**Exhibit 10.1**

** **

**FIRSTAMENDMENT TO LEASE**

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ThisFirst Amendment (the “**First Amendment**”)to Lease is made as of October 30, 2007, by and between **ARE-TECH SQUARE, LLC**, a Delaware limited liability company,having an address at 385 East Colorado Boulevard, Suite 299, Pasadena,California 91101 (“**Landlord**”), and**SIRTRIS PHARMACEUTICALS, INC.**, aDelaware corporation, having an address at 790 Memorial Drive, Cambridge,Massachusetts 02139 (“**Tenant**”).

 

**RECITALS**

 

# A.          Landlordand Tenant have entered into that certain Lease (the “**Lease**”) dated as of June 22, 2007 (the “**Lease**”), wherein Landlord leased to Tenantcertain premises (the “**Premises**”)located at 200 Technology Square, Cambridge, Massachusetts, more particularlydescribed in the Lease.

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# B.           Tenantdesires to expand the Premises demised under the Lease by adding 3,786 rentablesquare feet (the “**Expansion Space**”)in the basement portion of the Building of which the Premises are a part, andLandlord is willing to lease such portion of the Project to Tenant on the termsherein set forth.

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# C.           Landlordand Tenant desire to amend the Lease to, among other things, add the ExpansionSpace to the Premises demised under the Lease and to provide for theimprovement of such space.

#  

**AGREEMENT**

 

NOW,THEREFORE, the parties hereto agree that the Lease is amended as follows:

 

## 1.            **CapitalizedTerms**. Capitalized terms used herein and not otherwise definedshall have the meaning thereto ascribed in the Lease.

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## 2.            **Premises**.Effective upon full execution hereof by Landlord and Tenant, the definition of “Premises”set forth in the Basic Lease Provisions of the Lease is hereby amended bydeleting the same and replacing it with the following:

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“Thatportion of the Project, containing a total of approximately 47,870 rentablesquare feet, as determined by Landlord, consisting of approximately (i) 17,357rentable square feet on the second (2nd) floor of the Building (“**Second Floor Space**”), (ii) 17,357 rentablesquare feet on the third (3rd) floor of the Building (“**Third Floor Space**”), (iii) 8,679 rentablesquare feet on the fourth (4th) floor of the Building (“**Fourth Floor Space**”); (iv) 471rentable square feet on the first (1st) floor of the Building (“**First Floor Space**”) and(v) 4,006 rentable square feet of space, in the basement of theBuilding (the “**Basement Space**”),as shown on **Exhibit A**.”

 

**ExhibitA** to the Lease is hereby deleted in itsentirety and replaced with **Exhibit A**attached hereto.

 

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## 3.            **RentableArea of Premises**. It is agreed that the Rentable Area ofPremises is 47,870 sq. ft. and that Tenant’s share of Operating Expenses, as ofthe date hereof, is 27.03%.

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## 4.            **SecurityDeposit**.

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### (a)           As a condition to the effectivenessof this First Amendment, the Security Deposit as defined in the Lease shall beincreased by the sum of $174,490.87, which amount shall be held by Landlord aspart of the Security Deposit subject to the terms of the Lease, it being agreedthat the amount subject to proportionate increase as set forth in thedefinition of Security Deposit in the Lease shall, for all purposes, be$2,100,296.25.

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### (b)           The amount by which the SecurityDeposit may be reduced, subject to and in accordance with the third paragraphof Section 6 of the Lease, shall be $233,366.25. Accordingly, wherever$213,978.38 appears in the third paragraph of Section 6 of the Lease, it shallbe deleted and replaced by $233,366.25.

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## 5.            **Landlord’sWork**.

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### (a)           **Definitionof Landlord’s Work With Respect to the Basement Space**. Landlord andTenant agree that the Work Letter attached as **ExhibitC** to the Lease shall be deemed to apply to all of the Premisesexcept the Basement Space, consequently with respect to such Work Letter,Section 5(b) thereof is hereby amended by deleting the first sentence thereofand replacing the same with the following:

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“ Landlord shall provideto Tenant a tenant improvement allowance (the “TI Allowance”) of $180.00 perrentable square foot of the Premises excluding the Basement Space (which, basedon 43,864 rentable square feet initially demised under the Lease, excluding theBasement Space, equates to $7,895,520.00 in the aggregate).”

 

### (b)           **Improvementof Basement Space**. Delivery and acceptance of the Basement Spaceshall be subject to and on the terms set forth in the last two paragraphs ofSection 2 of the Lease, it being agreed, however, that the Work Letter attachedhereto as **Exhibit B** shall applywith respect to the Basement Space.

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## 6.            **CommencementDate and Rent Commencement Date**. The first two sentences of thesecond paragraph of Section 2 of the Lease are hereby amended by deleting thesame and replacing them with the following:

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“ The “**Commencement Date**” with respect to the Basement Space, theFirst Floor Space, the Second Floor Space, the Third Floor Space and the FourthFloor Space shall be the earliest of: (i) the later of (a) December 1, 2007,(b) the date Landlord Delivers such portion of the Premises to Tenant or (c)the date Landlord could have Delivered such portion of the Premises but forTenant Delays; and (ii) the date Tenant conducts any business in suchportion of the Premises or any part thereof. The “**Rent****Commencement Date**”shall be (a) the Commencement Date, with respect to each of the Basement Space,First Floor Space, Second Floor Space, and Third Floor Space, and (b) with respect

 

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to the Fourth FloorSpace only, the earlier of (X) one year after the Commencement Date or (Y) thedate Tenant conducts any business in the Fourth Floor Space or any partthereof.”

 

## 7.            **TargetCommencement Date**. Landlord and Tenant agree, with respect tothe Basement Space, only, the Target Commencement Date shall be February 15,2008.

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## 8.            **Parking**. The phrase inparentheses in the first sentence of Section 10 of the Lease, “(which, based on44,084 rentable square feet, equates to 66 parking spaces)”, shall be deletedand replaced with “(which, based on 47,870 rentable square feet, equates to 72parking spaces)”.

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## 9.            **Miscellaneous**.

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### (a)           This First Amendment is the entireagreement between the parties with respect to the subject matter hereof andsupersedes all prior and contemporaneous oral and written agreements anddiscussions. This First Amendment may be amended only by an agreement inwriting, signed by the parties hereto.

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### (b)           This First Amendment is binding uponand shall inure to the benefit of the parties hereto and their respectivepermitted successors and assigns.

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### (c)           This First Amendment may be executedin any number of counterparts, each of which shall be deemed an original, butall of which when taken together shall constitute one and the same instrument. Thesignature page of any counterpart may be detached therefrom without impairingthe legal effect of the signature(s) thereon provided such signature page isattached to any other counterpart identical thereto except having additionalsignature pages executed by other parties to this First Amendment attachedthereto.

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### (d)           Landlord and Tenant each representand warrant that it has not dealt with any broker, agent or other person(collectively “**Broker**”) inconnection with this transaction other than Richards Barry Joyce & Partnersand Cushman & Wakefield, and that no Broker other than Richards Barry Joyce& Partners and Cushman & Wakefield*,* who shall be paid by Landlord pursuant to aseparate Agreement, brought about this transaction. Landlord and Tenanteach hereby agree to indemnify and hold the other harmless from and against anyclaims by any Broker other than Richards Barry Joyce & Partners and Cushman& Wakefield claiming a commission or other form of compensation by virtueof having dealt with Tenant or Landlord, as applicable, with regard to thisleasing transaction.

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### (e)           Except as amended and/or modified bythis First Amendment, the Lease is hereby ratified and confirmed and all otherterms of the Lease shall remain in full force and effect, unaltered andunchanged by this First Amendment. In the event of any conflict between theprovisions of this First Amendment and the provisions of the Lease, theprovisions of this First Amendment shall prevail. Whether or not specificallyamended by this First Amendment, all of the terms and provisions of the Leaseare hereby amended to the extent necessary to give effect to the purpose andintent of this First Amendment.

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**(Signatures on Next Page)**

 

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INWITNESS WHEREOF, the parties hereto have executed this First Amendment as ofthe day and year first above written.

 
|   | TENANT**:**                                                 |
|--------|-------------------------------------------------------------|
|   |                                                        |   |
|   | SIRTRIS  PHARMACEUTICALS, INC.,                             |
|   | a  Delaware corporation                                     |
|   |                                                        |   |
|   | By:                                                         | /s/  Garen Bohlin |
|   | Its:                                                        | Chief  Operating Officer |
|   |                                                        |   |
|   |                                                        |   |
|   | LANDLORD:                                                   |
|   |                                                        |   |
|   | ARE-TECH  SQUARE, LLC, a Delaware limited liability company |
|   |                                                        |
|   | By:                                                         | ARE-MA  REGION NO. 31, LLC, a Delaware limited   liability company, its Member |
|   |                                                        |   |
|   |                                                        | By: | ALEXANDRIA  REAL ESTATE EQUITIES,   L.P., a Delaware limited partnership, its   Member |
|   |                                                        |   |   |
|   |                                                        |   | By: | ARE-QRS  CORP., a Maryland   corporation, its General Partner |
|   |                                                        |   |   |   |
|   |                                                        |   |   | By: | /s/ Jackie Clem |
|   |                                                        |   |   | Name: | Jackie Clem |
|   |                                                        |   |   | Title: | VP-Real Estate Legal Affairs |
|        |                                                             |  |  |  |  |  |  |  |

 

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**EXHIBIT A TO FIRSTAMENDMENT**

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**Descriptionof Premises**

 

Exhibit A

200 Technology Square

First Floor

 

 

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Exhibit A

200 Technology Square

Second Floor

 

 

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Exhibit A

200 Technology Square

Third Floor

 

 

 

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Exhibit A

200 Technology Square

Fourth Floor

 

 

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Exhibit A

200 Technology Square

Basement Floor

 

 

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**EXHIBIT B TO FIRSTAMENDMENT**

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**WorkLetter**

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THIS WORK LETTER (this “**Work Letter**”) is incorporated into that certain FirstAmendment to Lease (the “**First Amendment toLease**”) dated as of October 30, 2007 by and between ARE-TECHSQUARE, LLC, a Delaware limited liability company (“**Landlord**”),and SIRTRIS PHARMACEUTICALS, INC., a Delaware corporation (“**Tenant**”). Any initially capitalized terms used but notdefined herein shall have the meanings given them in the First Amendment toLease.

 

## 1.            **GeneralRequirements**.

##  

### (a)           **Tenant’sAuthorized Representative**. Tenant designates Peggy Romero and PaulBrannelly (either such individual acting alone, “Tenant’s Representative”) asthe only persons authorized to act for Tenant pursuant to this Work Letter. Landlordshall not be obligated to respond to or act upon any request, approval, inquiryor other communication (“Communication”) from or on behalf of Tenant inconnection with this Work Letter unless such Communication is in writing fromTenant’s Representative. Tenant may change either Tenant’s Representative atany time upon not less than 5 business days advance written notice to Landlord.Neither Tenant nor Tenant’s Representative shall be authorized to directLandlord’s contractors in the performance of Landlord’s Work (as hereinafterdefined).

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### (b)           **Landlord’sAuthorized Representative**. Landlord designates Tom Andrews and TimWhite (either such individual acting alone, “Landlord’s Representative”) as theonly persons authorized to act for Landlord pursuant to this Work Letter. Tenantshall not be obligated to respond to or act upon any request, approval, inquiryor other Communication from or on behalf of Landlord in connection with thisWork Letter unless such Communication is in writing from Landlord’sRepresentative. Landlord may change either Landlord’s Representative at anytime upon not less than 5 business days advance written notice to Tenant.Landlord’s Representative shall be the sole persons authorized to directLandlord’s contractors in the performance of Landlord’s Work.

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### (c)           **Architects,Consultants and Contractors.**Landlord and Tenant hereby acknowledgeand agree that:  (i) the generalcontractor and any subcontractors for the Tenant Improvements shall be selectedby Landlord, subject to Tenant’s approval, which approval shall not beunreasonably withheld, conditioned or delayed, and (ii) R.E. DineenAssociates shall be the architect (the “TI Architect”) for the TenantImprovements.

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## 2.            **TenantImprovements**.

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### (a)           **TenantImprovements Defined.**As used herein, “Tenant Improvements” shallmean all improvements to the Basement Space of a fixed and permanent nature asshown on the TI Construction Drawings, as defined in Section 2(c) below. Otherthan Landlord’s Work (as defined in Section 3(a) below), Landlord shall nothave any obligation whatsoever with respect to the finishing of the BasementSpace for Tenant’s use and occupancy.

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### (b)           **Tenant’sSpace Plans.**Tenant’s schematic drawings and outline specifications(the “TI Design Drawings”) detailing Tenant’s requirements for the TenantImprovements are listed on Exhibit 1 attached hereto and made a parthereof. Not more than 10 days after the date of the First Amendment to Lease,Landlord shall deliver to Tenant the written objections, questions or commentsof Landlord and the TI Architect with regard to the TI Design Drawings. Tenantshall cause the TI Design Drawings to be revised to address such written 

 

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### commentsand shall resubmit said drawings to Landlord for approval within 10 daysthereafter. Such process shall continue until Landlord has approved the TIDesign Drawings.

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### (c)           **WorkingDrawings.**Not Later than 10 business days following the approval ofthe TI Design Drawings, Landlord shall cause the TI Architect to prepare anddeliver to Tenant for review and comment construction plans, specifications anddrawings for the Tenant Improvements (the “TI Construction Drawings”), which TIConstruction Drawings shall be prepared substantially in accordance with the TIDesign Drawings. Tenant shall be solely responsible for ensuring that the TIConstruction Drawings reflect Tenant’s requirements for the Tenant Improvements.Tenant shall deliver its written comments on the TI Construction Drawings toLandlord not later than 10 business days after Tenant’s receipt of the same;provided, however, that Tenant may not disapprove any matter that is consistentwith the TI Design Drawings without submitting a Change Request. Landlord andthe TI Architect shall consider all such comments in good faith and shall,within 10 business days after receipt, notify Tenant how Landlord proposes torespond to such comments, but Tenant’s review rights pursuant to the foregoingsentence shall not delay the design or construction schedule for the TenantImprovements. Any disputes in connection with such comments shall be resolvedin accordance with Section 2(d) hereof. Provided that the design reflected inthe TI Construction Drawings is consistent with the TI Design Drawings, Tenantshall approve the TI Construction Drawings submitted by Landlord, unless Tenantsubmits a Change Request. Once approved by Tenant, subject to the provisions ofSection 4 below, Landlord shall not materially modify the TI ConstructionDrawings except as may be reasonably required in connection with the issuanceof the TI Permit (as defined in Section3(b) below).

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### (d)           **Approvaland Completion.**It is hereby acknowledged by Landlord and Tenantthat the TI Construction Drawings must be completed and approved not later thanthe date of this Work Letter, in order for the Landlord’s Work to beSubstantially Complete by the Target Commencement Date (as defined in the FirstAmendment to Lease). Upon any dispute regarding the design of the TenantImprovements, which is not settled within 10 business days after notice of suchdispute is delivered by one party to the other, Tenant may make the finaldecision regarding the design of the Tenant Improvements, provided (i) Tenantacts reasonably and such final decision is either consistent with or acompromise between Landlord’s and Tenant’s positions with respect to suchdispute, (ii) that all costs and expenses resulting from any such decision byTenant shall be payable out of the TI Fund (as defined in Section 5(d) below),and (iii) Tenant’s decision will not affect the base Building, structuralcomponents of the Building or any Building systems. Any changes to the TIConstruction Drawings following Landlord’s and Tenant’s approval of samerequested by Tenant shall be processed as provided in Section 4 hereof.

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## 3.            **Performanceof Landlord’s Work**.

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### (a)           **Definitionof Landlord’s Work.**As used herein, “Landlord’s Work” shall mean thework of constructing the Tenant Improvements.

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### (b)           **Commencementand Permitting.**Landlord shall commence construction of the TenantImprovements upon obtaining a building permit (the “TI Permit”) authorizing theconstruction of the Tenant Improvements consistent with the TI ConstructionDrawings approved by Tenant. The cost of obtaining the TI Permit shall bepayable from the TI Fund. Tenant shall assist Landlord in obtaining the TIPermit. If any Governmental Authority having jurisdiction over the constructionof Landlord’s Work or any portion thereof shall impose terms or conditions uponthe construction thereof that:  (i) areinconsistent with Landlord’s obligations hereunder, (ii) increase the cost ofconstructing Landlord’s Work, or (iii) will materially delay the constructionof Landlord’s Work,

 

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### Landlordand Tenant shall reasonably and in good faith seek means by which to mitigateor eliminate any such adverse terms and conditions.

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### (c)           **Completionof Landlord’s Work.**On or before the Target Commencement Date(subject to Tenant Delays and Force-Majeure Delays), Landlord shallsubstantially complete or cause to be substantially completed Landlord’s Workin a good and workmanlike manner, in accordance with the TI Permit subject, ineach case, to Minor Variations and normal “punch list” items of a non-materialnature that do not interfere with the use of the Basement Space and obtain acertificate of occupancy or temporary certificate of occupancy from the officeof the Building Inspector of the City of Cambridge with respect to the Landlord’sWork (“Substantial Completion” or “Substantially Complete”). Upon SubstantialCompletion of Landlord’s Work, Landlord shall require the TI Architect and thegeneral contractor to execute and deliver, for the benefit of Tenant andLandlord, a Certificate of Substantial Completion in the form of the AmericanInstitute of Architects (“AIA”) document G704. For purposes of this WorkLetter, “Minor Variations” shall mean any modifications reasonablyrequired:  (i) to comply with allapplicable Legal Requirements and/or to obtain or to comply with any requiredpermit (including the TI Permit) provided that such modification is not likelyto have a material adverse effect on Tenant’s use of the Basement Space ormaterially affect the ability to promptly obtain a permanent Certificate ofOccupancy for the Basement Space; (ii) to comply with any request by Tenant formodifications to Landlord’s Work; (iii) to comport with good design,engineering, and construction practices that are not material; or (iv) to makereasonable adjustments for field deviations or conditions encountered duringthe construction of Landlord’s Work.

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### (d)           **Selectionof Materials.**Where more than one type of material or structure isindicated on the TI Construction Drawings approved by Landlord and Tenant, theoption will be selected at Landlord’s sole and absolute subjective discretion. Asto all building materials and equipment that Landlord is obligated to supplyunder this Work Letter, Landlord shall select the manufacturer thereof in itssole and absolute subjective discretion.

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### (e)           **Deliveryof the****Basement Space.**WhenLandlord’s Work is Substantially Complete, subject to the remaining terms andprovisions of this Section 3(e), Tenant shall accept the Basement Space. Tenant’staking possession and acceptance of the Basement Space shall not constitute awaiver of:  (i) any warranty with respectto workmanship (including installation of equipment) or material (exclusive ofequipment provided directly by manufacturers), (ii) any non-compliance ofLandlord’s Work with applicable Legal Requirements, or (iii) any claim thatLandlord’s Work was not completed substantially in accordance with the TIConstruction Drawings (subject to Minor Variations and such other changes asare permitted hereunder) (collectively, a “Construction Defect”). Tenant shallhave one year after Substantial Completion within which to notify Landlord ofany such Construction Defect discovered by Tenant, and Landlord shall usereasonable efforts to remedy or cause the responsible contractor to remedy anysuch Construction Defect within 30 days thereafter. Notwithstanding theforegoing, Landlord shall not be in default under the Lease if the applicablecontractor, despite Landlord’s reasonable efforts, fails to remedy suchConstruction Defect within such 30-day period, in which case Landlord shallhave no further obligation with respect to such Construction Defect other thanto cooperate, at no cost to Landlord, with Tenant should Tenant elect to pursuea claim against such contractor, provided that Tenant shall defend with counselreasonably acceptable to Landlord, indemnify and hold Landlord harmless fromand against any claims arising out of or in connection with any such claim.

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Tenant shall be entitledto receive the benefit of all construction warranties and manufacturer’sequipment warranties relating to equipment installed in the Basement Space. Ifrequested by Tenant, Landlord shall attempt to obtain extended warranties frommanufacturers and 

 

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suppliersof such equipment, but the cost of any such extended warranties shall be bornesolely out of the TI Fund. Landlord shall promptly undertake and complete, orcause to be completed, all punch list items.

 

### (f)            **Commencement Date Delay.**Except asotherwise provided in the Lease, Delivery of the Basement Space shall occurwhen Landlord’s Work has been Substantially Completed, except to the extentthat completion of Landlord’s Work shall have been actually delayed by any oneor more of the following causes (“Tenant Delay”):

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#### (i)            Tenant’s Representative was notavailable to give or receive any Communication or to take any other actionrequired to be taken by Tenant hereunder;

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#### (ii)           Tenant’s request for Change Requests(as defined in Section 4(a) below) whether or not any such Change Requests areactually performed;

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#### (iii)          Construction of any Change Requests;

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#### (iv)          Tenant’s request for materials,finishes or installations requiring unusually long lead times;

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#### (v)           Tenant’s delay in reviewing, revisingor approving plans and specifications beyond the periods set forth herein;

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#### (vi)          Tenant’s delay in providinginformation critical to the normal progression of the Project. Tenant shallprovide such information as soon as reasonably possible, but in no event longerthan one week after receipt of any request for such information from Landlord;

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#### (vii)         Tenant’s delay in making payments toLandlord for Excess TI Costs (as defined in Section 5(d) below); or

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#### (viii)        Any other act or omission by Tenant orany Tenant Party (as defined in the Lease), or persons employed by any of suchpersons.

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If Delivery is delayedfor any of the foregoing reasons, then Landlord shall cause the TI Architect tocertify the date on which the Tenant Improvements would have been completed butfor such Tenant Delay and such certified date shall be the date of Delivery.

 

## 4.            **Changes.**Any changes requested by Tenant to the Tenant Improvements after thedelivery and approval by Landlord of the TI Design Drawings shall be requestedand instituted in accordance with the provisions of this Section 4 and shall besubject to the written approval of Landlord and the TI Architect, such approvalnot to be unreasonably withheld, conditioned or delayed.

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### (a)           **Tenant’sRequest For Changes.**If Tenant shall request changes to the TenantImprovements (“Changes”), Tenant shall request such Changes by notifyingLandlord in writing in substantially the same form as the AIA standard changeorder form (a “Change Request”), which Change Request shall detail the natureand extent of any such Change. Such Change Request must be signed by Tenant’sRepresentative. Landlord shall, before proceeding with any Change, usecommercially reasonable efforts to respond to Tenant as soon as is reasonablypossible with an estimate of:  (i) thetime it will take, and (ii) the architectural and engineering fees and coststhat will be incurred, to analyze such Change Request (which costs shall bepaid from the TI Fund to the extent actually incurred, whether or not suchchange is implemented). Landlord shall 

 

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### thereaftersubmit to Tenant in writing, within 5 business days of receipt of the ChangeRequest (or such longer period of time as is reasonably required depending onthe extent of the Change Request), an analysis of the additional cost orsavings involved, including, without limitation, architectural and engineeringcosts and the period of time, if any, that the Change will extend the date onwhich Landlord’s Work will be Substantially Complete. Any such delay in thecompletion of Landlord’s Work caused by a Change, including any suspension ofLandlord’s Work while any such Change is being evaluated and/or designed, shallbe Tenant Delay.

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### (b)           **Implementationof Changes.**If Tenant:  (i)approves in writing the cost or savings and the estimated extension in the timefor completion of Landlord’s Work, if any, and (ii) deposits with Landlord anyExcess TI Costs required in connection with such Change, Landlord shall causethe approved Change to be instituted. Notwithstanding any approval ordisapproval by Tenant of any estimate of the delay caused by such proposedChange, the TI Architect’s determination of the amount of Tenant Delay inconnection with such Change shall be final and binding on Landlord and Tenant.

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## 5.            **Costs**.

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### (a)           **BudgetFor Tenant Improvements.**Before the commencement of construction ofthe Tenant Improvements, Landlord shall obtain from The Richmond Group oranother contractor reasonably approved by Landlord and Tenant a detailedbreakdown by trade of the costs incurred or that will be incurred in connectionwith the design and construction of the Tenant Improvements (the “Budget”). TheBudget shall be based upon the TI Construction Drawings approved by Tenant andshall include a payment to Landlord of administrative rent (“AdministrativeRent”) equal to 3% of the TI Costs (net of soft costs, including architectural,consulting and engineering costs) for monitoring and inspecting theconstruction of the Tenant Improvements and Changes, which sum shall be payablefrom the TI Fund (as defined in Section 5(d). Administrative Rent shallinclude, without limitation, all out-of-pocket costs, expenses and feesincurred by or on behalf of Landlord arising from, out of, or in connectionwith monitoring the construction of the Tenant Improvements and Changes, andshall be payable out of the TI Fund. If the Budget is greater than the TIAllowance, Tenant shall deposit with Landlord the difference, in cash, prior tothe commencement of construction of the Tenant Improvements or Changes, fordisbursement by Landlord as described in Section 5(d).

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### (b)           **TIAllowance.**Landlord shall provide to Tenant a tenant improvementallowance (the “TI Allowance”) of $180.00 per rentable square foot of theBasement Space (which, based on 4,006 rentable square feet of Basement Spacedemised under the Lease, equates to $721,080.00 in the aggregate). Within 10business days of receipt of the Budget from Landlord, Tenant shall notifyLandlord how much of the TI Allowance Tenant has elected to receive fromLandlord. Such election shall be final and binding on Tenant, and may notthereafter be modified without Landlord’s consent, which may be granted orwithheld in Landlord’s sole and absolute subjective discretion. The TIAllowance shall be disbursed in accordance with this Work Letter. Tenant shallhave no right to the use or benefit (including any reduction to or payment ofBase Rent) of any portion of the TI Allowance not required for TI Costs (“UnrequiredTI Allowance”), except that Tenant shall be entitled to receive any UnrequiredTI Allowance with respect to any space leased to Tenant directly by Landlord inthe Building (pursuant to this Lease or otherwise), for Alterations theretoprovided that (i) such Alterations are completed no later than twenty-four(24) months after the Commencement Date, (ii) the disbursement of suchUnrequired TI Allowance shall be subject to Landlord’s reasonable requirementsconsistent with the Lease and this Work Letter and (iii) a written requestfor such disbursement satisfying all such requirements shall have been receivedby Landlord no later than twenty-four (24) months after the Commencement Date.

 

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### (c)           **CostsIncludable in TI Fund.**The TI Fund shall be used solely for thepayment of design, permits and construction costs in connection with theconstruction of the Tenant Improvements, including, without limitation, thecost of electrical power and other utilities used in connection with theconstruction of the Tenant Improvements, the cost of preparing the TI DesignDrawings and the TI Construction Drawings, all costs set forth in the Budget,including Landlord’s Administrative Rent, Landlord’s out-of-pocket expenses,costs resulting from Tenant Delays and the cost of Changes (collectively, “TICosts”), provided, however, that Tenant shall not be entitled to utilize anymore than 5% of the TI Allowance for architectural, consulting and engineeringcosts. Notwithstanding anything to the contrary contained herein, the TI Fundshall not be used to purchase any furniture, personal property or othernon-Building system materials or equipment, including, but not limited to,Tenant’s voice or data cabling, non-ducted biological safety cabinets and otherscientific equipment not incorporated into the Tenant Improvements.

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### (d)           **ExcessTI Costs.**Landlord shall have no obligation to bear any portion ofthe cost of any of the Tenant Improvements except to the extent of the TIAllowance, it being agreed that Landlord will enter into a so-called “open book”construction contract for the Tenant Improvements with The Richmond Group orsuch other contractor reasonably approved by Landlord and Tenant. If at anytime the remaining TI Costs under the Budget exceed the remaining unexpended TIAllowance, Tenant shall deposit with Landlord, as a condition precedent toLandlord’s obligation to complete the Tenant Improvements, 100% of the thencurrent TI Cost in excess of the remaining TI Allowance (“Excess TI Costs”). IfTenant fails to deposit any Excess TI Costs with Landlord, Landlord shall haveall of the rights and remedies set forth in the Lease for nonpayment of Rent(including, but not limited to, the right to interest at the Default Rate andthe right to assess a late charge). For purposes of any litigation institutedwith regard to such amounts, those amounts will be deemed Rent under the Lease.The TI Allowance and Excess TI Costs are herein referred to as the “TI Fund.”  Funds deposited by Tenant shall be the firstdisbursed to pay TI Costs. Notwithstanding anything to the contrary set forthin this Section 5(d), Tenant shall be fully and solely liable for TI Costs andthe cost of Minor Variations in excess of the TI Allowance. If upon SubstantialCompletion of the Tenant Improvements and the payment of all sums due inconnection therewith there remains any undisbursed portion of the TI Fund,Tenant shall be entitled to such undisbursed TI Fund solely to the extent ofany Excess TI Costs deposit Tenant has actually made with Landlord.

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## 6.            **TenantAccess**.

##  

### (a)           **Tenant’sAccess Rights.**Landlord hereby agrees to permit Tenant access, atTenant’s sole risk and expense, to the Building (i) subject to Landlord’s priorwritten consent, prior to the Commencement Date to perform any work (“Tenant’sWork”) required by Tenant other than Landlord’s Work, provided that such Tenant’sWork is coordinated with the TI Architect and the general contractor, andcomplies with the Lease and all other reasonable restrictions and conditionsLandlord may impose, and (ii) prior to the completion of Landlord’s Work, toinspect and observe work in process; all such access shall be during normalbusiness hours or at such other times as are reasonably designated by Landlord.Notwithstanding the foregoing, Tenant shall have no right to enter onto theBasement Space or the Project unless and until Tenant shall deliver to Landlordevidence reasonably satisfactory to Landlord demonstrating that any insurancereasonably required by Landlord in connection with such pre-commencement access(including, but not limited to, any insurance that Landlord may requirepursuant to the Lease) is in full force and effect. Any entry by Tenant shall complywith all established safety practices of Landlord’s contractor and Landlorduntil completion of Landlord’s Work and acceptance thereof by Tenant.

 

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### (b)           **NoInterference.**Neither Tenant nor any Tenant Party (as defined in theLease) shall interfere with the performance of Landlord’s Work, nor with anyinspections or issuance of final approvals by applicable GovernmentalAuthorities, and upon any such interference, Landlord shall have the right toexclude Tenant and any Tenant Party from the Premises and the Project untilSubstantial Completion of Landlord’s Work.

###  

### (c)           **NoAcceptance of Basement Space.**The fact that Tenant may, withLandlord’s consent, enter into the Project prior to the date Landlord’s Work isSubstantially Complete for the purpose of performing Tenant’s Work shall not bedeemed an acceptance by Tenant of possession of the Basement Space, but in suchevent Tenant shall defend with counsel reasonably acceptable by Landlord,indemnify and hold Landlord harmless from and against any loss of or damage toTenant’s property, completed work, fixtures, equipment, materials ormerchandise, and from liability for death of, or injury to, any person, causedby the act or omission of Tenant or any Tenant Party.

###  

## 7.            **Miscellaneous**.

##  

### (a)           **Consents.**Whenever consent or approval of either party is required under thisWork Letter, that party shall not unreasonably withhold, condition or delaysuch consent or approval, unless expressly set forth herein to the contrary.

###  

### (b)           **Modification.**No modification, waiver or amendment of this Work Letter or of anyof its conditions or provisions shall be binding upon Landlord or Tenant unlessin writing signed by Landlord and Tenant.

 

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Exhibit 1 to Work Letter

 

List of TI DesignDrawings

 
| Project Name: | Sirtris  Pharmaceuticals, Inc. |
|---------------|--------------------------------|
|          | Vivarium Facility              |
|          | 200 Technology Square          |
|          | Cambridge,  Massachusetts      |

 

Architect:  R E Dineen Architects& Planners, Inc.

 

**Specifications (Dated 14 September 2007)**

 

Section 15300 Fire Protection

Section 15400 Plumbing

Section 15500 Heating, Ventilating and Air Conditioning

 

Section 16000 Electrical

Section 16700 Fire Alarm

 

**Construction Drawings (Dated 14 September 2007)**

 

Architectural

 

T-0.1 Title Sheet

T-0.2 Code Plans

T-0.3 Partition Types, Wall Details

A-1 Construction Plan

A-2 Reflected Ceiling Plan

A-3 Furniture & Equipment Plan

A-4 Finish Plan & Schedule

A-5 Interior Elevations & Sections

A-6 Not Used

A-7 Door & Frame Schedule, Hardware Schedule

A-8 Lab Casework Elevations

 

Fire Protection

 

FP-1.0 Fire Protection Legend, Details & Floor Plan

 

Fire Alarm

 

FA-1.0 Fire Alarm Legend, Details & Floor Plan

 

Plumbing

 

P-1 Plumbing Legends & Diagram Sheet

P-2 Plumbing Basement Plan

 

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HVAC

 

H-0.1 HVAC Legend, Abbreviations & General Notes

H-0.2 HVAC Schedules

H-0.3 HVAC Details 1

H-0.4 HVAC Details 2

HD-1.0 HVAC Basement Demolition Plan

H-1.1 HVAC Basement New Work Plan

H-1.1 HVAC Exhaust Risers Through Building To Roof

 

Electrical

 

E-0.1 Electrical Legend

E-0.2 Electrical Schedules

E-1.01 Electrical Power Plan

E-2.01 Electrical Lighting Plan

 

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