Myokardia Inc., of South San Francisco, Calif., said it priced an underwritten public offering of 3.8 million shares of its common stock at $15 each. In addition, the underwriters have a 30-day option to purchase up to an additional 570,000 shares of common stock. Credit Suisse Securities (USA) LLC and Cowen and Co. are acting as joint lead book-running managers for the offering. BMO Capital Markets Corp. is acting as book-running manager. Wedbush Securities Inc. is acting as co-manager.