Exhibit 10.14

Infinity

Pharmaceuticals

Effective as of March 31, 2006

Adelene Q. Perkins

83 Lincoln Road

Wayland, MA 01778

Dear Adelene:

Reference is hereby made to that certain Restricted Stock Agreement (the “Stock
Restriction Agreement”) dated March 19, 2002 between Infinity Pharmaceuticals,
Inc. (the “Company”) and you, pursuant to which the Company issued and sold to
you an aggregate of 450,000 shares (the “Shares”) of common stock, $.0001 par
value per share (the “Common Stock”), of the Company. As of April 1, 2006, all
450,000 Shares (the “Vested Shares”) had vested and were no longer subject to
the Purchase Option (as defined in the Stock Restriction Agreement).

The aggregate purchase price for the Shares was paid by you by delivery of that
certain Secured Promissory Note and Pledge Agreement dated as of March 19, 2002
in the principal amount of $67,500 (the “Promissory Note”), except that the
aggregate par value of the Shares was paid by you by check. As of March 31,
2006, you owe the Company an aggregate of $81,153.91, representing the entire
principal amount and accrued interest due under the Promissory Note.

By signing below, (a) the Company hereby agrees to forgive, as of the date
hereof, the entire principal amount and accrued interest owed by you to the
Company pursuant to the Promissory Note and (b) in exchange therefor, you agree
that, as of April 1, 2006, (i) 14,750 of the Vested Shares (the “Forgiveness
Shares”), which were issued to you pursuant to the Stock Restriction Agreement,
shall be subject to a right of repurchase in favor of the Company for a period
of twenty-four months following April 1, 2006 and (ii) in furtherance of the
foregoing, such Forgiveness Shares shall become Unvested Shares (as defined in
the Stock Restriction Agreement) as of April 1, 2006, and shall be subject to
all of the terms and conditions applicable to Unvested Shares, including the
Purchase Option and vesting schedule (vesting in the same manner as Unvested
Shares vest after January 1, 2003), set forth in the Stock Restriction
Agreement.

By signing below, you also acknowledge that the forgiveness of the principal and
interest on the Promissory Note will constitute compensation income to you and
will be subject to federal, state and local withholding taxes. The forgiveness
will not be effective unless and until you provide the Company with cash equal
to the withholding taxes payable, or you make other provisions satisfactory to
the Company for the payment of the withholding taxes payable.

 

INFINITY PHARMACEUTICALS, INC.

By:

 

/s/ Thomas J. Burke

Name:

 

Thomas J. Burke

Title:

 

Controller

 

Agreed and acknowledged as

of the date first written above.

/s/ Adelene Q. Perkins

Adelene Q. Perkins

Infinity Pharmaceuticals, Inc. 780 Memorial Drive Cambridge, MA 02139

tel: 617.453.1000 fax: 617.453.1001 www.ipi.com