X0306 4 2017-03-23 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 Stock Option (Right to Buy) 1.51 2017-03-23 4 A 0 5102 0.00 A 2017-03-23 2025-06-03 Common Stock 5102 10204 D On June 4, 2015, the Reporting Person was granted an option to purchase 20,408 shares of Common Stock under the issuer's 2012 Equity Incentive Plan, the vesting of which was subject to various conditions (other than the passage of time and continued employment) that were not tied to the market price of the issuer's securities. On March 23, 2017, one of the conditions was deemed to be achieved, resulting in the vesting and exercisability of 5,102 of the shares underlying such option. Senior Vice President, Finance and Corporate Development /s/ Jake Bauer 2017-03-27