X0306 4 2021-01-20 0 0001496671 Calithera Biosciences, Inc. CALA 0001553389 Molineaux Susan C/O CALITHERA BIOSCIENCES, INC. 343 OYSTER POINT BLVD. #200 SOUTH SAN FRANCISCO CA 94080 1 1 0 0 PRESIDENT & CEO Common Stock 2021-01-20 4 A 0 85000 0.00 A 95000 D Common Stock 457188 I By Trust Common Stock 52000 I By Spouse Employee Stock Option (Right to Buy) 2.98 2021-01-20 4 A 0 375000 0.00 A 2031-01-20 Common Stock 375000 375000 D The shares of Common Stock are to be acquired upon the vesting of a Restricted Stock Unit award granted to the Reporting Person. The Restricted Stock Units shall vest as follows: one-fourth (1/4th) of the shares subject to the Restricted Stock Unit will vest each year after January 20, 2021 until the Restricted Stock Units are fully vested. The Restricted Stock Unit shall be subject to accelerated vesting as set forth in the optionee's employment agreement with the Company. Includes 2,500 shares acquired on each of December 10, 2019, June 10, 2020, and December 10, 2020 under the Company's 2014 Employee Stock Purchase Plan. Shares are held by the Molineaux Family Trust of which the Reporting Person is a Trustee. One-fourth (1/4th) of the Option vests one year after January 20, 2021; the balance of the Option vests in a series of thirty-six (36) successive equal monthly installments thereafter. The Option shall be subject to accelerated vesting as set forth in the optionee's employment agreement with the Company. /s/ Susan M. Molineaux 2021-01-22