LEASE

Exhibit 10.5

EXECUTION COPY
#42352696v5

LEASE

BETWEEN

PDM UNIT 850, LLC

AND

ALKERMES, INC.

FOR PREMISES LOCATED AT

850 AND 852 WINTER STREET

RESERVOIR WOODS, WALTHAM, MASSACHUSETTS

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LEASE

     LEASE dated as of April 22, 2009, by and between PDM 850 Unit, LLC, a Delaware limited liability company (hereinafter called “ Landlord ”), and Alkermes, Inc., a Pennsylvania corporation (hereinafter called “ Tenant ”).

Article 1.

Premises — Term of Lease

     Section 1.01. Premises . Upon and subject to the conditions and limitations hereinafter set forth, Landlord does hereby lease and demise unto Tenant on an “as is” basis (except as otherwise expressly set forth herein) a portion of each of the lower level, first (including the main lobby and entryway serving the Premises), second, and third floors of a building with an address of 850 and 852 Winter Street, Waltham, Massachusetts and constructed substantially in accordance with the specifications attached as Exhibit 1.01-3 , subject to reasonably equivalent substitutions for materials described therein (such building being referred to herein as the “ Building ”), as such demised premises is more particularly described on Exhibit 1.01-1 (the “ Premises ”), together with the right to use, in common with others, the walkways, driveways, parking areas, loading areas, and utility lines (including telecommunications lines) serving the Premises. The parties agree that the rentable area for the Premises is 100,235 rentable square feet, as measured in accordance with the measurement standard described on Exhibit 1.01-4 , attached.

     The Building is a condominium unit within the Reservoir Woods Primary Condominium (the “ Condominium ”), a condominium created by Master Deed dated February 26, 2007, recorded in Book 49037, Page 229 of the Middlesex South Registry of Deeds, as amended. The Building and its undivided interest in the common elements of the Condominium are referred to herein as the “ Property ” and are more particularly described on Exhibit 1.01-2 . This Lease, and Tenant’s leasehold interest in the Premises, are subject to the terms, covenants and conditions of agreements, easements and restrictions of record applicable to the Property, all of which Tenant shall perform and observe insofar as the same are applicable to the Premises; provided, however, that Tenant shall not be bound by any easements or restrictions made after the date of this Lease that materially and adversely affect Tenant’s rights and obligations under this Lease unless and until Landlord has obtained Tenant’s prior written consent. Landlord hereby represents and warrants that none of the existing agreements, easements and restrictions of record prohibit or restrict use of the Premises for the Permitted Uses.

     The Premises exclude common areas and facilities of the Building, including without limitation exterior walls, roofs, the common stairways and stairwells, the parking garage, elevators and elevator wells, fan rooms, electric and telephone closets (other

than those exclusively serving the Premises, if any), janitor closets, freight elevators, and pipes, ducts, conduits, wires and appurtenant fixtures serving other parts of the Property (exclusively or in common) and other common areas and facilities from time to time designated as such by Landlord; provided that, in any event, the designation of such common areas and facilities does not adversely affect the Premises, Tenant’s use of the Premises, or access to the Premises in more than a de minimis manner. If the Premises include less than the entire rentable area of any floor, then the Premises also exclude the common corridors, common elevator lobby and common toilets located on such floor.

     Section 1.02. Special Appurtenant Rights .

               (a) Tenant shall, subject to reasonable closures for repairs and the like, casualty, and condemnation, have the appurtenant, non-exclusive right, in common with others, to use the common fitness center (subject only to nominal charges for use of basic services) and cafeteria (with associated patio area) located at the Building, in each case subject to reasonable rules established by Landlord from time to time pursuant to Section 5.04 of this Lease, and which services shall, subject to the matters set forth above, be available throughout the term of this Lease (the facilities referred to in this paragraph, collectively, the “ Amenities ”).

     Landlord and Tenant acknowledge that Landlord intends to retain a third-party vendor for the operation of the cafeteria in the Building. If the service provided by any third-party vendor operating the cafeteria from time to time is inconsistent with first-class standards for a suburban office, laboratory and research and development park in more than a de minimus manner, Tenant shall have the right to give Landlord written notice of such event with sufficient detail for Landlord to investigate the complaint. At the written request of Tenant, Landlord shall exercise its right to terminate the contract of such vendor, in which event Landlord shall use reasonable efforts to replace the applicable vendor with a substitute vendor experienced in operating similar facilities in first class suburban office, laboratory and research and development buildings, subject to Tenant’s rights under the immediately preceding paragraph. Landlord shall consult with Tenant in the process of making menu selections for the cafeteria.

               (b) So long as Landlord or an entity controlled by, under common control with, or controlling Landlord is the owner of the property known as 840 Winter Street, Waltham, Massachusetts (also known as “ Healthpoint ”), Tenant shall be entitled to the benefit of any discounted rates for the fitness facilities located at Healthpoint, if any, that are negotiated between Landlord and the owner of Healthpoint for the benefit of tenants at the Building.

               (c) Tenant shall have the appurtenant, non-exclusive right, in common with others, to reasonably access any Building communication system serving the Premises (which access shall be reasonably coordinated and facilitated by Landlord) and the exclusive right and obligation to use and maintain the heating, ventilation and air-conditioning units installed on the roof and exclusively serving the second and third floors of the Premises, together with the rights to use the roof further described in Article 21, below.

               (d) Landlord shall cooperate with Tenant during Tenant’s design of the Finish Work to identify an appropriate portion or portions of the parking garage beneath the Building in which Tenant may install a pH neutralization system and other lab equipment and systems serving the Premises (such areas collectively being referred to as the “ PH Rooms ”). In no event shall the PH Rooms exceed 750 square feet in gross floor area in the aggregate. Landlord and Tenant shall enter into a written instrument identifying the location of the PH Rooms upon determining their location, in which event such areas shall be deemed to be appurtenant to the Premises and available for Tenant’s exclusive use. If the location of the PH Rooms, as agreed to by Landlord, results in the loss of one or more parking spaces serving the Building, then such eliminated parking space(s) shall be counted towards Tenant’s parking allocation under Section 20.10 of this Lease.

               (e) Tenant shall, subject to reasonable closures for maintenance and repairs (for which Landlord shall provide Tenant with reasonable prior notice where feasible), casualty, and condemnation, have the appurtenant, exclusive right to use the two (2) elevators identified as “ Tenant Exclusive Elevators ” on Exhibit 1.01-1 for access and egress to the Premises. Notwithstanding the foregoing, except for casualty or condemnation and subject to the provisions of Section 3.02, at least one of the Tenant Exclusive Elevators shall be available 24 hours per day, 365 days per year during the Term.

     Section 1.03. Term Commencement . Tenant and Landlord acknowledge and agree that the Premises shall be delivered by Landlord in two phases: the first and third floor of the Premises and associated basement areas (the “ Office Portion ”) shall be delivered first, and the second floor of the Premises and associated basement areas shall be delivered second (the “ Lab Portion ”; either the Office Portion or the Lab Portion being referred to herein as a “ Portion ”).

               (a) The term of this Lease for each Portion of the Premises shall commence on the earlier of (i) the Delivery Date (as defined below), or (ii) the date Tenant enters into possession of all or any substantial portion of such Portion for the conduct of its business (for the purposes of this Section 1.03, “conduct of its business” shall not include installation of furniture, fixtures, equipment, or the like). The date of commencement for each Portion as so determined is hereinafter referred to as the “ Commencement Date .” The term shall expire at 11:59 p.m. on the date (the “ Expiration Date ”) that is the last day of the calendar month in which the 10th anniversary of the initial Rent Commencement Date (as defined in Section 2.01) occurs, unless extended or sooner terminated as hereinafter provided and shall include the period between the Commencement Date and the initial Rent Commencement Date. Landlord will provide Tenant with at least fourteen (14) days prior notice of each Delivery Date. If the Delivery Date designated in such notice does not occur on the initially designated date, Landlord shall keep Tenant informed of the anticipated Delivery Date and shall be required to give Tenant at least two (2) business days prior notice of the applicable Delivery Date as so extended.

     The “ Delivery Date ” shall mean the date on which Landlord Substantially Completes the Landlord Work (as defined in Exhibit 7.02 ) for a Portion of the Premises and delivers such Portion to Tenant. The “ Estimated Delivery Date ” means December 1, 2009, with respect to the Office Portion and February 1, 2010, with respect to the Lab Portion, as such dates are extended for Tenant Delay

and matters described in Section 20.14. Landlord’s failure to Substantially Complete the Finish Work and deliver the Premises on or before the applicable Estimated Delivery Date, for any reason, shall not give rise to any liability of Landlord hereunder, shall not constitute a Landlord’s default, shall not affect the validity of this Lease, and shall have no effect on the beginning or end of the term of this Lease as otherwise determined hereunder or on Tenant’s obligations associated therewith except that:

          (i) if the Commencement Date for the Office Portion occurs more than 30 days after the Estimated Delivery Date for the Office Portion as it may be extended, then, as liquidated damages Tenant shall receive an abatement of Base Rent allocable to the Office Portion equal to (x) one day for each day following such 30-day period through the 60th day following the Estimated Delivery Date with respect to the Office Portion, and (y) two days for each day thereafter until the Commencement Date for the Office Portion occurs.

          (ii) if the Commencement Date for the Lab Portion occurs more than 60 days after the Estimated Delivery Date for the Lab Portion as it may be extended, then, as liquidated damages Tenant shall receive an abatement of Base Rent allocable to the Lab Portion equal to (i) one day for each day following such sixty-day period through the 90th day following the Estimated Delivery Date with respect to the Lab Portion, and (ii) two days for each day thereafter until the Commencement Date for the Lab Portion occurs; and

          (iii) Notwithstanding the foregoing, in the event that the Commencement Date for the Office Portion fails to occur within 135 days after the Estimated Delivery Date for the Office Portion, then Tenant shall have the one-time option to elect either to (A) terminate this Lease or (B) complete all of the Landlord Work at its sole cost and expense (except as set forth below) and in compliance with Article 8 hereof, in either case upon thirty (30) days prior written notice to Landlord; provided, however, that if the Commencement Date for the Office Portion occurs within such thirty (30) day period, then such election shall be of no force or effect. Notwithstanding anything to the contrary herein, if Tenant makes the election set forth in clause (B), above, then Tenant may apply any unused Finish Work Allowance towards any work undertaken pursuant to clause (B) pursuant to (and subject to the provisions of) Exhibit 7.02 and shall, to the extent not reimbursed through use of the Finish Work Allowance, have the right to reimbursement by Landlord (on 30 days prior notice) for Tenant’s reasonable third party costs and expenses to complete such Landlord Work to the extent exceeding the amount of Excess Finish Work costs that Tenant would otherwise have incurred in the completion of such Landlord Work by Landlord; and

          (iv) Notwithstanding the foregoing, in the event that the Commencement Date for the Lab Portion fails to occur within 135 days after the Estimated Delivery Date for the Lab Portion, then Tenant shall have the one time option to elect either to (A) terminate this Lease solely with respect to the Lab Portion of the Premises, or (B) complete the Landlord Work for the Lab Portion at its sole cost and expense (except as set forth below) and in compliance with Article 8 hereof, in either case upon thirty (30) days prior written notice to Landlord; provided, however, that if the Commencement Date for the Lab Portion occurs within such thirty (30) day

period, then such election shall be of no force or effect. In the event that Tenant makes the election set forth in (A), above, then the Lab Portion (which the parties agree consists of 33,443 rentable square feet) shall be deemed to be removed from the Premises and the Base Rent, Tenant’s Pro Rata Share, Finish Work Allowance and any other rights under this Lease that are expressly derived on a per-square-foot basis shall be adjusted accordingly. Notwithstanding anything to the contrary herein, if Tenant makes the election set forth in clause (B), above, then Tenant may apply any unused Finish Work Allowance towards any work undertaken pursuant to clause (B) to the extent elected by Tenant pursuant to (and subject to the provisions of) Exhibit 7.02 and shall, to the extent not reimbursed through use of the Finish Work Allowance, have the right to reimbursement by Landlord (on 30 days prior notice) for Tenant’s reasonable third party costs and expenses to complete such Landlord Work to the extent exceeding the amount of Excess Finish Work costs that Tenant would otherwise have incurred in the completion of such Landlord Work by Landlord.

          (v) In connection with the exercise of this Lease, Landlord has provided Tenant with a guaranty from The Prudential Insurance Company of America, acting solely on behalf of or for the benefit of its insurance company separate account PRISA II, in the form attached as Exhibit 1.03.

     The remedies set forth in this Section 1.03(a) are Tenant’s sole and exclusive remedies, at law or in equity, with respect to Landlord’s timely delivery of the Premises and timely Substantial Completion of the Landlord Work.

               (b) Tenant and Landlord agree to execute an agreement in recordable form identifying the actual Commencement Dates, the Rent Commencement Dates, and the Expiration Date, but a failure to execute such an agreement shall not affect the commencement or expiration of the term of this Lease.

     THIS LEASE IS MADE UPON THE COVENANTS, AGREEMENTS, TERMS, PROVISIONS, CONDITIONS AND LIMITATIONS SET FORTH HEREIN, ALL OF WHICH TENANT AND LANDLORD EACH COVENANT AND AGREE TO PERFORM AND COMPLY WITH, EXCEPTING ONLY AS TO THE COVENANTS OF THE OTHER:

Article 2.

Rent

     Section 2.01. Base Rent . (a) The “ Rent Commencement Date ” shall mean, respectively, (x) the date that is six months after the Commencement Date for the Office Portion and (y) the date that is five months month after the Commencement Date for the Lab Portion . Beginning on the Rent Commencement Date for the applicable Portion, and on the first day of each month thereafter, the Tenant shall pay the Landlord base rent (“ Base Rent ”) in equal monthly installments, in advance, pursuant to the following schedule:

     If any Rent Commencement Date is other than the first day of the month, then, with respect to the partial month following such Rent Commencement Date, Tenant shall pay to Landlord on the applicable Rent Commencement Date a pro-rated share of the Base Rent that would have otherwise been payable for such month (based on the number of days remaining in such month) had such Rent Commencement Date occurred on the first day of such month.

     Section 2.02. Additional Rent for Operating Expenses and Taxes .

               (a) Commencing on the Commencement Date for each Portion of the Premises, Tenant shall pay as Additional Rent to Landlord Tenant’s Pro Rata Share of Taxes (as defined below) and Tenant’s Pro Rata Share of all Operating Expenses (as defined below). If at any time within any calendar year, less than 95% of the rentable space of the Building or Property is leased and occupied under agreements for which the lease term has commenced, Operating Expenses that vary with such occupancy for that calendar year during the term of this Lease shall be computed and adjusted upward so that Operating Expenses shall at all times equal the greater of (i) actual Operating Expenses or (ii) an amount extrapolated as if the Building or Property, as applicable, were ninety-five (95%) leased.

     Additional Rent computed under this Section 2.02 shall be prorated should this Lease commence or terminate before: (i) the end of any fiscal tax year for that portion related to Taxes; or (ii) the end of any calendar year for that portion related to Operating Expenses. Tenant shall make monthly payments of Additional Rent, in advance, on the applicable Commencement Date and the first of each month thereafter equal to one-twelfth (1/12) of the annual amount of such Additional Rent reasonably projected by Landlord to be due from Tenant (pro-rated for any partial month at the beginning or end of the term) from time to time. Tenant’s monthly payments may be reasonably revised by Landlord from time to time so that Tenant’s aggregate monthly payments shall equal the Additional Rent then projected to be due for the year in question. A final accounting and payment for each real estate tax and operating period shall be made within thirty (30) days after written notice from Landlord of the exact amount of such Additional Rent for the fiscal tax year or calendar year in question (each, a “ Reconciliation Notice ”), which notice Landlord shall endeavor to deliver to Tenant within ninety (90) days after the end of each fiscal tax year or calendar year, as applicable, and, in any event, Landlord shall deliver within 270 days after the end of each fiscal tax year or calendar year, as applicable. Landlord’s statements of Additional Rent for Operating Expenses and Taxes shall be conclusive and binding on Tenant unless disputed within six months after the respective year-end statements are issued. In the event that the Additional Rent due with respect such period is finally determined to be less than the Additional Rent paid by Tenant on account of Landlord’s projection of Additional Rent, Landlord shall credit the difference against the next installment of Rent coming due under this Lease or, if no such installment is coming due, then Landlord shall promptly refund such difference. In the event Taxes for the Premises, based upon which Tenant shall have paid Additional Rent, are subsequently reduced or abated, Tenant shall be entitled to receive its allocable share of the amount abated, provided that the amount of the rebate allocable to Tenant shall in no event exceed the amount of Additional Rent paid by Tenant for such fiscal year on account of Taxes under this Section 2.02, and further provided the rebate allocable to Tenant shall be reduced by its allocable share of the reasonable cost of obtaining such reduction or abatement not otherwise paid by Tenant. The obligations of this paragraph shall survive the expiration of the Lease.

     “ Tenant’s Pro Rata Share ” is calculated by dividing the rentable square foot area of the Premises by the rentable square foot area of the Building, as of the date of the computation. Tenant’s Pro Rata Share is initially 37.1% for the Office Portion and 55.7% for the entire Premises and is subject to adjustment if the rentable square footages of the Premises changes on account of any

amendment to the Lease or the Building changes on account of any remeasurement, reconstruction or expansion by Landlord. The Building consists of 180,039 rentable square feet, subject to adjustment pursuant to the immediately preceding sentence.

               (b) “ Operating Expenses ” for the purpose of this Section shall mean:

                    (1) All expenses incurred by the Landlord or its agents which shall be directly related to employment of day and night supervisors, janitors, handymen, engineers, mechanics, electricians, plumbers, porters, cleaners, accounting and management personnel, and other personnel (including amounts incurred for wages, salaries and other compensation for services, payroll, social security, unemployment and similar taxes, workmen’s compensation, insurance, disability benefits, pensions, hospitalization, retirement plans and group insurance, uniforms and working clothes and the cleaning thereof, and expenses imposed on the Landlord or its agents pursuant to any collective bargaining agreement), for services in connection with the operation, management, repair, maintenance, cleaning and protection of the Property and appurtenant common areas and facilities serving the Premises in a manner customarily provided to first class suburban mixed use office, laboratory and research and development parks in the suburban Boston area including without limitation repair and maintenance and providing the services required by this Lease, and, subject to clause (c)(1) below, personnel engaged in supervision of any of the persons mentioned above (collectively the “ Operation of the Property ”);

                    (2) The cost of services, materials and supplies furnished or used in the Operation of the Property;

                    (3) The cost of replacements for tools and equipment used in the Operation of the Property;

                    (4) Commercially reasonable management fees paid to managing agents and for reasonable legal and other professional fees relating to the Operation of the Property, but excluding legal and other professional fees paid in connection with negotiation, administration or enforcement of leases; provided, however, that so long as an affiliate of the Landlord manages the Property, management fees for the Property shall not exceed the greater of $75,000 or three percent (3%) of the gross income from tenants of the Property (including Base Rent and all Additional Rent) computed on an annual basis plus reimbursements;

                    (5) Insurance premiums in connection with the Operation of the Property, including without limitation for such insurance coverages and amounts as Landlord or its mortgagees may require from time to time;

                    (6) The costs of plowing and snow removal, maintaining landscaping and storm water drainage systems, maintaining parking garages, other parking areas, driveways, roadways, light poles, entry areas, and loading docks in good repair reasonably free of snow and ice (costs for shared facilities shall be allocated as set forth in clause 8 below), and the cost to provide the shuttle services described in Exhibit 3.02 ;

                    (7) Amounts paid to independent contractors for services, materials and supplies furnished for the Operation of the Property;

                    (8) Condominium assessments and charges;

                    (9) All other expenses incurred in connection with the Operation of the Property, including expenditures for maintenance and repairs that are classified as capital expenditures in accordance with generally accepted accounting principles, consistently applied, and for capital improvements and replacements that (A) will, in Landlord’s reasonable estimate, result in a reduction in Operating Expenses payable by Tenant (but only to the extent of such reduction) or (B) are required by changes in law occurring after the first Delivery Date to occur or enforcement of laws not generally occurring on such Delivery Date) to the extent not otherwise excluded as Operating Expenses, phone charges, travel (to the extent related to the performance of services included in Operating Expenses), costs of customary waste and recyclables removal, security and life safety systems testing, common area electricity and cleaning, and utilities, any expenses in the nature of common area charges for operation, maintenance and repair of driveways, parking garages, if any, and other facilities or services shared with other buildings or premises, and any condominium common expenses assessed against a condominium unit comprising the Premises. Any capital expenditures included in Operating Expenses pursuant to this paragraph shall be amortized on a straight line basis over the useful life of the item in question, as determined by Landlord using generally accepted accounting principles, consistently applied, together with interest at Landlord’s actual interest rate incurred in financing such capital improvements, or, if no part of such expenditure is financed, at an imputed interest rate equal to the prime rate of interest as reported by Bank of America, N.A., plus three (3%) percent; and

                    (10) Costs incurred in connection with the operation of the common fitness room and cafeteria, except to the extent covered by fees for use of such facilities.

               (c) Operating Expenses shall be computed on an accrual basis and shall be determined in accordance with generally accepted accounting principles consistently applied. They must be actually incurred, but may be incurred directly or by way of reimbursement, and shall include taxes applicable thereto. The following shall be excluded from Operating Expenses:

                    (1) Salaries and related benefits or any portion thereof for officers and executives of the Landlord or Landlord’s managing agent above the level of property manager.

                    (2) Depreciation of the Premises or any improvements thereon.

                    (3) Interest and amortization on indebtedness (except as expressly provided above).

                    (4) Expenses for which the Landlord, by the terms of this Lease or otherwise, makes a separate charge.

                    (5) The cost of any electric current or other utilities or services paid for by the Tenant or by other tenants as a separate charge.

                    (6) Leasing fees or commissions.

                    (7) Repairs or other work occasioned by the exercise of right of eminent domain.

                    (8) Renovating or otherwise improving or decorating, painting or redecorating space for tenants or other occupants or vacant tenant space, other than maintenance and repairs required by this Lease and work in common areas.

                    (9) Landlord’s costs of utilities and other services sold separately to tenants for which Landlord is entitled to be reimbursed by such tenants as a separate charge over and not as part of the base rent, operating expense, or other rental amounts payable under the lease with such tenant.

                    (10) Expenses in connection with services or other benefits of a type which Tenant is not entitled to receive under the Lease but which are provided to another tenant or occupant.

                    (11) Expenses, including rental, created under any ground or underlying leases.

                    (12) Any particular items and services for which a tenant otherwise reimburses Landlord by direct payment over and above the base rent, operating expenses and other rental amounts payable under the applicable lease.

                    (13) Any expense for which Landlord is compensated through proceeds of insurance, condemnation or otherwise.

                    (14) Expenses for periods of time not included within the term of this Lease.

                    (15) Expenses that are considered capital improvements and replacements under generally accepted accounting principles, except to the extent expressly permitted pursuant to clause (b)(9), above.

                    (16) Cost of rebuilding after casualty or taking, other than insurance deductibles.

                    (17) All Operating Expenses shall be reduced by the amount (net of collection costs) of any insurance reimbursement, discount or allowance received by the Landlord in connection with such costs.

                    (18) Costs incurred in the acquisition and development of the Property including the correction of any defective Base Building Work.

                    (19) Environmental testing, and the cost of complying with applicable federal, state and local laws, regulations and rules dealing with handling, storage and disposal of Hazardous Materials (other than those ordinarily found or used in the customary operation of first class office buildings), including clean up costs, and any related matters, except in each case to the extent caused by Tenant or any party for whom Tenant is legally responsible.

                    (20) That portion of employee expenses allocable to work that is not for the benefit of the Property or common areas and facilities serving the same; if employees work at more than one location, their compensation and other labor costs shall be properly allocated.

                    (21) Administrative fees and compensation for Landlord’s and managing agent’s general administrative staff, to the extent not directly attributable to the management, operation, maintenance and repair of the Property or common areas and facilities serving the Property (other than the management fee referred to in subsection (b)(4), above).

                    (22) Franchise or income taxes imposed on Landlord.

                    (23) Costs incurred by Landlord as a result of any violation by Landlord or any other tenant of the terms and conditions of any lease of space.

                    (24) Costs related to maintaining Landlord’s existence, either as a corporation, partnership, or other entity, or costs incurred by Landlord relative to any debt that encumbers the Property (by example these costs shall include, but not be limited to income tax return preparation, filing costs, legal costs, etc.).

                    (25) Costs arising from Landlord’s charitable contributions not to exceed $500 per year (such amount to be increased, but never decreased, annually in proportion to any increase in the Consumer Price Index — All Urban Consumers for the Boston Metropolitan area published by the U.S. Department of Labor or a comparable index reasonably selected by Landlord (such index being referred to herein as the “ CPI ”)).

                    (26) Costs for reserves of any kind.

                    (27) Costs incurred in connection with Building events for tenants, including, but not limited to, tenant parties, holiday gifts and tenant welcoming gifts.

                    (28) Costs for any services to the Premises that are assumed by Tenant pursuant to Section 3.03 of this Lease, whether provided to Tenant or to other tenants of the Building in their premises.

                    (29) Costs of audited financial statements, but only to the extent the same is in excess of $15,000 in any single lease year (such amount to be increased, but never decreased, annually in proportion to any increase in the CPI).

               (d) “ Taxes ” means all taxes, assessments, betterments, excises, user fees imposed by governmental authorities, and all other governmental charges and fees of any kind or nature, or impositions or agreed payments in lieu thereof or voluntary payments made in connection with the provision of governmental services or improvements of benefit to the Building or the Property), assessed or imposed against the Building or the Property (including without limitation any personal property taxes levied on such property or on fixtures or equipment used in connection therewith), other than a federal or state income tax of general application. Notwithstanding anything to the contrary herein, Taxes shall exclude (a) any land acquisition costs, and any other fee, cost or tax (other than increases in real property taxes resulting from reassessments of the Property) associated with the development or construction of the Property and (b) any interest or penalties for late payments to the extent relating to a period in which Tenant was not in default of its obligations to pay Tenant’s Pro Rata Share of Taxes, and (c) any income, capital levy, transfer, capital stock, gift, estate or inheritance tax. The amount of any special taxes, special assessments and agreed or governmentally imposed “in lieu of tax” or similar charges shall be included in Taxes for any year but shall be limited to the amount of the installment (plus any interest, other than penalty interest, payable thereon) of such special tax, special assessment or such charge required to be paid during or with respect to the year in question. Betterments and assessments, whether or not paid in installments, shall be included in Taxes in any tax year as if the betterment or assessment were paid in installments over the longest period permitted by law, together with the interest thereon charged by the assessing authority for the payment of such betterment or assessment in installments.

     If during the term of this Lease the present system of ad valorem taxation of property shall be changed so that, in lieu of or in addition to the whole or any part of such ad valorem tax there shall be assessed, levied or imposed on such property or on Landlord any kind or nature of federal, state, county, municipal or other governmental capital levy, income, sales, franchise, excise or similar tax, assessment, levy, charge or fee (as distinct from the federal and state income tax in effect on the date of this Lease) measured by or based in whole or in part upon building valuation, mortgage valuation, rents, services or any other incidents, benefits or measures of real property or real property operations, then any and all of such taxes, assessments, levies, charges and fees shall be included within the term of Taxes, but only to the extent that the same would be payable if the Property were the only property of Landlord. Taxes shall also include expenses, including reasonable fees of attorneys, appraisers and other consultants, incurred in connection with any efforts to obtain abatements or reduction or to assure maintenance of Taxes for any year wholly or partially included in the term of this

Lease, whether or not successful and whether or not such efforts involved filing of actual abatement applications or initiation of formal proceedings.

               (e) Tenant shall have the right for a period of ninety (90) days (the “ Audit Period ”) following its receipt of Landlord’s statement of Additional Rent due on account of Operating Expenses to examine and copy Landlord’s books and records concerning Operating Expenses for the calendar year covered by such statement in the offices of the property manager or another location reasonably designated by Landlord in the greater Boston area, so long as Tenant pays any amount billed by Landlord on account of Additional Rent without protest (but subject to Tenant’s right to recover any overpayments pursuant to this paragraph). Tenant’s audit may be conducted by its employees or its designated accountants, provided that the accountants must be employed on a regular fee for services basis and not on a contingency fee basis. If, by notice to Landlord given after such examination but during the Audit Period (which notice shall be accompanied by documentation evidencing the results of Tenant’s audit to Landlord’s reasonable satisfaction), Tenant disputes the amount of Additional Rent for Operating Expenses shown on the statement, then Tenant may request that the amount of Additional Rent for Operating Expenses for the year in question be determined by an audit conducted by a certified public accountant reasonably selected by both parties, provided that if the parties are unable so to agree on an accountant within ten (10) days after receipt of Tenant’s notice, then within twenty (20) days after Tenant’s notice is given Tenant may submit the dispute for determination by an arbitration conducted by a single arbitrator in the Boston Office of the American Arbitration Association (“ AAA ”) in accordance with the AAA’s Commercial Arbitration Rules. The arbitrator shall be selected by the AAA and shall be a certified public accountant with at least ten (10) years of experience in auditing mixed use office, laboratory and research and development buildings in the suburban Boston area. The cost of the accountant selected by both parties, and the arbitrator, if applicable, shall be shared equally by the parties. Tenant and each person reviewing Landlord’s books and records or participating in the arbitration shall agree in an instrument prepared by Landlord that all information obtained from Landlord’s books and records shall be kept confidential and used only for the purpose of determining amounts properly due under this Lease. If the Additional Rent due is finally determined to be less than the Additional Rent paid by Tenant on account of Landlord’s calculation of Operating Expenses, Landlord shall either promptly refund to Tenant the difference or credit same against Rent next due from Tenant. If the Additional Rent due was less than ninety-five percent (95%) of the Additional Rent paid by Tenant on account of Landlord’s calculation of Operating Expenses, Landlord shall reimburse Tenant for the reasonable third-party costs of reviewing Landlord’s books and records, but in any event not to exceed $4,000 (such amount to be increased, but never decreased, annually in proportion to any increase in the CPI).

               (f) Operating Expenses which are incurred jointly for the benefit of the Building and another building or premises shall be allocated between the Building and the other building or premises in accordance with the ratio of their respective rentable areas calculated using a consistent methodology, unless Landlord reasonably determines that the other building or premises is used for a purpose materially different than the Building or that the Operating Expense in question results from a service provided or used in a materially disproportionate manner, in which case the affected cost items shall be allocated on a reasonable basis by

Landlord. Landlord may elect to allocate Operating Expenses separately among tenants with different use categories in the Building from time to time based on such factors as the Landlord reasonably determines (rather than on a proportionate basis based on square feet) if Landlord reasonably determines it is necessary to fairly allocate the Operating Expenses. If the Building and the land appurtenant thereto are not assessed as a separate tax parcel, then real estate taxes shall be allocated between the Building and the balance of the tax parcel based on the factors taken into account by the municipal tax assessor or such other reasonable method as Landlord may elect, which may be based on the relative square footages of the buildings and their use or may be in accordance with the ratio of their respective fair market values . In the event of a dispute concerning the allocation of Operating Expenses or Taxes, then the matter shall be submitted by Landlord and Tenant for resolution by arbitration in accordance with the procedures set forth in Section 2.02(e).

     Section 2.03. Payment of Rent . The term “ Additional Rent ” shall mean all amounts due under Section 2.02 for Operating Expenses and Taxes, and all other amounts (except Base Rent) to be paid by Tenant to Landlord in accordance with the terms of this Lease, including without limitation payments to Landlord for reimbursement of any costs expended upon an Event of Default by Tenant. The term “ Rent ” shall mean Base Rent and Additional Rent. All payments of Rent shall be made without set-off, deduction or offset except as expressly provided in this Lease. All payments of Rent shall be made to the Landlord at c/o  Davis Marcus Management, One Appleton Street, Boston, Massachusetts 02116, Attn: Larry Lenrow, or as may be otherwise directed by the Landlord in writing, which may include a direction to pay by wire transfer to an account specified by Landlord. Without limiting the foregoing, Tenant’s obligation to pay Rent shall be absolute, unconditional, and independent and shall not be discharged or otherwise affected by any law or regulation now or hereafter applicable to the Premises, or any other restriction on Tenant’s use, or, except as provided in Article 11, any casualty or taking, or any failure by Landlord to perform or other occurrence; and, except as expressly provided in this Lease, Tenant assumes the risk of the foregoing and waives all rights now or hereafter existing to quit or surrender the Premises or any part thereof, to terminate or cancel this Lease, or to assert any defense in the nature of constructive eviction to any action seeking to recover rent. Subject to the provisions of this Lease, however, Tenant shall have the right to injunctive relief or to seek judgments for direct money damages occasioned by Landlord’s breach of its Lease covenants.

     Section 2.04. Rent from Real Property. It is intended that all Rent payable by Tenant to Landlord, which includes all sums, charges, or amounts of whatever nature to be paid by Tenant to Landlord in accordance with the provisions of this Lease, shall qualify as “rents from real property” within the meaning of both Sections 512(b)(3) and 856(d) of the Internal Revenue Code of 1986, as amended (the “ Code ”) and the U.S. Department of Treasury Regulations promulgated thereunder (the “ Regulations ”). If Landlord, in its sole discretion, determines that there is any risk that all or part of any Rent shall not qualify as “rents from real property” for the purposes of Sections 512(b)(3) or 856(d) of the Code and the Regulations, Tenant agrees (i) to cooperate with Landlord by entering into such amendment or amendments to this Lease as Landlord reasonably deems necessary to qualify all Rent as “rents from real property,” and (ii) to permit an assignment of this Lease; provided, however, that any adjustments required under this section shall be made so as to produce the equivalent (in economic terms) Rent as payable before the adjustment.

     Section 2.05. Security Deposit . On or before April 27, 2009, Tenant shall deliver to Landlord as security for the performance of the obligations of Tenant hereunder a letter of credit in the initial amount of $1,000,000 (the “ Letter of Credit Amount ”) in accordance with this Section 2.05 (as renewed, replaced, increased and/or reduced pursuant to this Section 2.05, the “ Letter of Credit ”). Tenant’s failure to timely deliver the Letter of Credit to Landlord, or increase the amount of the Letter of Credit as required under this Section 2.05, at any time pursuant to this Section 2.05 shall constitute an Event of Default under this Lease, without any notice or cure period under Article 14. The Letter of Credit (i) shall be irrevocable and shall be issued by a commercial bank reasonably acceptable to Landlord that has an office for presentment in the City of Waltham or City of Boston, in the form attached as Exhibit 2.05 or such other substantially similar form as is reasonably acceptable to Landlord, (ii) shall require only the presentation to the issuer of a certificate of the holder of the Letter of Credit stating that Landlord is entitled to draw on the Letter of Credit pursuant to the terms of this Lease, (iii) shall be payable to Landlord or its successors in interest as the Landlord and shall be freely transferable without cost to Landlord, any such successor or any lender holding a collateral assignment of Landlord’s interest in the Lease, (iv) shall be for an initial term of not less than one year and contain a provision that such term shall be automatically renewed for successive one-year periods unless the issuer shall, at least 45 days prior to the scheduled expiration date, give Landlord notice of such non-renewal, and (v) shall otherwise be in form and substance reasonably acceptable to Landlord. Landlord acknowledges that, as of the date of this Lease, Bank of America is an approved issuer of the Letter of Credit. Notwithstanding the foregoing, the term of the Letter of Credit for the final period shall be for a term ending not earlier than the date sixty (60) days after the last day of the Term. Tenant acknowledges that Landlord may be required to pledge the proceeds of the Letter of Credit to any lender holding a collateral assignment of Landlord’s interest in the Lease and agrees to provide Landlord with such documentation as Landlord may reasonably request, and to cooperate with Landlord as is necessary, to evidence the consent to such pledge by the issuer of the Letter of Credit.

               (a) The Letter of Credit Amount shall be increased by Tenant (via amendment to the then-existing Letter of Credit or by supplying Landlord with a replacement Letter of Credit) by the amount of $1,500,000 if Tenant fails, at any time during the term of this Lease, to meet the Financial Test (as hereinafter defined). The “ Financial Test ” shall mean that Tenant has unrestricted cash and cash equivalents, as determined in accordance with generally accepted accounting principles, consistently applied, equal to at least $50,000,000 in United States dollars. If, at any time after the Letter of Credit is increased pursuant to the foregoing, Tenant subsequently meets the Financial Test for three complete calendar quarters in a row and reasonably evidences the same to Landlord, then, provided that Tenant is not then in default beyond applicable notice or cure periods and no Bankruptcy Event (as defined below) is then in effect, Tenant shall be entitled to reduce the Letter of Credit by the amount of $1,500,000 (but to an amount equal to no less than $1,000,000) until such time, if any, that Tenant subsequently fails to meet the Financial Test. A “ Bankruptcy Event ” shall mean that Tenant files a voluntary petition in bankruptcy or shall be adjudicated a bankrupt or insolvent, shall file any petition or answer seeking any reorganization, arrangement, composition, dissolution or similar relief under any present or future federal, state or other statute, law or regulation relating to bankruptcy, insolvency or other relief for debtors, or shall seek, or consent, or acquiesce in the appointment of any trustee, receiver or liquidator of Tenant of all or any substantial part of their respective

properties, or of the Premises, or shall make any general assignment for the benefit of creditors; or any court enters an order, judgment or decree approving a petition filed against Tenant seeking any reorganization, arrangement, composition, dissolution or similar relief under any present or future federal, state or other statute, law or regulation relating to bankruptcy, insolvency or other relief for debtors.

     Landlord shall be entitled to draw upon the Letter of Credit in part or for its full amount, as Landlord may elect (i) if an Event of Default is then continuing (or if Tenant has failed to timely pay rent or perform any of its other obligations under the Lease and transmittal of a default notice or running of any cure period is barred or tolled by applicable law), (ii) if, not less than 30 days before the scheduled expiration of the Letter of Credit, Tenant has not delivered to Landlord a new Letter of Credit in accordance with this Section 2.05 (which failure shall be deemed a default without notice or cure period) or (iii) if the credit rating of the long-term debt of the issuer of the Letter of Credit (according to Moody’s or similar national rating agency) is downgraded to a grade below investment rate), or if the issuer of the Letter of Credit shall enter into any supervisory agreement with any governmental authority, or if the issuer of the Letter of Credit shall fail to meet any capital requirements imposed by applicable law. Landlord may, but shall not be obligated to, apply the amount so drawn to the extent necessary to cure an Event of Default under the Lease and/or make any payments due to Landlord hereunder on account of such Event of Default including without limitation any unpaid Rent, any damages arising from a termination of this Lease in accordance with its terms, and for any damages arising from any rejection of this Lease in a bankruptcy proceeding commenced by or against Tenant. Any amount drawn in excess of the amount applied by Landlord pursuant to the immediately preceding sentence shall be held by Landlord as a security deposit for the performance by Tenant of its obligations hereunder. Said security deposit may be mingled with other funds of Landlord, and no fiduciary relationship shall be created with respect to such deposit, nor shall Landlord be liable to pay Tenant interest thereon. If Tenant shall fail to perform any of its obligations under this Lease, Landlord may, but shall not be obliged to, apply the security deposit to the extent necessary to cure the Event of Default and/or make any payments due to Landlord hereunder on account of such Event of Default. After any such application by Landlord of the Letter of Credit or security deposit, Tenant shall reinstate the Letter of Credit to the amount then required to be maintained hereunder, upon demand (and, upon such reinstatement, Landlord shall return any cash security deposit then being held by Landlord to Tenant). Within forty-five (45) days after the expiration or sooner termination of the Term the Letter of Credit and any security deposit, to the extent not applied, shall be returned to the Tenant, without interest. For purposes of this Section 2.05, an Event of Default shall also include any default that is prevented or delayed from ripening into an Event of Default due to Landlord’s inability to give any required notice or the tolling of any grace or cure period caused by any stay or injunction arising from the bankruptcy of Tenant.

     In the event of a sale of the Property or lease, conveyance or transfer of the Property, Landlord shall have the right to transfer the security to the transferee (“New Landlord”) and Landlord shall thereupon be released by Tenant from all liability for the return of such security; and Tenant agrees to look to the New Landlord solely for the return of said security. The provisions hereof shall apply to every transfer or assignment made of the security to a New Landlord. Tenant further covenants that it will not assign or encumber

or attempt to assign or encumber the Letter of Credit or the monies deposited herein as security, and that neither Landlord nor its successors or assigns shall be bound by any assignment, encumbrance, attempted assignment or attempted encumbrance

Article 3.

Utility Services

     Section 3.01. Electricity . From and after the Commencement Date for each Portion of the Premises, Tenant agrees to pay, or cause to be paid, as Additional Rent, all charges for electricity consumed in the applicable Portion of the Premises (or by any special facilities serving the Premises). Tenant will comply with all contracts relating to any such services. Tenant’s charges for such utility usage shall be based upon Tenant’s actual usage as determined by Landlord’s reading of check-meters serving the Premises provided as part of the Finish Work. Tenant shall make monthly payments of Additional Rent on account of electricity, in advance, on the applicable Commencement Date and the first of each month thereafter equal to one-twelfth (1/12) of the annual amount of such Additional Rent reasonably projected by Landlord, based upon prior usage at the relevant building or as projected by Landlord’s engineer, to be due from Tenant (pro-rated for any partial month at the beginning or end of the term) from time to time. Tenant’s monthly payments may be reasonably revised by Landlord from time to time so that Tenant’s aggregate monthly payments shall equal the Additional Rent then projected to be due for the year in question. Landlord shall provide Tenant with a statement showing Tenant’s actual usage of electricity based on the reading of Tenant’s check-meters no less often than annually. If the Additional Rent due for electricity is less than the Additional Rent for electricity paid by Tenant on account of Landlord’s calculation of estimated electrical charges, Landlord shall either promptly refund to Tenant the difference or credit same against Rent next due from Tenant. If the Additional Rent due for electricity is more than Landlord’s calculation of estimated electrical charges, Tenant shall pay such amount to Landlord within 30 days following receipt of the bill therefor. If such usage is not separately or check-metered from time to time, such usage and billing shall be based upon the reasonable estimate of Landlord’s consulting engineer. If Tenant is directed by Landlord to make payments directly to the utility company for separately metered electricity, then Tenant shall pay such bills directly to the utility company, Tenant shall contract directly for electric service, and shall pay all bills for such utility service as and when due. Tenant shall pay all costs associated with obtaining the electricity service, including costs for equipment installation, maintenance and repair; exit fees, stranded cost charges, and the like.

     Section 3.02. Other Landlord Services . Landlord shall provide Tenant with access to the Premises, the Building and the parking areas serving the Building 24 hours per day, 365 days per year, subject to matters described in Section 20.14 and Landlord’s reasonable security measures, and subject to Landlord’s right to prohibit, restrict or limit access to the Building or the Premises in emergency situations if Landlord determines, in its reasonable discretion, that it is necessary or advisable to do so in order to prevent or protect against death or injury to persons or damage to property. Landlord agrees to furnish to the Premises the services, and for the

periods, set forth on Exhibit 3.02 (Tenant paying for such services as Operating Expenses). All other services necessary for the use, occupancy or operation of the Premises, or to maintain the same in good condition and repair (except to the extent set forth in Section 7.01, below), shall be provided by Tenant. In the event of an unanticipated maintenance or repair cost that is incurred by Landlord as an Operating Expense, Landlord may notify Tenant upon determining the maintenance or repair is needed and, if requested by Landlord, Tenant shall pay the reasonable cost thereof to Landlord within thirty (30) days after request in addition to the estimated monthly payments for Operating Expenses under Section 2.02 and the additional payment shall be credited against the total amount of Operating Expenses due under Section 2.02 for the year in question. Landlord shall not be required to provide services which exceed the capacity of the building systems serving the Premises and shall not be required to act (or prevented from acting) in any manner which might create unsafe conditions, violate applicable legal requirements, or be inconsistent with standards for the operation of comparable institutionally-financed mixed use office, laboratory and research and development buildings. In any event, subject to Section 7.06 below, Landlord’s obligation to provide such services shall be subject to interruption due to any act or omission of Tenant (including a failure to pay for utilities), accident, to the making of repairs, alterations or improvements (other than those due to the willful misconduct of Landlord), to labor difficulties, to trouble in obtaining fuel, electricity, service or supplies from the sources from which they are usually obtained for such building, governmental restraints, or to any cause beyond the Landlord’s reasonable control. In the event of any such disruption or interruption (other than an act or omission of Tenant) prior to the time when Tenant is responsible for providing such services, Landlord will use diligent efforts to restore the services, or to cause the services to be restored, as promptly as reasonably possible. In no event shall Landlord be liable for any interruption or delay in any of the above services for any of such causes except as provided in Section 7.06.

     Normal Building hours of operation are Monday through Friday, 8 a.m. to 6 p.m., and Saturday 8 a.m. to 1 p.m., exclusive of state and federal holidays and such other days as Landlord may reasonably designate as Building holidays (e.g. the day after Thanksgiving).

     Section 3.03. Facilities Management Rights .

               (a) So long as an Event of Default does not then exist, Tenant shall have the right to assume all or any portion of the on-site management services with respect to the Building systems serving the Premises described on Exhibit 3.03-1 commencing on a date no earlier than the initial Commencement Date. If Tenant desires to assume all or any portion of such on-site management responsibilities pursuant to this Section 3.03, Tenant shall notify Landlord in writing (a “ Facilities Management Notice ”) at least sixty (60) days prior to the first day of the month in which Tenant intends to assume such management responsibilities and identify by reference to Exhibit 3.03-1 the responsibilities to be assumed. In connection with any such change in management, the parties shall cooperate and coordinate with each other so as to effect a smooth transition and transfer of information and responsibility. During any period that Tenant is exercising its facilities management rights pursuant to this Section 3.03, the provisions of Exhibit 3.03-2 shall apply.

     Tenant shall have the right voluntarily to terminate any portion of its management services under this Section 3.03 and to relinquish all or any portion of such services under this Section 3.03 upon sixty (60) days notice and may subsequently again exercise its management rights hereunder (in whole or in part) provided that the conditions set forth in this Section 3.03 are then satisfied and more than twelve (12) months have elapsed following the effective date of the termination of the applicable portion of its management services. If Landlord terminates Tenant’s management services pursuant to the provisions of Exhibit 3.03-2 , then Tenant shall have no further right to manage any portion of the Building under this Section 3.03. In no event shall Tenant, in the exercise of its rights under this Section 3.03, be permitted to assume the management of areas or facilities of the Building serving tenants other than Tenant.

               (b) During such time as Tenant is exercising its facilities management rights pursuant to this Section 3.03, Tenant will cooperate and work with Landlord to manage the same cooperatively with the remainder of the Property. In all events, Tenant shall be fully responsible for all costs and expenses of facilities management under this Section, subject to reimbursement for capital expenditures as set forth below. Tenant’s rights under this Section 3.03 shall be personal to the Tenant originally named hereunder. In no event may Tenant’s facilities management rights pursuant to this Section 3.03 be transferred to or exercised by any other transferee.

     Notwithstanding anything in this Lease to the contrary, so long as Tenant is exercising its facilities management rights pursuant to this Section 3.03, Tenant will maintain, repair and replace, at its sole cost and expense (subject to reimbursement with respect to capital expenditures as set forth below) portions of the Building as further described on Exhibit 3.03-1 and designated in Tenant’s Facilities Management Notice (the “ Self-Managed Components ”) and Landlord shall, during such period, have no obligation to maintain, repair, or replace the Self-Managed Components. If any element of the Self-Managed Components cannot be fully repaired or restored, and Landlord authorizes replacement of such item or replacement, or such replacement item is included in an Approved Budget (as defined in Exhibit 3.03-2 ) Tenant shall replace it at Tenant’s cost even if the benefit or useful life of such replacement extends beyond the term of this Lease and Landlord shall reimburse Tenant for such costs to the extent that such costs are capital expenditures that would not have been includable in Operating Expenses payable by Tenant under this Lease. Landlord shall reimburse Tenant for the costs set forth in the preceding sentence by paying such costs within 30 days after receiving Tenant’s invoice therefor. If Landlord pays costs for capital expenditures when invoiced under this paragraph and Tenant subsequently exercises an option to extend the term in accordance with this Lease, Tenant shall reimburse Landlord for all such costs allocable to the extension term or terms (to the extent that such costs would have been includable in Operating Expenses payable by Tenant) within 30 days after written request by Landlord made at any time after Tenant exercises the applicable extension option. Landlord’s and Tenant’s obligations under the prior two sentences shall survive the expiration of the term.

Article 4.

Insurance

     Section 4.01. Compliance with Property Insurance . The Tenant shall not permit any use of the Premises which will make voidable any insurance on the Property, or on the contents of said property, or which shall be contrary to any law or regulation from time to time established by the Insurance Services Office, or any similar body succeeding to its powers. The Tenant shall, on demand, reimburse the Landlord in full for its allocable share of any extra insurance premiums caused by the particular use or manner of use of the Premises by Tenant.

     Section 4.02. Tenant’s Required Insurance . The Tenant shall maintain with respect to the Premises and the property of which the Premises are a part, the following insurance:

               (a) Commercial general liability insurance, including Broad Form Project Damage and Contractual Liability, with respect to the Premises, their use, occupancy and operation, under which Tenant is the named insured and Landlord, Landlord’s managing agent, any mortgagee, the association of unit owners under the Reservoir Woods Primary Condominium, The Prudential Insurance Company of America, and any Landlord agents or contractors (provided that Landlord has identified such mortgagee, agents and/or contractors by notice to Tenant) are named as additional insureds with respect to their vicarious liability for covered claims arising from Tenant’s use or occupancy of the Premises or the Property. Such coverage shall be written on an occurrence basis, with the following minimum limits: General Aggregate $2,000,000.00; Products/Completed Operations Aggregate $2,000,000.00; Each Occurrence $1,000,000.00; Personal and Advertising Injury $1,000,000.00; Medical Payments $5,000.00 per person. In addition, Tenant shall maintain  Umbrella/Excess Liability insurance on a following form basis with the following minimum limits: General Aggregate $5,000,000.00; Each Occurrence $5,000,000.00;

               (b) Commercial property insurance on an “all risk” basis, and specifically including sprinkler leakages, vandalism, and malicious mischief and plate glass damage covering all property of every description owned or brought into the Premises by Tenant, its employees, agents, contractors, subtenants, or assignees including stock-in-trade, furniture, fittings, installations, alterations, additions, partitions and fixtures or anything in the nature of a leasehold improvement made or installed by or on behalf of the Tenant, including without limitation any Tenant Work and the Finish Work, in an amount of not less than one hundred percent (100%) of the full replacement cost thereof as shall from time to time be reasonably approved by Landlord in form satisfactory to Landlord in its reasonable discretion and plate glass insurance coverage covering all plate glass within the Premises. Landlord shall be named as loss payee on such property insurance to the extent of its interest;

               (c) Policies of insurance against loss or damage arising from incidents relating to the air-conditioning and/or heating system, electrical systems, steam pipes, steam turbines, steam engines, steam boilers, other pressure vessels, high pressure piping and machinery, if any, installed in, or serving, the Premises in an amount satisfactory to Landlord in its reasonable discretion;

               (d) Worker’s compensation and occupational disease insurance with statutory limits and Employer’s Liability insurance with the following limits: Bodily injury by disease per person $1,000,000.00; Bodily injury by accident policy limit $1,000,000.00; Bodily injury by disease policy limit $1,000,000.00;

               (e) Business automobile liability insurance including owned, hired and non-owned automobiles, in an amount not less than One Million Dollars ($1,000,000) combined single limit per occurrence, with such commercially reasonable increases as Landlord may require from time to time;

               (f) Business interruption insurance insuring interruption or stoppage of Tenant’s business at the Premises for a period of not less than twelve (12) months; and

               (g) with increases in the foregoing limits, and any other form or forms of insurance as Landlord may reasonably require from time to time, with any other form(s) of insurance in amounts and for insurable risks (on commercially reasonable terms) against which a prudent tenant would protect itself to the extent landlords of comparable buildings in the vicinity of the Property require their tenants to carry such other form(s) of insurance.

     Each policy of insurance required under this Section 4.02 shall be issued by companies rated not less than A-/X by Best’s Rating Service (or its successor) or otherwise acceptable to Landlord in the Landlord’s reasonable discretion and licensed to do business in The Commonwealth of Massachusetts, and shall be noncancellable with respect to Landlord and any mortgagee (provided that Landlord has identified such mortgagee by notice to Tenant), without thirty (30) days prior notice to Landlord and such mortgagee. Tenant shall deliver to Landlord and any mortgagee (provided that Landlord has identified such mortgagee by notice to Tenant) certificate(s) of insurance evidencing the coverage required hereunder upon commencement of the term of this Lease and no later than thirty (30) days prior to the expiration of the coverage evidenced by a prior certificate. All such insurance certificates shall provide that such policy shall not be canceled or reduced as to coverage or amount without at least thirty (30) days prior written notice to each insured named therein. Tenant’s liability insurance policy shall be primary with respect to all claims for which Tenant is to indemnify Landlord under Article 12. All furnishings, fixtures, equipment, effects and property of Tenant and of all persons claiming through Tenant which from time to time may be on the Premises or Property or in transit thereto or therefrom (“ Tenant Property ”) shall be at the sole risk of Tenant, and if the whole or any part thereof shall be destroyed or damaged by fire, water or otherwise, or by the leakage or bursting of water pipes, or other pipes, by theft or from any other cause, no part of said loss or damage is to be charged to or be borne by Landlord.

     Section 4.03. Landlord’s Required Insurance . The Landlord shall maintain at least Seven Million ($7,000,000.00) Dollars of commercial general liability insurance (including so-called umbrella coverage) covering the Building. Landlord shall maintain physical damage and casualty insurance on an “all risk” basis on the Building (excluding furnishings, fixtures, equipment and other personal property of Tenant) in the amount of the full replacement cost of the Premises (other than Tenant Work and any Finish Work) as reasonably determined by Landlord, and shall also maintain boiler and rent loss insurance in amounts required by Landlord’s mortgage lender or otherwise reasonably determined by Landlord. Landlord’s insurance shall be issued by companies rated not less than A-/X by Best’s Rating Service (or its successor) and licensed to do business in The Commonwealth of Massachusetts. Landlord shall cause the casualty insurance replacement cost coverage to be updated as reasonably necessary. Any or all of Landlord’s insurance may be provided by blanket coverage maintained by Landlord or any affiliate of Landlord under its insurance program for its portfolio of properties. Landlord may maintain other coverages in such amounts as are required by Landlord’s mortgage lender or otherwise as reasonably determined by Landlord.

     Section 4.04. Tenant Work Insurance . In addition, during the performance of any Tenant Work, in addition to the above coverage required to be maintained by Tenant, Tenant shall cause the general contractor performing any work in the Premises (and the general contractor shall cause its subcontractors) to carry: (a) workers’ compensation and occupational disease insurance in statutory amounts; (b) employer’s liability insurance with a limit of not less than One Million Dollars ($1,000,000); (c) commercial general liability insurance, including personal injury and property damage, on an occurrence basis in the amount of a combined single limit of not less than One Million Dollars ($1,000,000.00) for each occurrence, such limit to be increased to Five Million Dollars ($5,000,000.00) if the cost of the work exceeds One Million Dollars ($1,000,000.00); and (d) all risk installation floater insurance (on the complete value/full coverage form) to protect Landlord’s interest and that of Tenant, contractors and subcontractors during the course of the construction, with limits of not less than the total replacement cost of the completed improvements under construction. Such contractor insurance policies shall be endorsed to include Landlord, The Prudential Insurance Company of America, the condominium association, Landlord’s managing agent, any mortgagee, and any other third party providing services to the Building (provided that Landlord has identified such mortgagee and/or third parties by notice to Tenant) as additional insureds.

     Section 4.05. Waiver of Subrogation . Any property insurance carried by either party under Sections 4.02(b), 4.02(c) or 4.03 shall, if it can be so written without additional premium or with an additional premium which the other party agrees to pay, include a clause or endorsement denying to the insurer rights of subrogation against the other party to the extent rights have been waived by the insured hereunder prior to occurrence of injury or loss. Each party, notwithstanding any provisions of this Lease to the contrary, hereby waives any rights of recovery against the other for injury or loss due to hazards covered by property insurance carried (or required to be carried) by the party suffering the injury or loss to the extent of the coverage provided (or to be provided) thereunder.

     Section 4.06. Certificates of Insurance . Within fifteen (15) days of request, each party shall provide the other with certificates of all insurance maintained or required to be maintained under this Lease.

Article 5.

Use of Premises

     Section 5.01. Permitted Use . The Tenant covenants and agrees to use the Premises only for the purposes of business and professional offices, research labs, and ancillary and subordinate uses customarily undertaken as accessory uses in connection therewith including without limitation an animal care facility not to exceed Tenant’s ACF Share (as defined below) of the Premises (measured in rentable square feet), and for no other purpose (the “ Permitted Use ”).

     “ Tenant’s ACF Share ” shall mean the percentage of the Premises that is proportionate to the percentage of accessory animal care facility space permitted in the Building from time to time under applicable laws, codes and ordinances, which, as of the date hereof, is 20%. If Tenant is then utilizing all or substantially all of Tenant’s ACF Share, and provided that no Event of Default is then continuing, then, following the initial lease-up of the entire Building, upon Tenant’s reasonable request from time to time Landlord shall allocate any then-excess animal care facility rights at the Building (i.e. rights in excess of Tenant’s ACF Share not then allocated to other tenants) to Tenant as an increase in the foregoing limit so long as such use, as increased, remains an accessory use ancillary and subordinate to Tenant’s other activities in the Premises.

     Section 5.02. Tenant’s Conduct; Hazardous Materials .

               (a) Tenant will not make or permit any occupancy or use of any part of the Premises for any hazardous, offensive, dangerous, noxious or unlawful occupation, trade, business or purpose or any occupancy or use thereof which is contrary to any law, by-law, ordinance, rule, permit or license, and will not cause, maintain or permit any nuisance in, at or on the Premises; provided, however, that the Permitted Use, if conducted in conformance with the terms of this Lease, all applicable legal requirements, and customary standards for first class office, laboratory and research and development space, shall not be deemed to be a hazardous, offensive, dangerous, or noxious occupation, trade, business or purpose or a nuisance unless it adversely affects tenants or occupants outside the Premises. Tenant shall not conduct or permit any foreclosure or going out of business auctions, or sheriff’