X0306 4 2017-01-11 0 0001412067 Cascadian Therapeutics, Inc. CASC 0001356256 Myers Scott Dunseth C/O CASCADIAN THERAPEUTICS, INC. 2601 4TH AVE., SUITE 500 SEATTLE WA 98121 1 1 0 0 President and CEO Stock Option (right to buy) 4.64 2017-01-11 4 A 0 190000 0.00 A 2027-01-11 Common Stock 190000 190000 D Restricted Share Unit (RSU) 2017-01-11 4 A 0 42000 0.00 A 2021-01-11 Common Stock 42000 42000 D The option vests and is exercisable at the rate of 1/4th of the total shares on January 11, 2018 and then 1/48th of the total shares vest and are exercisable monthly thereafter, with 100% vested and exercisable on January 11, 2021, subject to the holder's continued employment with the issuer on each vesting date. Approximately 67% of each RSU represents a contingent right to receive approximately 0.67 share of the issuer's Common Stock upon vesting and approximately 33% represents a contingent right to receive cash upon vesting, which cash will be used to facilitate the holder's satisfaction of U.S. federal tax obligations in connection with the vesting of the RSUs. Twenty-five percent of the shares underlying the RSU vest on each of January 11, 2018, January 11, 2019, January 11, 2020 and January 11, 2021, subject to the holder's continued employment with the issuer on each vesting date. /s/ Julia M. Eastland as attorney-in-fact for Scott D. Myers 2017-01-13