**Exhibit 10.2**

SIRTRIS PHARMACEUTICALS, INC.

 

### Amendment to

Warrant to Purchase Shares of Series C  Preferred Stock of Sirtris Pharmaceuticals, Inc.

 

Dated: April 17, 2008

 

Reference is made hereby to the warrant (the “Warrant”) issued toHercules Technology Growth Capital, Inc., a Maryland corporation (the “Warrantholder”)by Sirtris Pharmaceuticals, Inc., a Delaware corporation (“the Company”)pursuant to a certain Warrant Agreement, dated April 18, 2006, by andbetween the Company and the Warrantholder. All capitalized terms used herein and not separately defined shall havethe meaning ascribed to them in the Warrant.

 

WHEREAS, the Company and the Warrantholder desire to amend the Warrant;

 

NOW, THEREFORE, the Warrantholder and the Company agree to the following:

 

1.     Amendment.  The Warrant is hereby amended as follows:

 

(a)           The definition of “Merger Event” in Section 1of the Warrant is hereby replaced in its entirety with the following:

 

“**Merger Event**” means a merger or consolidation involving theCompany in which the Company is not the surviving entity or in which theoutstanding shares of the Company’s capital stock are otherwise converted intoor exchanged for shares of capital stock of another entity or cash or otherproperty.

 

(b)           Section 8(a) of the Warrantis hereby replaced in its entirety with the following:

 

**(a) MergerEvent.** If at any timethere shall be Merger Event, the Warrantholder shall be entitled to receive,upon exercise of this Warrant at any time after the consummation of such MergerEvent, in lieu of the shares of common stock of the Company issuable upon suchexercise prior to the consummation of such Merger Event, the number of sharesof preferred stock or other securities or cash or other property that wouldhave been issuable to Warrantholder if Warrantholder had exercised this Warrantimmediately prior to the Merger Event. In any such case, appropriate adjustment(as determined in good faith by the Company’s Board of Directors) shall be madein the application of the provisions of this Warrant with respect to the rightsand interests of the Warrantholder after the Merger Event to the end that theprovisions of this Warrant (including adjustments of the Exercise Price andnumber of shares of Preferred Stock purchasable) shall be applicable in theirentirety, and to the greatest extent possible. Without limiting the foregoing,in connection with any Merger Event, upon the closing thereof, the successor orsurviving entity shall assume the obligations of this Warrant.

 

1

----

 

2.     Governing Law.  This Amendment shall be governed by andconstrued in accordance with the laws of the State of Delaware withoutreference to the choice of law principles thereof that would require theapplication of the laws of any other state.

 

3.     Counterparts. This Amendment may beexecuted in any number of counterparts, including by electronic or facsimiletransmission, each of which when so delivered shall be deemed an original, butall such counterparts taken together shall constitute but one and the sameinstrument.

 

*[Remainder of Page IntentionallyLeft Blank]*

 

2

----

 

ThisAmendment is executed as of the date first written above.

 

 

**SIRTRISPHARMACEUTICALS, INC.**

 

 
| By:    | /s/  Garen Bohlin        |   |
|--------|--------------------------|--------|
| Name:  | Garen  Bohlin            |
| Title: | Chief  Operating Officer |
|        |                          |        |  |

 

 

**HERCULESTECHNOLOGY GROWTH CAPITAL, INC.**

 

 
| By:    | /s/ Scott  Harvey |   |
|--------|------------------------|--------|
| Name:  | Scott Harvey           |
| Title: | Chief Legal Officer    |
|        |                        |        |  |

 

 

[Signature Page toWarrant Amendment]

 

----