X0206 3/A 2019-10-01 2019-10-03 0 0001629137 Global Blood Therapeutics, Inc. GBT 0001789673 Lehrer-Graiwer Joshua C/O GLOBAL BLOOD THERAPEUTICS, INC. 171 OYSTER POINT BLVD., SUITE 300 SOUTH SAN FRANCISCO CA 94080 0 1 0 0 Chief Medical Officer Stock Option (Right to Buy) 12.95 2026-02-08 Common Stock 1250 D Represents stock options outstanding from an original grant of options to purchase 10,000 shares of Common Stock. The shares of Common Stock underlying the original option grant shall vest in 16 equal quarterly installments over 4 years from February 9, 2016, so long as the Reporting Person continues as an employee or other service provider of the Issuer through each vesting date. This option is subject to accelerated vesting upon termination without cause or resignation for good reason after a change of control of the Issuer. This amendment to the Reporting Person's Form 3, filed on October 3, 2019, revises the number of shares of the Reporting Person's stock option which was reported incorrectly as granting options to purchase 3,125 shares of Common Stock and which did not account for the Reporting Person's previous exercise of 1,875 shares of the underlying options. The Form 3 filed by the Reporting Person on October 3, 2019 incorrectly included an entry in Table II reporting that the Reporting Person held stock options to purchase 625 shares of Common Stock. The Form 3 is hereby amended to delete such entry as the Reporting Person previously exercised the 625 shares of Common Stock underlying the options. /s/ Lesley Ann Calhoun, as Attorney-in-Fact 2020-01-29