AMENDMENT NO. 4 TO
INFINITY PHARMACEUTICALS, INC.
2000 STOCK INCENTIVE PLAN
The Infinity Pharmaceuticals, Inc. 2000 Stock Incentive Plan, as amended (the “Plan”), be and hereby is amended as
Subject to, and effective upon, the filing of the Restated Certificate of Incorporation with the Secretary of State of the State
of Delaware approved by stockholders at the 2007 Annual Stockholders Meeting, Article Five, Section I.A. is hereby deleted in
its entirety and a new Article Five, Section I.A. is inserted in lieu thereof, which reads as follows:
“Notwithstanding anything to the contrary contained herein:
(1) Each non-employee director initially elected to the Board following September 12, 2006, on the date of his or her
initial election to the Board, shall receive a Non-Statutory Option to purchase 9,375 shares of Common Stock (the “Initial
Option”). Shares of Common Stock subject to the Initial Option will become exercisable in equal quarterly installments
beginning at the end of the first quarter after the date of grant, provided that the holder of the Initial Option continues to
serve as a director.
(2) Each non-employee director shall, on the date of the first Annual Stockholders Meeting following the first
anniversary of his or her initial election to the Board and on the date of each Annual Stockholders Meeting thereafter,
receive a Non-Statutory Option to purchase 5,625 shares of Common Stock (an “Annual Option”); provided, however, that
Annual Options shall not be granted to non-employee directors serving on the Board on September 13, 2006 until the first
Annual Stockholders Meeting after September 12, 2009. Shares of Common Stock subject to the Annual Option will be
exercisable in equal quarterly installments beginning at the end of the first quarter after the date of grant, provided that the
holder of the Annual Option continues to serve as a director.
(3) The non-employee director who serves as the lead outside director of the Board shall receive an add