Option Rent. The annual Rent payable by Tenant during the Option Term (the "Option Rent XE "Option Rent" ") shall be equal to the "Fair Rental Value," as that term is defined below, for the Premises as of the commencement date of the Option Term. The "Fair Rental Value XE "Fair Rental Value" ," as used in this Lease, shall be equal to the annual rent per rentable square foot (including additional rent and considering any "base year" or "expense stop" applicable thereto), including all escalations, at which tenants (pursuant to leases consummated within the twelve (12) month period preceding the first day of the Option Term), are leasing non-sublease, non-encumbered, non-equity space which is not significantly greater or smaller in size than the subject space, with a comparable level of improvements (excluding any property that Tenant would be allowed to remove from the Premises at the termination of the Lease), for a comparable lease term, in an arm's length transaction, which comparable space is located in the "Comparable Buildings," as that term is defined in this Section 2.2.2, below (transactions satisfying the foregoing criteria shall be known as the " XE "Comparable Transactions" Comparable Transactions"), taking into consideration the following concessions (the " XE "Concessions" Concessions"): # rental abatement concessions, if any, being granted such tenants in connection with such comparable space; # tenant improvements or allowances provided or to be provided for such comparable space, and taking into account the value, if any, of the existing improvements in the subject space (other than improvements installed by Tenant at Tenant’s sole cost and expense), such value to be based upon the age, condition, design, quality of finishes and layout of the improvements and the extent to which the same can be utilized by a general office/lab user other than Tenant; and # other reasonable monetary concessions being granted such tenants in connection with such comparable space; provided, however, that in calculating the Fair Rental Value, no consideration shall be given to the fact that Landlord is or is not required to pay a real estate brokerage commission in connection with Tenant's exercise of its right to extend the Lease Term, or the fact that landlords are or are not paying real estate brokerage commissions in connection with such comparable space. The Concessions shall be reflected in the effective rental rate (which effective rental rate shall take into consideration the total dollar value of such Concessions as amortized on a straight-line basis over the applicable term of the Comparable Transaction (in which case such Concessions evidenced in the effective rental rate shall not be granted to Tenant)) payable by Tenant. The term “ XE “Comparable Buildings” Comparable Buildings” shall mean the Building and those other life sciences buildings which are comparable to the Building in terms of age (based upon the date of completion of construction or major renovation to the building), quality of

Option Rent. The Rent payable by [[Tenant:Organization]] during an Option Term (the “Option Rent”) shall be equal to one hundred percent (100%) of the “Market Rent,” as that term is defined in, and determined pursuant to, Exhibit G attached hereto.

Determination of Option Rent. In the event Tenant timely and appropriately exercises an option to extend the Lease Term, Landlord shall notify Tenant of Landlord's determination of the Option Rent within thirty (30) days thereafter. If Tenant, on or before the date which is ten (10) business days following the date upon which Tenant receives Landlord's determination of the Option Rent, in good faith objects to Landlord's determination of the Option Rent, then Landlord and Tenant shall attempt to agree upon the Option Rent using their best good-faith efforts. If Landlord and Tenant fail to reach agreement within ten (10) business days following Tenant's objection to the Option Rent (the "Outside Agreement Date XE "Outside Agreement Date" "), then Tenant shall have the right to withdraw its exercise of the option by delivering written notice thereof to Landlord within five (5) days thereafter, in which event Tenant's right to extend the Lease pursuant to this Section 2.2 shall be of no further force or effect. If Tenant does not withdraw its exercise of the extension option, each party shall make a separate determination of the Option Rent, as the case may be, within ten (10) days after the Outside Agreement Date, and such determinations shall be submitted to arbitration in accordance with [Sections 2.2.3.1 through 2.2.3.7], below. If Tenant fails to accept Landlord's determination of the Option Rent within the time period set forth herein, then Tenant shall be deemed to have objected to Landlord's determination of Option Rent.

Rent. All Rent and other payments required to be made by Tenant to Landlord hereunder shall be payable to Landlord at Landlord’s Remittance Address set forth in the Basic Lease Information, or at such other address as Landlord may specify from time to time by written notice delivered in accordance herewith. Tenant’s obligation to pay Rent and any other amounts to Landlord under the terms of this Lease shall not be deemed satisfied until such Rent and other amounts have been actually received by Landlord.

RENT. LESSEE shall pay LESSOR base rent of one hundred five thousand nine hundred ninety nine (105,999) U.S. dollars per year, drawn on a U.S. bank, in monthly installments of $8,833.25 on or before the first day of each calendar month, without offset or deduction. One monthly rental payment, plus an appropriate traction of a monthly payment for any portion of a month at the commencement of the lease term, shall be made upon LESSEE’S execution of this lease. All payments shall be made to LESSOR at 200 West Cummings Park, Woburn, Massachusetts 01801, or at such other place designated in writing by LESSOR. If the “Cost of Living” has increased as shown by the Consumer Price Index (Boston, Massachusetts, all items, all urban consumers), U.S. Bureau of Labor Statistics (“Index”), then base rent due during each calendar year of this lease and all extensions thereof shall be adjusted in proportion to any increase in the Index. The base month from which to determine the amount of each increase shall be January 2016, which figure shall be compared with the figure for November 2016, and each November thereafter to determine the increase (if any) in base rent to be paid during the following calendar year commencing each January 1.

Option Rent has not yet been finally determined. [[Landlord:Organization]] shall, no later than ninety (90) days prior to the expiration of the initial Lease Term or the then-current Option Term, as applicable, notify [[Tenant:Organization]] of [[Landlord:Organization]]’s good faith determination of the applicable Option Rent (the “[[Landlord:Organization]]’s Option Rent Notice”). [[Tenant:Organization]] shall deliver notice (the “[[Tenant:Organization]] Response Notice”) to [[Landlord:Organization]] on or before the date which is thirty (30) days after [[Tenant:Organization]]’s receipt of [[Landlord:Organization]]’s Option Rent Notice, stating that # [[Tenant:Organization]] is accepting [[Landlord:Organization]]’s Option Rent calculation as the Option Rent, or # rejecting [[Landlord:Organization]]’s Option Rent calculation and setting forth [[Tenant:Organization]]’s calculation of the Option Rent. If [[Tenant:Organization]] does not affirmatively accept or [[Tenant:Organization]] rejects the Option Rent specified in the [[Landlord:Organization]]’s Option Rent Notice, the parties shall follow the procedure set forth in Section 2.2.4 below, and the Option Rent shall be determined in accordance with the terms of Section 2.2.4 below.

In the event that the Option Rent shall not have been determined pursuant to the terms hereof prior to the commencement of the Option Term, Tenant shall be required to pay as Option Rent, an amount equal to 103% of the Base Rent payable by Tenant as of the expiration of the initial Lease Term, and upon the final determination of the Option Rent, the payments made by Tenant shall be reconciled with the actual amounts of Option Rent due, and the appropriate party shall make any corresponding payment to the other party.

Additional Rent. In addition to Base Rent, Tenant agrees to pay to Landlord as additional rent (“Additional Rent”): # Tenant’s Share of “Operating Expenses” (as defined in Section 5), and # any and all other amounts Tenant assumes or agrees to pay under the provisions of this Lease, including, without limitation, any and all other sums that may become due by reason of any default of Tenant or failure to comply with the agreements, terms, covenants and conditions of this Lease to be performed by Tenant, after any applicable notice and cure period.

Base Rent. Tenant shall continue paying Base Rent with respect to the Original Premises as provided for in the Lease through June 30, 2016. Commencing on the Expansion Premises Commencement Date, Tenant shall pay Base Rent for the Expansion Premises at the same Base Rent per rentable square foot that Tenant is then paying for the Original Premises. Commencing on July 1, 2016, Tenant shall commence paying Base Rent with respect to the entire Premises (the Original Premises and the Expansion Premises) in the amount of $3.25 per rentable square foot of the entire Premises per month. Base Rent for the Premises shall be increased on July 1, 2017, and on each subsequent July 1st during the Base Term (each, an “Premises Adjustment Date”) by multiplying the Base Rent payable with respect to the Premises immediately before such Premises Adjustment Date by the Rent Adjustment Percentage and adding the resulting amount to the Base Rent payable with respect to the Premises immediately before such Premises Adjustment Date.

Base Rent. The first month’s Base Rent shall be due and payable on delivery of an executed copy of this Lease to Landlord. The Security Deposit shall be due on the date that is 5 days after the mutual execution and delivery of this Lease by the parties. Tenant shall pay to Landlord in advance, without demand, abatement, deduction or set-off, monthly installments of Base Rent on or before the first day of each calendar month during the Term hereof, in lawful money of the United States of America, at the office of Landlord for payment of Rent set forth above, or to such other person or at such other place as Landlord may from time to time designate in writing. Payments of Base Rent for any fractional calendar month shall be prorated. The obligation of Tenant to pay Base Rent and other sums to Landlord and the obligations of Landlord under this Lease are independent obligations. Tenant shall have no right at any time to abate, reduce, or set-off any Rent (as defined in Section 5) due hereunder except for any abatement as may be expressly provided in this Lease.