X0306 4 2019-08-01 0 0001373707 TETRAPHASE PHARMACEUTICALS INC TTPH 0001494425 Stahl Maria D C/OTETRAPHASE PHARMACEUTICALS, INC. 480 ARSENAL STREET, SUITE 110 WATERTOWN MA 02472 0 1 0 0 CBO and General Counsel Common Stock 2019-04-02 5 A 0 E 13913 A 37611 D Restricted Stock Units 2019-08-01 4 A 0 18000 0.00 A Common Stock 18000 18000 D Restricted Stock Units 2019-08-01 4 A 0 57000 0.00 A Common Stock 57000 57000 D On April 2, 2018, the Reporting person was granted 40,000 restricted stock units ("RSUs")( the "2018 RSU grant") that were previously reported on Table II Of Form 4, which form was filed with the Securities and Exchange Commission on April 4, 2018. Of the 2018 RSU grant, 20,000 shares vested on April 2, 2019 of which 6,087 shares were withheld by the Issuer to satisfy the reporting person's tax withholding obligations in connection with the delivery of the conversion of the RSUs into common stock on the vesting date. The total number of shares beneficially owned by the reporting person includes the 13,913 RSUs converted into shares of common stock of the Issuer on the April 2019 vesting date. Each restricted stock unit represents a contingent right to receive one share of common stock of Tetraphase Pharmaceuticals, Inc. for no consideration. The restricted stock units shall be eligible to be earned upon achievement of certain performance conditions and, if such conditions are met, shall vest no earlier than August 1, 2020 and no later than August 1, 2021. The restricted stock units vest in three equal installments on each of August 1, 2020, August 1, 2021 and August 1, 2022. /s/Maria Stahl 2019-08-02