X0206 3 2015-10-28 0 0001552451 MyoKardia Inc MYOK 0001654909 Bauer Jake C/O MYOKARDIA, INC. 333 ALLERTON AVENUE SOUTH SAN FRANCISCO CA 94080 0 1 0 0 See Remarks Common Stock 81632 D Stock Option (Right to Buy) 1.51 2025-06-03 Common Stock 16326 D These shares of Common Stock are subject to the Issuer's right of repurchase, which lapsed with respect to 25% of the shares on July 16, 2015, and lapses in 36 equal monthly installments thereafter. 25% of the shares subject to this option shall vest and become exercisable on June 4, 2016, and the remaining shares subject to this option shall vest and become exercisable in 36 equal monthly installments thereafter. Vice President, Business Development and Business Operations Exhibit List: Exhibit 24.1 - Power of Attorney /s/ Steven Chan, attorney-in-fact 2015-10-28