X0306 4 2018-01-02 0 0001113148 INFINITY PHARMACEUTICALS, INC. INFI 0001680745 Tasker Seth A C/O INFINITY PHARMACEUTICALS, INC., 784 MEMORIAL DRIVE CAMBRIDGE MA 02139 0 1 0 0 General Counsel Common Stock 2018-01-02 4 A 0 22351 0.00 A 41284 D Common Stock 6756.49 I 401(k) Stock Option (right to buy) 2.23 2018-01-02 4 A 0 65000 0.00 A 2028-01-02 Common Stock 65000 65000 D Represents the reporting person's 2017 contingent compensation award paid in shares of common stock in lieu of cash at the election of the Compensation Committee of the issuer's Board of Directors. Includes 1,100 shares of common stock acquired by the reporting person on December 15, 2017 through participation in the issuer's Employee Stock Purchase Plan. The option vests over a period of two years in equal annual installments on the first and second anniversary of the date of grant. /s/ Seth A. Tasker 2018-01-04