portions,  (ii)
commercial  general public  liability  insurance with a single limit of not less
than  $10,000,000,   including   contractual  liability  coverage  insuring  the
obligations  assumed  by  Tenant  under  this  Lease,  premises  and  operations
coverage,  broad form  property  damage  coverage  and  independent  contractors
coverage,  (iii)  worker's  compensation  insurance  as  required  by Law,  (iv)
business interruption insurance in the amount of $4,500,000,  and (v) employer's
liability  insurance in an amount not less than  $2,000,000  for each  accident,
$2,000,000 disease- policy limit and $2,000,000 disease-each employee.

               (b) The insurance referred to in Paragraph 15(a) shall be written
by companies of recognized financial standing which are authorized to conduct an
insurance business in the State of Maryland and which are reasonably  acceptable
to Landlord,  the Credit Facility Provider,  MIDFA and the State. All commercial
public  liability  insurance  shall  name  as  the  insured  parties  thereunder
Landlord,  Tenant,  MIDFA, the State and the Credit Facility Provider,  as their
interests  may appear.  Landlord  shall not be required to  prosecute  any claim
against,  or to contest any settlement  proposed by, any insurer,  provided that
Tenant  may,  at its  expense,  prosecute  any such  claim or  contest  any such



                                       31
<PAGE>

settlement.  In such event,  Tenant may bring such prosecution or contest in the
name of Landlord,  Tenant,  or both,  and Landlord will join therein at Tenant's
written  request upon the receipt by Landlord of a  satisfactory  indemnity from
Tenant  against all costs,  liabilities  and  expenses in  connection  with such
prosecution or contest.

               (c) So long as no Event of Default  exists  hereunder,  insurance
claims  by  reason of damage to or  destruction  of any  portion  of the  Leased
Premises  shall be adjusted by Tenant,  but  Landlord,  the State and the Credit
Facility Provider shall have the right to join with Tenant in adjusting any such
loss. In furtherance of Tenant's right to adjust, collect and compromise, in its
discretion,  all claims  under any of the  insurance  policies  required by this
Paragraph 15,  Tenant is authorized to execute and deliver all necessary  proofs
of loss, receipts, vouchers and releases required by the insurers.

                  (d)  Every  fire,  casualty,  extended  coverage  or all  risk
insurance policy required above (other than on Tenant's Equipment) shall contain
a  non-contributory  mortgagee  endorsement  in favor of  Landlord,  the  Credit
Facility  Provider,  the State and MIDFA. Every policy which Tenant is obligated
to carry under the terms of  Paragraph  15(a) shall  contain an agreement by the
insurer that it will not cancel such policy  except after 30 days' prior written
notice to Landlord,  the Credit Facility Provider, the State and MIDFA, and that
any loss otherwise payable thereunder shall be payable  notwithstanding  any act
or negligence of Landlord or Tenant which might,  absent such agreement,  result
in a forfeiture of all or a part of such insurance  payment and  notwithstanding
any  foreclosure  or  other  action  or  proceeding   taken  by  either  of  the
Beneficiaries pursuant to any provision of the Deeds of Trust upon the happening
of an Event of Default,  as defined therein, or any change in title or ownership
of the Leased Premises.

                  (e) Any and all  insurance  which Tenant is obligated to carry
pursuant to Paragraph 15(a) may be carried under a "blanket"  policy or policies
covering  other  properties  or  liabilities  of Tenant and may be effected by a
combination  of basic  and  excess or  umbrella  policies,  provided,  that such
"blanket"  policy or  policies  otherwise  comply  with the  provisions  of this
Paragraph 15. The amount of total  insurance  allocated to the Leased  Premises,
which  amount  shall  not be less than the  amounts  required  pursuant  to this
Paragraph  15, shall be specified  either (i) in each such  "blanket"  policy or
(ii) in a written  statement,  which Tenant shall  deliver to landlord  from the
insurer thereunder.

                  (f) Tenant shall  promptly  comply with and conform to (i) all
provisions of each insurance  policy and (ii) all



                                       32
<PAGE>

requirements  of the insurers  thereunder,  applicable to Landlord,  MIDFA,  the
Credit  Facility  Provider,  the State,  Tenant or the Leased Premises or to the
use, manner of use, occupancy, possession, operation, maintenance, alteration or
repair of the Leased Premises,  even if such compliance  necessitates structural
changes or improvements or results in interference  with the use or enjoyment of
any of the Leased  Premises.  Tenant  shall not use the Leased  Premises  in any
manner  which would  permit the insurer to cancel any  insurance  policy  unless
Tenant obtains,  prior to such cancellation,  substitute insurance in accordance
with the  provisions  of this  Paragraph 15 which permits such use of the Leased
Premises.

               (g) Any loss under any policy of casualty  insurance  required to
be carried by Landlord or Tenant  hereunder  (other than on Tenant's  Equipment)
shall be made payable to the Credit  Facility  Provider or, if references to the
Credit Facility Provider shall be ineffective as provided in Paragraph 35(f), to
the State as long as the State  Loans are  outstanding,  and then to such  other
party as the Landlord may designate (in any such case,  the "Insurance and Award
Trustee")  and each casualty  insurer  shall be authorized  and directed to make
payment  under said  policies  directly to the  Insurance  and Award Trustee for
disbursement in accordance with the provisions of first,  the Bond Deed of Trust
second, the State Loan Deed of Trust, and third, this Lease. As used herein, the
term "Net Proceeds" means any casualty  insurance proceeds received by Landlord,
less Landlord's expenses and Tenant's expenses,  if any, in collecting same. The
term  "Net  Proceeds"  shall not  include  proceeds  of  insurance  on  Tenant's
Equipment, which proceeds shall be paid directly to Tenant or the lessor of such
Tenant's Equipment.

               (h) Tenant shall not carry separate insurance  concurrent in form
or  continuing  in the event of loss with that  required  in this  Paragraph  15
unless (i)  Landlord,  MIDFA,  the State and the Credit  Facility  Provider  are
included therein as named insureds,  with lender's loss payable  endorsements as
provided  herein,  and (ii)  such  separate  insurance  complies  with the other
provisions  of this  Paragraph  15. Tenant shall  immediately  notify  Landlord,
MIDFA, the State and the Credit Facility Provider of such separate insurance and
shall deliver to Landlord,  MIDFA,  the State and the Credit  Facility  Provider
duplicate original policies therefor.  Notwithstanding the foregoing, Tenant may
maintain insurance to compensate Tenant for loss of use of the Improvements.



                                       33
<PAGE>

         16.   Casualty and Restoration.

               (a) In the  event of any  casualty  resulting  in  damage  to the
Leased Premises, including any casualty which renders the entire Leased Premises
or a substantial  portion thereof unsuitable for continued use, this Lease shall
continue in full force and effect and there shall be no  abatement  or reduction
of rent payable hereunder.

               (b)  Until  such  time as the  Deeds of  Trust  shall  have  been
released  and  discharged,  any Net  Proceeds and any Net Award shall be applied
either to the restoration or replacement of the property that was lost or to the
redemption of Bonds and payment of the State Loans,  as provided in the Deeds of
Trust.

               (c) Unless there shall have  occurred and be  continuing an Event
of  Default  hereunder  pursuant  to which  Landlord  is  taking  action to take
possession  of the  Leased  Premises  or to  terminate  this  Lease,  or the Net
Proceeds  or  the  Net  Award  are to be  used  as  directed  by  either  of the
Beneficiaries  as provided in the Deeds of Trust,  Landlord  shall cause the Net
Proceeds  or Net  Award  to be held by the  Insurance  and  Award  Trustee  in a
restoration fund which shall be disbursed as follows:

                  (i)  If  the  estimated  cost  of  restoration  is  less  than
$100,000,  and if prior to commencement  of restoration,  no Event of Default or
event which would  constitute an Event of Default  pursuant to which Landlord is
taking  action to take  possession of the Leased  Premises or to terminate  this
Lease shall exist and no mechanics' or materialmen's liens shall have been filed
and remain undischarged,  and if the architects,  contracts,  contractors, plans
and  specifications  for the  restoration  shall have been  approved by Landlord
(which  approval shall not be  unreasonably  withheld or delayed),  and Landlord
shall be provided with reasonable assurance against mechanics' liens, accrued or
incurred,  as Landlord may reasonably  require,  and acceptable  performance and
payment bonds  reasonably  acceptable to Landlord in an amount and form having a
surety  reasonably  acceptable  to  Landlord,  and naming  Landlord,  the Credit
Facility Provider,  MIDFA and the State each as additional  obligees;  then such
proceeds  shall  be  payable  to  Landlord  and made  available  to  Tenant  for
application to pay the costs of restoration  incurred by Tenant and Tenant shall
promptly complete such restoration.

                  (ii) If the  estimated  cost of  restoration  is  equal  to or
exceeds  $100,000,  and if the  conditions set forth in  subparagraph  (i) above
shall have been  satisfied,  and if Tenant  provides  evidence  satisfactory  to
Landlord,  the Credit  Facility  Provider,  MIDFA and the State that  sufficient
funds are available to restore the Leased Premises,  disbursements shall be made
from



                                       34
<PAGE>

time to time in an amount not exceeding the cost of the work completed since the
date  covered  by the  last  disbursement,  upon  receipt  of  (A)  satisfactory
evidence, including architect's certificates, of the stage of completion, of the
estimated  cost of completion  and of  performance of the work to date in a good
and   workmanlike   manner  in  accordance   with  the   contracts,   plans  and
specifications, (B) waivers of liens, (C) contractors' and subcontractors' sworn
statements,  (D) a satisfactory  bring-to-date of title insurance, and (E) other
evidence  of cost and  payment  so that  Landlord  can verify  that the  amounts
disbursed from time to time are represented by work that is completed,  in place
and free and clear of mechanics' lien claims.

                  (iii) Each request for disbursement  shall be accompanied by a
certificate of Tenant,  signed by the President or any Vice  President  thereof,
describing the work for which payment is requested, stating the cost incurred in
connection therewith and stating that Tenant has not previously received payment
for such work; the  certificate to be delivered by Tenant upon completion of the
work shall,  in addition,  state that the work has been  completed  and complies
with the applicable requirements of this Lease.

                  (iv) Landlord may retain 10% of each  requisition  against the
restoration  fund until the restoration is fully completed  subject to reduction
of the  retained  amount  upon  approval  by the  Credit  Facility  Provider  in
accordance with local custom;

                  (v) The  restoration  fund shall be  invested  in an  interest
bearing account of the Insurance and Award Trustee;

                  (vi) At all times the  undisbursed  balance of the restoration
fund shall be not less than the cost of completing the restoration work free and
clear of all liens; and

                  (vii) Landlord may impose other reasonable conditions provided
the same are consistent with those imposed upon such  disbursements by either of
the Beneficiaries  under the Deeds of Trust. In addition,  prior to commencement
of  restoration  and at any time during  restoration,  if the estimated  cost of
restoration,  as  determined  by  the  evaluation  of  an  independent  engineer
acceptable to Landlord,  exceeds the amount of the Net Proceeds or the Net Award
available for such  restoration,  Tenant will provide  evidence  satisfactory to
Landlord  that the amount of such excess will be available to restore the Leased
Premises.  Any sum which  remains in the  restoration  fund upon  completion  of
restoration  shall be refunded  to Tenant up to the amount of Tenant's  deposits
pursuant to the immediately preceding sentence. If no such refund is required or
any sum remains in the



                                       35
<PAGE>

restoration  fund after such refund,  such sum remaining in the restoration fund
(including  the  residue  of any Net  Award in a  condemnation  remaining  after
restoration)  upon  completion  of  restoration  shall be applied (x) during any
period  in  which  the  Credit   Facility  is  in  effect,   to  the  Landlord's
reimbursement  obligations to the Credit Facility  Provider to the extent of any
drawings  honored by the Bank to pay the  redemption  price of Bonds redeemed in
accordance  with Section 3.1(b) of the Indenture or to pay the purchase price of
Bonds  purchased  pursuant  to Section  4.4 of the  Indenture  or (y) during any
period  in which  any  Bonds  are  outstanding,  to the  redemption  of Bonds in
accordance  with Section  3.1(b) of the Indenture or to the purchase of Bonds as
set forth in Section 4.4 of the Indenture.  During any period in which any Bonds
are  outstanding,  any  sums  remaining  in an  amount  less  than  the  minimum
Authorized  Denomination (as defined in the Indenture) shall be deposited in the
Principal  Account (as defined in the Indenture).  If no Bonds are  outstanding,
and the Credit Facility  Agreement is still in effect,  such remaining sum shall
be  applied  to the  Landlord's  Credit  Facility  Obligations  under the Credit
Facility  Documents.  If no  Bonds  are  outstanding  and  the  Credit  Facility
Agreement is no longer in effect, such remaining sum shall be distributed to the
State for  repayment  of the  State  Loans and then to  Landlord  and  Tenant in
proportion  to the value of each  party's  interest  in the Leased  Premises  as
determined by mutual agreement.

                  (d) Tenant  shall be solely  responsible  for the  replacement
and/or repair of any of Tenant's Equipment damaged by casualty.



                                       36
<PAGE>

         17.      Assignment and Subletting.

                  (a)  Provided  no Event of  Default or event  which,  with the
giving  of notice or the  lapse of time or both,  would  constitute  an Event of
Default,  shall have occurred and be continuing,  with prior notice to Landlord,
Tenant may sublet all or any part of the Leased  Premises  to an  Affiliate,  or
assign this Lease to an Affiliate,  which Affiliate will use the Leased Premises
for the  Permitted  Use.  Provided no Event of Default or event which,  with the
giving  of notice or the  lapse of time or both,  would  constitute  an Event of
Default,  shall have occurred and be  continuing,  with the consent of Landlord,
(which consent shall not be unreasonably  withheld) Tenant may sublet all or any
part of the Leased  Premises to a Person  which is not an  Affiliate,  or assign
this  Lease to a Person  which is not a  Affiliate,  which  Person  will use the
Leased  Premises for the Permitted Use.  Notwithstanding  the foregoing,  in any
instance in which Landlord may not unreasonably  withhold its consent,  it shall
not be  unreasonable  for Landlord to withhold its consent,  or to condition its
consent,  if the Credit  Facility  Provider,  MIDFA or the State  withholds  its
consent to any assignment or subletting,  or requires that certain conditions or
requirements  be satisfied or observed.  Tenant shall give  Landlord at least 30
days'  advance  written  notice of its  intention to enter into any  transaction
governed by this Paragraph 17, together with such  information as Landlord,  the
Credit Facility  Provider,  MIDFA or the State may reasonably request concerning
the business and  financial  background  of the proposed  subtenant or assignee.
Within 10 days after the  execution  and delivery of any  assignment or sublease
permitted  pursuant to this  Paragraph 17, Tenant shall deliver a conformed copy
thereof to Landlord,  and within 10 days after the execution and delivery of any
permitted  sublease,  Tenant shall give notice to Landlord of the  existence and
term thereof, and of the name and address of the sublessee thereunder.

                  (b) If Tenant assigns all its rights and interests  under this
Lease,  the  assignee  under  such  assignment  shall  expressly  assume all the
obligations of Tenant hereunder in a written instrument delivered to Landlord at
the time of such  assignment.  No assignment or sublease  shall affect or reduce
any of the  obligations  of Tenant  hereunder,  and all such  obligations  shall
continue in full effect as  obligations of a principal and not as obligations of
a guarantor or surety,  to the same extent as though no assignment or subletting
had been made.  No  assignment  or  sublease  shall  impose any  obligations  on
Landlord  beyond those of Landlord  under this Lease or otherwise  affect any of
the  rights  of  Landlord  under  this  Lease.  Any  assignment  or  subletting,
Landlord's consent thereto, or Landlord's  collection or acceptance of rent from
any assignee or subtenant shall not be construed  either as waiving or releasing
Tenant  from any of its  liabilities



                                       37
<PAGE>

or  obligations  under this Lease,  or as  relieving  Tenant or any  assignee or
subtenant from the obligation of obtaining  Landlord's  prior written consent to
any subsequent assignment or subletting.

                  (c) Upon the  occurrence  of an Event of  Default  under  this
Lease,  Landlord  shall have the right to collect  and enjoy all rents and other
sums of money  payable  under any  sublease of any of the Leased  Premises,  and
Tenant hereby  irrevocably and  unconditionally  assigns such rents and money to
Landlord,  which assignment may be exercised upon and after (but not before) the
occurrence  of an Event of Default.  From and after the date,  if any, that such
Event of Default is cured,  such rents shall again become  payable to Tenant and
the excess,  if any, of the sublease rents collected by Landlord over the amount
thereof  applied toward Tenant's  obligations  under this Lease shall be paid to
Tenant.

                  (d) All restrictions and obligations  imposed pursuant to this
Lease on Tenant  shall be deemed to extend to any  subtenant  or  assignee,  and
Tenant shall cause such Person to comply with such restrictions and obligations.
Each  sublease is subject to the  condition  that if the Term is  terminated  or
Landlord  succeeds to  Tenant's  interest  in the Leased  Premises by  voluntary
surrender or  otherwise,  at Landlord's  option the subtenant  shall be bound to
Landlord  for the balance of the term of such  sublease  and shall attorn to and
recognize  Landlord  as its  landlord  under  the then  executory  terms of such
sublease.

         18.  Permitted  Contests.  Notwithstanding  any other provision of this
Lease to the contrary,  Tenant shall not be required to (i) pay any  Imposition,
or (ii)  discharge  or remove any lien,  encumbrance  or charge  referred  to in
Paragraph  10 or 12, so long as Tenant shall  contest,  in good faith and at its
expense,  the existence,  the amount or the validity thereof,  the amount of the
damages caused thereby, or the extent of its liability therefor,  by appropriate
proceedings,  provided  that such contest  shall operate at all times during the
pendency  thereof to prevent (i) the collection of, or other  realization  upon,
the sums payable to satisfy any Imposition or lien,  encumbrance or other charge
so contested,  (ii) the sale,  forfeiture or loss of the Leased Premises, or any
part thereof,  or any interest  therein or Basic Rent or any Additional Rent, or
any portion  thereof,  (iii) any  interference  with the use or occupancy of the
Leased Premises or any part thereof,  (iv) any interference  with the payment of
Basic Rent or any Additional Rent, or any portion thereof,  (v) the cancellation
of any fire or other insurance  policy,  unless such policy is replaced prior to
its  cancellation by another policy complying with the provisions of this Lease,
and (vi) the imposition of any civil or criminal liability upon Landlord.  While
any such  proceedings  are  pending,  Landlord  shall not have the right to pay,
remove or cause to be discharged the tax,



                                       38
<PAGE>

assessment,  levy,  fee, rent or charge or lien,  encumbrance  or charge thereby
being  contested,  provided that Landlord shall have the right to require Tenant
to establish  reasonable  reserves for such  liabilities  being contested if the
Landlord  reasonably  determines  such reserves to be necessary.  Tenant further
agrees to give  Landlord  prompt  notice of  Tenant's  intention  to contest any
Imposition  and that each such contest  shall be promptly  prosecuted to a final
conclusion.  Tenant will pay, and save Landlord  harmless  against,  any and all
losses,  judgments,  decrees and costs (including all reasonable attorneys' fees
and expenses) in connection  with any such contest and will,  promptly after the
final  settlement,  compromise or determination  of such contest,  fully pay and
discharge the amounts which shall be levied, assessed,  charged or imposed or be
determined to be payable therein or in connection  therewith,  together with all
penalties,  fines,  interests,  costs  and  expenses  thereof  or in  connection
therewith,  and  perform all acts the  performance  of which shall be ordered or
decreed as a result thereof.

         19.      Default Provisions.

                  (a) Any of the following  occurrences or acts shall constitute
an Event of Default under this Lease:

                           (i) Tenant  fails to pay,  within 5 days after notice
from Landlord to Tenant, any installment of Basic Rent.

                           (ii) Tenant  fails to pay any  payment of  Additional
Rent, or any other payment required to be paid by Tenant  hereunder,  including,
without  limitation,  payment of Impositions  and insurance  premiums,  and such
failure continues for 30 days after written notice thereof shall have been given
to Tenant by Landlord.

                           (iii)  Tenant  fails to observe or perform  any other
provision  hereof for 30 days (or such  shorter  period of time as Landlord  may
reasonably  determine if such default endangers life or property) after Landlord
shall  have  delivered  to  Tenant  written  notice  (except  in the  case of an
emergency) of such failure  (provided that, in the case of any default  referred
to in this clause  (iii)  which does not  endanger  life or  property  and which
cannot  with  diligence  be cured  within such 30 day  period,  if Tenant  shall
proceed  promptly to cure the same and thereafter  shall prosecute the curing of
such default with diligence, then upon receipt by Landlord of a certificate from
an authorized  officer of Tenant  stating the reason that such default cannot be
cured within 30 days and stating  that Tenant is  proceeding  with  diligence to
cure such  default,  the time  within  which such  failure may be cured shall be
extended for such  additional  period as may be necessary to complete the curing
of the same with diligence.



                                       39
<PAGE>

                           (iv) An Act of  Bankruptcy  occurs  with  respect  to
Tenant,  or Tenant becomes generally unable to pay its debts as they become due;
provided, however, if a proceeding with respect to an Act of Bankruptcy is filed
or commenced  against Tenant,  the same shall not constitute an Event of Default
if such  proceeding  is  dismissed  within  90 days from the date of such Act of
Bankruptcy.

                           (v) Default is made (A) with  respect to any evidence
of indebtedness of liability for borrowed money of Tenant to the Credit Facility
Provider,  or (B) with respect to any evidence of  indebtedness  or liability of
Tenant to any other Person for borrowed money or pursuant to a lease obligation,
if the  effect  of such  default  described  in  clause  (A) or (B)  above is to
accelerate the maturity of such evidence of  indebtedness  or liability prior to
its stated maturity (whether automatically,  following an election by the holder
or obligee thereof to accelerate,  or otherwise) or any such indebtedness is not
paid  as and  when  due and  payable;  provided,  however,  that  it  shall  not
constitute  an Event of Default  if the  outstanding  principal  balance of such
indebtedness or liability of Tenant to any Person other than the Credit Facility
Provider or the State is not in excess of $1,000,000 or Tenant  certifies to the
Credit Facility Provider, the State and MIDFA that it is contesting such default
in good faith and by appropriate and diligent proceedings.

                           (vi) Any amendment to this Lease shall have been made
without the prior written consent of the Credit Facility Provider, the State and
MIDFA, which consent shall not be unreasonably withheld, conditioned or delayed,
and, except for material  changes which would require the consent or approval of
the State Board of Public Works or the State Legislative Policy Committee, which
consent  shall be deemed  given by the Credit  Facility  Provider,  the State or
MIDFA if the Credit Facility Provider, the State or MIDFA does not object to any
proposed  amendment  within 15 business  days after the  receipt  thereof by the
Credit Facility Provider, the State or MIDFA.

                           (vii) Tenant abandons the Leased Premises.

                           (viii) The interest of Tenant in the Leased  Premises
or any part thereof shall be assigned or subleased in violation of Paragraph 17,
or shall be levied  upon or  attached  in any  proceeding  involving  a claim in
excess of $1,000,000  and such  proceeding is not vacated,  discharged or bonded
against  to  the  reasonable  satisfaction  of  Landlord,  the  Credit  Facility
Provider, the State and MIDFA within 30 days thereafter.

                           (ix) Any representation or warranty made by Tenant



                                       40
<PAGE>

or its  representatives in this Lease or any of the Lease Documents executed and
delivered  by Tenant or any  statement or  representation  made by Tenant or its
representatives in any certificate, report or opinion (including legal opinions)
financial statement or other instrument  furnished in connection with this Lease
or any of the Lease  Documents  executed and  delivered by Tenant proves to have
been incorrect, false or misleading in any material respect when made.

                           (x) Any judgment  against Tenant or any attachment or
other levy  against the property of Tenant with respect to a claim for an amount
in excess of  $1,000,000  remains  unpaid,  unstayed  on  appeal,  undischarged,
unbonded or undismissed for a period of 60 days.

                           (xi)  Tenant   fails  to  comply  with  any  material
requirement of any governmental  authority having  jurisdiction  over the Leased
Premises  within  the  time  required  by such  governmental  authority;  or any
proceeding is commenced or action taken to enforce any remedy for a violation of
any material requirement of a governmental authority or any restrictive covenant
affecting the Leased Premises or any part thereof;  provided,  however, it shall
not  constitute  an Event of Default if Tenant is  contesting  the  validity  or
applicability of any such requirement or covenant, at its sole cost and expense,
in good faith and by appropriate and diligent proceedings.

                           (xii) If any material  provision of this Lease at any
time for any reason ceases to be valid and binding on Tenant,  or is declared to
be null and void,  or the  validity or  enforceability  thereof is  contested by
Tenant or any governmental agency or authority, or Tenant denies that it has any
further  liability or obligation  under this Lease or any of the Lease Documents
executed and delivered by Tenant.

                           (xiii) Landlord,  the Credit Facility  Provider,  the
State or MIDFA, or any of their respective representatives are not permitted, at
all  reasonable  times (after at least 48 hours prior written  notice to Tenant,
unless an Event of Default  shall have occurred and be continuing in which event
notice will not be required),  to enter upon the Leased Premises, to inspect the
Leased Premises and all materials,  equipment,  fixtures and other items used or
to be used in the construction  thereof, and to examine all detailed plans, shop
drawings and specifications  which relate to or the appurtenances  thereto or to
be used in the operation thereof, provided,  however, any person conducting such
inspection  shall  comply  with  Tenant's  safety  and  operating  policies  and
procedures.

                 (b) If an Event of Default shall have happened and be



                                       41
<PAGE>

continuing,  Landlord shall have the right at its election,  then or at any time
thereafter  while such Event of Default shall  continue,  to give Tenant written
notice of Landlord's  intention to terminate  this Lease on a date  specified in
such  notice  (such  termination  being  hereinafter  referred  to as a "Default
Termination"  and  such  notice  being  hereinafter  referred  to as a  "Default
Termination Notice"). Upon giving a Default Termination Notice, the Term and the
estate  hereby  granted  shall  terminate  on the date  specified in the Default
Termination  Notice as fully and  completely and with the same effect as if such
date were the date  hereinbefore  fixed for the  expiration of the Term, and all
rights of Tenant  hereunder shall  terminate,  but Tenant shall remain liable as
hereinafter  provided.  Notwithstanding  the foregoing,  no Default  Termination
Notice  shall be  effective  unless it is also  executed by the Credit  Facility
Provider and the State and MIDFA.

                  (c)  If an  Event  of  Default  shall  have  happened  and  be
continuing,  Landlord  shall have the immediate  right,  whether or not the Term
shall  have been  terminated  pursuant  to  Paragraph  19(b),  to  re-enter  and
repossess the Leased Premises or any part thereof by force (if legally permitted
in the State of Maryland),  summary proceedings,  ejectment or otherwise and the
right  (subject to the rights and interests of equipment  lessors) to remove all
Persons and property  therefrom.  Landlord shall be under no liability for or by
reason of any such entry, repossession or removal. No such re-entry or taking of
possession of the Leased  Premises by Landlord shall be construed as an election
on Landlord's part to terminate this Lease unless a Default  Termination  Notice
shall  have been given to Tenant,  or unless  the  termination  of this Lease be
finally decreed by a court of competent jurisdiction.

                  (d) At any time or from time to time after the repossession of
the Leased Premises or any part thereof pursuant to Paragraph 19(c),  whether or
not this Lease shall have been terminated pursuant to Paragraph 19(b),  Landlord
shall use  reasonable  efforts to relet the Leased  Premises or any part thereof
for the account of Tenant or Landlord or  otherwise,  without  notice to Tenant,
for such term or terms and on such conditions (which may include  concessions of
free  rent) and for such  uses as  Landlord,  in its  absolute  discretion,  may
determine,  and Landlord may collect and receive any rents  payable by reason of
such  reletting.  Landlord shall not be responsible or liable for any failure to
relet the Leased  Premises or any part thereof or for any failure to collect any
rent due upon any such reletting.

                  (e) In the  event of the  termination  of this  Lease  upon an
Event of Default or  repossession  of the Leased  Premises  or any part  thereof
pursuant to Paragraph 19(c) or otherwise, or the



                                       42
<PAGE>

reletting  of the Leased  Premises or any part  thereof  pursuant  to  Paragraph
19(d), Tenant shall remain liable as hereinafter provided.

                  (f) In the event of any Default Termination or repossession of
the Leased  Premises or any part thereof by reason of the occurrence of an Event
of Default,  Tenant will pay to Landlord Basic Rent,  Additional  Rent and other
sums required to be paid by Tenant to and including the date of such termination
or repossession  (including,  without  limitation,  the amount of all sums which
have become due and payable by Landlord under the Credit Facility  Documents and
the Bond Documents and the State Loan Documents); and, thereafter, Tenant shall,
until  the  end of  what  would  have  been  the  Term  in the  absence  of such
termination or repossession,  and whether or not the Leased Premises or any part
thereof  shall have been  relet,  be liable to  Landlord  for,  and shall pay to
Landlord,  as liquidated and agreed  current  damages on each Basic Rent Payment
Date and on any other date when due and payable: (i) Basic Rent, Additional Rent
and other sums which would be payable  under this Lease by Tenant in the absence
of such termination or repossession,  less (ii) the net proceeds, if any, of any
reletting  effected for the account of Tenant pursuant to Paragraph 19(d), after
deducting  from such proceeds all  Landlord's  expenses in connection  with such
reletting  (including,  without limitation,  all repossession  costs,  brokerage
commissions,  legal expenses,  attorneys' fees, employees' expenses,  alteration
costs and  expenses of  preparation  for such  reletting).  Tenant will pay such
current  damages on the days on which Basic Rent would have been  payable  under
this Lease in the absence of such  termination  or  repossession,  and  Landlord
shall be entitled to recover the same from Tenant on each such day.

                  (g) At any time after a Default Termination, Landlord shall be
entitled to recover from Tenant, and Tenant will pay to Landlord within 120 days
of demand  therefor,  an amount equal to Basic Rent,  Additional  Rent and other
sums which  would be payable  under this  Lease,  from the date to which  Tenant
shall  have  satisfied  in full its  obligations  under  Paragraph  19(f) to pay
current  damages,  to the end of the remaining Term of this Lease in the absence
of such termination (assuming,  in computing the amount of Basic Rent that would
have been due under  Paragraph  7, an  interest  rate which is equal to the rate
applicable to such  obligations  on the date the Default  Termination  Notice is
issued "the "Assumed Rate"),  discounted at the Assumed Rate, or such lower rate
as shall be necessary to provide that the sum payable by Tenant  hereunder shall
satisfy in full the sum of (I) all Landlord's  Credit Facility  Obligations" and
"Landlord's Bond Obligations" and the Landlord's State Loan Obligations  accrued
through  the date of the  payment  due under  this  Paragraph  19(g),  including
without limitation, all accrued fees, costs and expenses



                                       43
<PAGE>

payable to the  Trustee,  Remarketing  Agent,  Rating  Agency,  Credit  Facility
Provider,  plus (II) all costs and expenses (including reasonable attorneys fees
and expenses) of the Credit Facility Provider,  Landlord, MIDFA and the State in
connection with such Default Termination.

                  (h) The words "enter",  "re-enter" or  "re-entry",  as used in
this Paragraph 19, are not restricted to their technical meaning.

         20.      Additional Rights of Landlord.

                  (a) No right or remedy  herein  conferred  upon or reserved to
Landlord  is  intended  to be  exclusive  of any  other  right or  remedy  given
hereunder  or now or  hereafter  existing  at Law or in equity.  The  failure of
either party to insist at any time upon the strict  performance  of any covenant
or agreement or to exercise any option, right, power or remedy contained in this
Lease shall not be  construed  as a waiver or a  relinquishment  thereof for the
future.  A receipt by Landlord of any Basic Rent,  Additional  Rent or any other
sum payable  hereunder with knowledge of the breach of any covenant or agreement
contained  in this  Lease  shall not be deemed a waiver of such  breach,  and no
waiver of any  provision  of this Lease shall be deemed to have been made unless
expressed  in writing  and signed by the  waiving  party.  In  addition to other
remedies  provided  in this Lease,  Landlord  shall be  entitled,  to the extent
permitted by applicable law, to injunctive  relief in case of the violation,  or
attempted  or  threatened  violation,  of  any  of  the  covenants,  agreements,
conditions or provisions of this Lease, or to a decree compelling performance of
any of the covenants, agreements,  conditions or provisions of this Lease, or to
any other remedy allowed to Landlord at Law or in equity.

                  (b) Tenant  hereby  waives and  surrenders,  to the extent not
prohibited  by Law,  for  itself  and all those  claiming  under  it,  including
creditors of all kinds,  (i) any right and privilege which it or any of them may
have under any present or future Law to redeem the Leased  Premises or to have a
continuance  of this Lease for the Term after  termination  of Tenant's right of
occupancy by order or judgment of any court or by any legal  process or writ, or
under the terms of this Lease,  or after the  termination  of the Term as herein
provided,  and (ii) the  benefits  of any  present or future  law which  exempts
property from liability for debt or for distress for rent.

                  (c) In the event Tenant shall be in default in the performance
of any of its obligations  under this Lease,  and an action shall be brought for
the  enforcement  thereof  in which it shall be  determined  that  Tenant was in
default, Tenant shall pay



                                       44
<PAGE>

to  Landlord  all  the  expenses  incurred  in  connection  therewith  including
reasonable  attorney's  fees. In the event Landlord shall,  without fault on its
part, be made a party to any litigation commenced against Tenant, and if Tenant,
at its expense,  shall fail to provide Landlord with counsel reasonably approved
by Landlord,  Tenant shall pay all costs and reasonable attorney's fees incurred
or paid by Landlord in connection with such litigation.

                  (d) If an Event of Default  has  happened  and is  continuing,
Landlord may, but shall not be obligated to, make any payment or perform any act
required  hereunder  to be  made or  performed  by  Tenant  which  has not  been
performed within the time period specified herein for such performance, with the
same  effect  as if made or  performed  by  Tenant,  provided  that no  entry by
Landlord upon the Leased Premises for such purpose shall create any liability to
Tenant on the part of Landlord or shall  constitute  or shall be deemed to be an
eviction of Tenant,  and no such entry  shall  waive or release  Tenant from any
obligation or default hereunder.  All sums so paid by Landlord and all costs and
expenses  (including  reasonable  attorney's  fees  and  expenses)  incurred  by
Landlord in  connection  with the  performance  of any such act,  together  with
interest at the Default Rate, shall constitute Additional Rent payable by Tenant
hereunder.

         21.  Inspection.  Tenant shall  permit  Landlord,  the Credit  Facility
Provider, the State, MIDFA, and the holder of any Encumbrance, and its and their
representatives  and agents to enter the Leased Premises,  with notice to Tenant
and with an escort provided by Tenant, unless (i) an Event of Default shall have
occurred and be continuing,  or (ii) an emergency  threatening  life or property
exists,  in either of which cases, no advance notice shall be required,  without
charge therefor and without  diminution of the rent payable by Tenant,  in order
to examine, inspect and protect the Leased Premises, or, during the last year of
the  Term,  to  exhibit  the  same to  brokers,  prospective  tenants,  lenders,
purchasers  and  others.  In  connection  with any such  entry,  Landlord  shall
endeavor to minimize the disruption to Tenant's  normal  business  operations in
the Leased Premises.

         22.  Notices,  Demands and Other  Instruments.  All  notices,  demands,
requests,  consents,  approvals,  certificates or other communications  required
under this Lease shall be in writing,  and shall be sufficiently given and shall
be deemed to have been  properly  given (i) if delivered  by hand,  when written
confirmation  of delivery  is received by the sender,  (ii) three days after the
same is mailed by certified mail, postage prepaid,  return receipt requested, or
(iii) if sent by overnight courier,  24 hours (plus 24 hours for any intervening
day  that is not a  business  day)  after  delivery  to such  overnight  courier
addressed  to the  Person to whom



                                       45
<PAGE>

any such  notice,  demand,  request,  consent,  approval,  certificate  or other
communication is to be given, at the appropriate address designated on Exhibit E
attached  hereto.  Any party  listed on Exhibit E shall each have the right from
time to time to  specify as its  address  for  purposes  of this Lease any other
address in the United  States of America  upon  giving 15 days'  written  notice
hereunder.

         23.  Estoppel  Certificates.  Landlord  or Tenant,  as the case may be,
shall,  at any time and from  time to time,  upon not less  than 20 days'  prior
written  notice by the other (but  neither  shall be required to do so more than
twice in any calendar year), execute,  acknowledge and deliver to the requesting
party a  statement  in  writing,  executed by an  authorized  representative  of
Landlord or by the President or a Vice President of Tenant,  as the case may be,
certifying  (i) that this Lease is  unmodified  and in full effect (or, if there
have been  modifications,  that this Lease is in full  effect as  modified,  and
setting  forth  such  modifications),  (ii)  the  dates  to  which  Basic  Rent,
Additional Rent and all other sums payable  hereunder have been paid, (iii) that
to the knowledge of the signer of such certificate no default by either Landlord
or Tenant exists  hereunder or specifying  each such default of which the signer
may have  knowledge;  and (iv) that, in the case of any statement being given by
Tenant,  to the  knowledge  of the  signer  of such  certificate,  there  are no
proceedings  pending  or  threatened  against  Tenant  before or by any court or
administrative  agency  which,  if  adversely  decided,   would  materially  and
adversely  affect the financial  condition and  operations of Tenant or Tenant's
ability to perform or fulfill its  obligations  under this Lease, or if any such
proceedings are pending or threatened to said signer's knowledge, specifying and
describing the same. It is intended that any such  statements may be relied upon
by the Credit Facility  Provider,  the State,  Landlord or their assignees or by
any  prospective  purchaser  of the  Leased  Premises  or by any  transferee  or
assignee  of Tenant's  interest in the Lease or a sublessee  of Tenant or by any
party  providing  financing  to  Tenant.  Any  certificate  required  under this
Paragraph 23 shall (i) state briefly the nature and scope of the  examination or
investigation upon which the statements contained in such certificate are based,
(ii) state that in the opinion of each Person  signing such  certificate  he has
made such  examination or investigation as is necessary to enable him to express
an informed  opinion as to the  subject  matter of such  certificate,  and (iii)
certify to the correctness of the statements contained therein.

         24.  No  Merger.  There  shall  be no  merger  of this  Lease or of the
leasehold  estate hereby created with any other estate or interest in the Leased
Premises  or any part  thereof  by reason of the fact that the same  Person  may
acquire or hold,  directly or



                                       46
<PAGE>

indirectly,  (a) any  interest  in this  Lease or the  leasehold  estate  hereby
created or (b) any such other  estate or interest in the Leased  Premises or any
part.

         25.   Representations  and  Warranties  of  Tenant.  Tenant  makes  the
following representations and warranties to Landlord:

                  (a) Good Standing.  Tenant (i) is a corporation duly organized
and existing,  in good standing,  under the laws of the State of Delaware,  (ii)
has the corporate power and all material governmental licenses,  authorizations,
consents and approvals required to own its property and to carry on its business
as now being  conducted,  and (iii) is duly  qualified  to do business and is in
good  standing in each  jurisdiction  in which the  character of the  properties
owned by it  therein  or in which the  transaction  of its  business  makes such
qualification necessary, including, but not limited to, the State of Maryland.

                  (b) Authority.  Tenant has full corporate  power and authority
to enter into and execute and deliver this Lease and each of the other documents
executed  and  delivered by Tenant in  connection  herewith  (collectively,  the
"Lease  Documents"),  and to incur and  perform  the  obligations  provided  for
therein and  herein,  all of which have been duly  authorized  by all proper and
necessary  corporate action by Tenant. No consent or approval of stockholders or
of any other  Person or public  authority  or  regulatory  body is required as a
condition  to the validity or  enforceability  of this Lease or any of the other
Lease Documents, or if required the same has been duly obtained.

                  (c) Binding Agreements. This Lease and each of the other Lease
Documents have been duly and properly  executed by Tenant,  constitute the valid
and legally binding obligations of the Tenant, and are fully enforceable against
Tenant in  accordance  with their  respective  terms;  except to the extent that
enforceability may be affected by any bankruptcy or insolvency  proceeding filed
by or against the Tenant and subject to the exercise of judicial  discretion  in
accordance with general principles of equity.

                  (d) Litigation.  There is no litigation or proceeding  pending
or, so far as  Tenant  knows,  threatened,  before  any court or  administrative
agency which,  in the opinion of Tenant,  will materially  adversely  affect the
financial  condition or  operations of Tenant,  Tenant's  ability to perform and
fulfill its  obligations  under this Lease,  or the authority of Tenant to enter
into, or the validity or enforceability of, this Lease or any of the other Lease
Documents.

                  (e) No  Conflicting  Agreements,  Laws,  etc.  There is



                                       47
<PAGE>

(i) no  charter,  by-law or  preference  stock  provision  of the  Tenant and no
provision of any existing mortgage,  indenture, contract or agreement binding on
the Tenant or affecting Tenant's property,  and (ii) to the knowledge of Tenant,
no provision of Law or order of court  binding on the Tenant or affecting any of
Tenant's  property,  which  would  conflict  with  or in  any  way  prevent  the
execution,  delivery,  or  performance  of the terms of this Lease or any of the
other Lease  Documents,  or which would be in default or violated as a result of
such  execution,  delivery or  performance,  or for which  adequate  consents or
waivers have not been obtained.

                  (f) Tax Returns.  Tenant has filed all required federal, state
and local tax  returns  and has paid all taxes as shown on such  returns as they
have become due. No claims  have been  assessed  and are unpaid with  respect to
such taxes, and Tenant has established reserves which it believes to be adequate
for the payment of additional taxes for years which have not been audited by the
respective tax authorities.

                  (g) Place of Business of Tenant.  Tenant's  principal place of
business is located at 9410 Key West Avenue, Rockville, Maryland 20850.

                  (h)  Brokers.  To the best of Tenant's  knowledge  (other than
Scheer Partners Inc. and Manekin Corporation,  the payment of whose fees are the
responsibility of Montgomery County, Maryland), no Person has, or as a result of
any  action of or by Tenant in  connection  with the  transactions  contemplated
hereby and by the Lease will have, any right, interest or valid claim against or
on the Landlord for any  commission,  fee or other  compensation  as a broker or
finder, or in any similar capacity . Tenant shall indemnify the Landlord against
any claimed fee, commission or other compensation  arising from or in connection
with the transactions contemplated hereby or by the Lease Documents.

                  (i) ERISA.  (i) Any Plan  established  and  maintained  by the
Tenant  or any  Commonly  Controlled  Entity  is a  qualifying  plan  under  the
applicable  requirements  of  Section  401 of the Code and  there is no  current
matter which would materially  adversely affect the qualified  tax-exempt status
of any Plan;  (ii)  neither the Tenant nor any  Commonly  Controlled  Entity has
engaged in or is engaging in any  Prohibited  Transaction  or has  incurred  any
Accumulated  Funding Deficiency in connection with any such Plan, whether or not
waived, and no Reportable Event has occurred with respect to any Plan subject to
the  minimum  funding  requirements  of  Section  412  of  the  Code;  (iii)  no
Multiemployer  Plan has  "terminated",  as that term is defined  in ERISA;  (iv)
neither  the Tenant  nor any  Commonly  Controlled  Entity  has  "withdrawn"  or
"partially withdrawn" from any Multiemployer Plan; and (v) no Multiemployer Plan
is in  "reorganization"  nor has notice been



                                       48
<PAGE>

received from the  administrator  of any  Multiemployer  Plan that any such Plan
will be placed in "reorganization".

         26.      Affirmative Covenants of Tenant. Tenant shall:

                  (a) Financial Statements.  Furnish or cause to be furnished to
Landlord:

                           (i) as soon as available but in no event more than 45
days after the close of each fiscal quarter of Tenant,  a copy of the 10Q Report
of  Tenant  filed  with the  Securities  and  Exchange  Commission  (the  "SEC")
accompanied  by a certificate of the chief  financial  officer of Tenant stating
whether any event has occurred which  constitutes an Event of Default,  or which
would constitute such an Event of Default with the giving of notice or the lapse
of time or both, and, if so, stating the facts with respect thereto; and

                           (ii) as soon as  available  but in no event more than
90 days after the close of each fiscal year of Tenant,  a copy of the 10K Report
of  Tenant  filed  with  the  SEC  and a copy of the  annual  audited  financial
statements  relating to Tenant prepared in accordance with GAAP, which financial
statements  shall include a balance sheet of Tenant as at the end of such fiscal
year and a statement of earnings and changes in  stockholder's  equity of Tenant
for such fiscal year; and

                           (iii) as soon as available  but in no event more than
90 days after the close of each  fiscal  year of Tenant,  a  certificate  of the
chief financial officer of Tenant stating whether any event which constitutes an
Event of  Default  under  this  Lease has  occurred,  or any event  which  would
constitute  such an Event of  Default  with the giving of notice or the lapse of
time or both has occurred,  and, if so, stating the facts with respect  thereto;
and



                                       49
<PAGE>

                           (iv) promptly upon  transmission  thereof,  copies of
any financial  statements,  proxy statements,  reports and the like which Tenant
sends to its  shareholders  and  copies  of all  registration  statements  (with
exhibits); and

                           (v) promptly upon request, access to the registration
materials  submitted to the Federal Drug  Administration (the "FDA") to evidence
the  internal   validation  and   registration  of  the  Leased  Premises  as  a
pharmaceutical-manufacturing  facility, any correspondence, notices and the like
received  from the FDA  relating  to the  initial and  on-going  validation  and
registration of the Leased Premises as a  pharmaceutical-manufacturing  facility
with the FDA and,  promptly upon receipt  thereof,  copies of any  threatened or
actual revocation,  restriction, suspension or expiration of any such validation
and/or registration; and

                           (vi)  with  reasonable  promptness,  such  additional
information,  reports  or  statements  as  the  Landlord,  the  Credit  Facility
Provider, MIDFA or the State may from time to time reasonably request.

                  (b) Taxes and Claims.  Pay and  discharge  or cause to be paid
and  discharged  all taxes imposed upon it or its income or properties  prior to
the date on which  penalties  attach  thereto,  and all lawful claims which,  if
unpaid,  might become a lien or charge upon any of its properties.  Tenant shall
have the right to contest the validity of any such tax, assessment, charge, levy
or claim, by timely and appropriate proceedings,  provided that Tenant shall (1)
give the Landlord  written  notice of its intention to contest,  (2)  diligently
prosecute  such  contest,  (3) at all  times  effectively  stay or  prevent  any
official or judicial  sale of the Leased  Premises or Building  Equipment or any
part  thereof  by reason of  nonpayment  of any such  taxes,  and (4)  establish
reasonable  reserves  for  such  liabilities  being  contested  if the  Landlord
reasonably determines such reserves to be necessary.

                  (c)  Insurance.  In  addition  to the  insurance  required  by
Paragraph  15 of this  Lease,  maintain  insurance  with  responsible  insurance
companies on such of its  properties,  in such amounts and against such risks as
is customarily  maintained by similar businesses operating in the same vicinity.
Tenant  shall file with  Landlord,  upon its  request,  a  detailed  list of the
insurance then in effect  covering Tenant and Tenant's  properties,  stating the
names of the insurance companies, the amounts and rates of the insurance,  dates
of the expiration  thereof and the properties  and risks covered  thereby;  and,
within 30 days after notice in writing from the Landlord, obtain such additional
insurance as the Landlord may reasonably request.



                                       50
<PAGE>

                  (d)  Corporate  Existence.  Maintain  its  existence  in  good
standing as a Delaware corporation,  qualified to transact business in the State
of Maryland.

                  (e) Compliance with Laws. Comply with all Legal  Requirements,
subject to Tenant's right to contest the validity or applicability of any of the
foregoing,  at its sole cost and expense,  in good faith and by appropriate  and
diligent    proceedings,    in    accordance    with    Paragraph   18   hereof.

                  (f) Books and Records.  Maintain appropriate books and records
with respect to the Leased  Premises and permit  access by Landlord,  the Credit
Facility  Provider,   the  State  and  MIDFA  and  their  respective  authorized
representatives  and employees to the books and records of Tenant at the offices
of Tenant during normal business hours.

                  (g)  Employment  Count.  Within 30 days after the Closing Date
and on  each  anniversary  date  thereafter,  and  upon  subsequent  request  of
Landlord,  the State or MIDFA,  the Tenant shall supply the Landlord,  the State
and MIDFA with the employment count at the Leased Premises.

                  (h) Equal Employment.  Tenant shall prohibit discrimination on
the basis of (i) political or religious opinion or affiliation,  marital status,
race,  color,  creed, or national origin, or (ii) sex or age, except when sex or
age constitutes a bona fide occupational qualification, or (iii) the physical or
mental disability of a qualified  individual with a disability;  and shall, upon
the  request  of  MIDFA  or  the  State  Department  of  Business  and  Economic
Development (the  "Department"),  submit information  relating to its employment
practices and operations  with regard to the above on a form to be prescribed by
the State.

                  (i) Drug and Alcohol Free Workplace.  Tenant shall make a good
faith effort to  eliminate  illegal drug use and alcohol and drug abuse from its
workplace during the Term and specifically, shall:

                           (i)    prohibit     the     unlawful     manufacture,
                                  distribution, dispensation, possession, or use
                                  of drugs in its workplace;

                           (ii)   prohibit its employees  from working under the
                                  influence of alcohol or drugs;

                           (iii)  not  hire or  assign  to  work on an  activity
                                  funded in whole or part with State of Maryland
                                  funds,   anyone  whom  it  knows,  or  in



                                       51
<PAGE>

                                  the  exercise of due  diligence  should  know,
                                  currently  abuses  alcohol or drugs and is not
                                  actively engaged in a bona fide rehabilitation
                                  program;

                           (iv)   promptly    inform   the    appropriate    law
                                  enforcement agency of every drug related crime
                                  that  occurs  in  its  workplace  if it or its
                                  employee  has   observed   the   violation  or
                                  otherwise  has  reliable  information  that  a
                                  violation has occurred; and



                                       52
<PAGE>

                           (v)    notify  employees  that drug and alcohol abuse
                                  is banned in the workplace,  impose  sanctions
                                  on  employees  who abuse  drugs and alcohol in
                                  the workplace, and institute steps to maintain
                                  a drug and alcohol free workplace.

                  (j)      Financial Covenants.  Maintain the following:



                                       53
<PAGE>

                           (i)    Unrestricted cash and securities (exclusive of
                                  any unrestricted cash or securities maintained
                                  by a consolidated subsidiary of Tenant) with a
                                  market  value of at least  $50,000,000  at all
                                  times,   of   which   unrestricted   cash  and
                                  securities at least  $10,000,000  (in addition
                                  to the  pledge  described  in  the  Collateral
                                  Pledge  Agreement)  shall be  maintained in an
                                  account  with the Bank or an  affiliate of the
                                  Bank.  The cash and/or  marketable  securities
                                  pledged by Tenant  pursuant to the  Collateral
                                  Pledge Agreement shall be credited against the
                                  foregoing  $50,000,000  requirement.   In  the
                                  event   that   the   market   value   of  such
                                  unrestricted  cash and securities  falls below
                                  $50,000,000,  Tenant shall pledge to Landlord,
                                  as security  for  Tenant's  obligations  under
                                  this   Lease,   in   addition  to  the  pledge
                                  described in the Collateral  Pledge Agreement,
                                  cash and/or marketable  securities  acceptable
                                  to the Bank,  as the assignee of Landlord,  in
                                  its sole  discretion  and margined as required
                                  by the Bank, as the assignee of Landlord, with
                                  a market  value at all times equal to at least
                                  $5,000,000. In the event that the market value
                                  of  unrestricted  cash  and  securities  falls
                                  below  $25,000,000,  Tenant  shall  pledge  to
                                  Landlord, as security for Tenant's obligations
                                  under this  Lease,  in  addition  to any other
                                  pledge  theretofore  made  to  Landlord,  cash
                                  and/or marketable securities acceptable to the
                                  Bank, as the assignee of Landlord, in its sole
                                  discretion  and  margined  as  required by the
                                  Bank,  as assignee of Landlord,  with a market
                                  value   at  all   times   equal  to  at  least
                                  $5,000,000.   Any   cash   and/or   marketable
                                  securities  pledged hereunder shall be held by
                                  the Bank.  Tenant shall deposit with the Bank,
                                  as the assignee of Landlord,  additional  cash
                                  and/or marketable securities acceptable to the
                                  Bank, as the assignee of Landlord, in its sole
                                  discretion  and  margined  as  required by the
                                  Bank,  as the assignee of  Landlord,  whenever
                                  the  market  value of each  additional  pledge
                                  hereunder  falls below  $5,000,000  to make up
                                  the deficiency. Whenever the market value



                                       54
<PAGE>

                                  of  any  cash  and/or  marketable   securities
                                  pledged to Landlord  (margined  as required by
                                  the Bank,  as the  assignee  of the  Landlord)
                                  exceeds the required amount, i.e.,  $5,000,000
                                  or $10,000,000,  as the case may be, the Bank,
                                  as  the  assignee  of  Landlord,   shall,   in
                                  accordance  with the  terms of the  Collateral
                                  Pledge Agreement, release from the pledge cash
                                  and/or  marketable  securities  equal  to such
                                  excess.

                           (ii)   A   "Tangible   Net  Worth"  (as   hereinafter
                                  defined)  with a market value of not less than
                                  $50,000,000.  Tangible  Net  Worth  of  Tenant
                                  shall not  include the  tangible  net worth of
                                  any consolidated  subsidiary of Tenant. In the
                                  event that the market  value of such  Tangible
                                  Net  Worth  falls  below  $50,000,000,  Tenant
                                  shall  pledge to  Landlord,  as  security  for
                                  Tenant's  obligations  under  this  Lease,  in
                                  addition  to  the  pledge   described  in  the
                                  Collateral  Pledge   Agreement,   cash  and/or
                                  marketable  securities acceptable to the Bank,
                                  as the  assignee  of  Landlord,  in  its  sole
                                  discretion  and  margined  as  required by the
                                  Bank,  as the  assignee  of  Landlord,  with a
                                  market  value at all  times  equal to at least
                                  $5,000,000.  In the event  that  Tangible  Net
                                  Worth falls below  $25,000,000,  Tenant  shall
                                  pledge to  Landlord,  as security for Tenant's
                                  obligations  under this Lease,  in addition to
                                  any other pledge theretofore made to Landlord,
                                  cash and/or marketable  securities  acceptable
                                  to the Bank,  as the assignee of Landlord,  in
                                  its sole  discretion  and margined as required
                                  by the Bank, as the assignee of Landlord, with
                                  a market  value at all times equal to at least
                                  $5,000,000.   Any   cash   and/or   marketable
                                  securities  pledged hereunder shall be held by
                                  the Bank.  Monthly,  Tenant shall deposit with
                                  the  Bank,   as  the   assignee  of  Landlord,
                                  additional cash and/or  marketable  securities
                                  acceptable  to the Bank,  as the  assignee  of
                                  Landlord,  in its sole discretion and margined
                                  as  required by the Bank,  as the  assignee of
                                  Landlord,  whenever  the market  value of each
                                  additional   pledge   hereunder   falls  below
                                  $5,000,000 to make up



                                       55
<PAGE>

                                  the  deficiency.  Whenever the market value of
                                  any cash and/or marketable  securities pledged
                                  to Landlord (margined as required by the Bank,
                                  as assignee of Landlord), exceeds the required
                                  amount,  i.e.,  $5,000,000 or $10,000,000,  as
                                  the  case  may be,  quarterly,  the  Bank,  as
                                  assignee of Landlord,  shall  release from the
                                  pledge cash and/or marketable securities equal
                                  to such excess.  Tangible Net Worth shall mean
                                  shareholder's   equity  less  all   intangible
                                  assets such as, but not limited to, good will,
                                  licenses,  trademarks,  patents, copyrights or
                                  consulting agreements.

                           (iii)  Any   pledge   of   cash   and/or   marketable
                                  securities  made pursuant to either clause (i)
                                  or (ii) above shall  satisfy the  requirements
                                  of the other clause.

                           (iv)   Any  investment  earnings  on the cash  and/or
                                  marketable   securities   pledged   by  Tenant
                                  pursuant  to clause (i) or (ii) above shall be
                                  distributed  quarterly  by  the  Bank,  as the
                                  assignee of Landlord, to Tenant.

                           (v)    If  Tenant  pledges  cash  and/or   marketable
                                  securities   to   Landlord   to  satisfy   the
                                  requirements  of  either  clause  (i) or  (ii)
                                  above  and  thereafter  for a  period  of  two
                                  consecutive  fiscal quarters Tenant returns to
                                  compliance   with   the   requirements   which
                                  necessitated  such  pledge,  the Bank,  as the
                                  assignee of Landlord,  shall release such cash
                                  and/or marketable securities from such pledge.
                                  By way of illustration, if the market value of
                                  Tenant's  Tangible  Net Worth  (as  calculated
                                  pursuant  to clause  (ii)  above)  falls below
                                  $25,000,000 and Tenant has pledged $10,000,000
                                  of  cash  and/or   marketable   securities  to
                                  Landlord  and  thereafter  the market value of
                                  Tenant's  Tangible  Net Worth is greater  than
                                  $25,000,000 but less than  $50,000,000 for two
                                  consecutive  fiscal  quarters the Bank, as the
                                  assignee of Landlord,  shall release from such
                                  pledge  $5,000,000  of cash and/or  marketable
                                  securities.

                           (vi)   Notwithstanding  the  foregoing  provisions of


                                       56
<PAGE>

                                  this  subparagraph  26(j),  the amount of cash
                                  and/or  marketable  securities  required to be
                                  pledged  to  Landlord  at any time  shall  not
                                  exceed  the   Stated   Amount  of  the  Credit
                                  Facility (as defined in the Credit Facility).

                  (k) Cooperate in  connection  with any appraisal of the Leased
Premises  conducted  by or at the  request  of  Landlord,  the  Credit  Facility
Provider, the State or MIDFA.

         27.  Negative  Covenants of Tenant.  Until all of Tenant's  obligations
under  this  Lease  have  been  paid  and  performed  in full  (other  than  any
indemnities  which  survive the  termination  of this Lease),  without the prior
written consent of Landlord, Tenant shall not, directly or indirectly:

                  (a) Declare any  dividends  (other than  dividends  payable in
capital  stock of Tenant) on any shares of any class of its capital stock (other
than  preferred  stock  outstanding  on the  Closing  Date) or apply  any of its
property or assets to the purchase,  redemption or other  retirement  of, or set
apart  any  sum  for the  payment  of any  dividends  on,  or for the  purchase,
redemption or other  retirement of, or make any other  distribution by reduction
of capital or otherwise in respect of, any shares of any class of capital  stock
of Tenant  unless (i) there is no Event of  Default  which has  occurred  and is
continuing,  and (ii) the  amount  of the  dividend  does  not  exceed  Tenant's
accumulated earnings at that time.

                  (b) Fail to notify  Landlord  of any  change  in the  officers
(within the meaning of Section 240.16a-1 of the Regulations under the Securities
Exchange Act of 1934, as amended) of Tenant.

                  (c) (i) Restate or amend any Plan  established  and maintained
by Tenant or any Commonly  Controlled  Entity and subject to the requirements of
ERISA, in a manner designed to disqualify such Plan and its related trusts under
the applicable  requirements  of the Code; (ii) permit any officers of Tenant or
any Commonly  Controlled  Entity to  materially  adversely  affect the qualified
tax-exempt  status of any Plan or  related  trusts  of  Tenant  or any  Commonly
Controlled  Facility  under the Code;  (iii)  engage in or permit  any  Commonly
Controlled Entity to engage in any Prohibited Transaction;  (iv) incur or permit
any Commonly  Controlled  Entity to incur any  Accumulated  Funding  Deficiency,
whether  or not  waived,  in  connection  with any Plan;  (v) take or permit any
Commonly  Controlled  Entity to take any



                                       57
<PAGE>

action or fail to take any action  which causes a  termination  of any Plan in a
manner which could result in the  imposition of a lien on the property of Tenant
or any Commonly  Controlled  Entity pursuant to Section 4068 of ERISA; (vi) fail
to notify the Credit  Facility  Provider  that  notice  has been  received  of a
"termination" (as defined in ERISA) of any Multiemployer Plan to which Tenant or
any Commonly  Controlled Entity has an obligation to contribute;  (vii) incur or
permit  any  Commonly  Controlled  Entity to incur a  "complete  withdrawal"  or
"partial  withdrawal" (as defined in ERISA) from any Multiemployer Plan to which
Tenant or any Commonly  Controlled  Entity has an obligation to  contribute;  or
(viii) fail to notify the Credit Facility Provider that notice has been received
from the administrator of any Multiemployer Plan to which Tenant or any Commonly
Controlled  Entity has an obligation  to  contribute  that any such Plan will be
placed in "reorganization" (as defined in ERISA).

         28.   Non-Recourse.   Anything   contained   herein  to  the   contrary
notwithstanding,  any claim based on or in respect of any  liability of Landlord
under this Lease  shall be  enforced  only  against  Landlord's  interest in the
Leased  Premises,  subject to the lien of the Deeds of Trust, and the Collateral
Pledge  Agreement,  and not against  any other  assets,  properties  or funds of
Landlord or against any assets,  properties or funds of (i) any general  partner
or limited  partner of  Landlord,  or any  employee or agent of Landlord (or any
director,  officer, legal representative,  successor, or assign of any thereof),
or (ii) any other Person affiliated with any of the foregoing, including without
limitation,  the State of Maryland or any department,  agency or instrumentality
thereof.

         29.  Separability.  Each and every covenant and agreement  contained in
this Lease is, and shall be construed to be, a separate and independent covenant
and  agreement,  and the breach of any such  covenant or  agreement  by Landlord
shall not  discharge or relieve  Tenant from any of its  obligations  under this
Lease. If any term or provision of this Lease or the application  thereof to any
Person or circumstances  shall to any extent be invalid and  unenforceable,  the
remainder  of this  Lease,  or the  ------------  application  of  such  term or
provision to persons or circumstances other than those as to which it is invalid
or unenforceable,  shall not be affected thereby, and each term and provision of
this Lease shall be valid and shall be enforced to the extent permitted by Law.



                                       58
<PAGE>

         30.      Subordination.

                  (a)  This  Lease  is  subject  and  subordinate  to the  lien,
provisions,  operation  and  effect  of the  Deeds of  Trust  or other  security
instruments which may now or hereafter  encumber the Improvements or the Land or
any  interest  therein   (collectively,   "Encumbrances"),   to  all  funds  and
indebtedness  intended to be secured thereby,  and to all renewals,  extensions,
modifications, recastings or refinancings thereof. The holder of any Encumbrance
to which this Lease is subordinate shall have the right (subject to any required
approval of the holders of any superior Encumbrance) at any time to declare this
Lease to be  superior  to the lien,  provisions,  operation  and  effect of such
Encumbrance,  and Tenant shall  execute,  acknowledge  and deliver all documents
required by such holder in confirmation thereof. Simultaneous with the execution
hereof,  Landlord,  Tenant,  the Credit  Facility  Provider  and the State shall
execute  the  Assignments.  In the event that the  Improvements  and/or the Land
become  subject to an  Encumbrance  after the date  hereof,  Landlord  agrees to
obtain a non-disturbance agreement from the holder of such Encumbrance,  in such
holder's standard form, provided that Tenant shall pay or reimburse Landlord for
any costs  associated  with such efforts and agrees to execute such agreement in
order  to  confirm  the  subordination  of this  Lease  to the  Encumbrance,  if
requested by the holder of such Encumbrance.

                  (b) Tenant shall at Landlord's  request  promptly  execute any
requisite or appropriate  document confirming such subordination.  Tenant waives
the provisions of any Law now or hereinafter in effect which may give or purport
to give Tenant any right to terminate or otherwise  adversely  affect this Lease
and Tenant's  obligations  hereunder in the event any foreclosure  proceeding is
prosecuted or completed or in the event the Improvements, the Land or Landlord's
interest  therein is transferred by foreclosure,  by deed in lieu of foreclosure
or  otherwise.  At the request of such  transferee,  Tenant shall attorn to such
transferee and shall recognize such transferee as the Landlord under this Lease.
Tenant agrees that upon any such  attornment,  such transferee  shall not be (i)
bound by any  payment  of Basic Rent or  Additional  Rent more than one month in
advance,  except  prepayments  in the nature of security for the  performance by
Tenant  of its  obligations  under  this  Lease,  but  only to the  extent  such
prepayments have been delivered to such transferee,  (ii) bound by any amendment
of this  Lease  made  without  the  consent  of the  holder of each  Encumbrance
existing  as of the date of such  amendment,  (iii)  liable for  damages for any
breach, act or omission of any prior landlord, or (iv) subject to any offsets or
defenses which Tenant might have against any prior landlord;  provided, however,
that after succeeding to Landlord's  interest under this Lease,  such transferee
shall agree to perform in



                                       59
<PAGE>

accordance  with the terms of this Lease all  obligations  of  Landlord  arising
after  the  date of  transfer.  Within  five  days  after  the  request  of such
transferee,  Tenant  shall  execute,  acknowledge  and deliver any  requisite or
appropriate document submitted to Tenant confirming such attornment.

                  (c) If any  prospective  or current  holder of an  Encumbrance
requires that  modifications  to this Lease be obtained,  and provided that such
modifications  (i) are  reasonable,  (ii) do not adversely  affect in a material
manner  Tenant's use of the Leased  Premises for the Permitted Use, (iii) do not
increase  the rent  and  other  sums to be paid by  Tenant,  (iv) do not  change
Tenant's  affirmative  or negative  covenants  set forth  herein,  or (v) affect
Tenant's  option to purchase the Leased  Premises as provided in Paragraph 6(b),
then Landlord may submit to Tenant an amendment to this Lease incorporating such
required modifications,  and Tenant shall execute,  acknowledge and deliver such
amendment to Landlord within five days after Tenant's receipt thereof.

         31. Binding  Effect.  All of the covenants,  conditions and obligations
contained  in this Lease  shall be binding  upon and inure to the benefit of the
respective  successors  and assigns of Landlord and Tenant to the same extent as
if each  successor  and assign were in each case named as a party to this Lease.
This Lease may not be changed, modified or discharged except by a writing signed
by Landlord and Tenant and  consented to by the Credit  Facility  Provider,  the
State and MIDFA.

         32. Heading.  The headings to the various paragraphs of this Lease have
been inserted for convenient reference only and shall not to any extent have the
effect of modifying,  amending or changing the expressed terms and provisions of
this Lease.

         33.      Environmental Matters.

                  (a) As used in this  Paragraph 33, the  following  items shall
have meanings set forth below:

                           (i) "CAA" - shall mean the Clean Air Act, codified at
42 U.S.C. " 7401, et seq., as amended.

                           (ii)   "CERCLA"  -  shall   mean  the   Comprehensive
Environmental Response,  Compensation, and Liability Act of 1980, codified at 42
U.S.C. " 9601, et seq., as amended.

                           (iii)  "CWA"  -  shall  mean  the  Clean  Water  Act,
codified at 33 U.S.C. 1251; et seq., as amended.

                           (iv) "Environmental  Laws" - shall mean CERCLA, HMTA,
RCRA, CAA, CWA, TSCA, RHA and the Right-to-Know Act and all



                                       60
<PAGE>

other  federal,  local and  municipal  laws,  statutes,  ordinances  and  codes,
guidelines  and  standards  relating  to  health,  safety,  sanitation,  and the
protection  of  the  environment  or  governing  the  use,  storage,  treatment,
generation,  transportation,  processing,  handling,  production  or disposal of
Hazardous  Materials,   including,  without  limitation,  laws  and  regulations
regarding  the discharge of water or other  materials or fluids into  waterways,
and the rules,  regulations,  guidelines,  decisions,  orders and  directives of
federal, local and municipal governmental agencies,  authorities and courts with
respect  thereto  presently  in  effect or  hereafter  enacted,  promulgated  or
implemented.

                           (v) "Environmental Permits" - shall mean all permits,
licenses, approvals,  authorizations,  consents or registrations required by any
applicable  Environmental  Laws,  on either an  individual  or group  basis,  in
connection with the construction, ownership, use or operation of the Land or the
Improvements, or the storage, treatment, generation, transportation, processing,
handling,  production  or disposal of Hazardous  Materials  related to the Land.

                           (vi)  "Hazardous  Materials"  - shall  mean,  without
limitation,   flammables,  explosives,  radioactive  materials,  asbestos,  urea
formaldehyde foam insulation,  polychlorinated biphenyls, petroleum or petroleum
based or related substances, hydrocarbons or like substances and their additives
or  constituents,  and any  substances  now or hereafter  defined as  "hazardous
substances,"  "extremely  hazardous  substances,"  "hazardous  wastes" or "toxic
chemicals" in CERCLA, HMTA, RCRA, CAA, CWA, TSCA, RHA, the Right-To-Know Act, or
any so-called  "superfund" or  "superlien"  law or the  regulations  promulgated
pursuant thereto,  or any other applicable  federal,  state or local law, common
law,  code,  rule,  regulation,  order,  or  ordinance,  presently  in effect or
hereafter enacted, promulgated or implemented.

                           (vii)  "HMTA" - shall  mean the  Hazardous  Materials
Transportation Act, codified at 49 U.S.C. " 1801, et seq., as amended.

                           (viii) "RCRA" - shall mean the Resource  Conservation
and Recovery Act of 1976,  codified at 42 U.S.C.  " 6901,  et seq.,  as amended.

                           (ix) "Release" - shall have the same meaning as given
to that term in CERCLA, as amended, and the regulations  promulgated thereunder.

                           (x)  "RHA"   shall  mean  the   Rivers  and   Harbors
Appropriation  Act,  codified at 33 U.S.C. " 401, et seq., as amended.



                                       61
<PAGE>

                           (xi)  "Right-To-Know  Act" - shall mean the Emergency
Planning and Community  Right-To-Know  Act,  codified at 42 U.S.C.  " 11001,  et
seq., as amended. 

                           (xii)  "TSCA"  -  shall  mean  the  Toxic  Substances
Control Act, codified at 15 U.S.C. " 2601, et seq., as amended. 

                  (b) Tenant shall comply at all times and in all respects  with
the provisions of all Environmental  Laws and Environmental  Permits,  and shall
not commit  any  actions  or  omissions  that  result in the  incurrence  of any
liability under such  Environmental Laws or Environmental  Permits.  Tenant will
not allow,  cause or permit any Hazardous  Materials to be deposited on or under
the Land,  or otherwise  Released or  threatened  to be Released  from or on the
Land, or otherwise  Released or threatened to be Released from or on the Land or
the Improvements,  by any Person whatsoever except as normally and properly used
in the construction and operation of the Improvements and in compliance with all
Environmental  Laws.  Tenant shall conduct all of its activities on the Land and
Improvements,  including,  without  limitation,  the  off-site  disposal  of any
Hazardous  Materials  originating  on or  from  the  Land  or  Improvements,  in
compliance with all Environmental Laws. Tenant shall obtain,  whenever necessary
and in its own name,  appropriate  Environmental  Permits for its operations and
shall  comply  in all  respects  with  the  requirements  of such  Environmental
Permits.

                  (c) Tenant  hereby  agrees to  indemnify,  hold  harmless  and
defend Landlord, the Trustee, the Credit Facility Provider, the State and MIDFA,
and their partners, officers,  directors, lenders, agents and employees from and
against any and all claims,  losses,  damages,  liabilities,  penalties,  costs,
assessments, expenses, demands, fines or liabilities of whatever kind or nature,
including,  without limitation,  costs, expenses (including expense of posting a
bond) and liabilities  imposed upon Landlord  pursuant to any indenture or other
document, in any way relating to or arising out of:

                           (i) The Release or threat of Release of any Hazardous
Materials in, on, above, from or under the Land or Improvements  during the Term
hereof;

                           (ii) Any  activity by any party on, off or within the
Land  or  Improvements  in  connection  with  the  use,   handling,   treatment,
monitoring, removal, storage, decontamination, clean up, testing, transportation
or disposal of any Hazardous  Materials  located at any time on, within or under
the Land or the Improvements and introduced onto the Land or the Improvements at



                                       62
<PAGE>

any time on or after the commencement of the Term and prior to the expiration or
other termination of this Lease

                           (iii)  The  use,  handling,  treatment,   monitoring,
removal, storage, decontamination, clean-up, testing, transportation or disposal
of any  Hazardous  Materials  on,  under or within the Land or the  Improvements
which were introduced  onto the Land or into the  Improvements at any time on or
after  the  commencement  of the  Term  and  prior  to the  expiration  or other
termination of this Lease;

                           (iv) The  performance  by Tenant or any other  Person
acting on behalf of Tenant  during  the Term of any  inspection,  investigation,
audit, study, sampling,  testing, removal,  containment or other remedial action
or other clean-up related to Hazardous Materials on, above, within,  related to,
or affected by, the Land or the Improvements;

                           (v) The  imposition,  recording or filing of any lien
(including, without limitation, a so-called "superlien") against the Land or the
Improvements as a result of the incurrence by any party of any claims, expenses,
demands,  losses,  costs,  fines or  liabilities of whatever kind or nature with
respect to any actual, suspected or threatened Release of Hazardous Materials or
environmental condition, on, above, within, related to, or affected by, the Land
or the Improvements at any time after the Lease  Commencement  Date and prior to
the expiration or other termination of this Lease; or

                           (vi)  The  violation  by  Tenant  of  any  applicable
Environmental  Laws or  Environmental  Permits  with  respect to the Land or the
Improvements.  The  provisions  of  this  subparagraph  (c)  shall  survive  the
expiration or any other termination of this Lease.

                  (d)  Landlord  has  delivered  to Tenant an undated  "Phase I"
environmental  report referred to as "Phase I Environmental  Assessment  Results
Belward Research Campus, Parcel A, Montgomery County, MD", prepared in June/July
1997 by ManTech  Environmental  Corporation,  as  supplemented  by the  reliance
letter from ManTech Environmental  Corporation dated as of December 23, 1997 and
the  letter  from  Apex  Environmental,  Inc.  dated as of  December  23,  1997,
indicating any presence of any Hazardous  Materials on, above or below the Land,
or of the Release or threat of Release of any Hazardous Materials existing prior
to the commencement of the Term.

                  (e) Unless Tenant purchases the Leased Premises as provided in
Paragraph  6(b),  no less than nine months prior to the  expiration  of the Term
hereof,  Tenant  shall  cause to be  prepared,



                                       63
<PAGE>

by  an  environmental   consultant   reasonably   acceptable  to  Landlord,   an
environmental  assessment of the Land and the Improvements  (the  "Assessment"),
which  shall  identify  the  presence  or  probable  presence  of any  Hazardous
Materials  on,  above or below the Land or the  Improvements,  or the Release or
threat  of  Release  of  any  Hazardous   Materials  or  any  violation  of  any
Environmental  Laws with  respect to the Land and the  Improvements  or Tenant's
operations thereon or therein. To the extent that the Assessment  identifies any
such Hazardous Materials,  Releases or threatened Releases or violations, Tenant
shall take all such measures,  including,  without limitation,  any and all such
measures as shall be recommended by such  environmental  consultant,  to remove,
remedy and/or cure such  condition,  so that, by the end of the Term hereof,  no
Hazardous  Materials shall be present on, above, within or under the Land or the
Improvements, no Release or threat of Release of Hazardous Materials exists, and
no violation of  Environmental  Laws shall exist with respect to the Land or the
Improvements  or  Tenant's  operations  thereon or  therein.  Any such  response
actions   undertaken   by  Tenant  shall   comply  fully  with  all   applicable
Environmental Laws. If Tenant fails to provide the Assessment to Landlord by the
date that is nine months prior to the  expiration  of the Term, or fails to take
such recommended  measures and to remove any Hazardous Materials and comply with
all  Environmental  Laws as aforesaid,  Landlord may, but shall not be obligated
to, have such  Assessment  prepared and such removal  and/or  remedial  measures
undertaken  at the  expense of Tenant,  the costs of which  shall be  considered
Additional Rent hereunder.  The foregoing  provisions of this  subparagraph  (e)
shall survive the  expiration or any other  termination  of this Lease and shall
not be  construed  to relieve  Tenant in any way of its  continuing  obligations
throughout the Term to comply with the provisions of subparagraph (b) above.

                  (f) Unless Tenant purchases the Leased Premises as provided in
Paragraph  6(b), as a condition of any  termination of this Lease,  Tenant shall
cause to be prepared,  by an environmental  consultant  reasonably acceptable to
Landlord,  an Assessment which shall identify the presence or probable  presence
of any Hazardous  Materials on, above or below the Land or the Improvements,  or
the Release or threat of Release of any Hazardous  Materials or any violation of
any Environmental Laws with respect to the Land and the Improvements or Tenant's
operations thereon or therein. To the extent that the Assessment  identifies any
such Hazardous Materials,  Releases or threatened Releases or violations, Tenant
shall take all such measures,  including,  without limitation,  any and all such
measures as shall be recommended by such  environmental  consultant,  to remove,
remedy and/or cure such  condition,  so that, as soon as  practicable  after the
termination of this Lease,  no Hazardous  Materials  shall be present on, above,
within or under the Land or the Improvements, no Release or threat



                                       64
<PAGE>

of Release of Hazardous Materials exists, and no violation of Environmental Laws
shall exist with respect to the Land or the Improvements or Tenant's  operations
thereon or therein.  Any such response actions undertaken by Tenant shall comply
fully  with all  applicable  Environmental  Laws.  If Tenant  fails to engage an
environmental  consultant to provide the  Assessment to Landlord  within fifteen
(15) days of the event which  causes or permits  termination  of this Lease,  or
fails to take such  recommended  measures and to remove any Hazardous  Materials
and comply with all Environmental Laws as aforesaid, Landlord may, but shall not
be obligated to, have such Assessment  prepared and such removal and/or remedial
measures  undertaken  at the  expense  of  Tenant,  the costs of which  shall be
considered   Additional  Rent  hereunder.   The  foregoing  provisions  of  this
subparagraph  (f) shall survive the expiration or any other  termination of this
Lease and shall not be construed to relieve  Tenant in any way of its continuing
obligations  throughout the Term to comply with the  provisions of  subparagraph
(b) above.

         34. Quiet Enjoyment.  So long as no Event of Default exists  hereunder,
and subject to the terms of this Lease, the Deeds of Trust, any Encumbrance, and
any other matters of record, Landlord warrants peaceful and quiet occupation and
enjoyment  of the Leased  Premises by Tenant,  free of  hindrance by Landlord or
anyone claiming by or through Landlord.

         35.      Miscellaneous.

                  (a) This Lease may be executed in any number of  counterparts,
each of which shall be an original,  but all of which shall together  constitute
one and the same instrument.

                  (b) References to the masculine shall include the feminine and
neuter and the plural shall include the singular, as the context may require.

                  (c) This Lease shall be construed  and enforced in  accordance
with the Law of the State of Maryland.

                  (d) Time is of the  essence  with  respect  to each and  every
provision of this Lease.

                  (e) With respect to any provision of this Lease which requires
Landlord to not unreasonably  withhold its consent or approval, if in connection
therewith  Landlord is obligated  under the Deeds of Trust,  the Credit Facility
Documents,  the Bond  Documents,  the State Loan  Documents or applicable Law to
obtain the  consent or  approval  of MIDFA,  the  Trustee,  the Credit  Facility
Provider, the State or any other third party, then Landlord's failure to provide
consent or failure to otherwise act in a



                                       65
<PAGE>

reasonable  manner because of its inability to obtain the consent or approval of
Landlord,  MIDFA, the Credit Facility  Provider,  the State or other third party
shall not be deemed  unreasonable,  so long as  Landlord  has made a good  faith
effort to obtain such consent.

                  (f) Upon the satisfaction of the Deeds of Trust, references in
this Lease to the Credit Facility Provider,  the Trustee,  MIDFA, the State, the
Credit  Facility,  the  Credit  Facility  Agreement,  the Deeds of Trust and the
Credit Facility  Documents  shall be ineffective,  and Tenant shall no longer be
obligated to comply with the covenants  contained in Paragraphs  26(g), (h), (i)
or (j) and in Paragraph 27.

                  (g) The parties hereto acknowledge that the provisions of this
Lease have been  tailored  to  specific  financing  accommodations  provided  by
Landlord, the Credit Facility Provider, MIDFA and the State, including the Bonds
and the Credit  Facility  pursuant  to the terms of the Bond  Documents  and the
Credit Facility  Documents.  In the event it becomes necessary to replace all or
any portion of these accommodations,  Landlord shall exert good faith efforts to
obtain  financing  on the best terms  available.  Landlord  and Tenant  agree to
negotiate in good faith to amend this Lease to re-tailor this Lease to suit such
replacement financing, upon terms mutually agreeable to Landlord, Tenant and the
financial  institution  providing or  participating  in such financing and it is
acknowledged  and agreed that  Tenant's  rental  obligations  hereunder  will be
restructured to provide for the payment of all interest and all related expenses
of such  replacement  financing in the event such interest and related  expenses
under the  replacement  financing  are not  identical to those payable under the
Bonds and the  Credit  Facility  Documents  and the State  Loan  Documents.  The
parties hereto also acknowledge that in the event it becomes necessary to obtain
replacement financing for any reason other than (i) Landlord's  misappropriation
of funds or (ii) a default by Landlord  hereunder or under the Bond Documents or
the Credit  Facility  Documents not caused  directly or indirectly by the act or
omission of Tenant,  all expenses  incurred by Landlord in connection  with such
replacement financing shall be paid by Tenant as Additional Rent.

                  (h)  Landlord  and Tenant  hereby  agree and consent  that any
action or proceeding arising out of or brought to enforce the provisions of this
Lease may be brought in any appropriate court in Montgomery County,  Maryland or
Baltimore City, Maryland, and by the execution of this Lease Landlord and Tenant
irrevocably consent to the jurisdiction of each such court.

                  (i) If for any reason  Landlord  or Tenant  should  become not
qualified  to do  business in the State,  Landlord  and Tenant



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<PAGE>

hereby agree to designate and appoint, without power of revocation, an agent for
service of process  within the State,  as the agent for  Landlord or Tenant,  as
applicable,  upon whom may be served  all  process,  pleadings,  notice or other
papers which may be served upon Landlord or Tenant,  as applicable,  as a result
of any of Landlord's or Tenant's, as applicable, obligations under this Lease.

                  (j) Landlord and Tenant  covenant that throughout the Term, if
a new agent for service of process  within the State is  designated  pursuant to
the terms of subparagraph  (i) above,  Landlord or Tenant,  as applicable,  will
immediately  file with the other  party  hereto the name and address of such new
agent and the date on which such appointment is to become effective.

                  (k) Landlord and Tenant hereby  jointly waive trial by jury in
any action or  proceeding to which  Landlord and Tenant may be parties,  arising
out of or in any way  pertaining  to  this  Lease.  This  waiver  is  knowingly,
willingly  and  voluntarily  made by Landlord  and Tenant,  each of which hereby
represents  that no  representations  of fact or  opinion  have been made by any
individual  to induce  this  waiver of trial by jury or to in any way  modify or
nullify its effect.  Each of Landlord and Tenant further  represents that it has
been  represented  in the signing of this Lease and in the making of this waiver
by independent legal counsel, selected of its own free will, and that it has had
the opportunity to discuss this waiver with counsel.

                  (l)  Landlord  has issued the Bonds to,  inter alia,  fund the
costs of construction of the Improvements,  and has created with the Trustee the
Facility Fund to pay for  construction  and other  construction and Bond related
expenses.  The Facility Fund is to be invested per  Landlord's  instructions  in
accordance with the Indenture.  In addition, with respect to the Bonds, Landlord
agrees that Landlord, upon Tenant's request, shall agree to procure a substitute
Credit Facility upon terms and conditions mutually  satisfactory to Landlord and
Tenant.

         IN WITNESS  WHEREOF,  Landlord  and Tenant have caused this Lease to be
signed on their behalf,  under seal, by their respective  signatories  thereunto
duly organized as of the date first above written.

WITNESS/ATTEST:                           MARYLAND ECONOMIC DEVELOPMENT

                                          CORPORATION, Landlord

                                          By:                             (SEAL)
-----------------------------------------    -----------------------------
                                               Hans F. Mayer
                                               Executive Director



                                       67
<PAGE>

                                          HUMAN GENOME SCIENCES, INC.,
                                          Tenant

                                          By:                             (SEAL)
-----------------------------------------    -----------------------------
                                               Steven C. Mayer
                                               Senior Vice President
                                               and Chief Financial Officer


                                       68
<PAGE>

                                                                       EXHIBIT A
                                                                       ---------
                               DESCRIPTION OF LAND
                               -------------------

         Lot Number 1, in Block A in the subdivision known as "Lots 1 & 2, Block
A, Lot 1,  Block B, Lots 1 & 2,  Block C, THE  JOHNS  HOPKINS  BELWARD  RESEARCH
CAMPUS",  as per plat  thereof duly  recorded in the Land Records of  Montgomery
County, Maryland in Plat Book 186 at Plat 20556.







                                      A-1


<PAGE>



                                                                       EXHIBIT B
                                                                       ---------

                         LIST OF CONSTRUCTION CONTRACTS
                         ------------------------------

         1.  Construction  Management  Agreement dated August 27, 1997,  between
Gilbane  Building  Company and MEDCO  (captioned  "Agreement  Between  Owner and
Construction Manager where the Construction Manager is also the Constructor").

         2.  Engineering  and  Procurement  Services  Agreement dated August 11,
1997, between Fluor Daniel, Inc. and MEDCO, as amended by Contract Amendment No.
1, dated August 20, 1997, and Contract  Amendment No. 2, dated as of October 13,
1997.

         3. Site Development Contract dated as of July 24, 1997, between Manekin
Corporation and MEDCO (captioned  "Abbreviated  Form of Agreement  Between Owner
and  Contractor  for  Construction  Project of Limited  Scope where the Basis of
Payment is a Stipulated Sum").



                                      B-1

<PAGE>



                                                                       EXHIBIT C
                                                                       ---------

                           LIST OF TENANT'S EQUIPMENT
                           --------------------------












                                      C-1

<PAGE>



                                                                       EXHIBIT D
                                                                       ---------

                       SCHEDULE OF OPTION PURCHASE PRICES
                       ----------------------------------



















                                      D-1

<PAGE>



                                                                       EXHIBIT E
                                                                       ---------

                          NOTICE AND PAYMENT ADDRESSES
                          ----------------------------

If to Landlord:

         Notices:             Maryland Economic Development
                               Corporation

                              36 South Charles Street
                              Suite 2410
                              Baltimore, Maryland 21202
                              Attention: Hans F. Mayer,
                                         Executive Director

                              with a copy to:

                              S. Nelson Weeks, Esquire
                              Ballard Spahr Andrews & Ingersoll
                              300 East Lombard Street
                              19th Floor
                              Baltimore, Maryland 21202

                              George W. Liebmann, Esquire
                              8 West Hamilton Street
                              Baltimore, Maryland 21201

         Payments:            Basic Rent

                              By Electronic Transfer:

                              The First National Bank of Maryland
                              Baltimore, Maryland 21203
                              Account No. 191 1047 0

                              By Mail:

                              MEDCO

                              36 South Charles Street
                              Suite 2410
                              Baltimore, Maryland 21202
                              Attention: Hans F. Mayer
                                         Executive Director

                                      E-1

<PAGE>

If to Tenant:

         Notices:             Human Genome Sciences, Inc.
                              9410 Key West Avenue
                              Rockville, Maryland 20850
                              Attention: Steven C. Mayer
                                         Senior Vice President
                                         and Chief Financial Officer

                              with a copy to:

                              James H. Davis
                              Senior Vice President and General

                                 Counsel and Secretary
                              Human Genome Sciences, Inc.
                              9410 Key West Avenue
                              Rockville, Maryland 20850

If to the Bank:

         Notices:             If by mail:

                              The First National Bank of Maryland
                              6303 Ivy Lane
                              Suite 200
                              Greenbelt, Maryland 20770
                              Attention: Joseph C. LeMense
                                         Vice President

                              The First National Bank of Maryland
                              International Operations
                              P.O. Box 17086
                              Mail Code 101-492
                              Baltimore, Maryland 21203
                              Attention: Phyllis Malekiania

                              Otherwise:

                              The First National Bank of Maryland
                              6303 Ivy Lane
                              Suite 200
                              Greenbelt, Maryland 20770
                              Attention: Joseph C. LeMense
                                         Vice President

                              The First National Bank of Maryland
                              International Operations
                              25 South Charles Street
                              15th Floor
                              Baltimore, Maryland 21201


                                      E-2

<PAGE>

                              Attention: Phyllis Malekiania

                              with a copy to:

                              John A. Stalfort, Esquire
                              Miles & Stockbridge, a Professional
                              Corporation
                              10 Light Street, 8th Floor
                              Baltimore, Maryland 21202


                                      E-3

<PAGE>



If to MIDFA:

         Notices:                      Maryland Industrial Development
                                         Financing Authority
                                       217 East Redwood Street
                                       Redwood Tower, 22nd Floor
                                       Baltimore, Maryland 21202
                                       Attention: Executive Director

If to State:

         Notices:                      Department of Business and Economic
                                       Development
                                       217 East Redwood Street, 22nd Floor
                                       Baltimore, Maryland 21202
                                       Attention: Director of Community
                                                  Financing Group Programs




                                      E-4