X0306 4 2019-11-27 0 0001552451 MyoKardia Inc MYOK 0001654909 Bauer Jake C/O MYOKARDIA INC. 333 ALLERTON AVENUE SOUTH SAN FRANCISCO CA 94080 0 1 0 0 Chief Business Officer Common Stock 2019-11-27 4 S 0 13096 65.1326 D 53134 D Common Stock 2019-11-29 4 S 0 7336 65.52 D 45798 D Common Stock 2019-11-29 4 S 0 800 66.32 D 44998 D This transaction was effected pursuant to a Rule 10b5-1 trading plan that was previously adopted by the Reporting Person. Represents the weighted average sale price of the shares sold ranging from $65.00 to $65.44 per share. The Reporting Person will provide, upon request by the Commission staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. Represents the weighted average sale price of the shares sold ranging from $65.00 to $65.99 per share. The Reporting Person will provide, upon request by the Commission staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. Represents the weighted average sale price of the shares sold ranging from $66.04 to $66.44 per share. The Reporting Person will provide, upon request by the Commission staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. /s/ Cynthia Ladd, as Attorney-in-Fact 2019-12-02