EX-10.6

THIS INDENTURE OF LEASE (this “Lease”) is hereby made and entered into on the Execution Date by and between Landlord and Tenant.

This Lease and all of its terms, covenants, representations, warranties, agreements and conditions are in all respects subject and subordinate to that certain Master Lease Agreement dated as of May 15, 2014 by and between MIT 620 Memorial LLC (“Fee Owner”), as landlord, and Landlord, as tenant (as it may be amended from time to time, the “Ground Lease”), a redacted copy of which has been delivered to Tenant. Tenant acknowledges notice and full knowledge of all of the terms, covenants and conditions of the Ground Lease.

Each reference in this Lease to any of the terms and titles contained in any Exhibit attached to this Lease shall be deemed and construed to incorporate the data stated under that term or title in such Exhibit. All capitalized terms not otherwise defined herein shall have the meanings ascribed to them as set forth in the Lease Summary Sheet which is attached hereto and incorporated herein by reference.

Lease Grant. Landlord hereby leases to Tenant, and Tenant hereby leases from Landlord, the Premises upon and subject to terms and conditions of this Lease, for a term of years commencing on the Term Commencement Date and, unless earlier terminated or extended pursuant to the terms hereof, ending on the Expiration Date (the “Initial Term”; the Initial Term and any duly exercised Extension Terms are hereinafter collectively referred to as the “Term”).

(a) Provided (i) Tenant, an Affiliated Entity (hereinafter defined) and/or a Successor (hereinafter defined) is/are then occupying² one hundred percent (100%) of the Premises; and (ii) there is no Event of Default (1) as of the date of the Extension Notice (hereinafter defined), and (2) at the commencement of the applicable Extension Term (hereinafter defined), Tenant shall have the option to extend the Term for one (1) additional term of three (3) years (the “Extension Term”), commencing as of the expiration of the Initial Term. Tenant must exercise such option to extend by giving Landlord written notice (the “Extension Notice”) on or before the date that is twelve (12) months prior to the expiration of the then-current term of this Lease, time being of the essence. Notwithstanding the foregoing, Landlord may nullify Tenant’s exercise of its option to extend the Term by written notice to Tenant (the “Nullification Notice”) if (A) on the date Landlord receives the applicable Extension Notice, there is an event which, with the passage of time and/or the giving of notice, would constitute an Event of Default hereunder and (B) Tenant fails to cure such default within the applicable cure period set forth in Section 20.1 after receipt of the Nullification Notice. Upon the timely giving of such notice, the Term shall be deemed extended upon all of the terms and conditions of this Lease, except that Base Rent during the Extension Term shall be calculated in accordance with this Section 1.2, Landlord shall have no obligation to construct or renovate the Premises and Tenant shall have no further right to extend the Term. If Tenant fails to give timely notice, as aforesaid, Tenant shall have no further right to extend the Term. Notwithstanding the fact that Tenant’s proper and timely exercise of such option to extend the Term shall be self executing, the parties shall promptly execute a lease amendment reflecting such Extension Term after Tenant exercises such option. The execution of such lease amendment shall not be deemed to waive any of the conditions to Tenant’s exercise of its rights under this Section 1.2.

(b) The Base Rent during the Extension Term (the “Extension Term Base Rent”) shall be determined in accordance with the process described hereafter. Extension Term Base Rent shall be the greater of (i) Base Rent for the last Rent Year of the Initial Term, or (ii) the fair market rental value of the Premises then demised to Tenant as of the commencement of the Extension Term as determined in accordance with the process described below, for renewals of combination laboratory and office space in the vicinity of the Building of equivalent quality, size, utility and location, with the length of the Extension Term and the credit standing of Tenant to be taken into account. Within thirty (30) days after receipt of the Extension Notice, Landlord shall deliver to Tenant written notice of its determination of the Extension Term Base Rent for the Extension Term. Tenant shall, within thirty (30) days after receipt of such notice, notify Landlord in writing whether Tenant accepts or rejects Landlord’s determination of the Extension Term Base Rent (“Tenant’s Response Notice”). If Tenant fails timely to deliver Tenant’s Response Notice, Landlord’s determination of the Extension Term Base Rent shall be binding on Tenant.

(c) If and only if Tenant’s Response Notice is timely delivered to Landlord and indicates both that Tenant rejects Landlord’s determination of the Extension Term Base Rent and desires to submit the matter to arbitration, then the Extension Term Base Rent shall be determined in accordance with the procedure set forth in this Section 1.2(c). In such event, within ten (10) days after receipt by Landlord of Tenant’s Response Notice indicating Tenant’s desire to submit the determination of the Extension Term Base Rent to arbitration, Tenant and Landlord shall each notify the other, in writing, of their respective selections of an appraiser (respectively, “Landlord’s Appraiser” and “Tenant’s Appraiser”). Landlord’s Appraiser and Tenant’s Appraiser shall then jointly select a third appraiser (the “Third Appraiser”) within ten (10) days of their appointment. All of the appraisers selected shall be individuals with at least five (5) consecutive years’ commercial appraisal experience in the area in which the Premises are located, shall be members of the Appraisal Institute (M.A.I.), and, in the case of the Third Appraiser, shall not have acted in any capacity for either Landlord or Tenant within five (5) years of his or her selection. The three appraisers shall determine the Extension Term Base Rent in accordance with the requirements and criteria set forth in Section 1.2(b) above, employing the method commonly known as Baseball Arbitration, whereby Landlord’s Appraiser and Tenant’s Appraiser each sets forth its determination of the Extension Term Base Rent as defined above, and the Third Appraiser must select one or the other (it being understood that the Third Appraiser shall be expressly prohibited from selecting a compromise figure). Landlord’s Appraiser and Tenant’s Appraiser shall deliver their determinations of the Extension Term Base Rent to the Third Appraiser within five (5) days of the appointment of the Third Appraiser and the Third Appraiser shall render his or her decision within ten (10) days after receipt of both of the other two determinations of the Extension Term Base Rent. The Third Appraiser’s decision shall be binding on both Landlord and Tenant. Each party shall bear the cost of its own appraiser and shall share equally in the cost of the Third Appraiser.

Notice of Lease. Neither party shall record this Lease, but each of the parties hereto agrees to join in the execution, in recordable form, of a statutory notice of lease and/or written declaration in which shall be stated the Term Commencement Date, the number and length of the Extension Terms and the Expiration Date, which notice of lease may be recorded by Tenant with the Middlesex South Registry of Deeds and/or filed with the Registry District of the Land Court, as appropriate (collectively, the “Registry”) at Tenant’s sole cost and expense. If a notice of lease was previously recorded with the Registry, upon the expiration or earlier termination of this Lease, Landlord shall deliver to Tenant a notice of termination of lease and Tenant shall promptly execute and deliver the same to Landlord for Landlord’s execution and recordation with the Registry. Tenant’s obligations under this Section 1.3 shall survive the expiration or earlier termination of the Lease.

(d) Common Areas. Subject to the terms of this Lease and the Rules and Regulations (hereinafter defined), Tenant shall have, as appurtenant to the Premises, rights to use in common with others entitled thereto, the areas designated from time to time for the common use of Tenant and other tenants of the Property (such areas are hereinafter referred to as the “Common Areas”). The Common Areas include: (i) the common lobbies, passenger and freight elevators, loading docks, hallways and stairways of the Building serving the Premises, (ii) common walkways necessary for access to the Building, (iii) if the Premises include less than the entire rentable area of any floor, the common toilets and other common facilities of such floor; and (iv) other areas designated by Landlord from time to time for the common use of Tenant and other tenants of the Building; and no other appurtenant rights or easements

(e) Parking. Commencing on the Term Commencement Date and thereafter throughout the Term, Landlord shall, subject to the terms hereof, make available nine (9) parking spaces for Tenant’s use in the parking areas serving the Building (which are, subject to the last sentence of this Section 1.4(b), located in the surface lot in front of the Building). The number of parking spaces in the parking areas reserved for Tenant, as modified pursuant to this Lease or as otherwise permitted by Landlord, are hereinafter referred to as the “Parking Spaces.” Tenant shall have no right to hypothecate or encumber the Parking Spaces, and shall not sublet, assign, or otherwise transfer the Parking Spaces other than to employees of Tenant occupying the Premises or to a Successor (hereinafter defined), an Affiliated Entity (hereinafter defined) or a transferee pursuant to an approved Transfer under Section 13 of this Lease. Throughout the Term, Tenant shall pay Landlord (or at Landlord’s direction, directly to the parking operator³) for all of the Parking Spaces at the then-current prevailing rate, as such rate may vary from time to time. As of the Execution Date, the monthly charge for parking is Two Hundred Dollars ($200) per Parking Space per month. If, for any reason, Tenant shall fail timely to pay the charge for any of said Parking Spaces, and if such default continues for ten (10) days after written notice thereof, Tenant shall have no further right to the Parking Spaces for which Tenant failed to pay the charge under this Section 1.4(b) and Landlord may allocate such Parking Spaces for use by other tenants of the Property free and clear of Tenant’s rights under this Section 1.4(b). Said Parking Spaces will be on an unassigned, non-reserved basis, and shall be subject to such reasonable rules and regulations as may be in effect for the use of the parking areas from time to time (including, without limitation, Landlord’s right, without additional charge to Tenant above the prevailing rate for Parking Spaces, to institute a valet or attendant-managed parking system). Reserved and handicap parking spaces must be honored. Notwithstanding anything to the contrary contained herein, in connection with the exercise of Landlord’s rights pursuant to Section 2.2 below, or in connection with the development or redevelopment of other property owned or controlled by Landlord, Landlord shall have the right to relocate the Parking Spaces from time to time to other property owned or controlled by Landlord or its affiliates, so long as such other property is within 1,000 feet of the Land.

(f) It is acknowledged that Tenant may generate certain hazardous, medical, bio-hazard or other waste (collectively, “Waste”) that requires specialty pick-up. If Landlord shall elect, in Landlord’s sole discretion, to make available to tenants of the Building, including Tenant, certain waste storage room(s) located in the Building so designated by Landlord, which room(s) is/are located near the Building’s loading dock, then Landlord shall make a portion of such room(s) available for Tenant’s use, subject to and in accordance with all applicable Legal Requirements (including without limitation Environmental Laws), solely for the storage of Tenant’s Waste awaiting pick-up by Tenant’s Waste removal vendor. Prior to storing any Waste in such room(s), Tenant must notify Landlord in writing of Tenant’s contact person regarding any matters pertaining to such Waste and the types and quantities of the Waste to ensure that adequate ventilation and fire protection is available therefor, it being understood and agreed that if Landlord reasonably determines that there is not adequate ventilation and/or fire

protection available (Landlord being under no obligation to provide ventilation and/or fire protection to accommodate the same), Tenant shall not store any Waste in such room(s). Tenant must arrange for pick-up of any of Tenant’s Waste within seven (7) days after the date on which the same are first stored in such room(s), time being of the essence. Tenant’s use of such room(s) shall comply at Tenant’s sole cost and expense with all rules and regulations promulgated from time to time by or on behalf of Landlord with respect thereto, including without limitation requirements for secondary containment. Tenant shall indemnify, defend and hold the Landlord Parties harmless from and against any and all Claims arising from Tenant’s use of such room(s) by any of the Tenant Parties. Landlord shall have the right to terminate Tenant’s right to use such room(s) (i) upon at least thirty (30) days’ notice if Landlord terminates the rights of all tenants of the Building to use such room(s), (ii) upon at least thirty (30) days’ notice if Landlord desires to lease such room(s) to one or more tenants, (iii) upon at least thirty (30) days’ notice if Landlord desires to convert the use of such room to another purpose, or (iv) immediately by notice if any of the Tenant Parties fails to comply with the terms of this Section 1.4(c) or if there is an Event of Default.

(g) From and after the Term Commencement Date and until the end of the Term, Tenant shall have access to the Premises twenty-four (24) hours a day, seven (7) days a week, subject to Legal Requirements, the Rules and Regulations, the terms of this Lease , Landlord’s Force Majeure (hereinafter defined) and matters of record.

(h) Tenant shall have the right to access the Premises, at Tenant’s sole risk, during the period commencing upon substantial completion of Landlord’s Work and ending on the day immediately prior to the Term Commencement Date, for the purpose of installing wiring, cabling, furniture, fixtures and equipment only. Tenant shall, prior to the first entry to the Premises pursuant to this Section 1.5(b), provide Landlord with certificates of insurance evidencing that the insurance required in Section 14 hereof is in full force and effect and covering any person or entity entering the Building. Tenant shall defend, indemnify and hold the Landlord Parties (hereinafter defined) harmless from and against any and all Claims (hereinafter defined) for injury to persons or property resulting from or relating to Tenant’s access to and use of the Premises prior to the Term Commencement Date as provided under this Section 1.5(b). Tenant shall coordinate any access to the Premises prior to the Term Commencement Date with Landlord’s property manager.

Exclusions. The following are expressly excluded from the Premises and reserved to Landlord: all the perimeter walls of the Premises (except the inner surfaces thereof), the Common Areas, and any space in or adjacent to the Premises used for shafts, stacks, pipes, conduits, wires and appurtenant fixtures, fan rooms, ducts, electric or other utilities, sinks or other Building facilities, and the use of all of the foregoing, except as expressly permitted pursuant to Sections 1.4(a) and 1.4(c) above.

Additions and Alterations. Landlord reserves the right, at any time and from time to time, to make such changes, alterations, additions, improvements, repairs or replacements in or to the Property (including the Premises but, with respect to the Premises, only for purposes of repairs, maintenance, replacements and other rights expressly reserved to Landlord herein) and the fixtures and equipment therein, as well as in or to the street entrances and/or the Common Areas, as it may deem necessary or desirable, provided, however, that there be no material obstruction of access to, or material interference with the use and enjoyment of, the Premises by Tenant. Subject to the foregoing, Landlord expressly reserves the right to temporarily close all, or any portion, of the Common Areas for the purpose of making repairs or changes thereto.

Additions to the Property. Landlord may at any time or from time to time construct additional improvements in all or any part of the Property, including, without limitation, adding additional buildings or changing the location or arrangement of any improvement in or on the Property or all or any part of the Common Areas, or add or deduct any land to or from the Property; provided that there shall be no material increase in Tenant’s obligations or material interference with Tenant’s rights under this Lease in connection with the exercise of the foregoing reserved rights.

Name and Address of Building. Landlord reserves the right at any time and from time to time to change the name or address of the Building and/or the Property, provided Landlord gives Tenant at least three (3) months’ prior written notice thereof.

Landlord’s Access. Subject to the terms hereof, Tenant shall (a) upon as much advance notice as is practical under the circumstances, and in any event at least twenty-four (24) hours’ prior written notice (except that no notice shall be required in emergency situations), permit Landlord and any holder of a Mortgage (hereinafter defined) (each such holder, a “Mortgagee”), and their agents, employees and contractors, to have free and unrestricted access to and to enter upon the Premises at all reasonable hours for the purposes of inspection, making repairs, replacements or improvements in or to the Premises or the Building or equipment therein (including, without limitation, sanitary, electrical, heating, air conditioning or other systems), complying with all applicable laws, ordinances, rules, regulations, statutes, by-laws, court decisions and orders and requirements of all public authorities (collectively, “Legal Requirements”), or exercising any right reserved to Landlord under this Lease (including without limitation the right to take upon or through, or to keep and store within the Premises all necessary materials, tools and equipment); (b) permit Landlord and its agents and employees, at reasonable times, upon reasonable advance notice, to show the Premises during normal business hours (i.e. Monday – Friday 8 A.M.—6 P.M., Saturday 8 A.M. – 1 P.M., excluding holidays) to any prospective Mortgagee or purchaser of the Building and/or the Property or of the interest of Landlord therein, and, during the last nine (9) months of the Term, prospective tenants; (c) upon reasonable prior written notice from Landlord, permit Landlord and its agents, at Landlord’s sole cost and expense, to perform environmental audits, environmental site investigations and environmental site assessments (“Site Assessments”) in, on, under and at the Premises and the Land, it being understood that Landlord shall repair any damage arising as a result of the Site Assessments, and such Site Assessments may include both above and below the ground testing and such other tests as may be necessary or appropriate to conduct the Site Assessments; and (d) in case any excavation shall be made for building or improvements or for any other purpose upon the land adjacent to or near the Premises, afford without charge to Landlord, or the person or persons, firms or corporations causing or making such excavation, license to enter upon the Premises for the purpose of doing such work as Landlord or such person or persons, firms or corporation shall deem to be necessary to preserve the walls or structures of the Building from injury, and to protect the Building by proper securing of foundations. The parties agree and acknowledge that, despite reasonable and customary precautions (which Landlord agrees it shall exercise), any property or equipment in the Premises of a delicate, fragile or vulnerable nature may nevertheless be damaged in the course of cleaning and maintenance services being performed. Accordingly, Tenant shall take reasonable protective precautions with unusually fragile, vulnerable or sensitive property and equipment. Tenant may identify certain areas of the Premises that require limited access and strict security measures (“Security Areas”) by written notice to Landlord from time to time. Except in the event of an emergency threatening personal injury, damage to property or a violation of any Legal Requirement (a “Secure Area Emergency”), and except as otherwise approved by Tenant, any entry in the Secure Areas must be done in the presence of a representative of Tenant so long as Tenant makes such representative available upon at least one (1) business day’s advance notice. Notwithstanding foregoing, in the event of a Secure Area Emergency, Landlord may enter any part of the Premises without prior notice or a representative of Tenant; provided that Landlord provides Tenant with notice of such entry as soon as reasonably possible thereafter and Landlord takes reasonable precautions to protect the health and safety of its entrants.

Nothing in this paragraph will be construed as permitting Tenant to prohibit such access to any portion of the Premises. Except in Secure Area Emergency situations, anyone who has access to a Secure Area may, at Tenant’s election, be subject to Tenant’s reasonable security measures and protocols, which may include limiting access to normal business hours and requiring the wearing of an ID badge.

Pipes, Ducts and Conduits. Tenant shall permit Landlord to erect, use, maintain and relocate pipes, ducts and conduits in and through the Premises, provided the same do not materially reduce the floor area or materially adversely affect the appearance thereof.

Minimize Interference. Subject to the provisions of this Lease, Tenant agrees to cooperate with Landlord as reasonably necessary in connection with the exercise of Landlord’s rights under this Section 2. Tenant further agrees that dust, noise, vibration, temporary closures of Common Areas, or other inconvenience or annoyance resulting from the exercise of Landlord’s rights under Section 2.1 and 2.2 shall not be deemed to be a breach of Landlord’s obligations under the Lease, so long as Landlord shall, except in the event of an emergency, use reasonable efforts, consistent with accepted construction practice when applicable, to avoid unreasonably interfering with the conduct of Tenant’s business and Tenant’s use and occupancy of the Premises. Notwithstanding the foregoing, in no event shall any of the space leased by Tenant at the Property under this Lease be deprived of safe and reasonable access or rendered untenantable for the Permitted Uses by reason of Landlord’s exercise of its rights under this Section 2.

Condition of Premises. On the Term Commencement Date, the Premises shall be broom-clean, and the Building structure and the Building systems serving the Premises and Common Areas shall be in good working order, condition and repair. Subject to the foregoing, and subject further to Landlord’s obligation to perform Landlord’s Work (hereinafter defined), Tenant acknowledges and agrees that Tenant is leasing the Premises in their “AS IS,” “WHERE IS” condition and with all faults on the Execution Date, without representations or warranties, express or implied, in fact or by law, of any kind, and without recourse to Landlord.

(i) Subject to delays due to governmental regulation, unusual scarcity of or inability to obtain labor or materials, labor difficulties, casualty or other causes reasonably beyond Landlord’s control (collectively “Landlord’s Force Majeure”) and subject to any act or omission by Tenant and/or Tenant’s agents, servants, employees, consultants, contractors, subcontractors, licensees and/or subtenants (collectively with Tenant, the “Tenant Parties”) which causes an actual delay in the performance of Landlord’s Work (a “Tenant Delay”), Landlord, at Landlord’s sole cost and expense, shall perform the work (“Landlord’s Work”) more particularly shown in the permit set prepared by Landlord’s architect, which permit set shall be based on the schematic plans attached hereto as Exhibit 3 and made a part hereof (the “Schematics”) and which permit set shall take into account Tenant’s input, if any, at weekly design meetings (as such permit set may be amended or modified pursuant to Section 3.2(b) below, the “Permit Set”). Landlord’s Work shall be deemed “substantially complete” on the date that all of Landlord’s Work has been completed, except for Punchlist Items, as certified in writing by Landlord’s architect.

(j) Tenant shall have the right, in accordance herewith, to submit for Landlord’s approval (which approval shall not be unreasonably withheld) change proposals to amend or modify the Permit Set (each, a “Change Proposal”). Landlord agrees to respond to any such Change Proposal within five (5) business days after the submission thereof by Tenant (unless Landlord has previously advised Tenant that a longer time period for such response is reasonably necessary due to the nature and scope of

the Change Proposal, together with Landlord’s good faith estimate as to the amount of additional time that will be necessary, or the fact that the information provided by Tenant in the Change Proposal is insufficient for the purposes of enabling Landlord to make the determination set forth herein), and if approved by Landlord, advising Tenant of any anticipated increase or decrease in costs associated with such Change Proposal (“Anticipated Costs”), as well as an estimate of any delay or time savings which would likely result in the completion of Landlord’s Work if a Change Proposal is made pursuant thereto (“Landlord’s Change Order Response”). If Landlord does not approve any Change Proposal, Landlord shall provide Tenant with a reasonably detailed explanation thereof in writing. Tenant shall have the right to then approve or withdraw such Change Proposal within five (5) business days after receipt of Landlord’s Change Order Response. If Tenant fails to respond to Landlord’s Change Order Response within such five (5) business day period, such Change Proposal shall be deemed withdrawn. If Tenant approves Landlord’s Change Order Response, then (a) such Change Proposal shall be deemed a “Change Order” hereunder, and (b) Landlord shall perform the work described in the Change Order as part of Landlord’s Work on all the terms and conditions applicable to Landlord’s Work except as expressly set forth herein with respect to Tenant’s payment obligation. Any actual delay in the substantial completion of Landlord’s Work resulting from Change Proposals (whether approved or not) shall constitute a Tenant Delay.

(k) Permitting. Landlord shall obtain all permits for construction of Landlord’s Work. The cost of all permits for construction of Landlord’s Work (and the cost of obtaining the same) shall be included in the Work Costs (hereinafter defined). Tenant shall cooperate with Landlord in executing permit applications and performing other ministerial acts reasonably necessary to enable Landlord to obtain any such permit or certificate of occupancy.

Punchlist Items. Promptly following delivery of the Premises to Tenant with Landlord’s Work substantially complete, Landlord shall provide Tenant with a list prepared by Landlord’s architect (the “Punchlist”) of outstanding items (the “Punchlist Items”) which (a) need to be performed to complete Landlord’s Work, (b) do not impair Tenant’s ability to obtain a certificate of occupancy for the Premises and (c) do not materially impair Tenant’s ability to use the Premises for the Permitted Use. Subject to Landlord’s Force Majeure and Tenant Delays, Landlord shall, unless otherwise specified on the Punchlist, complete all Punchlist Items within sixty (60) days of the date of the Punchlist.

1.2 Remedies. Subject to Landlord’s Force Majeure and Tenant Delays, if the Term Commencement Date has not occurred on or before (a) January 4, 2016, then the Rent Commencement Date shall be delayed one day for each day after such date that the Term Commencement Date does not occur⁴, and (b) March 2, 2016, then Tenant shall be entitled to terminate this Lease by thirty (30) days’ prior written notice to Landlord (provided that such notice shall be of no force and effect if the Term Commencement Date occurs within such 30 day period). The remedies set forth in this Section 3.4 are Tenant’s sole and exclusive rights and remedies if the Term Commencement Date does not occur on or before December 2, 2015.

(a) Landlord’s Contribution. As an inducement to Tenant’s entering into this Lease, Landlord shall pay for up to Seven Hundred Seventy-Seven Thousand Seven Hundred Fifty Dollars ($777,750) (“Landlord’s Contribution”) of the costs incurred in connection with the performance of Landlord’s Work other than the following costs (collectively, “Excluded Construction Costs”), which

shall be paid for by Tenant within thirty (30) days of demand from time to time (but in no event more often than monthly): (i) the cost of acquiring or installing any of Tenant’s Property (hereinafter defined), including without limitation telecommunications and computer equipment and all associated wiring and cabling, any de-mountable decorations, artwork and partitions, signs, and trade fixtures, or (ii) the cost of any fixtures or Alterations that will be removed at the end of the Term, or (iii) more than Seventy-Seven Thousand Seven Hundred Seventy-Five Dollars ($77,775) of any so-called “soft costs” (which “soft costs” shall include, without limitation, architectural, engineering and consultant fees and design and permitting costs). Landlord shall not charge any supervisory or management fees with respect to Landlord’s Work, provided that the costs of any third party construction/project manager(s) engaged by Landlord shall be included in the cost of the Landlord’s Work. Landlord and Tenant agree that Consigli Construction Co., Inc. (or such other general contractor of comparable or greater experience and reputation selected by Landlord) shall be the general contractor for the performance of Landlord’s Work.

(i) For purposes hereof, “Work Costs” means (A) all costs incurred in connection with Landlord’s Work, including without limitation the costs of designing, permitting and performing Landlord’s Work, as affected by any Change Orders and any changes made in accordance with Section 3.5(b)(ii) below and the costs of any third party construction/project manager(s) engaged by Landlord, less (B) the Excluded Construction Costs.

(ii) Landlord shall provide Tenant with a detailed cost estimate based on the original Permit Set (the “Cost Estimate”). The Cost Estimate shall include a line item for the cost of any third party construction/project manager(s). Tenant shall have a period of three (3) business days after receipt of the Cost Estimate, time being of the essence, to notify Landlord whether Tenant approves such Cost Estimate, or that Tenant wishes to conduct value engineering in order to reduce the cost of Landlord’s Work. If Tenant does not timely provide such notice, Tenant shall be deemed to have (A) approved such Cost Estimate, and (B) elected not to conduct such value engineering. If Tenant elects to conduct value engineering, then (i) any delays to substantial completion of Landlord’s Work arising from such value engineering shall be deemed to be Tenant Delays, and (ii) until mutually approved (or deemed approved), Landlord and Tenant shall confer and negotiate reasonably and in good faith to reach agreement on the Cost Estimate and the Permit Set on which the Cost Estimate is based. The Cost Estimate approved (or deemed approved) by Tenant is herein referred to as the “Final Cost Estimate.”

(iii) If the Final Cost Estimate discloses that the Work Costs exceed Landlord’s Contribution (such excess, the “Excess Costs”), Tenant shall pay, within thirty (30) days after demand from time to time (but in no event more than monthly), Tenant’s Proportion (hereinafter defined) of the Work Costs reflected on each requisition from Landlord, to which shall be attached invoices and/or other documentation supporting the requisition. “Tenant’s Proportion” shall be a fraction, the numerator of which is the estimated Excess Costs, and the denominator of which is the estimated Work Costs. After final completion of Landlord’s Work, Landlord shall prepare and submit to Tenant a final reconciliation in sufficient detail to reasonably determine actual Work Costs (including without limitation all Punchlist Items) (the “Final Reconciliation”). Landlord shall use reasonable efforts to deliver the Final Reconciliation to Tenant within ninety (90) days after final completion of Landlord’s Work. Within thirty (30) days after delivery of the Final Reconciliation, Tenant shall pay to Landlord any remaining Excess Costs.

Permitted Uses. During the Term, Tenant shall use the Premises only for the Permitted Uses and for no other purposes. Service and utility areas (whether or not a part of the Premises) shall be used only for the particular purpose for which they are designed. All corridor doors, when not in use, shall be kept closed.

(c) Notwithstanding any other provision of this Lease, Tenant shall not use the Premises or the Building, or any part thereof, or suffer or permit the use or occupancy of the Premises or the Building or any part thereof by any of the Tenant Parties (i) in a manner which would violate any of the covenants, agreements, terms, provisions and conditions of this Lease or otherwise applicable to or binding upon the Premises; (ii) for any unlawful purposes or in any unlawful manner; (iii) which, in the reasonable judgment of Landlord (taking into account the use of the Building as a combination laboratory, research and development and office building and the Permitted Uses) shall (a) impair the appearance or reputation of the Building; (b) impair, interfere with or otherwise diminish the quality of any of the Building services or the proper and economic heating, cleaning, ventilating, air conditioning or other servicing of the Building or Premises, or the use or occupancy of any of the Common Areas; (c) occasion discomfort, inconvenience or annoyance in any material respect (and Tenant shall not install or use any electrical or other equipment of any kind which, in the reasonable judgment of Landlord, will cause any such impairment, interference, discomfort, inconvenience, annoyance or injury), or cause any injury or damage to any occupants of the Premises or other tenants or occupants of the Building or their property; or (d) cause harmful air emissions, laboratory odors or noises or any unusual or other objectionable odors, noises or emissions to emanate from the Premises; (iv) in a manner which is inconsistent with the operation and/or maintenance of the Building as a first-class combination office, research, development and laboratory facility; or (v) for any fermentation processes whatsoever; (vi) in a manner which shall increase such insurance rates on the Building or on property located therein over that applicable when Tenant first took occupancy of the Premises hereunder.

(d) With respect to the use and occupancy of the Premises and the Common Areas, Tenant will not: (i) place or maintain any signage, trash, refuse or other articles in any vestibule or entry of the Premises, on the footwalks or corridors adjacent thereto or elsewhere on the exterior of the Premises, nor obstruct any driveway, corridor, footwalk, parking area, mall or any other Common Areas; (ii) permit undue accumulations of or burn garbage, trash, rubbish or other refuse within or without the Premises; (iii) permit the parking of vehicles so as to interfere with the use of any driveway, corridor, footwalk, parking area, or other Common Areas; (iv) receive or ship articles of any kind outside of those areas reasonably designated by Landlord; (v) conduct or permit to be conducted any auction, going out of business sale, bankruptcy sale (unless directed by court order), or other similar type sale in or connected with the Premises; (vi) use the name of the Building, the Property, Landlord, or any of Landlord’s affiliates or subsidiaries or any photograph, film, drawing, or other depiction or representation of the Building and/or the Property or any part thereof, which contains signage or distinctive architectural characteristics that cause the scene photographed, filmed, drawn, depicted, or represented to be identifiable as being the Building and/or the Property, in any publicity, promotion, trailer, press release, advertising, printed, or display materials without Landlord’s prior written consent; or (vii) except in connection with Alterations (hereinafter defined) approved by Landlord, cause or permit any hole to be drilled or made in any part of the Building.

Base Rent. During the Term, Tenant shall pay to Landlord Base Rent in equal monthly installments, in advance and without demand on the first day of each month for and with respect to such month, except that, if the Rent Commencement Date is any day other than the first day of a calendar month, Base Rent due for the period between the Rent Commencement Date and the last day of the calendar month in which the Rent Commencement Date occurs shall be due on the Rent Commencement

Date. The payment of Base Rent and additional rent and other charges reserved and covenanted to be paid under this Lease with respect to the Premises (collectively, “Rent”) shall commence on the Rent Commencement Date, and shall be prorated for any partial months. Rent shall be payable to Landlord or, if Landlord shall so direct in writing, to Landlord’s agent or nominee, in lawful money of the United States which shall be legal tender for payment of all debts and dues, public and private, at the time of payment.

(e) “Operating Costs” shall mean all costs incurred and expenditures of whatever nature made by Landlord in the operation and management of the Building or allocated to the Building, including without limitation any costs for utilities supplied to the Common Areas, the costs of maintaining the MWRA permit(s) for the Building, and any costs for repair and replacements, cleaning and maintenance of the Common Areas, related equipment, facilities and appurtenances and HVAC equipment, a management fee paid to Landlord’s property manager, the costs of Landlord’s management office for the Property, the cost of operating any amenities in the Property available to all tenants of the Property and any subsidy provided by Landlord for or with respect to any such amenity. For costs and expenditures made by Landlord in connection with the operation, management, repair, replacement, maintenance and insurance of the Building as a whole, Landlord shall make a reasonable allocation thereof between the retail and non-retail portions of the Building, if applicable. To the extent that a cost included in Operating Costs is also allocable to property other than the Property, such cost shall be equitably allocated to each parcel of property which benefits from such cost. Operating Costs shall not include Excluded Costs (hereinafter defined). Landlord shall have the right but not the obligation, from time to time, to equitably allocate some or all of the Operating Costs among different tenants of the Building (for example, and without limiting the generality of the foregoing, based in whole or in part on shared or similar use of particular systems or equipment).

(f) “Excluded Costs” shall be defined as (i) any mortgage charges (including interest, principal, points and fees); (ii) brokerage commissions; (iii) salaries of executives and owners not directly employed in the management/operation of the Property; (iv) the cost of work done by Landlord for a particular tenant; (v) subject to Subsection 5.2(h) below, capital expenditures; (vi) the costs of Landlord’s Work and any contributions made by Landlord to any tenant of the Property in connection with the build-out of its premises; (vii) franchise or income taxes imposed on Landlord or Taxes; (viii) costs paid directly by individual tenants to suppliers, including tenant electricity, telephone and other utility costs; (ix) increases in premiums for insurance when such increase is caused by the use of the Building by Landlord or any other tenant of the Building; (x) maintenance and repair of capital items not a part of the Building or the Property; (xi) depreciation of the Building; (xii) costs relating to maintaining Landlord’s existence as a corporation, partnership or other entity; (xiii) advertising and other fees and costs incurred in procuring tenants; (xiv) the cost of any items for which Landlord is reimbursed by insurance, condemnation awards, refund, rebate or otherwise, and any expenses for repairs or maintenance to the extent covered by warranties, guaranties and service contracts; (xv) costs incurred in connection with any disputes between Landlord and its employees, between Landlord and Building management, or between Landlord and other tenants or occupants; (xvi) the cost of testing, remediation or removal, transportation or storage of Hazardous Materials (hereinafter defined) in the Building or on the Property required by Environmental Laws (hereinafter defined), provided however, that with respect to the testing, remediation or removal of (i) any material or substance located in the Building on the Execution Date and which, as of the Execution Date, is not considered, as a matter of law, to be a Hazardous Material, but which is subsequently determined to be a Hazardous Material as a matter of law, and (ii) any material or substance located in the Building after the Execution Date and which, when placed in the Building, was not considered, as a matter of law, to be a Hazardous Material, but which is subsequently determined to be a Hazardous Material as a matter of law, the costs thereof may be included in Operating Costs; (xvii) capital expenditures not expressly permitted under Section 5.2(h) below; and (xviii) amounts paid by Landlord to or at the direction of Fee Owner pursuant to the Ground Lease.

(g) “Capital Interest Rate” shall be defined as an annual rate of either one percentage point over the AA Bond rate (Standard & Poor’s corporate composite or, if unavailable, its equivalent) as reported in the financial press at the time the capital expenditure is made or, if the capital item is acquired through third party financing, then the actual (including fluctuating) rate paid by Landlord in financing the acquisition of such capital item.

(h) “Annual Charge Off” shall be defined as the annual amount of principal and interest payments which would be required to repay a loan (“Capital Loan”) in equal monthly installments over the Useful Life (hereinafter defined), of the capital item in question on a direct reduction basis at an annual interest rate equal to the Capital Interest Rate, where the initial principal balance is the cost of the capital item in question.

(i) “Useful Life” shall be reasonably determined by Landlord in accordance with sound accounting principles and practices consistently applied. Notwithstanding the foregoing, if Landlord reasonably concludes on the basis of engineering estimates that a particular capital expenditure will effect savings in Operating Costs including, without limitation, energy related costs, and that such annual projected savings will exceed the Annual Charge Off of Capital Expenditures computed as aforesaid, then and in such event, the Annual Charge Off shall be determined based upon a Useful Life which would cause the principal and interest payments in a full repayment of the Capital Loan in question to equal the amount of projected savings of such Useful Life.

(j) Payment of Operating Costs. Tenant shall pay to Landlord, as additional rent, Tenant’s Share of Operating Costs. Landlord may make a good faith estimate of Tenant’s Share of Operating Costs for any fiscal year or part thereof during the Term, and Tenant shall pay to Landlord, on the Term Commencement Date and on the first (1st) day of each calendar month thereafter, an amount equal to Tenant’s Share of Operating Costs for such fiscal year and/or part thereof divided by the number of months therein. Landlord may estimate and re-estimate Tenant’s Share of Operating Costs and deliver a copy of the estimate or re-estimate to Tenant. Thereafter, the monthly installments of Tenant’s Share of Operating Costs shall be appropriately adjusted in accordance with the estimations so that, by the end of the fiscal year in question, Tenant shall have paid all of Tenant’s Share of Operating Costs as estimated by Landlord. Any amounts paid based on such an estimate shall be subject to adjustment as herein provided when actual Operating Costs are available for each fiscal year.

(k) Annual Reconciliation. Landlord shall, within one hundred twenty (120) days after the end of each fiscal year, deliver to Tenant a reasonably detailed statement of the actual amount of Operating Costs for such fiscal year (“Year End Statement”). Failure of Landlord to provide the Year End Statement within the time prescribed shall not relieve Tenant from its obligations hereunder. If the total of such monthly remittances on account of any fiscal year is greater than Tenant’s Share of Operating Costs actually incurred for such fiscal year, then, provided no Event of Default has occurred nor any event which, with the passage of time and/or the giving of notice would constitute an Event of Default, Tenant may credit the difference against the next installment of additional rent on account of Operating Costs due hereunder, except that if such difference is determined after the end of the Term, Landlord shall refund such difference to Tenant within thirty (30) days after such determination to the extent that such difference exceeds any amounts then due from Tenant to Landlord (it being understood and agreed that if Tenant cures any default prior to the expiration of the notice and/or cure periods set forth in Section 20.1 below, Tenant shall then be entitled to take such credit). If the total of such remittances is less than Tenant’s Share of Operating Costs actually incurred for such fiscal year, Tenant shall pay the difference to Landlord, as additional rent hereunder, within ten (10) days of Tenant’s receipt

of an invoice therefor. Landlord’s estimate of Operating Costs for the next fiscal year shall be based upon the Operating Costs actually incurred for the prior fiscal year as reflected in the Year-End Statement plus a reasonable adjustment based upon estimated increases in Operating Costs. The provisions of this Section 5.2(g) shall survive the expiration or earlier termination of this Lease.

(l) Capital Expenditures. If, during the Term, Landlord shall replace any capital items or make any capital expenditures (collectively, “Capital Expenditures”) the total amount of which (net of any warranty claims) is not properly includable in Operating Costs for the fiscal year in which they were made, in accordance with sound accounting principles and practices consistently applied in effect at the time of such replacement, there shall nevertheless be included in such Operating Costs (and in Operating Costs for each succeeding fiscal year) the amount, if any, by which the Annual Charge Off (determined as hereinafter provided) of such Capital Expenditure (less insurance proceeds, if any, collected by Landlord by reason of damage to, or destruction of the capital item being replaced) exceeds the Annual Charge Off of the Capital Expenditure for the item being replaced. If a new capital item is acquired which does not replace another capital item, and such new capital item being acquired is either (i) required by any Legal Requirements enacted after the Execution Date or (ii) reasonably projected to reduce Operating Costs, then there shall be included in Operating Costs for each fiscal year in which and after such capital expenditure is made the Annual Charge Off of such capital expenditure.

(m) Part Years. If the Term Commencement Date or the Expiration Date occurs in the middle of a fiscal year, Tenant shall be liable for only that portion of the Operating Costs with respect to such fiscal year within the Term.

(n) Gross-Up. If, during any fiscal year, less than all of the Building is occupied by tenants or if Landlord was not supplying all tenants with the services being supplied to Tenant hereunder, actual Operating Costs incurred shall be reasonably extrapolated by Landlord on an item-by-item basis to the reasonable Operating Costs that would have been incurred if the Building was fully occupied and such services were being supplied to all tenants, and such extrapolated Operating Costs shall, for all purposes hereof, be deemed to be the Operating Costs for such fiscal year.

(o) Audit Right. Provided there is no Event of Default nor any event which, with the passage of time and/or the giving of notice would constitute an Event of Default, Tenant may, upon at least sixty (60) days’ prior written notice, inspect or audit Landlord’s records relating to Operating Costs for any periods of time within the previous fiscal year before the audit or inspection. However, no audit or inspection shall extend to periods of time before the Term Commencement Date. If Tenant fails to object to the calculation of Tenant’s Share of Operating Costs on the Year-End Statement within sixty (60) days after such statement has been delivered to Tenant and/or fails to complete any such audit or inspection within ninety (90) days after receipt of the Year End Statement, then Tenant shall be deemed to have waived its right to object to the calculation of Tenant’s Share of Operating Costs for the year in question and the calculation thereof as set forth on such statement shall be final. Tenant’s audit or inspection shall be conducted only at Landlord’s offices or the offices of Landlord’s property manager during business hours reasonably designated by Landlord. Tenant shall pay the cost of such audit or inspection. Tenant may not conduct an inspection or have an audit performed more than once during any fiscal year. If such inspection or audit reveals that an error was made in the calculation of Tenant’s Share of Operating Costs previously charged to Tenant, then, provided no Event of Default has occurred nor an event which, with the passage of time and/or the giving of notice would constitute an Event of Default, Tenant may credit the difference against the next installment of additional rent on account of Operating Costs due hereunder, except that if such difference is determined after the end of the Term, Landlord shall refund such difference to Tenant within thirty (30) days after such determination to the extent that such difference exceeds any amounts then due from Tenant to Landlord. If such inspection or audit reveals an underpayment by Tenant, then Tenant shall pay to Landlord, as additional rent hereunder, any

underpayment of any such costs, as the case may be, within ten (10) days after receipt of an invoice therefor. Tenant shall maintain the results of any such audit or inspection confidential and shall not be permitted to use any third party to perform such audit or inspection, other than an independent firm of certified public accountants (A) reasonably acceptable to Landlord, (B) which is not compensated on a contingency fee basis or in any other manner which is dependent upon the results of such audit or inspection, and (C) which executes Landlord’s standard confidentiality agreement whereby it shall agree to maintain the results of such audit or inspection confidential. The provisions of this Section 5.2(k) shall survive the expiration or earlier termination of this Lease.

(p) “Taxes” shall mean the real estate taxes and other taxes, levies and assessments imposed upon the Building, and upon any personal property of Landlord used in the operation of the Building, or on Landlord’s interest in the Building or such personal property or reasonably allocated thereto; charges, fees and assessments for transit, housing, police, fire or other services or purported benefits to the Building (including without limitation any community preservation assessments); service or user payments in lieu of taxes; and any and all other taxes, levies, betterments, assessments and charges arising from the ownership, leasing, operation, use or occupancy of the Building or based upon rentals derived therefrom, which are or shall be imposed by federal, state, county, municipal or other governmental authorities. Taxes shall not include any inheritance, estate, succession, gift, franchise, rental, income or profit tax, capital stock tax, capital levy or excise, or any income taxes arising out of or related to the ownership and operation of the Building, provided, however, that any of the same and any other tax, excise, fee, levy, charge or assessment, however described, that may in the future be levied or assessed as a substitute for or an addition to, in whole or in part, any tax, levy or assessment which would otherwise constitute Taxes, whether or not now customary or in the contemplation of the parties on the Execution Date of this Lease, shall constitute Taxes, but only to the extent calculated as if the Property were the only real estate owned by Landlord. “Taxes” shall also include reasonable expenses (including without limitation legal and consultant fees) of tax abatement or other proceedings contesting assessments or levies.

(q) “Tax Period” shall be any fiscal/tax period in respect of which Taxes are due and payable to the appropriate governmental taxing authority (i.e., as mandated by the governmental taxing authority), any portion of which period occurs during the Term of this Lease.

(r) Payment of Taxes. Tenant shall pay to Landlord, as additional rent, Tenant’s Tax Share of Taxes. Landlord may make a good faith estimate of the Taxes to be due by Tenant for any Tax Period or part thereof during the Term, and Tenant shall pay to Landlord, on the Term Commencement Date and on the first (1st) day of each calendar month thereafter, an amount equal to Tenant’s Tax Share of Taxes for such Tax Period or part thereof divided by the number of months therein. Landlord may estimate and re-estimate Tenant’s Tax Share of Taxes and deliver a copy of the estimate or re-estimate to Tenant. Thereafter, the monthly installments of Tenant’s Tax Share of Taxes shall be appropriately adjusted in accordance with the estimations so that, by the end of the Tax Period in question, Tenant shall have paid all of Tenant’s Tax Share of Taxes as estimated by Landlord. Any amounts paid based on such an estimate shall be subject to adjustment as herein provided when actual Taxes are available for each Tax Period. If the total of such monthly remittances is greater than Tenant’s Tax Share of Taxes actually due for such Tax Period, then, provided no Event of Default has occurred nor any event which, with the passage of time and/or the giving of notice would constitute an Event of Default, Tenant may credit the difference against the next installment of additional rent on account of Taxes due hereunder, except that if such difference is determined after the end of the Term, Landlord shall refund such difference to Tenant within thirty (30) days after such determination to the extent that such difference exceeds any amounts then due from Tenant to Landlord (it being understood and agreed that if Tenant cures any default prior to

the expiration of the notice and/or cure periods set forth in Section 20.1 below, Tenant shall then be entitled to take such credit). If the total of such remittances is less than Tenant’s Tax Share of Taxes actually due for such Tax Period, Tenant shall pay the difference to Landlord, as additional rent hereunder, within thirty (30) days of Tenant’s receipt of an invoice therefor. Landlord’s estimate for the next Tax Period shall be based upon actual Taxes for the prior Tax Period plus a reasonable adjustment based upon estimated increases in Taxes. In the event that Payments in Lieu of Taxes (“PILOT”), instead of or in addition to Taxes, are separately assessed to certain portions of the Building or the Property including the Premises, Tenant agrees, except as otherwise expressly provided herein to the contrary, to pay to Landlord, as additional rent, the portion of such PILOT attributable to the Premises in the same manner as provided above for the payment of Taxes. The provisions of this Section 5.3(c) shall survive the expiration or earlier termination of this Lease.

(s) Effect of Abatements. Appropriate credit against Taxes or PILOT shall be given for any refund obtained by reason of a reduction in any Taxes by the assessors or the administrative, judicial or other governmental agency responsible therefor after deduction of Landlord’s expenditures for reasonable legal fees and for other reasonable expenses incurred in obtaining the Tax or PILOT refund.

(t) Part Years. If the Term Commencement Date or the Expiration Date occurs in the middle of a Tax Period, Tenant shall be liable for only that portion of the Taxes, as the case may be, with respect to such Tax Period within the Term.

(u) Any payment of Rent due hereunder not paid when due shall bear interest for each month or fraction thereof from the due date until paid in full at the annual rate of twelve percent (12%), or at any applicable lesser maximum legally permissible rate for debts of this nature (the “Default Rate”). Acceptance of interest shall not constitute a waiver of Tenant’s default with respect to the overdue amount or prevent Landlord from exercising any of the other rights and remedies available to Landlord under this Lease or at law or in equity now or hereafter in effect.

(v) For each Tenant payment check to Landlord that is returned by a bank for any reason, Tenant shall pay a returned check charge equal to the amount as shall be customarily charged by Landlord’s bank at the time.

(w) Money paid by Tenant to Landlord shall be applied to Tenant’s account in the following order: first, to any unpaid additional rent, including without limitation late charges, returned check charges, legal fees and/or court costs chargeable to Tenant hereunder; and then to unpaid Base Rent.

No Offset; Independent Covenants; Waiver. Rent shall be paid without notice or demand, and without setoff, counterclaim, defense, abatement, suspension, deferment, reduction or deduction, except as expressly provided herein. TENANT WAIVES ALL RIGHTS (I) TO ANY ABATEMENT, SUSPENSION, DEFERMENT, REDUCTION OR DEDUCTION OF OR FROM RENT, AND (II) TO QUIT, TERMINATE OR SURRENDER THIS LEASE OR THE PREMISES OR ANY PART THEREOF, EXCEPT AS EXPRESSLY PROVIDED HEREIN. TENANT HEREBY ACKNOWLEDGES AND AGREES THAT THE OBLIGATIONS OF TENANT HEREUNDER SHALL BE SEPARATE AND INDEPENDENT COVENANTS AND AGREEMENTS, THAT RENT SHALL CONTINUE TO 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. LANDLORD

AND TENANT EACH ACKNOWLEDGES AND AGREES THAT THE INDEPENDENT NATURE OF THE OBLIGATIONS OF TENANT HEREUNDER REPRESENTS FAIR, REASONABLE, AND ACCEPTED COMMERCIAL PRACTICE WITH RESPECT TO THE TYPE OF PROPERTY SUBJECT TO THIS LEASE, AND THAT THIS AGREEMENT IS THE PRODUCT OF FREE AND INFORMED NEGOTIATION DURING WHICH BOTH LANDLORD AND TENANT WERE REPRESENTED BY COUNSEL SKILLED IN NEGOTIATING AND DRAFTING COMMERCIAL LEASES IN MASSACHUSETTS, AND THAT THE ACKNOWLEDGEMENTS AND AGREEMENTS CONTAINED HEREIN ARE MADE WITH FULL KNOWLEDGE OF THE HOLDING IN WESSON V. LEONE ENTERPRISES, INC., 437 MASS. 708 (2002). SUCH ACKNOWLEDGEMENTS, AGREEMENTS AND WAIVERS BY TENANT ARE A MATERIAL INDUCEMENT TO LANDLORD ENTERING INTO THIS LEASE.

Survival. Any obligations under this Section 5 which shall not have been paid at the expiration or earlier termination of the Term shall survive such expiration or earlier termination and shall be paid when and as the amount of same shall be determined and be due.

(x) Contemporaneously with the execution of this Lease, Tenant shall deliver to Landlord either (i) cash in an amount specified in the Lease Summary Sheet (the “Cash Security Deposit”), which shall be held by Landlord in accordance with Section 7.5 below, or (ii) an irrevocable letter of credit which shall (a) be in the amount specified in the Lease Summary Sheet and otherwise in the form attached hereto as Exhibit 4; (b) issued by a bank reasonably acceptable to Landlord upon which presentment may be made in Boston, Massachusetts (if Landlord so requires at the time of its approval thereof); and (c) be for a term of one (1) year, subject to extension in accordance with the terms hereof (the “Letter of Credit”). The Letter of Credit shall be held by Landlord, without liability for interest, as security for the faithful performance by Tenant of all of the terms, covenants and conditions of this Lease by the Tenant to be kept and performed during the Term. In no event shall the Letter of Credit be deemed to be a prepayment of Rent nor shall it be considered a measure of liquidated damages. Unless the Letter of Credit is automatically renewing, at least thirty (30) days prior to the maturity date of the Letter of Credit (or any replacement Letter of Credit), Tenant shall deliver to Landlord a replacement Letter of Credit which shall have a maturity date no earlier than the next anniversary of the Term Commencement Date or one (1) year from its date of delivery to Landlord, whichever is later.

(y) If no Event of Default has occurred and there is no event which, with the passage of time and/or the giving of notice, would constitute an Event of Default and further provided that there is no material adverse change in Tenant’s net worth at the commencement of such Rent Year as verified by Landlord based upon a certificate from Tenant’s chief financial officer and audited financials, then the Cash Security Deposit or face amount of the Letter of Credit, as applicable, may be reduced by Tenant to (a) $130,000.00 at the commencement of the second Rent Year, and (b) $120,000.00 at the commencement of the third Rent Year; it being understood that if and when Tenant cures a default prior to the expiration of the applicable grace period, Tenant shall then be entitled to effect such reduction in accordance with this Section 7.1(b). Landlord shall, at no cost to Landlord, cooperate with Tenant and the issuer of the Letter of Credit, if applicable, in connection with such reduction.

Application of Proceeds of Letter of Credit. Upon an Event of Default, or if any proceeding shall be instituted by or against Tenant pursuant to any of the provisions of any Act of Congress or State law relating to bankruptcy, reorganizations, arrangements, compositions or other relief from creditors (and, in the case of any proceeding instituted against it, if Tenant shall fail to have such proceedings dismissed within thirty (30) days) or if Tenant is adjudged bankrupt or insolvent as a result of any such proceeding, or upon the end of the Term if there remains any uncured default of which Tenant shall have received notice, Landlord at its sole option may draw down all or a part of the Letter of Credit. The balance of any Letter of Credit cash proceeds shall be held in accordance with Section 7.5 below. Should the entire Letter of Credit, or any portion thereof, be drawn down by Landlord, Tenant shall, upon the written demand of Landlord, deliver a replacement Letter of Credit in the amount drawn, and Tenant’s failure to do so within ten (10) days after receipt of such written demand shall constitute an additional Event of Default hereunder. The application of all or any part of the cash proceeds of the Letter of Credit to any obligation or default of Tenant under this Lease shall not deprive Landlord of any other rights or remedies Landlord may have nor shall such application by Landlord constitute a waiver by Landlord.

Transfer of Letter of Credit. In the event that Landlord transfers its interest in the Premises, Tenant shall upon notice from and at no cost to Landlord, deliver to Landlord an amendment to the Letter of Credit or a replacement Letter of Credit naming Landlord’s successor as the beneficiary thereof. If Tenant fails to deliver such amendment or replacement within ten (10) days after written notice from Landlord, Landlord shall have the right to draw down the entire amount of the Letter of Credit and hold the proceeds thereof in accordance with Section 7.5 below.

Credit of Issuer of Letter of Credit. In event of a material adverse change in the financial position of any bank or institution which has issued the Letter of Credit or any replacement Letter of Credit hereunder, Landlord reserves the right to require that Tenant change the issuing bank or institution to another bank or institution reasonably approved by Landlord. Tenant shall, within ten (10) days after receipt of written notice from Landlord, which notice shall include the basis for Landlord’s reasonable belief that there has been a material adverse change in the financial position of the issuer of the Letter of Credit, replace the then-outstanding letter of credit with a like Letter of Credit from another bank or institution approved by Landlord.

Security Deposit. Landlord shall hold the Cash Security Deposit and/or the balance of proceeds remaining after a draw on the Letter of Credit (each hereinafter referred to as the “Security Deposit”) as security for Tenant’s performance of all its Lease obligations. After an Event of Default, or upon the end of the Term if there remains any uncured default of which Tenant shall have received notice, Landlord may apply the Security Deposit, or any part thereof, to Landlord’s damages without prejudice to any other Landlord remedy. Should Landlord apply all or any portion of the Security Deposit in accordance with the terms of this Lease, Tenant shall, upon the written demand of Landlord, deliver cash in the amount applied, and Tenant’s failure to do so within twenty (20) days after receipt of such written demand shall constitute an additional Event of Default hereunder. Tenant shall have the right to deliver a replacement Letter of Credit in the form and amount required hereunder, and upon receipt of such replacement Letter of Credit, Landlord shall return the Security Deposit to Tenant. Landlord has no obligation to pay interest on the Security Deposit and may co-mingle the Security Deposit with Landlord’s funds. If Landlord conveys its interest under this Lease, the Security Deposit, or any part not applied previously, may be turned over to the grantee in which case Tenant shall look solely to the grantee for the proper application and return of the Security Deposit.

Return of Security Deposit or Letter of Credit. Should Tenant comply with all of such terms, covenants and conditions and promptly pay all sums payable by Tenant to Landlord hereunder, the Security Deposit and/or Letter of Credit or the remaining proceeds therefrom, as applicable, shall be returned to Tenant within sixty (60) days after the end of the Term, less any portion thereof which may have been utilized by Landlord to cure any default or applied to any actual damage suffered by Landlord.

Electricity. Commencing on the Term Commencement Date, Tenant shall pay all charges for electricity furnished to the Premises and/or any equipment exclusively serving the same as additional rent as provided hereafter. Such charges shall be based in part on (a) reasonable estimates by Landlord based on percentage of air flow used by Tenant (measured through Landlord’s Building energy management system) as to equipment in the Building serving the Building, Tenant and other tenants, to be separately billed by Landlord, (b) metering equipment installed as part of Landlord’s Base Building Work, as to other electricity used in the Premises, which Tenant shall pay directly to the supplier, and (c) if applicable, such other metering equipment, if any, approved by Landlord in its reasonable discretion. Landlord shall, at Tenant’s sole cost and expense, maintain and keep in good order, condition and repair any such metering equipment. Tenant shall pay the full amount of any charges attributable to such meter on or before the due date therefor either to Landlord or directly to the supplier thereof, at Landlord’s election.

Water. Commencing on the Term Commencement Date, Tenant shall pay all water and sewer charges for water furnished to the Premises and/or any equipment exclusively serving the same as additional rent. Such charges shall be reasonably estimated by Landlord based on the percentage of air flow used by Tenant (measured through Landlord’s Building energy management system).

Gas. Commencing on the Term Commencement Date, Tenant shall pay all charges for natural gas service furnished to the Premises and/or any equipment exclusively serving the same as additional rent as provided hereafter. Such charges shall be based in part on (a) reasonable estimates by Landlord based on percentage of air flow used by Tenant (measured through Landlord’s Building energy management system) as to equipment in the Building serving the Building, Tenant, and other tenants, to be separately billed by Landlord, and (b) metering equipment installed as part of Landlord’s Base Building Work, as to natural gas used in the Premises, which Tenant shall pay directly to the supplier, and (c) if applicable, such other metering equipment, if any, approved by Landlord in its reasonable discretion.

HVAC. Consistent with the levels provided by Class A laboratory/office buildings in East Cambridge, Landlord shall provide to the Common Areas and the Premises on a twenty-four (24) hours per day, seven (7) days per week basis (i) heat 365 days/year and (ii) air conditioning during the normal cooling season; provided, however, that Landlord will provide air conditioning at such other times as reasonably requested by Tenant and (iii) general exhaust/ventilation. Excluded from such services are air conditioning requirements for (A) personal computers in excess of an average of one personal computer per person in occupancy of the Premises, or (B) exceptional office machinery. It is expressly acknowledged and agreed that Tenant shall be solely responsible for specialty exhaust, including without limitation exhaust for H2 rooms, radiation hoods and isotope hoods, vivarium, chemical storage rooms which require Class I, Division II classification, if any, and any other special Tenant equipment. Whenever the air conditioning systems are in operation, Tenant agrees to use reasonable efforts to lower and close the blinds or drapes when necessary because of the sun’s position, and to cooperate fully with Landlord with regard to, and to abide by all the reasonable regulations and requirements which Landlord may prescribe for the proper functioning and protection of the air conditioning systems.

Other Utilities; Utility Information. Subject to Landlord’s reasonable rules and regulations governing the same, Tenant shall obtain and pay, as and when due, for all other utilities and services consumed in and/or furnished to the Premises, together with all taxes, penalties, surcharges and maintenance charges pertaining thereto. Within ten (10) business days after Landlord’s request from time to time, Tenant shall provide Landlord with reasonably detailed information regarding tenant’s utility usage in the Premises.

Interruption or Curtailment of Utilities. When necessary by reason of accident or emergency, or for repairs, alterations, replacements or improvements which in the reasonable judgment of Landlord are desirable or necessary to be made, Landlord reserves the right, upon as much prior notice to Tenant as is practicable under the circumstances and no less than twenty-four (24) hours’ notice except in the event of an emergency, to interrupt, curtail, or stop (i) the furnishing of hot and/or cold water, and (ii) the operation of the plumbing and electric systems. Landlord shall exercise reasonable diligence to eliminate the cause of any such interruption, curtailment, stoppage or suspension, but there shall be no diminution or abatement of Rent or other compensation due from Landlord to Tenant hereunder, nor shall this Lease be affected or any of Tenant’s obligations hereunder reduced, and Landlord shall have no responsibility or liability for any such interruption, curtailment, stoppage, or suspension of services or systems.

Telecommunications Providers. Notwithstanding anything to the contrary herein or in this Lease contained, Landlord has no obligation to allow any particular telecommunications service provider to have access to the Building or to Premises other than Verizon and LightTower (collectively, the “Approved Providers”). If Landlord permits such access, Landlord may condition such access upon (a) the execution of Landlord’s standard telecommunications agreement (which shall include a provision requiring the payment of fair market rent for any space in the Property dedicated, licensed and/or leased to such provider), and (b) the payment to Landlord by Tenant or the service provider of any costs incurred by Landlord in facilitating such access. Subject to the preceding sentence, Landlord’s consent to providing access to the Building to any service provider other than the Approved Providers shall not be unreasonably withheld, conditioned or delayed provided such access does not require any street opening permits or approvals (unless otherwise agreed to by the City of Cambridge) or would unreasonably interfere with the use of the Common Areas.

Landlord’s Services. Subject to reimbursement pursuant to Section 5.2 above, Landlord shall provide the services described in Exhibit 8 attached hereto and made a part hereof (“Landlord’s Services”).

Maintenance and Repairs by Tenant. Tenant shall keep all and singular the Premises (including, without limitation, doors and door frames and plate glass (provided that Landlord shall have the right to repair plate glass at Tenant’s cost)) neat and clean and free of insects, rodents, vermin and other pests and in such good repair, order and condition as the same are in on the Term Commencement Date or in such better condition as the Premises may be put in during the Term, reasonable wear and tear and damage by insured Casualty excepted. Tenant shall be solely responsible, at Tenant’s sole cost and expense, for the proper maintenance of all building systems, sanitary, electrical, heating, air conditioning, plumbing, security or other systems and of all equipment and appliances installed and/or operated by Tenant and/or exclusively serving the Premises. Tenant agrees to provide regular maintenance by contract with a reputable qualified service contractor for the heating and air conditioning equipment servicing the Premises. Such maintenance contract and contractor shall be subject to Landlord’s reasonable approval. Tenant, at Landlord’s request, shall at reasonable intervals provide Landlord with copies of such contracts and maintenance and repair records and/or reports.

Maintenance and Repairs by Landlord. Except as otherwise provided in Section 15, and subject to Tenant’s obligations in Section 10.1 above, Landlord shall keep and maintain the roof, Building structure, exterior window frames, structural floor slabs and columns in good repair, order and condition. In addition, Landlord shall operate and maintain the Common Areas in substantially the same manner as other first-class combination office and laboratory facilities in the vicinity of the Building.

Accidents to Sanitary and Other Systems. Tenant shall give to Landlord prompt notice of any fire or accident in the Premises or in the Building and of any damage to, or defective condition in, any part or appurtenance of the Building including, without limitation, sanitary, electrical, ventilation, heating and air conditioning or other systems located in, or passing through, the Premises. Except as otherwise provided in Section 15, and subject to Tenant’s obligations in Section 10.1 above, such damage or defective condition shall be remedied by Landlord with reasonable diligence, but, subject to Section 14.5 below, if such damage or defective condition was caused by any of the Tenant Parties, the cost to remedy the same shall be paid by Tenant.

Floor Load—Heavy Equipment. Tenant shall not place a load upon any floor of the Premises exceeding the floor load per square foot of area which such floor was designed to carry and which is allowed by Legal Requirements. Landlord reserves the right to prescribe the weight and position of all safes, heavy machinery, heavy equipment, freight, bulky matter or fixtures (collectively, “Heavy Equipment”), which shall be placed so as to distribute the weight. Heavy Equipment shall be placed and maintained by Tenant at Tenant’s expense in settings sufficient in Landlord’s reasonable judgment to absorb and prevent vibration, noise and annoyance. Tenant shall not move any Heavy Equipment into or out of the Building without giving Landlord prior written notice thereof and observing all of Landlord’s Rules and Regulations with respect to the same. If such Heavy Equipment requires special handling, Tenant agrees to employ only persons holding a Master Rigger’s License to do said work, and that all work in connection therewith shall comply with Legal Requirements. Any such moving shall be at the sole risk and hazard of Tenant and Tenant will defend, indemnify and save Landlord and Landlord’s agents (including without limitation its property manager), contractors and employees (collectively with Landlord, the “Landlord Parties”) harmless from and against any and all claims, damages, losses, penalties, costs, expenses and fees (including without limitation reasonable legal fees) (collectively, “Claims”) resulting directly or indirectly from such moving. Proper placement of all Heavy Equipment in the Premises shall be Tenant’s responsibility.

Landlord’s Consent Required. Tenant shall not make any alterations, decorations, installations, removals, additions or improvements (collectively, “Alterations”) in or to the Premises without Landlord’s prior written approval of the contractor(s), written plans and specifications, a time schedule therefor and the items listed in Exhibit 5 attached hereto and made a part hereof. Landlord reserves the right to require that Tenant use Landlord’s preferred vendor(s) for any Alterations that involve roof penetrations, alarm tie-ins, sprinklers, fire alarm and other life safety equipment. Tenant shall not make any amendments or additions to plans and specifications approved by Landlord without Landlord’s prior written consent. Landlord’s approval of non-structural Alterations shall not be unreasonably withheld, conditioned or delayed. Notwithstanding the foregoing, Landlord may withhold its consent in its sole discretion (a) to any Alteration to or affecting the lab benches, fume hoods, roof and/or building systems, (b) with respect to matters of aesthetics relating to Alterations to or affecting the exterior of the Building, and (c) to any Alteration affecting the Building structure. Notwithstanding the foregoing, Landlord’s consent shall not be required with respect to non-structural Alterations costing less than $25,000.00 in any one instance and $75,000 in the aggregate per year, so long as such Alterations do not adversely affect the roof, Building systems or Building exterior (each, a “Permitted Alteration”), provided Tenant shall provide Landlord with reasonably detailed written notice thereof and the applicable Exhibit 5 items shall

be provided if reasonably required by Landlord. Tenant shall be responsible for all elements of the design of Tenant’s plans (including, without limitation, compliance with Legal Requirements, functionality of design, the structural integrity of the design, the configuration of the Premises and the placement of Tenant’s furniture, appliances and equipment), and Landlord’s approval of Tenant’s plans shall in no event relieve Tenant of the responsibility for such design. Landlord shall have no liability or responsibility for any claim, injury or damage alleged to have been caused by the particular materials (whether building standard or non-building standard), appliances or equipment selected by Tenant in connection with any work performed by or on behalf of Tenant. Except as otherwise expressly set forth herein, all Alterations shall be done at Tenant’s sole cost and expense and at such times and in such manner as Landlord may from time to time reasonably designate. If Tenant shall make any Alterations, then Landlord may elect, at the time Landlord approves such Alterations (or, for Permitted Alterations, promptly after Tenant notifies the Landlord of Tenant’s intent to make such Permitted Alterations and provides Landlord with the applicable Exhibit 5 items related thereto), to require Tenant at the expiration or sooner termination of the Term to restore the Premises to substantially the same condition as existed immediately prior to the Alterations. Subject to Section 21.1, if Landlord does not so elect, then any such Alteration shall become a part of the Premises upon installation, and shall be surrendered with the Premises at the end of the Term. Tenant shall provide Landlord with reproducible record drawings (in CAD format) of all Alterations within sixty (60) days after completion thereof.

Supervised Work. Landlord and Tenant recognize that to the extent Landlord permits Tenant to perform any Alterations outside the Premises and/or affecting the Building systems, or if required by Legal Requirements, Landlord will need to make arrangements to have supervisory personnel on site. Accordingly, Landlord and Tenant agree as follows: Tenant shall give Landlord at least two (2) business days’ prior written notice of any time outside of normal construction hours when Tenant intends to perform portions of Alterations (the “Supervised Work”). Tenant shall reimburse Landlord, within thirty (30) days after demand therefor, for the reasonable cost of Landlord’s supervisory personnel overseeing the Supervised Work.

Harmonious Relations. Tenant agrees that it will not, either directly or indirectly, use any contractors and/or materials if their use will create any difficulty, whether in the nature of a labor dispute or otherwise, with other contractors and/or labor engaged by Tenant or Landlord or others in the construction, maintenance and/or operation of the Building, the Property or any part thereof. In the event of any such difficulty, upon Landlord’s request, Tenant shall cause all contractors, mechanics or laborers causing such difficulty to leave the Property immediately.

Liens. No Alterations shall be undertaken by Tenant until Tenant has made provision for written waiver of liens from all contractors for such Alteration and taken other appropriate protective measures approved and/or required by Landlord. Tenant shall either: (a) demonstrate to Landlord, to Landlord’s reasonable satisfaction, that Tenant is able to pay for the cost of such Alteration, or (b) provide to Landlord security, in form and amount reasonably satisfactory to Landlord (such as a letter of credit, escrowed funds, payment, performance and lien bonds or a guaranty), securing Tenant’s obligation to pay for the entire cost of such Alteration. Any mechanic’s lien filed against the Premises or the Building for work claimed to have been done for, or materials claimed to have been furnished to, Tenant shall be discharged by Tenant within ten (10) days thereafter, at Tenant’s expense by filing the bond required by law or otherwise.

General Requirements. Unless Landlord and Tenant otherwise agree in writing, Tenant shall (a) obtain Landlord’s written approval of any and all building permit applications relating to Alterations (including without limitation Permitted Alterations) to the Premises prior to submission thereof; (b) procure or cause others to procure on its behalf all necessary permits before undertaking any Alterations in the Premises (and provide copies thereof to Landlord); (c) perform all of such Alterations in a good and

workmanlike manner, employing materials of good quality and in compliance with Landlord’s construction rules and regulations, all insurance requirements of this Lease, and Legal Requirements; and (d) defend, indemnify and hold the Landlord Parties harmless from and against any and all Claims occasioned by or growing out of such Alterations. Tenant shall cause contractors employed by Tenant to (i) carry Worker’s Compensation Insurance in accordance with statutory requirements, (ii) carry Automobile Liability Insurance and Commercial General Liability Insurance (A) naming Landlord as an additional insured, and (B) covering such contractors on or about the Premises in the amounts stated in Section 14 hereof or in such other reasonable amounts as Landlord shall require, and (iii) submit binders evidencing such coverage to Landlord prior to the commencement of any such Alterations. In addition, if construction during normal business hours unreasonably disturbs other tenants of the Property, in Landlord’s sole discretion, Landlord may require Tenant to stop the performance of Alterations during normal business hours and to perform the same after hours.

Restrictions. Tenant shall have the right to install Building standard signage identifying Tenant’s business at the entrance to the Premises, which signage shall be subject to Landlord’s prior written consent (which consent shall not be unreasonably withheld, conditioned or delayed so long as the same complies with Landlord’s then-current signage guidelines for the Building). Subject to the foregoing, Tenant shall not place or suffer to be placed or maintained on the exterior of the Premises, or any part of the interior visible from the exterior thereof, any sign, banner, advertising matter or any other thing of any kind (including, without limitation, any hand-lettered advertising), and shall not place or maintain any decoration, letter or advertising matter on the glass of any window or door of the Premises without first obtaining Landlord’s written approval. No signs or blinds may be put on or in any window or elsewhere if visible from the exterior of the Building. Landlord may provide Tenant with building standard blinds for each window within the Premises and Tenant shall install the same at Tenant’s sole cost and expense. Tenant may not remove the building standard blinds without Landlord’s prior written consent. Tenant may hang its own drapes, provided that they shall not in any way interfere with any building standard drapery or blinds provided by Landlord or be visible from the exterior of the Building, and that such drapes are so hung and installed that, when drawn, the building standard drapery or blinds are automatically also drawn.

Building Directory. Landlord shall list Tenant within the directory in the Building lobby at Landlord’s sole cost and expense. Subject to reasonable limits on the number of lines on the directory Landlord can provide and all such additional signage in the lobby directory, Landlord shall add the names of any approved subtenants or licensees occupying any portion of the Premises at Tenant’s sole cost and expense.

Monument Sign. Subject to the issuance of applicable permits and approvals and subject further to Legal Requirements, Landlord intends to install a monument sign on the Property on which Landlord shall list Tenant’s name (as well as the names of other tenants or occupants of the Building). Such listing shall comply with Landlord’s then-current signage guidelines for the Property.

Landlord’s Consent Required. Tenant shall not, without Landlord’s prior written consent, which consent may be withheld in Landlord’s sole discretion, mortgage or otherwise encumber this Lease or the Premises in whole or in part Except as expressly otherwise set forth herein, Tenant shall not, without Landlord’s prior written consent, which consent shall be granted or withheld in accordance with Section 13.3 below, assign, sublet, mortgage, license, transfer or encumber this Lease or the Premises in whole or in part whether by changes in the ownership or control of Tenant, or any direct or indirect owner

of Tenant, whether at one time or at intervals, by sale or transfer of stock, partnership or beneficial interests, operation of law or otherwise, or permit the occupancy of all or any portion of the Premises by any person or entity other than Tenant’s employees (each of the foregoing, a “Transfer”). Any purported Transfer made without Landlord’s consent, if required hereunder, shall be void and confer no rights upon any third person, provided that if there is a Transfer, Landlord may collect rent from the transferee without waiving the prohibition against Transfers, accepting the transferee, or releasing Tenant from full performance under this Lease. In the event of any Transfer in violation of this Section 13, Landlord shall have the right to terminate this Lease upon thirty (30) days’ written notice to Tenant given within sixty (60) days after receipt of written notice from Tenant to Landlord of any Transfer, or within one (1) year after Landlord first learns of the Transfer if no notice is given. No Transfer shall relieve Tenant of its primary obligation as party Tenant hereunder, nor shall it reduce or increase Landlord’s obligations under this Lease. In no event shall any transfer of shares in Tenant over a nationally recognized stock exchange be deemed to be a Transfer.

(z) Subject to Section 13.7 below, Tenant shall, prior to offering or advertising the Premises or any portion thereof for a Transfer, give a written notice (the “Recapture Notice”) to Landlord which: (i) states that Tenant desires to make a Transfer, (ii) identifies the affected portion of the Premises (the “Recapture Premises”), (iii) identifies the period of time (the “Recapture Period”) during which Tenant proposes to sublet the Recapture Premises, or indicates that Tenant proposes to assign its interest in this Lease, and (iv) offers to Landlord to terminate this Lease with respect to the Recapture Premises (in the case of a proposed assignment of Tenant’s interest in this Lease or a subletting for the remainder of the term of this Lease) or to suspend the Term for the Recapture Period (i.e. the Term with respect to the Recapture Premises shall be terminated during the Recapture Period and Tenant’s rental obligations shall be proportionately reduced). Landlord shall have fifteen (15) business days within which to respond to the Recapture Notice.

(aa) If Tenant does not enter into a Transfer on the terms and conditions contained in the Recapture Notice on or before the date which is one hundred eighty (180) days after the earlier of: (x) the expiration of the 15-business day period specified in Section 13.2(a) above, or (y) the date that Landlord notifies Tenant that Landlord will not accept Tenant’s offer contained in the Recapture Notice, time being of the essence, then prior to entering into any Transfer after such 180-day period, Tenant must deliver to Landlord a new Recapture Notice in accordance with Section 13.2(a) above.

(bb) Notwithstanding anything to the contrary contained herein, if Landlord notifies Tenant that it accepts the offer contained in the Recapture Notice or any subsequent Recapture Notice, Tenant shall have the right, for a period of fifteen (15) days following receipt of such notice from Landlord, time being of the essence, to notify Landlord in writing that it wishes to withdraw such offer and this Lease shall continue in full force and effect.

(cc) The terms of this Section 13.2 shall not apply to any Transfer to an Affiliated Entity or Successor (each as hereinafter defined).

Standard of Consent to Transfer. If Landlord does not timely give written notice to Tenant accepting an offer contemplated in a Recapture Notice or declines to accept the same, then Landlord agrees that, subject to the provisions of this Section 13, Landlord shall not unreasonably withhold, condition or delay its consent to a Transfer at fair market rent and otherwise on the terms contained in the Recapture Notice to an entity which will use the Premises for the Permitted Uses (provided that such consent shall be given or denied within thirty (30) days after Tenant’s request therefor) and, in Landlord’s reasonable opinion: (a) has a tangible net worth and other financial indicators sufficient to meet the

Transferee’s obligations under the Transfer instrument in question; (b) has a business reputation compatible with the operation of a first-class combination laboratory, research, development and office building; and (c) the intended use of such entity does not violate any exclusive or restrictive use provisions of any leases then in effect with respect to space in the Building; provided, however, if there shall be, at the time that Landlord is otherwise required to provide its consent, an event which, with the passage of time and/or the giving of notice, would constitute an Event of Default, then it shall be reasonable for Landlord to condition its consent to the Transfer in question on Tenant’s cure of such default prior to the expiration of applicable cure periods set forth in Section 20.1.

Listing Confers no Rights. The listing of any name other than that of Tenant, whether on the doors of the Premises or on the Building directory, or otherwise, shall not operate to vest in any such other person, firm or corporation any right or interest in this Lease or in the Premises or be deemed to effect or evidence any consent of Landlord, it being expressly understood that any such listing is a privilege extended by Landlord revocable at will by written notice to Tenant.

Profits In Connection with Transfers. Tenant shall, within thirty (30) days of receipt thereof, pay to Landlord fifty percent (50%) of any rent, sum or other consideration to be paid or given in connection with any Transfer, either initially or over time, after deducting reasonable actual out-of-pocket legal, and brokerage expenses incurred by Tenant, market concessions granted to the applicable Transferee and unamortized improvements paid for by Tenant in connection therewith, in excess of Rent hereunder as if such amount were originally called for by the terms of this Lease as additional rent. This Section 13.5 shall not apply to any Transfer to a Successor.

Prohibited Transfers. Notwithstanding any contrary provision of this Lease, Tenant shall have no right to make a Transfer unless on both (i) the date on which Tenant notifies Landlord of its intention to enter into a Transfer and (ii) the date on which such Transfer is to take effect, there is not an Event of Default. Notwithstanding anything to the contrary contained herein, Tenant agrees that in no event shall Tenant make a Transfer to (a) any government agency; (b) any tenant, subtenant or occupant of other space in the Building; or (c) any entity with whom Landlord shall have negotiated for space in the Property in the six (6) months immediately preceding such proposed Transfer.

Exceptions to Requirement for Consent. Notwithstanding anything to the contrary herein contained, Tenant shall have the right, without obtaining Landlord’s consent and without giving Landlord a Recapture Notice, upon prior written notice to Landlord, to (a) enter into license agreements with respect to the use of desks or benches or collaboration agreements with respect to up to 50% of the Premises in the aggregate, (b) make a Transfer to an Affiliated Entity (hereinafter defined) so long as such entity remains in such relationship to Tenant, and (b) assign Tenant’s interest in this Lease and the Premises to a Successor, provided that prior to or simultaneously with any assignment, such Affiliated Entity or Successor, as the case may be, and Tenant execute and deliver to Landlord an assignment and assumption agreement in form and substance reasonably acceptable to Landlord whereby such Affiliated Entity or Successor, as the case may be, shall agree to be independently bound by and upon all the covenants, agreements, terms, provisions and conditions set forth in the Lease on the part of Tenant to be performed, and whereby such Affiliated Entity or Successor, as the case may be, shall expressly agree that the provisions of this Section 13 shall, notwithstanding such Transfer, continue to be binding upon it with respect to all future Transfers. For the purposes hereof, an “Affiliated Entity” shall be defined as any entity which is controlled by, is under common control with, or which controls Tenant. For the purposes hereof, a “Successor” shall be defined as any entity into or with which Tenant is merged or with which Tenant is consolidated or which acquires all or substantially all of Tenant’s stock or assets, provided that the surviving entity shall have a net worth greater than or equal to the net worth of Tenant prior to such assignment. Notwithstanding the provisions of this Section 13.7, no transaction or series of transactions which are effected solely for the purpose of qualifying as a transaction which does not require Landlord’s consent (i.e. and thereby avoiding the operation of the provisions of this Article 13) shall be permitted pursuant to this Section 13.7.

(dd) Tenant shall procure, pay for and keep in force throughout the Term (and for so long thereafter as Tenant remains in occupancy of the Premises) commercial general liability insurance insuring Tenant on an occurrence basis against all claims and demands for personal injury liability (including, without limitation, bodily injury, sickness, disease, and death) or damage to property which may be claimed to have occurred from and after the time any of the Tenant Parties shall first enter the Premises, of not less than Two Million Dollars ($2,000,000) per occurrence, Four Million Dollars ($4,000,000) aggregate, and from time to time thereafter shall be not less than such higher amounts, if procurable, as may be reasonably required by Landlord. Tenant shall also carry umbrella liability coverage in an amount of no less than Four Million Dollars ($4,000,000). Such policy shall also include contractual liability coverage covering Tenant’s liability assumed under this Lease, including without limitation Tenant’s indemnification obligations. Such insurance policy(ies) shall name Landlord, Landlord’s managing agent and persons claiming by, through or under them (and of whom Tenant has been provided written notice), if any, as additional insureds.

(ee) Tenant shall take out and maintain throughout the Term a policy of fire, vandalism, malicious mischief, extended coverage and so-called “all risk” coverage insurance in an amount equal to one hundred percent (100%) of the replacement cost insuring (i) all items or components of Tenant’s Alterations (collectively, the “Tenant-Insured Improvements”), and (ii) Tenant’s furniture, equipment, fixtures and property of every kind, nature and description related or arising out of Tenant’s leasehold estate hereunder, which may be in or upon the Premises or the Building (collectively, “Tenant’s Property”). Such insurance shall insure the interests of both Landlord and Tenant as their respective interests may appear from time to time.

(ff) Tenant shall take out and maintain a policy of business interruption insurance throughout the Term sufficient to cover Tenant’s business losses, including Rent due hereunder, during a 12-month period.

(gg) Tenant shall procure and maintain at its sole expense such additional insurance as may be necessary to comply with any Legal Requirements.

(hh) During periods when any Alterations are being performed, Builders Risk Insurance.

(ii) The insurance required pursuant to Sections 14.1(a), (b), (c), (d) and (e) (collectively, “Tenant’s Insurance Policies”) shall be effected with insurers approved by Landlord, with a rating of not less than “A-XI” in the current Best’s Insurance Reports, and authorized to do business in the Commonwealth of Massachusetts under valid and enforceable policies. Tenant shall use good faith efforts to include within Tenant’s Insurance Policies provisions stating that Tenant’s Insurance Policies shall not be canceled without at least thirty (30) days’ prior written notice to each insured named therein. Tenant shall provide, and shall use good faith efforts to cause its broker of record to provide, prior written notice to Landlord of any reduction in the coverage amounts of any of Tenant’s Insurance Policies below the coverages required hereunder. Tenant’s Insurance Policies may include deductibles in an amount no greater than the greater of $25,000 or commercially reasonable amounts. Tenant shall deliver to Landlord on or before the date on which any of the Tenant Parties shall first enter the Premises and thereafter not

less than fifteen (15) days prior to the expiration date of each expiring policy, binders of Tenant’s Insurance Policies issued by the respective insurers setting forth in full the provisions thereof together with evidence satisfactory to Landlord of the payment of all premiums for such policies. In the event of any claim, and upon Landlord’s request, Tenant shall deliver to Landlord complete copies of Tenant’s Insurance Policies. Upon request of Landlord, Tenant shall deliver to any Mortgagee copies of the foregoing documents.

(jj) Except to the extent caused by the negligence or willful misconduct of any of the Landlord Parties, Tenant shall defend, indemnify and save the Landlord Parties harmless from and against any and all Claims asserted by or on behalf of any person, firm, corporation or public authority arising from:

(ii) Any injury to or death of any person, or loss of or damage to property, sustained or occurring in, upon, at or about the Premises;

(iii) Any injury to or death of any person, or loss of or damage to property arising out of the use or occupancy of the Premises by or the negligence or willful misconduct of any of the Tenant Parties; and

(iv) On account of or based upon any work or thing whatsoever done (other than by Landlord or any of the Landlord Parties) at the Premises during the Term and during the period of time, if any, prior to the Term Commencement Date that any of the Tenant Parties may have been given access to the Premises.

(kk) Except to the extent caused by the negligence or willful misconduct of any of the Tenant Parties, Landlord shall defend, indemnify and save Tenant harmless from and against any and all Claims asserted by or on behalf of any person, firm, corporation or public authority arising from (i) Landlord’s breach of any covenant or obligation under this Lease, or (ii) any injury to or death of any person, or loss of or damage to property arising out of the negligence or willful misconduct of any of the Landlord Parties.

Property of Tenant. Tenant covenants and agrees that, to the maximum extent permitted by Legal Requirements, all of Tenant’s Property at the Premises shall be at the sole risk and hazard of Tenant, and that if the whole or any part thereof shall be damaged, destroyed, stolen or removed from any cause or reason whatsoever, no part of said damage or loss shall be charged to, or borne by, Landlord, except, subject to Section 14.5 hereof, to the extent such damage or loss is due to the negligence or willful misconduct of any of the Landlord Parties.

Limitation of Landlord’s Liability for Damage or Injury. Landlord shall not be liable for any injury or damage to persons, animals, or property resulting from fire, explosion, falling plaster, steam, gas, air contaminants or emissions, electricity, electrical or electronic emanations or disturbance, water, rain or snow or leaks from any part of the Building or from the pipes, appliances, equipment or plumbing works or from the roof, street or sub-surface or from any other place or caused by dampness, vandalism, malicious mischief or by any other cause of whatever nature, except to the extent caused by or due to the negligence or willful misconduct of any of the Landlord Parties, and then, where notice and an opportunity to cure are appropriate (i.e., where Tenant has an opportunity to know or should have known of such condition sufficiently in advance of the occurrence of any such injury or damage resulting

therefrom as would have enabled Landlord to prevent such damage or loss had Tenant notified Landlord of such condition) only after (i) notice to Landlord of the condition claimed to constitute negligence or willful misconduct, and (ii) the expiration of a reasonable time after such notice has been received by Landlord without Landlord having commenced to take all reasonable and practicable means to cure or correct such condition; and pending such cure or correction by Landlord, Tenant shall take all reasonably prudent temporary measures and safeguards to prevent any injury, loss or damage to persons or property. Notwithstanding the foregoing, in no event shall any of the Landlord Parties be liable for any loss which is covered by insurance policies actually carried or required to be so carried by this Lease; nor shall any of the Landlord Parties be liable for any such damage caused by other tenants or persons in the Building or caused by operations in construction of any private, public, or quasi-public work; nor shall any of the Landlord Parties be liable for any latent defect in the Premises or in the Building.

Waiver of Subrogation; Mutual Release. Landlord and Tenant each hereby waives on behalf of itself and its property insurers (none of which shall ever be assigned any such claim or be entitled thereto due to subrogation or otherwise) any and all rights of recovery, claim, action, or cause of action against the other and its agents, officers, servants, partners, shareholders, or employees (collectively, the “Related Parties”) for any loss or damage (excluding rights of recovery, claims, actions, and causes of action relating to damage to the roof of the Building caused by Tenant but including rights of recovery, claims, actions, and causes of action relating to damage to the roof of the Building caused by any Casualty (hereinafter defined)) that may occur to or within the Premises or the Building or any improvements thereto, or any personal property of such party therein which is insured against under any property insurance policy actually being maintained by the waiving party from time to time, even if not required hereunder, or which would be insured against under the terms of any insurance policy required to be carried or maintained by the waiving party hereunder, whether or not such insurance coverage is actually being maintained, including, in every instance, such loss or damage that may be caused by the negligence of the other party hereto and/or its Related Parties. Landlord and Tenant each agrees to cause appropriate clauses to be included in its property insurance policies necessary to implement the foregoing provisions.

Tenant’s Acts—Effect on Insurance. Tenant shall not do or permit any Tenant Party to do any act or thing upon the Premises or elsewhere in the Building which will invalidate or be in conflict with any insurance policies or warranties covering the Building and the fixtures and property therein; and shall not do, or permit to be done, any act or thing upon the Premises which shall subject Landlord to any liability or responsibility for injury to any person or persons or to property by reason of any business or operation being carried on upon said Premises or for any other reason. If by reason of the failure of Tenant to comply with the provisions hereof the insurance rate applicable to any policy of insurance shall at any time thereafter be higher than it otherwise would be, Tenant shall reimburse Landlord upon demand for that part of any insurance premiums which shall have been charged because of such failure by Tenant, together with interest at the Default Rate until paid in full, within ten (10) days after receipt of an invoice therefor.

Damage. If the Premises are damaged in whole or part because of fire or other insured casualty (“Casualty”), or if the Premises are subject to a taking in connection with the exercise of any power of eminent domain, condemnation, or purchase under threat or in lieu thereof (any of the foregoing, a “Taking”), then unless this Lease is terminated in accordance with Section 15.2 below, Landlord shall restore the Building and/or the Premises to substantially the same condition as existed immediately following completion of Landlord’s Work, or in the event of a partial Taking which affects the Building and the Premises, restore the remainder of the Building and the Premises not so Taken to substantially the same condition as is reasonably feasible. Within ninety (90) days following such Casualty or Taking,

Landlord shall provide Tenant with a written notice (the “Restoration Notice”) indicating the expected timeframe for completion of Landlord’s repair and restoration. If, in Landlord’s reasonable judgment, any element of the Tenant-Insured Improvements can more effectively be restored as an integral part of Landlord’s restoration of the Building or the Premises, such restoration shall also be made by Landlord, but at Tenant’s sole cost and expense. Subject to rights of Mortgagees, Tenant Delays, Legal Requirements then in existence and to delays for adjustment of insurance proceeds or Taking awards, as the case may be, and instances of Landlord’s Force Majeure, Landlord shall substantially complete such restoration within one (1) year after Landlord’s receipt of all required permits therefor. Upon substantial completion of such restoration by Landlord, Tenant shall use diligent efforts to complete restoration of the Premises to substantially the same condition as existed immediately prior to such Casualty or Taking, as the case may be, as soon as reasonably possible. Tenant agrees to cooperate with Landlord in such manner as Landlord may reasonably request to assist Landlord in collecting insurance proceeds due in connection with any Casualty which affects the Premises or the Building. In no event shall Landlord be required to expend more than the Net (hereinafter defined) insurance proceeds Landlord receives for damage to the Premises and/or the Building or the Net Taking award attributable to the Premises and/or the Building. “Net” means the insurance proceeds or Taking award actually paid to Landlord (and not paid over to a Mortgagee) less all costs and expenses, including adjusters and attorney’s fees, of obtaining the same. In the Operating Year in which a Casualty occurs, there shall be included in Operating Costs Landlord’s deductible under its property insurance policy. Except as Landlord may elect pursuant to this Section 15.1, under no circumstances shall Landlord be required to repair any damage to, or make any repairs to or replacements of, any Tenant-Insured Improvements.

(ll) Landlord’s Termination Rights. Landlord may terminate this Lease upon thirty (30) days’ prior written notice to Tenant if:

(i) any material portion of the Building or any material means of access thereto is taken;

(ii) more than thirty-five percent (35%) of the Building is damaged by Casualty; or

(iii) if the estimated time to complete restoration exceeds one (1) year from the date on which Landlord receives all required permits for such restoration.

(mm) Tenant’s Termination Right. If (i) Landlord is so required but fails to complete restoration of the Premises within the time frames and subject to the conditions set forth in Section 15.1 above, or (ii) the expected timeframe for completion of Landlord’s repair and restoration set forth by Landlord in the Restoration Notice exceeds one (1) year from the date of Casualty or Taking, then Tenant may terminate this Lease upon thirty (30) days’ written notice to Landlord; provided, however, that if Landlord completes such restoration within thirty (30) days after receipt of any such termination notice, such termination notice shall be null and void and this Lease shall continue in full force and effect. The remedies set forth in this Section 15.2(b) and in Section 15.2(c) below are Tenant’s sole and exclusive rights and remedies based upon Landlord’s failure to complete the restoration of the Premises as set forth herein.

(nn) Either Party May Terminate. In the case of any Casualty or Taking affecting the Premises and occurring during the last six (6) months of the Term, then (i) if such Casualty or Taking results in more than twenty-five percent (25%) of the floor area of the Premises being unsuitable for the Permitted Uses, or (ii) the damage to the Premises costs more than $100,000 to restore, then either

Landlord or Tenant shall have the option to terminate this Lease upon thirty (30) days’ written notice to the other. In addition, if any Mortgagee does not release sufficient insurance proceeds to cover the cost of Landlord’s restoration work and Landlord does not agree in writing to cover the difference, Landlord or Tenant may terminate this Lease by written notice to the other.

(oo) Automatic Termination. In the case of a Taking of the entire Premises, then this Lease shall automatically terminate as of the date of possession by the Taking authority.

(pp) Notwithstanding anything to the contrary contained herein, Tenant may not terminate this Lease pursuant to this Section 15 if the Casualty in question was caused by the willful misconduct of any of the Tenant Parties.

Taking for Temporary Use. If the Premises are Taken for temporary use, this Lease and Tenant’s obligations, including without limitation the payment of Rent, shall continue. For purposes hereof, a “Taking for temporary use” shall mean a Taking of ninety (90) days or less.

Disposition of Awards. Except for any separate award for Tenant’s movable trade fixtures, relocation expenses, and unamortized leasehold improvements paid for by Tenant (provided that the same may not reduce Landlord’s award), all Taking awards to Landlord or Tenant shall be Landlord’s property without Tenant’s participation, and Tenant hereby assigns to Landlord Tenant’s interest, if any, in such award. Tenant may pursue its own claim against the Taking authority.

1.4 Abatement. If all or any portion of the Premises are damaged or made inaccessible by a Casualty or subject to a Taking, Base Rent, Additional Rent on account of Operating Costs and Additional Rent on account of Taxes shall be equitably abated for the period from the date of such Casualty or Taking until the earlier of (a) the date that Landlord substantially completes Landlord’s restoration work (provided that if Landlord would have completed Landlord’s restoration work at an earlier date but for (i) Tenant having failed to reasonably cooperate with Landlord in effecting such work or collecting insurance proceeds, and/or (ii) Tenant Delays, then the Premises shall be deemed to have been repaired and restored on such earlier date), or (b) the date Tenant or other occupant reoccupies all or such affected portion of the Premises (in which case the Base Rent and Additional Rent allocable to such reoccupied portion shall be payable by Tenant from the date of such occupancy). The reasonable determination of Landlord’s architect of the date Landlord’s restoration work shall have been substantially completed shall be controlling unless Tenant disputes same by notice to Landlord given within fifteen (15) days after receipt of written notice from Landlord setting forth such determination by Landlord, and pending resolution of such dispute, Tenant’s restoration period (and Tenant’s obligation to re-commence the payment of Rent) shall commence in accordance with Landlord’s architect’s reasonable determination. In the event of a Taking where the Lease is not terminated, a just proportion of the Rent, based on the nature and extent of the interference with Tenant’s business operations, shall, subject to Section 15.3 above, be abated for the duration of the Taking.

ESTOPPEL CERTIFICATE. Tenant shall at any time and from time to time upon not less than ten (10) days’ prior notice from Landlord, execute, acknowledge and deliver to Landlord a statement in writing certifying that this Lease is unmodified and in full force and effect (or if there have been modifications, that the same is in full force and effect as modified and stating the modifications), and the dates to which Rent has been paid in advance, if any, stating whether or not Landlord is in default in performance of any covenant, agreement, term, provision or condition contained in this Lease and, if so, specifying each such default, and such other facts as Landlord may reasonably request, it being intended that any such statement delivered pursuant hereto may be relied upon by Landlord, any prospective purchaser of the Building or of any interest of Landlord therein, any Mortgagee or prospective mortgagee thereof, any lessor or prospective lessor thereof, any lessee or prospective lessee thereof, or any prospective assignee of any mortgage thereof. Time is of the essence with respect to any such requested certificate, Tenant hereby acknowledging the importance of such certificates in mortgage financing arrangements, prospective sales and the like.

Prohibition. Tenant shall not, without the prior written consent of Landlord, bring or permit to be brought or kept in or on the Premises or elsewhere in the Building or the Property (i) any inflammable, combustible or explosive fluid, material, chemical or substance (except for standard office supplies stored in proper containers); and (ii) any Hazardous Material (hereinafter defined), other than the types and quantities of Hazardous Materials which are listed on Exhibit 6 attached hereto (“Tenant’s Hazardous Materials”), provided that the same shall at all times be brought upon, kept or used in so-called ‘control rooms’ and in accordance with all applicable Environmental Laws (hereinafter defined) and prudent environmental practice and (with respect to medical waste and so-called “biohazard” materials) good scientific and medical practice, and provided further that in no event shall Tenant generate, produce, bring upon, use, store or treat any infectious biological micro-organisms or any other Hazardous Materials in the Premises with a risk category above the level of Biosafety Level 2 as established and described by the Department of Health and Human Services Publication Biosafety in Microbiological and Biomedical Laboratories (Fifth Edition) (the “BMBL”), as it may be further revised (or such nationally recognized new or replacement standards as may be reasonably selected by Landlord). In all events, Tenant shall comply with all applicable provisions of the BMBL. Tenant shall be responsible for assuring that all laboratory uses are adequately and properly vented. On or before each anniversary of the Rent Commencement Date, and on any earlier date during the 12-month period on which Tenant intends to add a new Hazardous Material to, or materially increase the quantity of any Hazardous Material already on, the list of Tenant’s Hazardous Materials, Tenant shall submit to Landlord an updated list of Tenant’s Hazardous Materials for Landlord’s review and approval, which approval shall not be unreasonably withheld, conditioned or delayed. Landlord shall have the right, from time to time, to inspect the Premises for compliance with the terms of this Section 17.1 at Tenant’s sole cost and expense. Notwithstanding the foregoing, with respect to any of Tenant’s Hazardous Materials which Tenant does not properly handle, store or dispose of in compliance with all applicable Environmental Laws (hereinafter defined), prudent environmental practice and (with respect to medical waste and so-called “biohazard” materials) good scientific and medical practice, Tenant shall, upon written notice from Landlord, no longer have the right to bring such material into the Building or the Property until Tenant has demonstrated, to Landlord’s reasonable satisfaction, that Tenant has implemented programs to thereafter properly handle, store or dispose of such material.

Environmental Laws. For purposes hereof, “Environmental Laws” shall mean all laws, statutes, ordinances, rules and regulations of any local, state or federal governmental authority having jurisdiction concerning environmental, health and safety matters, including but not limited to any discharge by any of the Tenant Parties into the air, surface water, sewers, soil or groundwater of any Hazardous Material (hereinafter defined) whether within or outside the Premises, including, without limitation (a) the Federal Water Pollution Control Act, 33 U.S.C. Section 1251 et seq., (b) the Federal Resource Conservation and Recovery Act, 42 U.S.C. Section 6901 et seq., (c) the Comprehensive Environmental Response, Compensation and Liability Act, 42 U.S.C. Section 9601 et seq., (d) the Toxic Substances Control Act of 1976, 15 U.S.C. Section 2601 et seq., (e) Chapter 21C of the General Laws of Massachusetts, and (f) Chapter 21E of the General Laws of Massachusetts. Tenant, at its sole cost and expense, shall comply with (i) all Environmental Laws, and (ii) any rules, requirements and safety procedures of the Massachusetts Department of Environmental Protection, the City of Cambridge and any insurer of the Building or the Premises with respect to Tenant’s use, storage and disposal of any Hazardous Materials.

Hazardous Material Defined. As used herein, the term “Hazardous Material” means asbestos, oil or any hazardous, radioactive or toxic substance, material or waste or petroleum derivative which is or becomes regulated by any Environmental Law, including without limitation live organisms, viruses and fungi, medical waste and any so-called “biohazard” materials, and any materials on the right to know list of the Occupational Safety and Health Administration. The term “Hazardous Material” includes, without limitation, oil and/or any material or substance which is (i) designated as a “hazardous substance,” “hazardous material,” “oil,” “hazardous waste” or toxic substance under any Environmental Law, or (ii) contains any component now or hereafter designated as such.

Testing. If any Mortgagee or governmental authority requires testing to determine whether there has been any release of Hazardous Materials and such testing is required as a result of the acts or omissions of any of the Tenant Parties, then Tenant shall reimburse Landlord upon demand, as additional rent, for the reasonable costs thereof, together with interest at the Default Rate until paid in full. Tenant shall execute affidavits, certifications and the like, as may be reasonably requested by Landlord from time to time concerning Tenant’s best knowledge and belief concerning the presence of Hazardous Materials in or on the Premises, the Building or the Property.

(a) Tenant hereby covenants and agrees to indemnify, defend and hold the Landlord Parties harmless from and against any and all Claims against any of the Landlord Parties arising out of contamination of any part of the Property or other adjacent property, which contamination arises as a result of: (i) the presence of any Hazardous Material in the Premises, the presence of which is caused by any act or omission of any of the Tenant Parties, or (ii) from a breach by Tenant of its obligations under this Section 17. This indemnification of the Landlord Parties by Tenant includes, without limitation, reasonable costs incurred in connection with any investigation of site conditions or any cleanup, remedial, removal or restoration work or any other response action required by any federal, state or local governmental agency or political subdivision because of Hazardous Material present in the soil, soil vapor, or ground water on or under, or any indoor air in, the Building based upon the circumstances identified in the first sentence of this Section 17.5. The indemnification and hold harmless obligations of Tenant under this Section 17.5 shall survive the expiration or any earlier termination of this Lease. Without limiting the foregoing, if the presence of any Hazardous Material in the Building or otherwise at the Property is caused by any of the Tenant Parties and results in any contamination of any part of the Property or any adjacent property, Tenant shall promptly take all actions at Tenant’s sole cost and expense as are necessary to return the Property and/or the Building or any adjacent property to their condition as of the date of this Lease, provided that Tenant shall first obtain Landlord’s approval of such actions, which approval shall not be unreasonably withheld, conditioned or delayed so long as such actions, in Landlord’s reasonable discretion, would not potentially have any adverse effect on the Property, and, in any event, Landlord shall not withhold its approval of any proposed actions which are required by applicable Environmental Laws.

(b) Without limiting the obligations set forth in Section 17.5(a) above, if any Hazardous Material is in, on, under, at or about the Building or the Property as a result of the acts or omissions of any of the Tenant Parties and results in any contamination of any part of the Property or any adjacent property that is in violation of any applicable Environmental Law or that requires the performance of any response action pursuant to any Environmental Law, Tenant shall promptly take all actions at Tenant’s sole cost and expense as are necessary to reduce such Hazardous Material to amounts below any applicable Reportable Quantity, any applicable Reportable Concentration and any other applicable standard set forth in Environmental Laws such that no further response actions are required; provided that Tenant shall first obtain Landlord’s written approval of such actions, which approval shall not be unreasonably withheld, conditioned or delayed so long as such actions would not be reasonably

expected to have an adverse effect on the market value or utility of the Property for the Permitted Uses, and in any event, Landlord shall not withhold its approval of any proposed actions which are required by applicable Environmental Laws (such approved actions, “Tenant’s Remediation”). For the avoidance of doubt, the parties acknowledge that Tenant’s Remediation with respect to the Property shall not contain any requirement that Tenant remediate any contamination to levels or standards more stringent than those associated with the use of the Property for office, research and development, laboratory, and vivarium uses.

(i) until the completion of Tenant’s Remediation (as evidenced by the certification of Tenant’s Licensed Site Professional (as such term is defined by applicable Environmental Laws), who shall be reasonably acceptable to Landlord) (the “Remediation Completion Date”), Tenant shall pay to Landlord, with respect to the portion of the Premises which reasonably cannot be occupied by a new tenant until completion of Tenant’s Remediation, (A) Additional Rent on account of Operating Costs and Taxes and (B) Base Rent in an amount equal to the greater of (1) the fair market rental value of such portion of the Premises (determined in substantial accordance with the process described in Section 1.2 above), and (2) Base Rent attributable to such portion of the Premises in effect immediately prior to the end of the Term; and

(ii) Tenant shall maintain responsibility for Tenant’s Remediation and Tenant shall complete Tenant’s Remediation as soon as reasonably practicable in accordance with all Environmental Laws. If Tenant does not diligently pursue completion of Tenant’s Remediation, Landlord shall have the right to either (A) assume control for overseeing Tenant’s Remediation, in which event Tenant shall pay all reasonable costs and expenses of Tenant’s Remediation (it being understood and agreed that all costs and expenses of Tenant’s Remediation incurred pursuant to contracts entered into by Tenant shall be deemed reasonable) within thirty (30) days of demand therefor (which demand shall be made no more often than monthly), and Landlord shall be substituted as the party identified on any governmental filings as the party responsible for the performance of such Tenant’s Remediation or (B) require Tenant to maintain responsibility for Tenant’s Remediation, in which event Tenant shall complete Tenant’s Remediation as soon as reasonably practicable in accordance with all Environmental Laws, it being understood that Tenant’s Remediation shall not contain any requirement that Tenant remediate any contamination to levels or standards more stringent than those associated with the Property’s current office, research and development, laboratory, and vivarium uses.

(d) The provisions of this Section 17.5 shall survive the expiration or earlier termination of this Lease.

Disclosures. Prior to bringing any Hazardous Material into any part of the Property, Tenant shall deliver to Landlord the following information with respect thereto: (a) a description of handling, storage, use and disposal procedures; (b) all plans or disclosures and/or emergency response plans which Tenant has prepared, including without limitation Tenant’s Spill Response Plan, and all plans which Tenant is required to supply to any governmental agency or authority pursuant to any Environmental Laws; and (c) other information reasonably requested by Landlord.

Removal. Tenant shall be responsible, at its sole cost and expense, for Hazardous Material and other biohazard disposal services for the Premises. Such services shall be performed by contractors reasonably acceptable to Landlord and on a sufficient basis to ensure that the Premises are at all times kept neat, clean and free of Hazardous Materials and biohazards except in appropriate, specially marked containers reasonably approved by Landlord. In addition, if any Legal Requirements or the trash removal company requires that any substances be disposed of separately from ordinary trash, Tenant shall make arrangements at Tenant’s expense for such disposal directly with a qualified and licensed disposal company at a lawful disposal site.

Rules and Regulations. Tenant will faithfully observe and comply with all rules and regulations promulgated from time to time with respect to the Building, the Property and construction within the Property (collectively, the “Rules and Regulations”). The current version of the Rules and Regulations is attached hereto as Exhibit 7. In the case of any conflict between the provisions of this Lease and any future rules and regulations, the provisions of this Lease shall control. Nothing contained in this Lease shall be construed to impose upon Landlord any duty or obligation to enforce the Rules and Regulations or the terms, covenants or conditions in any other lease as against any other tenant and Landlord shall not be liable to Tenant for violation of the same by any other tenant, its servants, employees, agents, contractors, visitors, invitees or licensees.

Energy Conservation. Notwithstanding anything to the contrary contained herein, Landlord may institute upon written notice to Tenant such policies, programs and measures as may be necessary, required, or expedient for the conservation and/or preservation of energy or energy services (collectively, the “Conservation Program”), provided however, that the Conservation Program does not, by reason of such policies, programs and measures, reduce the level of energy or energy services being provided to the Premises below the level of energy or energy services then being provided in comparably aged, first-class combination laboratory, research and development and office buildings in the vicinity of the Building, or as may be necessary or required to comply with Legal Requirements or standards or the other provisions of this Lease. Upon receipt of such notice, Tenant shall comply with the Conservation Program.

Recycling. Upon written notice, Landlord may establish policies, programs and measures for the recycling of paper, products, plastic, tin and other materials (a “Recycling Program”). Upon receipt of such notice, Tenant will comply with the Recycling Program at Tenant’s sole cost and expense.

Legal Requirements. Tenant shall be responsible at its sole cost and expense for complying with (and keeping the Premises in compliance with) all Legal Requirements which are applicable to Tenant’s particular use or occupancy of, or Alterations made by or on behalf of Tenant to, the Premises. Tenant shall furnish all data and information to governmental authorities, with a copy to Landlord, as required in accordance with Legal Requirements as they relate to Tenant’s use or occupancy of the Premises or the Building. If Tenant receives notice of any violation of Legal Requirements applicable to the Premises or the Building, it shall give prompt notice thereof to Landlord. Nothing contained in this Section 19.1 shall be construed to expand the uses permitted hereunder beyond the Permitted Uses. Landlord shall comply with any Legal Requirements and with any direction of any public office or officer relating to the maintenance or operation of the Building as a combination laboratory, research and development and office building, and the costs so incurred by Landlord shall be included in Operating Costs in accordance with the provisions of Section 5.2.

Required Permits. Tenant shall, at Tenant’s sole cost and expense, use diligent good faith efforts to apply for, seek and obtain all necessary state and local licenses, permits and approvals needed for the operation of Tenant’s business, excluding the certificate of occupancy which Tenant must obtain prior to operating its business in the Premises (collectively, the “Required Permits”), on or before the Rent Commencement Date, time being of the essence. Tenant shall thereafter maintain all Required Permits. Tenant, at Tenant’s expense, shall at all times comply with the terms and conditions of each such Required Permit. Landlord shall cooperate with Tenant, at Tenant’s sole cost and expense, in connection with its application for Required Permits.

Events of Default. The occurrence of any one or more of the following events shall constitute an “Event of Default” hereunder by Tenant:

(e) If Tenant fails to make any payment of Rent or any other payment required hereunder, as and when due, and such failure shall continue for a period of five (5) business days after notice thereof from Landlord to Tenant; provided, however, an Event of Default shall occur hereunder without any obligation of Landlord to give any notice if (i) Tenant fails to make any payment within five (5) business days after the due date therefor, and (ii) Landlord has given Tenant written notice under this Section 20.1(a) on two (2) or more occasions during the twelve (12) month interval preceding such failure by Tenant;

(f) If Tenant shall abandon the Premises (whether or not the keys shall have been surrendered or the Rent shall have been paid);

(g) If Tenant shall fail to execute and deliver to Landlord an estoppel certificate pursuant to Section 16 above or a subordination and attornment agreement pursuant to Section 22 below, within the timeframes set forth therein and such failure continues for five (5) days after notice thereof;

(i) If Tenant shall fail to restore the Security Deposit to its original amount or deliver a replacement Letter of Credit as required under Section 7 above;

(j) If Tenant causes or suffers any release of Hazardous Materials in or near the Property;

(k) If Tenant shall make a Transfer in violation of the provisions of Section 13 above, or if any event shall occur or any contingency shall arise whereby this Lease, or the term and estate thereby created, would (by operation of law or otherwise) devolve upon or pass to any person, firm or corporation other than Tenant, except as expressly permitted under Section 13 hereof and Tenant does not cure such default within ten (10) days following written notice from Landlord;

(l) If Tenant shall fail to timely perform its obligations under Section 3 and such failure continues for fifteen (15) days after notice;

(m) The failure by Tenant to observe or perform any of the covenants or provisions of this Lease to be observed or performed by Tenant, other than as specified above, and such failure continues for more than thirty (30) days after notice thereof from Landlord; provided, further, that if the nature of Tenant’s default is such that more than thirty (30) days are reasonably required for its cure, then Tenant shall not be deemed to be in default if Tenant shall commence such cure within said thirty (30) day period and thereafter diligently prosecute such cure to completion, which completion shall occur not later than ninety (90) days from the date of such notice from Landlord;

(n) Tenant shall be involved in financial difficulties as evidenced by an admission in writing by Tenant of Tenant’s inability to pay its debts generally as they become due, or by the making or offering to make a composition of its debts with its creditors;

(o) Tenant shall make an assignment or trust mortgage, or other conveyance or transfer of like nature, of all or a substantial part of its property for the benefit of its creditors,

(p) an attachment on mesne process, on execution or otherwise, or other legal process shall issue against Tenant or its property and a sale of any of its assets shall be held thereunder;

(q) any judgment, attachment or the like in excess of $100,000 shall be entered, recorded or filed against Tenant in any court, registry, etc. and Tenant shall fail to pay such judgment within thirty (30) days after the judgment shall have become final beyond appeal or to discharge or secure by surety bond such lien, attachment, etc. within thirty (30) days of such entry, recording or filing, as the case may be;

(r) the leasehold hereby created shall be taken on execution or by other process of law and shall not be revested in Tenant within thirty (30) days thereafter;

(s) a receiver, sequesterer, trustee or similar officer shall be appointed by a court of competent jurisdiction to take charge of all or any part of Tenant’s Property and such appointment shall not be vacated within thirty (30) days; or

(t) any proceeding shall be instituted by or against Tenant pursuant to any of the provisions of any Act of Congress or State law relating to bankruptcy, reorganizations, arrangements, compositions or other relief from creditors, and, in the case of any proceeding instituted against it, if Tenant shall fail to have such proceedings dismissed within thirty (30) days or if Tenant is adjudged bankrupt or insolvent as a result of any such proceeding.

Tenant shall reimburse Landlord, within thirty (30) days after demand, for up to $1,000.00 of Landlord’s reasonable out-of-pocket costs and expenses (including without limitation legal fees and costs) incurred in connection with the preparation and delivery of each notice of default delivered pursuant to this Section 20.1.

Remedies. Upon an Event of Default, Landlord may, by notice to Tenant, elect to terminate this Lease; and thereupon (and without prejudice to any remedies which might otherwise be available for arrears of Rent or preceding breach of covenant or agreement and without prejudice to Tenant’s liability for damages as hereinafter stated), upon the giving of such notice, this Lease shall terminate as of the date specified therein as though that were the Expiration Date. Upon such termination, Landlord shall have the right to utilize the Security Deposit or draw down the entire Letter of Credit, as applicable, and apply the proceeds thereof to its damages hereunder. Without being taken or deemed to be guilty of any manner of trespass or conversion, and without being liable to indictment, prosecution or damages therefor, Landlord may, by lawful process, enter into and upon the Premises (or any part thereof in the name of the whole); repossess the same, as of its former estate; and expel Tenant and those claiming under Tenant. The words “re-entry” and “re-enter” as used in this Lease are not restricted to their technical legal meanings.

(u) Upon the termination of this Lease under the provisions of this Section 20, Tenant shall pay to Landlord Rent up to the time of such termination, shall continue to be liable for any preceding breach of covenant, and in addition, shall pay to Landlord as damages, at the election of Landlord, either:

(i) the amount (discounted to present value at the rate of five percent (5%) per annum) by which, at the time of the termination of this Lease (or at any time thereafter if Landlord shall have initially elected damages under Section 20.3(a)(ii) below), (x) the aggregate of Rent projected over the period commencing with such termination and ending on the Expiration Date, exceeds (y) the aggregate projected fair market rental value of the Premises for such period, taking into account a reasonable time period during which the Premises shall be unoccupied, plus all Reletting Costs (hereinafter defined); or

(ii) amounts equal to Rent which would have been payable by Tenant had this Lease not been so terminated, payable upon the due dates therefor specified herein following such termination and until the Expiration Date, provided, however, if Landlord shall re-let the Premises during such period, that Landlord shall credit Tenant with the net rents received by Landlord from such re-letting, such net rents to be determined by first deducting from the gross rents as and when received by Landlord from such re-letting the expenses incurred or paid by Landlord in terminating this Lease, as well as the expenses of re-letting, including altering and preparing the Premises for new tenants, brokers’ commissions, and all other similar and dissimilar expenses properly chargeable against the Premises and the rental therefrom (collectively, “Reletting Costs”), it being understood that any such re-letting may be for a period equal to or shorter or longer than the remaining Term; and provided, further, that (x) in no event shall Tenant be entitled to receive any excess of such net rents over the sums payable by Tenant to Landlord hereunder and (y) in no event shall Tenant be entitled in any suit for the collection of damages pursuant to this Section 20.3(a)(ii) to a credit in respect of any net rents from a re-letting except to the extent that such net rents are actually received by Landlord prior to the commencement of such suit. If the Premises or any part thereof should be re-let in combination with other space, then proper apportionment on a square foot area basis shall be made of the rent received from such re-letting and of the expenses of re-letting. Landlord shall use reasonable efforts to mitigate any damages hereunder following any termination of this Lease or any termination of Tenant’s possession of the Premises. The obligation of Landlord to use reasonable efforts to mitigate damages shall not be construed to require Landlord to rent all or any portion of the Premises for a use which, or to a tenant who, would not qualify pursuant to the assignment provisions of this Lease, or to prioritize the renting of the Premises over other space which Landlord may have available in the Building or in other buildings owned by Landlord or its affiliates.

(v) In calculating the amount due under Section 20.3(a)(i), above, there shall be included, in addition to the Base Rent, all other considerations agreed to be paid or performed by Tenant, including without limitation Tenant’s Share of Operating Costs and Tenant’s Tax Share of Taxes, on the assumption that all such amounts and considerations would have increased at the rate of five percent (5%) per annum for the balance of the full term hereby granted.

(w) Suit or suits for the recovery of such damages, or any installments thereof, may be brought by Landlord from time to time at its election, and nothing contained herein shall be deemed to require Landlord to postpone suit until the date when the Term would have expired if it had not been terminated hereunder.

(x) Nothing herein contained shall be construed as limiting or precluding the recovery by Landlord against Tenant of any sums or damages to which, in addition to the damages particularly provided above, Landlord may lawfully be entitled by reason of any Event of Default hereunder.

(y) In lieu of any other damages or indemnity and in lieu of full recovery by Landlord of all sums payable under all the foregoing provisions of this Section 20.3, Landlord may, by written notice to Tenant, at any time after this Lease is terminated under any of the provisions herein

contained or is otherwise terminated for breach of any obligation of Tenant and before such full recovery, elect to recover, and Tenant shall thereupon pay, as liquidated damages, an amount equal to the aggregate of (x) an amount equal to the lesser of (1) Rent accrued under this Lease in the twelve (12) months immediately prior to such termination, or (2) Rent payable during the remaining months of the Term if this Lease had not been terminated, plus (y) the amount of Rent accrued and unpaid at the time of termination, less (z) the amount of any recovery by Landlord under the foregoing provisions of this Section 20.3 up to the time of payment of such liquidated damages.

Landlord’s Self-Help; Fees and Expenses. If Tenant shall default in the performance of any covenant on Tenant’s part to be performed in this Lease contained, including without limitation the obligation to maintain the Premises in the required condition pursuant to Section 10.1 above, Landlord may, upon reasonable advance notice, except that no notice shall be required in an emergency, immediately, or at any time thereafter, perform the same for the account of Tenant. Tenant shall pay to Landlord upon demand therefor any costs incurred by Landlord in connection therewith, together with interest at the Default Rate until paid in full. In addition, Tenant shall pay all of Landlord’s costs and expenses, including without limitation reasonable attorneys’ fees, incurred (i) in enforcing any obligation of Tenant under this Lease or (ii) as a result of Landlord or any of the Landlord Parties, without its fault, being made party to any litigation pending by or against any of the Tenant Parties.

Waiver of Redemption, Statutory Notice and Grace Periods. Tenant does hereby waive and surrender all rights and privileges which it might have under or by reason of any present or future Legal Requirements to redeem the Premises or to have a continuance of this Lease for the Term hereby demised after being dispossessed or ejected therefrom by process of law or under the terms of this Lease or after the termination of this Lease as herein provided. Except to the extent prohibited by Legal Requirements, any statutory notice and grace periods provided to Tenant by law are hereby expressly waived by Tenant.

Landlord’s Remedies Not Exclusive. The specified remedies to which Landlord may resort hereunder are cumulative and are not intended to be exclusive of any remedies or means of redress to which Landlord may at any time be lawfully entitled, and Landlord may invoke any remedy (including the remedy of specific performance) allowed at law or in equity as if specific remedies were not herein provided for.

No Waiver. Landlord’s failure to seek redress for violation, or to insist upon the strict performance, of any covenant or condition of this Lease, or any of the Rules and Regulations promulgated hereunder, shall not prevent a subsequent act, which would have originally constituted a violation, from having all the force and effect of an original violation. The receipt by Landlord of Rent with knowledge of the breach of any covenant of this Lease shall not be deemed a waiver of such breach. The failure of Landlord to enforce any of such Rules and Regulations against Tenant and/or any other tenant in the Building shall not be deemed a waiver of any such Rules and Regulations. No provisions of this Lease shall be deemed to have been waived by either party unless such waiver be in writing signed by such party. No payment by Tenant or receipt by Landlord of a lesser amount than the Rent herein stipulated shall be deemed to be other than on account of the stipulated Rent, nor shall any endorsement or statement on any check or any letter accompanying any check or payment as Rent be deemed an accord and satisfaction, and Landlord may accept such check or payment without prejudice to Landlord’s right to recover the balance of such Rent or pursue any other remedy in this Lease provided.

Restrictions on Tenant’s Rights. During the continuation of any Event of Default, (a) Landlord shall not be obligated to provide Tenant with any notice pursuant to Sections 2.3 and 2.4 above; and (b) Tenant shall not have the right to make, nor to request Landlord’s consent or approval with respect to, any Alterations.

Landlord Default. Notwithstanding anything to the contrary contained in the Lease, Landlord shall in no event be in default in the performance of any of Landlord’s obligations under this Lease unless Landlord shall have failed to perform such obligations within thirty (30) days (or such additional time as is reasonably required to correct any such default, provided Landlord commences cure within 30 days) after notice by Tenant to Landlord properly specifying wherein Landlord has failed to perform any such obligation. Except as expressly set forth in this Lease, Tenant shall not have the right to terminate or cancel this Lease or to withhold rent or to set-off or deduct any claim or damages against rent as a result of any default by Landlord or breach by Landlord of its covenants or any warranties or promises hereunder, except in the case of a wrongful eviction of Tenant from the Premises (constructive or actual) by Landlord, and then only if the same continues after notice to Landlord thereof and an opportunity for Landlord to cure the same as set forth above. In addition, Tenant shall not assert any right to deduct the cost of repairs or any monetary claim against Landlord from rent thereafter due and payable under this Lease.

(a) Upon the expiration or earlier termination of the Term, Tenant shall (i) peaceably quit and surrender to Landlord the Premises (including without limitation all lab benches, fume hoods, electric, plumbing, heating and sprinkling systems, fixtures and outlets, vaults, paneling, molding, shelving, radiator enclosures, cork, rubber, linoleum and composition floors, ventilating, silencing, air conditioning and cooling equipment therein) broom clean, in good order, repair and condition excepting only ordinary wear and tear and damage by fire or other insured Casualty or loss by Taking; (ii) remove all of Tenant’s Property, all autoclaves and cage washers and, to the extent specified by Landlord in accordance with Section 11 above, Alterations made by Tenant; and (iii) repair any damages to the Premises or the Building caused by the installation or removal of Tenant’s Property and/or such Alterations. Tenant’s obligations under this Section 21.1(a) shall survive the expiration or earlier termination of this Lease. Notwithstanding any other provision of this Lease to the contrary, Tenant shall have the right to remove any wall-mounted IT panels, lab benches, autoclaves, glass washers, recirculated tissue culture hoods and centrifuges installed by or on behalf of Tenant to the extent such items were not (A) paid for in whole or in part by Landlord or (B) installed as part of Landlord’s Work.

(b) At least thirty (30) days prior to the expiration of the Term (or, if applicable, within five (5) business days after any earlier termination of this Lease), Tenant shall deliver to Landlord a narrative description of the actions proposed (or required by any Legal Requirements) to be taken by Tenant in order to render the Premises (including, without limitation, floors, walls, ceilings, counters, piping, supply lines, waste lines and plumbing in or serving the Premises and all exhaust or other ductwork in or serving the Premises) free of Hazardous Materials other than Third Party Hazardous Materials⁵ and otherwise released for unrestricted use and occupancy (the “Surrender Plan”). The Surrender Plan (i) shall be accompanied by a current list of (A) all local, state and federal licenses, permits and approvals held by or on behalf of any Tenant Party with respect to Hazardous Materials in, on, under, at or about the Premises, and (B) Tenant’s Hazardous Materials, and (ii) shall be subject to the review and approval of Landlord’s environmental consultant. In connection with review and approval of the Surrender Plan, upon request of Landlord, Tenant shall deliver to Landlord or its consultant such additional non-proprietary information concerning the use of and operations within the Premises as

Landlord shall reasonably request. On or before the expiration of the Term or within thirty (30) days after any earlier termination of this Lease (during which period Tenant’s use and occupancy of the Premises shall be governed by Section 21.3 below unless such termination is due to a Casualty or Taking), Tenant shall (i) perform or cause to be performed all actions described in the approved Surrender Plan, and (ii) deliver to Landlord a certification from a certified industrial hygienist reasonably acceptable to Landlord certifying that the Premises do not contain any Hazardous Materials other than Third Party Hazardous Materials and evidence that the approved Surrender Plan shall have been satisfactorily completed by a contractor acceptable to Landlord (the “Surrender Report”), and Landlord shall have the right, subject to reimbursement at Tenant’s expense as set forth below, to cause Landlord’s environmental consultant to inspect the Premises and perform such additional procedures as may be deemed reasonably necessary to confirm that the Premises are, as of the expiration of the Term (or, if applicable, the date which is thirty (30) days after any earlier termination of this Lease), free of Hazardous Materials other than Third Party Hazardous Materials and otherwise available for unrestricted use and occupancy. Landlord shall have the unrestricted right to deliver the Surrender Plan, the Surrender Report and any report by Landlord’s environmental consultant with respect to the surrender of the Premises to third parties, and such third parties and the Landlord Parties shall be entitled to rely thereon. If Tenant shall fail to prepare or submit a Surrender Plan approved by Landlord, or if Tenant shall fail to complete the approved Surrender Plan, or if such Surrender Plan, whether or not approved by Landlord, shall fail to adequately address the use of Hazardous Materials by any of the Tenant Parties in, on, at, under or about the Premises, (A) Landlord shall have the right to take any such actions as Landlord may deem reasonable or appropriate to assure that the Premises and the Property are surrendered in the condition required hereunder, the cost of which actions shall be reimbursed by Tenant as Additional Rent upon demand; and (B) if the Term shall have ended, unless and until Landlord elects to take such actions to assure that the Premises are surrendered in the condition required hereunder, Tenant shall be deemed to be a holdover tenant subject to the provisions of Section 21.3 below until the date on which Tenant delivers the Surrender Report (in the form required hereunder) to Landlord. Tenant’s obligations under this Section 21.1(b) shall survive the expiration or earlier termination of the Term.

(c) No act or thing done by Landlord during the Term shall be deemed an acceptance of a surrender of the Premises, and no agreement to accept such surrender shall be valid, unless in writing signed by Landlord. Unless otherwise agreed by the parties in writing, no employee of Landlord or of Landlord’s agents shall have any power to accept the keys of the Premises prior to the expiration or earlier termination of this Lease. The delivery of keys to any employee of Landlord or of Landlord’s agents shall not operate as a termination of this Lease or a surrender of the Premises.

(d) Notwithstanding anything to the contrary contained herein, Tenant shall, at its sole cost and expense, remove from the Premises, prior to the end of the Term, any item installed by or for Tenant and which, pursuant to Legal Requirements, must be removed therefrom before the Premises may be used by a subsequent tenant.

(e) Tenant hereby assigns to Landlord any warranties in effect on the last day of the Term with respect to any fixtures and Alterations installed in the Premises. Tenant shall provide Landlord with copies of any such warranties prior to the expiration of the Term (or, if the Lease is earlier terminated, within 5 days thereafter).

Abandoned Property. After the expiration or earlier termination hereof, if Tenant fails to remove any property from the Building or the Premises which Tenant is obligated by the terms of this Lease to remove within five (5) business days after written notice from Landlord, such property (the “Abandoned Property”) shall be conclusively deemed to have been abandoned, and may either be retained by Landlord as its property or sold or otherwise disposed of in such manner as Landlord may see fit. If any item of Abandoned Property shall be sold, Tenant hereby agrees that Landlord may receive and retain the proceeds of such sale and apply the same, at its option, to the expenses of the sale, the cost of moving and storage, any damages to which Landlord may be entitled under Section 20 hereof or pursuant to law, and to any arrears of Rent.

Holdover. If any of the Tenant Parties holds over after the end of the Term, Tenant shall be deemed a tenant-at-sufferance subject to the provisions of this Lease; provided that whether or not Landlord has previously accepted payments of Rent from Tenant, (i) Tenant shall pay Base Rent at 150% of the highest rate of Base Rent payable during the Term, (ii) Tenant shall continue to pay to Landlord all additional rent, and (iii) if such holdover continues for more than thirty (30) days, Tenant shall be liable for all damages, including without limitation lost business and consequential damages, incurred by Landlord as a result of such holding over, Tenant hereby acknowledging that Landlord may need the Premises after the end of the Term for other tenants and that the damages which Landlord may suffer as the result of Tenant’s holding over cannot be determined as of the Execution Date. Nothing contained herein shall grant Tenant the right to holdover after the expiration or earlier termination of the Term.

Subordination. Tenant’s rights and interests under this Lease shall be (i) subject and subordinate to any ground lease (including without limitation the Ground Lease), and to any mortgages, deeds of trust, overleases, or similar instruments covering the Premises, the Building and/or the Land and to all advances, modifications, renewals, replacements, and extensions thereof (each of the foregoing, a “Mortgage”), or (ii) if any Mortgagee elects, prior to the lien of any present or future Mortgage. Tenant further shall attorn to and recognize any successor landlord, whether through foreclosure or otherwise, as if the successor landlord were the originally named landlord. The provisions of this Section 22.1 shall be self-operative and no further instrument shall be required to effect such subordination or attornment; however, Tenant agrees to execute, acknowledge and deliver such instruments, confirming such subordination and attornment in such form as shall be requested by any such holder within fifteen (15) days of request therefor. Landlord agrees to request that each Mortgagee execute a so-called subordination, non-disturbance and attornment agreement, using such Mortgagee’s standard recordable form, provided that this sentence shall not apply so long as the fee owner of the Property is MIT 620 Memorial LLC, Massachusetts Institute of Technology or any entity controlled by Massachusetts Institute of Technology.

Notices. Tenant shall give each Mortgagee the same notices given to Landlord concurrently with the notice to Landlord, and each Mortgagee shall have a reasonable opportunity thereafter to cure a Landlord default, and Mortgagee’s curing of any of Landlord’s default shall be treated as performance by Landlord.

Mortgagee Liability. Tenant acknowledges and agrees that if any Mortgage shall be foreclosed, (a) the liability of the Mortgagee and its successors and assigns shall exist only so long as such Mortgagee or purchaser is the owner of the Premises, and such liability shall not continue or survive after further transfer of ownership; and (b) such Mortgagee and its successors or assigns shall not be (i) liable for any act or omission of any prior lessor under this Lease; (ii) liable for the performance of Landlord’s covenants pursuant to the provisions of this Lease which arise and accrue prior to such entity succeeding to the interest of Landlord under this Lease or acquiring such right to possession; (iii) subject to any offsets or defense which Tenant may have at any time against Landlord; (iv) bound by any base rent or other sum which Tenant may have paid previously for more than one (1) month; or (v) liable for the performance of any covenant of Landlord under this Lease which is capable of performance only by the original Landlord.

QUIET ENJOYMENT. Landlord covenants that so long as Tenant keeps and performs each and every covenant, agreement, term, provision and condition herein contained on the part and on behalf of Tenant to be kept and performed, Tenant shall peaceably and quietly hold, occupy and enjoy the Premises during the Term from and against the claims of all persons lawfully claiming by, through or under Landlord subject, nevertheless, to the covenants, agreements, terms, provisions and conditions of this Lease, any matters of record or of which Tenant has knowledge and to any Mortgage to which this Lease is subject and subordinate, as hereinabove set forth.

NOTICES. Any notice, consent, request, bill, demand or statement hereunder (each, a “Notice”) by either party to the other party shall be in writing and shall be deemed to have been duly given when either delivered by hand or by nationally recognized overnight courier (in either case with evidence of delivery or refusal thereof) addressed as follows:


If to Landlord:		620 Memorial Leasehold LLC
		c/o MIT Investment Management Company 238 Main Street, Suite 200
		Cambridge, MA 02142
		Attention: Steven C. Marsh

With copies to:		Goulston & Storrs
		400 Atlantic Avenue
		Boston, MA 02110
		Attention: Colleen P. Hussey, Esquire
and
		Colliers International 336 Main Street
		Cambridge, MA 02142 Attention: Kristina Descoteaux

if to Tenant:		Evelo Therapeutics, Inc.
		c/o Flagship Ventures
		One Memorial Drive, 7th Floor
		Cambridge, MA 02142

With copies to:		WilmerHale LLP
		60 State Street
		Boston, MA 02109
		Attention: William R. O’Reilly, Jr., Esquire

Notwithstanding the foregoing, any notice from Landlord to Tenant regarding ordinary business operations (e.g., exercise of a right of access to the Premises, maintenance activities, invoices, etc.) may also be given by written notice delivered by facsimile to any person at the Premises whom Landlord reasonably believes is authorized to receive such notice on behalf of Tenant without copies as specified above, provided that no such notice shall be relied upon for purposes of determining the running of any periods with respect to any Event of Default hereunder. Either party may at any time change the address or specify an additional address for such Notices by delivering or mailing, as aforesaid, to the other party a notice stating the change and setting forth the changed or additional address, provided such changed or additional address is within the United States. Notices shall be effective upon the date of receipt or refusal thereof.

Separability. If any provision of this Lease or portion of such provision or the application thereof to any person or circumstance is for any reason held invalid or unenforceable, the remainder of this Lease (or the remainder of such provision) and the application thereof to other persons or circumstances shall not be affected thereby.

Captions. The captions are inserted only as a matter of convenience and for reference, and in no way define, limit or describe the scope of this Lease or the intent of any provisions thereof.

Broker. Tenant and Landlord each warrants and represents that it has dealt with no broker in connection with the consummation of this Lease other than Cushman & Wakefield (“Broker”). Tenant and Landlord each agrees to defend, indemnify and save the other harmless from and against any Claims arising in breach of the representation and warranty set forth in the immediately preceding sentence. Landlord shall be solely responsible for the payment of any brokerage commissions to Broker.

Entire Agreement. This Lease, Lease Summary Sheet and Exhibits 1-8 attached hereto and incorporated herein contain the entire and only agreement between the parties and any and all statements and representations, written and oral, including previous correspondence and agreements between the parties hereto, are merged herein. Tenant acknowledges that all representations and statements upon which it relied in executing this Lease are contained herein and that Tenant in no way relied upon any other statements or representations, written or oral. This Lease may not be modified orally or in any manner other than by written agreement signed by the parties hereto.

Governing Law. This Lease is made pursuant to, and shall be governed by, and construed in accordance with, the laws of the Commonwealth of Massachusetts and any applicable local municipal rules, regulations, by-laws, ordinances and the like.

Representation of Authority. By his or her execution hereof, each of the signatories on behalf of the respective parties hereby warrants and represents to the other that he or she is duly authorized to execute this Lease on behalf of such party. Upon Landlord’s request, Tenant shall provide Landlord with evidence that any requisite resolution, corporate authority and any other necessary consents have been duly adopted and obtained.

Expenses Incurred by Landlord Upon Tenant Requests. Tenant shall, upon demand, reimburse Landlord for all reasonable expenses, including, without limitation, legal fees, incurred by Landlord in connection with all requests by Tenant for consents, approvals or execution of collateral documentation related to this Lease, including, without limitation, costs incurred by Landlord in the review and approval of Tenant’s plans and specifications in connection with proposed Alterations to be made by Tenant to the Premises or in connection with requests by Tenant for Landlord’s consent to make a Transfer. Such costs shall be deemed to be additional rent under this Lease.

Survival. Without limiting any other obligation of Tenant which may survive the expiration or prior termination of the Term, all obligations on the part of Tenant to indemnify, defend, or hold Landlord harmless, as set forth in this Lease shall survive the expiration or prior termination of the Term.

Limitation of Liability. Tenant shall neither assert nor seek to enforce any claim against Landlord or any of the Landlord Parties, or the assets of any of the Landlord Parties, for breach of this Lease or otherwise, other than against Landlord’s interest in the Building and in the uncollected rents, issues and profits thereof, and Tenant agrees to look solely to such interest for the satisfaction of any liability of Landlord under this Lease. This Section 25.9 shall not limit any right that Tenant might otherwise have to obtain injunctive relief against Landlord. Landlord and Tenant specifically agree that in no event shall any officer, director, trustee, employee or representative of Landlord or any

of the other Landlord Parties ever be personally liable for any obligation under this Lease, nor shall Landlord or any of the other Landlord Parties be liable for consequential or incidental damages or for lost profits whatsoever in connection with this Lease, nor shall Tenant or any other Tenant Party or any officer, director, shareholder, trustee, employee, agent or representative of any of them be liable for consequential or incidental damages or for lost profits whatsoever in connection with this Lease except with respect to the potential liability of Tenant under Sections 17 or 21.3 hereof.

Binding Effect. The covenants, agreements, terms, provisions and conditions of this Lease shall bind and benefit the successors and assigns of the parties hereto with the same effect as if mentioned in each instance where a party hereto is named or referred to, except that no violation of the provisions of Section 13 hereof shall operate to vest any rights in any successor or assignee of Tenant.

Landlord Obligations upon Transfer. Upon any sale, transfer or other disposition of the Building, Landlord shall be entirely freed and relieved from the performance and observance thereafter of all covenants and obligations hereunder on the part of Landlord to be performed and observed, it being understood and agreed in such event (and it shall be deemed and construed as a covenant running with the land) that the person succeeding to Landlord’s ownership of said reversionary interest shall thereupon and thereafter assume, and perform and observe, any and all of such covenants and obligations of Landlord, except as otherwise agreed in writing.

No Grant of Interest. Tenant shall not grant any security interest whatsoever in (a) any fixtures within the Premises or (b) any item paid in whole or in part by Landlord without the consent of Landlord.

1.7 No Air Rights. No rights to any view or to light or air over any property, whether belonging to Landlord or any other person, are granted to Tenant by this Lease. If at any time any windows of the Premises are temporarily darkened or the light therefrom is obstructed by reason of any repairs, improvements, maintenance or cleaning in or about the Property, the same shall be without liability to Landlord and without any reduction or diminution of Tenant’s obligations under this Lease.

1.8 Financial Information. Tenant shall deliver to Landlord, within thirty (30) days after Landlord’s reasonable request, Tenant’s most recently completed balance sheet and related statements of income, shareholder’s equity and cash flows statements (audited if available) certified by an officer of Tenant as being true and correct in all material respects. Any such financial information may be relied upon by any actual or potential lessor, purchaser, or mortgagee of the Property or any portion thereof.

IN WITNESS WHEREOF the parties hereto have executed this Lease as a sealed instrument as of the Execution Date.

The land with the buildings thereon in Cambridge, Middlesex County, Massachusetts situated on the northerly side of Memorial Drive and the westerly side of Vassar Street, now known as and numbered 620 Memorial Drive, and shown as the parcel marked “AREA = 44,677 +1- SF” on a plan entitled “Plan of Land in Cambridge, MA Middlesex County”, prepared by Beals and Thomas, Inc., dated January 28, 1994 recorded with the Middlesex South Deeds on February 17, 1994 as Plan No. 134 of 1994 and bounded and described according to said plan as follows:

Together with the benefit of and subject to the terms of, a Grant of Easement from the City of Cambridge to Charles River Building Limited Partnership dated January 9, 1997, and recorded on January 17, 1997, as Instrument No. 268 in Book 26997, Page 351.

A parcel of land on Memorial Drive, formerly Charles River Parkway, in Cambridge, Middlesex County, Massachusetts, shown as Lot 3 on a plan entitled “Subdivision Plan of Land in Cambridge” by W.T. Fairclough, dated June 23, 1953, filed for registration with the Middlesex County South Registry District of the Land Court as Plan No., 2495C with Certificate of Title No. 78992, bounded and described as follows:

We hereby establish our irrevocable letter of credit in your favor for account of the applicant up to an aggregate amount not to exceed and /100 US Dollars ($ . ) available by your draft(s) drawn on ourselves at sight (i) bearing the clause “Drawn under Irrevocable Standby Letter of Credit Number ,” and (ii) including a Beneficiary’s dated statement purportedly signed by an authorized signatory or agent reading: “This draw in the amount of U.S. Dollars ($ ) under your Irrevocable Standby Letter of Credit No. represents funds due and owing to us pursuant to the terms of that certain lease by and between , a , as landlord, and , as tenant (the “Lease”), and/or any amendment to the Lease or any other agreement between such parties related to the Lease,” and (iii) indicating whether payment should be made by wire transfer (including wiring instructions) or by certified check (including mailing address), accompanied by the original of this Letter of Credit and all amendments, if any. The original Letter of Credit and all amendments, if any, shall be returned to you unless fully utilized.

Unless otherwise stated, all correspondence, documents and sight drafts are to be sent via facsimile to ( ) - with originals to follow by hand delivery with receipted delivery, nationally recognized overnight courier with receipted delivery or certified mail, return receipt requested to our counters at <address>. The date of presentment of any draw shall be the date copies of the Letter of Credit and sight draft are faxed by Beneficiary to <bank>.

You shall have the right to make partial draws against this Letter of Credit, from time to time.

You shall be entitled to assign your interest in this Irrevocable Standby Letter of Credit from time to time to your lender(s) and/or your successors in interest without our approval and without charge. In the event of an assignment, we reserve the right to require reasonable evidence of such assignment as a condition to any draw hereunder.

Except as otherwise expressly stated herein, this Letter of Credit is subject to the “International Standby Practices 1998” promulgated jointly by the Institute for International Banking Law and Practice and the International Chamber of Commerce, effective January 1, 1999.

This Letter of Credit shall expire at our office on , 20 (the “Stated Expiration Date”). It is a condition of this Letter of Credit that the Stated Expiration Date shall be deemed automatically extended without amendment for successive one (1) year periods from such Stated Expiration Date, unless at least sixty (60) days prior to such Stated Expiration Date (or any anniversary thereof) we shall send a written notice to you, with a copy to Goulston & Storrs, 400 Atlantic Avenue, Boston, MA 02110, Attention: Colleen P. Hussey and to the Accountee/Applicant, by hand delivery, nationally recognized overnight courier with receipted delivery or by certified mail (return receipt requested) that we elect not to consider this Letter of Credit extended for any such additional one (1) year period. In the event that this Letter of Credit is not extended for an additional period as provided above, you may draw the entire amount available hereunder.

If at any time prior to presentation of documents for payment hereunder, we receive a notarized certificate signed by one who purports to be a duly authorized representative on your behalf to execute and deliver such certificate, stating that this Letter of Credit has been lost, stolen, damaged or destroyed, we will mail you a “Certified True Copy” of this Letter of Credit, which shall be treated by us as an original.

In order to cancel this Letter of Credit prior to expiration, you must return this original Letter of Credit and any amendments hereto to our counters with a statement signed by you stating that the Letter of Credit is no longer required and is being returned to the issuing bank for cancellation. In addition, this Letter of Credit may be canceled prior to expiration upon our receipt of a dated statement purportedly signed by (i) an authorized signatory or agent of the Accountee/Applicant and (ii) an authorized signatory or agent of the beneficiary.

We hereby agree with the drawers, endorsers and bonafide holders that the drafts drawn under and in accordance with the terms and condition of this Letter of Credit shall be duly honored within two (2) business days after the date of presentment.

Scope letter describing project, design/construction team, and appropriate vendors.

Construction Documents (CDs) - Plans and Specifications - stamped by licensed AIA.

Code Review by licensed code engineer incorporated in CDs and/or by stamped letter.

Code specific - fire protection, sprinkler distribution, horns/strobes/signage locations.

Landlord Approved architect, MEPFP engineer, code engineer, structural engineer.

If installer is employee, copy of valid government issued electrical license (to the extent legally required)

To the extent of any conflict between these Rules and Regulations and the body of the Lease, the body of the Lease shall govern.

This First Amendment to Lease (this “First Amendment”) is made as of January 24, 2018 by and between 620 MEMORIAL LEASEHOLD LLC, a Massachusetts limited liability company with an address c/o MIT Investment Management Company, 238 Main Street, Suite 200, Cambridge, MA 02142 (“Landlord”), and EVELO BIOSCIENCES, INC., a Delaware corporation with an address of 620 Memorial Drive, Cambridge, MA 02139 (“Tenant”).

WHEREAS, Landlord and Tenant are the current parties to that certain Lease dated July 14, 2015, as affected by that certain letter regarding square footage dated February 22, 2016 and as further affected by that certain letter agreement regarding dates dated May 15, 2016 (collectively and as amended hereby, the “Lease”), pursuant to which Landlord is leasing to Tenant approximately 9,132 rentable square feet (as more particularly described in the Lease, the “Premises”) located on the second (2^nd) floor of the building located at 620 Memorial Drive, Cambridge, MA (the “Building”); and

WHEREAS, pursuant to that certain Consent to Sublease dated on or about the date hereof (the “Consent”), Landlord has consented to a sublease for other space in the Building naming Tenant as subtenant (the “Sublease”); and

WHEREAS, Landlord and Tenant have agreed to amend the Lease as hereinafter set forth.

NOW, THEREFORE, in consideration of Landlord’s execution of the Consent, the covenants herein reserved and contained, and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, Landlord and Tenant hereby agree as follows:

1. Recitals; Capitalized Terms. The foregoing recitals are hereby incorporated by reference. All capitalized terms not otherwise defined herein shall have the meanings ascribed to them as set forth in the Lease.

2. Termination. The Lease shall terminate upon the earlier to occur of (a) the date which is sixty (60) days after Landlord’s receipt of written notice from Tenant terminating the Lease pursuant to this Section 2, or (b) the Outside Termination Date, as hereinafter defined (such earlier date, the “Termination Date”). The “Outside Termination Date” shall mean June 30, 2018; provided, however, if Landlord fails to respond to Tenant’s request for Landlord’s approval of any Alterations to the space subject to the Sublease within ten (10) business days after Landlord’s receipt of (a) evidence that such Alterations have been approved by Tenant’s sublandlord, and (b) all information required by the Primary Lease (as such term is defined in the Sublease) to be submitted in connection with such Alterations, then the Outside Termination Date shall be delayed on a day for day basis for each day beyond such 10-business day period until Landlord does so respond.

3. Holdover. Section 21.3 of the Lease is hereby deleted in its entirety and replaced with the following: “

21.3 Holdover. Notwithstanding anything set forth in the Lease to the contrary, if any of the Tenant Parties fails to vacate and surrender the Premises as provided in the Lease on or before the Termination Date, Tenant shall be deemed a tenant-at-sufferance subject to the provisions of this Lease; provided that whether or not Landlord has previously accepted payments of Rent from Tenant, (i) during any holdover period (i.e., the period commencing on the day immediately after the Termination Date and ending on the date Tenant vacates and surrenders the Premises as provided in the Lease), Tenant shall pay Base Rent at 200% of the highest rate of Base Rent payable during the Term, (ii) during any holdover period, Tenant shall continue to pay to Landlord all additional rent, and (iii) if, as a result of such holdover, the Premises cannot be delivered to any new tenant who has signed a lease for the same or any such new tenant does not accept delivery of the Premises, then Tenant shall pay to Landlord, as liquidated damages, within fifteen (15) days after receipt of demand therefor from time to time, an amount equal to $1,851.77 per day for the period of time commencing on the day immediately after Tenant vacates and surrenders the Premises as provided in the Lease and ending on the earlier to occur of (x) December 31, 2020, and (y) the term commencement date for a subsequent new lease for the Premises (Tenant hereby acknowledging that Landlord intends to lease the Premises for a term commencing on the day immediately after the Termination Date, and that the damages Landlord will suffer as the result of Tenant’s holding over cannot be determined as of the date of this First Amendment). For clarification, upon commencement of liquidated damages paid pursuant to clause (iii) above, Tenant shall no longer be responsible for paying Base Rent or additional rent pursuant to clauses (i) and (ii) above. Nothing contained herein shall grant any of the Tenant Parties the right to holdover after the Termination Date. (The amounts payable pursuant to clause (iii) above are only applicable if Landlord has signed a new lease for the Premises.) If Tenant is obligated to make payments pursuant to clause (iii) above, Landlord shall use commercially reasonable efforts to relet the Premises, subject, however, to the reasonable requirements of Landlord to lease other available space for comparable use prior to reletting the Premises and to lease to high quality tenants in a harmonious manner with an appropriate mix of uses, tenants, floor areas and terms of tenancies, and the like.

4. Landlord’s Right to Terminate this First Amendment. Landlord shall have the right, by written notice delivered to Tenant on or before February 28, 2018, to terminate this First Amendment without penalties, liabilities or costs, in which event this First Amendment shall be rendered null and void, and the Lease shall remain in full force and effect in accordance with its terms, unaffected by this First Amendment.

5. Brokers. Landlord and Tenant each warrants and represents that it has dealt with no broker in connection with this First Amendment. Landlord and Tenant each agrees to defend, indemnify and save the other harmless from and against any Claims arising as a result of its breach of the foregoing representation and warranty. Landlord shall be solely responsible for the payment of any brokerage commissions to Broker.

6. Authority. Tenant hereby guarantees, warrants and represents to Landlord that (i) Tenant is duly incorporated or otherwise established or formed and validly existing under the laws of its state of incorporation, establishment or formation, (ii) Tenant has and is duly qualified to do

business in the state in which the Property is located, (iii) Tenant has full corporate, partnership, trust, association or other appropriate power and authority to enter into this First Amendment and to perform all of Tenant’s obligations hereunder, (iv) each person (and all of the persons if more than one signs) signing this First Amendment on behalf of Tenant is duly and validly authorized to do so; and (v) neither the execution, delivery or performance of this First Amendment, nor the consummation of the transactions contemplated hereby, will violate or conflict with any provision of documents or instruments under which Tenant is constituted or to which Tenant is a party.

7. Ratification. Except as amended hereby, the terms and conditions of the Lease shall remain unaffected. From and after the date hereof, all references to the Lease shall mean the Lease as amended hereby. Additionally, Landlord and Tenant each confirms and ratifies that, as of the date hereof and to its actual knowledge, (a) the Lease is and remains in good standing and in full force and effect, and (b) neither party has any claims, counterclaims, set-offs or defenses against the other party arising out of the Lease or the Premises or in any way relating thereto.

8. Miscellaneous. This First Amendment shall be deemed to have been executed and delivered within the Commonwealth of Massachusetts, and the rights and obligations of Landlord and Tenant hereunder shall be construed and enforced in accordance with, and governed by, the laws of the Commonwealth of Massachusetts without regard to the laws governing conflicts of laws. If any term of this First Amendment or the application thereof to any person or circumstances shall be invalid and unenforceable, the remaining provisions of this First Amendment, the application of such term to persons or circumstances other than those as to which it is invalid or unenforceable, shall not be affected. This First Amendment is binding upon and shall inure to the benefit of Landlord and Tenant and their respective successors and assigns. Each party has cooperated in the drafting and preparation of this First Amendment and, therefore, in any construction to be made of this First Amendment, the same shall not be construed against either party. In the event of litigation relating to this First Amendment, the prevailing party shall be entitled to reimbursement from the other party of its reasonable attorneys’ fees and costs. This First Amendment constitutes the entire agreement of the parties with respect to the subject matter hereof and supersedes all prior and contemporaneous oral and written agreements and discussions, and may not be amended, waived, discharged or terminated except by a written instrument signed by all the parties hereto. A facsimile, PDF or other electronic signature on this First Amendment shall be equivalent to, and have the same force and effect as, an original signature.


Execution Date:		July 14, 2015

Tenant:		Evelo Therapeutics, Inc., a Delaware corporation

Tenant’s Mailing Address Prior to Occupancy:		c/o Flagship Ventures One Memorial Drive, 7^th Floor Cambridge, MA 02142

Landlord:		620 Memorial Leasehold LLC, a Massachusetts limited liability company

Building:		620 Memorial Drive, Cambridge, Massachusetts. The Building consists of approximately 89,443 rentable square feet. The land on which the Building is located (the “Land”) is more particularly described in Exhibit 2 attached hereto and made a part hereof (the Land, together with the Building, are hereinafter collectively referred to as the “Property”).

Premises:		Approximately 9,150 rentable square feet of space on the second floor of the Building, as more particularly shown as hatched, highlighted or outlined on the plan attached hereto as Exhibit 1 and made a part hereof (the “Lease Plan”).

Term Commencement Date:		The date on which Landlord delivers the Premises to Tenant with Landlord’s Work substantially complete. Targeted delivery date: December 2, 2015.

Rent Commencement Date:		The date which is two (2) months after the Term Commencement Date

Expiration Date:		The last day of the fifth Rent Year (hereinafter defined)

Extension Terms:		Subject to Section 1.2 below, one (1) extension term of three (3) years

Landlord’s Contribution:		Subject to Section 3.5 below, Seven Hundred Seventy-Seven Thousand Seven Hundred Fifty Dollars ($777,750)

Permitted Uses:		Subject to Legal Requirements, general office, research, development and laboratory use, and other ancillary uses related to the foregoing (all in proportions consistent with the design of the base Building).


Base Rent:	RENT YEAR¹	ANNUAL BASE RENT	MONTHLY RENT
	1	$532,987.50	$44,415.63
	2	$548,977.13	$45,748.09
	3	$565,446.44	$47,120.54
	4	$582,409.83	$48,534.15
	5	$599,882.13	$49,990.18


Operating Costs and Taxes:		See Sections 5.2 and 5.3

Tenant’s Share:		A fraction, the numerator of which is the number of rentable square feet in the Premises and the denominator of which is the number of rentable square feet in the Building. As of the Execution Date, Tenant’s Share is 10.23%.

Tenant’s Tax Share:		A fraction, the numerator of which is the number of rentable square feet in the Premises and the denominator of which is the number of rentable square feet in the Building recognized by the City of Cambridge as being used for purposes which are not exempt from real estate taxation as of the date on which the assessment is made for the tax year in question. As of the Execution Date, Tenant’s Tax Share is 10.23%.

Security Deposit/ Letter of Credit:		Subject to Section 7.1, One Hundred Seventy-Five Thousand Dollars ($175,000.00)



EXHIBIT 1		LEASE PLAN

EXHIBIT 2		LEGAL DESCRIPTION

EXHIBIT 3		SCHEMATIC PLANS FOR LANDLORD’S WORK

EXHIBIT 4		FORM OF LETTER OF CREDIT

EXHIBIT 5		ALTERATIONS CHECKLIST

EXHIBIT 6		TENANT’S HAZARDOUS MATERIALS

EXHIBIT 7		RULES AND REGULATIONS

EXHIBIT 8		LANDLORD’S SERVICES


1.	LEASE GRANT; TERM; APPURTENANT RIGHTS; EXCLUSIONS		1

	1.1	Lease Grant	1
	1.2	Extension Terms	1
	1.3	Notice of Lease	2
	1.4	Appurtenant Rights	3
	1.5	Tenant’s Access	4
	1.6	Exclusions	4

2.	RIGHTS RESERVED TO LANDLORD		4

	2.1	Additions and Alterations	4
	2.2	Additions to the Property	5
	2.3	Name and Address of Building	5
	2.4	Landlord’s Access	5
	2.5	Pipes, Ducts and Conduits	6
	2.6	Minimize Interference	6

3.	CONDITION OF PREMISES; CONSTRUCTION		6

	3.1	Condition of Premises	6
	3.2	Landlord’s Work	6
	3.3	Punchlist Items	7
	3.4	Remedies	7
	3.5	Cost of Landlord’s Work	7

4.	USE OF PREMISES		9

	4.1	Permitted Uses	9
	4.2	Prohibited Uses	9

5.	RENT; ADDITIONAL RENT		9

	5.1	Base Rent	9
	5.2	Operating Costs	10
	5.3	Taxes	13
	5.4	Late Payments	14
	5.5	No Offset; Independent Covenants; Waiver	14
	5.6	Survival	15

6.	INTENTIONALLY OMITTED		15

7.	LETTER OF CREDIT		15

	7.1	Amount	15
	7.2	Application of Proceeds of Letter of Credit	16
	7.3	Transfer of Letter of Credit	16
	7.4	Credit of Issuer of Letter of Credit	16
	7.5	Security Deposit	16
	7.6	Return of Security Deposit or Letter of Credit	16

8.	INTENTIONALLY OMITTED		17



9.	UTILITIES, HVAC; WASTE		17

	9.1	Electricity	17
	9.2	Water	17
	9.3	Gas	17
	9.4	HVAC	17
	9.5	Other Utilities; Utility Information	18
	9.6	Interruption or Curtailment of Utilities	18
	9.7	Telecommunications Providers	18
	9.8	Landlord’s Services	18

10.	MAINTENANCE AND REPAIRS		18

	10.1	Maintenance and Repairs by Tenant	18
	10.2	Maintenance and Repairs by Landlord	19
	10.3	Accidents to Sanitary and Other Systems	19
	10.4	Floor Load—Heavy Equipment	19

11.	ALTERATIONS AND IMPROVEMENTS BY TENANT		19

	11.1	Landlord’s Consent Required	19
	11.2	Supervised Work	20
	11.3	Harmonious Relations	20
	11.4	Liens	20
	11.5	General Requirements	20

12.	SIGNAGE		21

	12.1	Restrictions	21
	12.2	Building Directory	21
	12.3	Monument Sign	21

13.	ASSIGNMENT, MORTGAGING AND SUBLETTING		21

	13.1	Landlord’s Consent Required	21
	13.2	Landlord’s Recapture Right	22
	13.3	Standard of Consent to Transfer	22
	13.4	Listing Confers no Rights	23
	13.5	Profits In Connection with Transfers	23
	13.6	Prohibited Transfers	23
	13.7	Exceptions to Requirement for Consent	23

14.	INSURANCE; INDEMNIFICATION; EXCULPATION		24

	14.1	Tenant’s Insurance	24
	14.2	Indemnification	25
	14.3	Property of Tenant	25
	14.4	Limitation of Landlord’s Liability for Damage or Injury	25
	14.5	Waiver of Subrogation; Mutual Release	26
	14.6	Tenant’s Acts—Effect on Insurance	26

15.	CASUALTY; TAKING		26

	15.1	Damage	26


	15.2	Termination Rights	27
	15.3	Taking for Temporary Use	28
	15.4	Disposition of Awards	28
	15.5	Abatement	28

16.	ESTOPPEL CERTIFICATE		28

17.	HAZARDOUS MATERIALS		29

	17.1	Prohibition	29
	17.2	Environmental Laws	29
	17.3	Hazardous Material Defined	30
	17.4	Testing	30
	17.5	Indemnity; Remediation	30
	17.6	Disclosures	31
	17.7	Removal	31

18.	RULES AND REGULATIONS		32

	18.1	Rules and Regulations	32
	18.2	Energy Conservation	32
	18.3	Recycling	32

19.	LAWS AND PERMITS		32

	19.1	Legal Requirements	32
	19.2	Required Permits	32

20.	DEFAULT		33

	20.1	Events of Default	33
	20.2	Remedies	34
	20.3	Damages—Termination	34
	20.4	Landlord’s Self-Help; Fees and Expenses	36
	20.5	Waiver of Redemption, Statutory Notice and Grace Periods	36
	20.6	Landlord’s Remedies Not Exclusive	36
	20.7	No Waiver	36
	20.8	Restrictions on Tenant’s Rights	36
	20.9	Landlord Default	37

21.	SURRENDER; ABANDONED PROPERTY; HOLD-OVER		37

	21.1	Surrender	37
	21.2	Abandoned Property	38
	21.3	Holdover	39

22.	MORTGAGEE RIGHTS		39

	22.1	Subordination	39
	22.2	Notices	39
	22.3	Mortgagee Liability	39

23.	QUIET ENJOYMENT		40

24.	NOTICES		40


25.	MISCELLANEOUS		41

	25.1	Separability	41
	25.2	Captions	41
	25.3	Broker	41
	25.4	Entire Agreement	41
	25.5	Governing Law	41
	25.6	Representation of Authority	41
	25.7	Expenses Incurred by Landlord Upon Tenant Requests	41
	25.8	Survival	41
	25.9	Limitation of Liability	41
	25.10	Binding Effect	42
	25.11	Landlord Obligations upon Transfer	42
	25.12	No Grant of Interest	42
	25.13	No Air Rights	42
	25.14	Financial Information	42


Name: Seth Alexander
Title: President, MIT Investment Management Company

TENANT

EVELO THERAPEUTICS, INC.


SOUTHERLY		by Memorial Drive by two curved lines, measuring respectively, 4.62 feet and 196.73 feet;

WESTERLY		by land now or formerly of Massachusetts Institute of Technology LC No. 2495C, 143.97 feet;

NORTHWESTERLY and NORTHERLY		by the southeasterly and southerly lines of a strip of land marked “Railroad Way” on said plan, four lines, the third of which is a curved line, measuring respectively 30.28 feet, 66.70 feet, 105.51 feet and 70.51 feet;

SOUTHEASTERLY and EASTERLY		by Vassar Street and by two lines, the first of which is a curved line, measuring respectively, 84.20 feet and 148.20 feet; and

SOUTHEASTERLY		by the intersection of Vassar Street and Memorial Drive by a curved line, 23.50 feet.


NORTHWESTERLY		by Lot 2 on said plan, 183,78 feet;

EASTERLY:		by land formerly of Benjamin F. Brown et al, 143.97 feet; and

SOUTHERLY:		by Memorial Drive (Charles River Road as shown on said plan) 139.13 feet.


BENEFICIARY:		ISSUANCE DATE:

< > [LANDLORD]
		IRREVOCABLE STANDBY
		LETTER OF CREDIT NO.

ACCOUNTEE/APPLICANT:		MAXIMUM/AGGREGATE
		CREDIT AMOUNT:
< >		USD: $_______.__
[TENANT]


LANDLORD:	620 MEMORIAL LEASEHOLD LLC

	By:	MIT Cambridge Real Estate, LLC, its manager

	By:	/s/ Seth D. Alexander
		Seth D. Alexander, President and not individually

TENANT:	EVELO BIOSCIENCES, INC.

	By:	/s/ Jennifer Glennon
	Name:	Jennifer Glennon
	Title:	Vice President, Finance and Operations
		Hereunto duly authorized