X0306 4 2020-05-09 1 0001001233 SANGAMO THERAPEUTICS, INC SGMO 0001755198 Boissel Stephane C/O SANGAMO THERAPEUTICS, INC. 7000 MARINA BLVD BRISBANE CA 94005 0 1 0 0 EVP, Corp. Strategy Free Shares Call Options (obligation to sell to Issuer) 2020-05-09 5 E 0 E 1 0.00 D 2020-03-09 2020-05-09 Common Stock 2 D Free Shares Call Options (obligation to sell to Issuer) 2020-07-03 5 E 0 E 1 0.00 D 2020-05-03 2020-07-03 Common Stock 1 D In connection with the acquisition by the Issuer of Sangamo Therapeutics France S.A.S. (formerly TxCell S.A.) ("Sangamo France"), the Reporting Person granted to the Issuer, effective November 27, 2018, the right to purchase up to 238,100 "free shares" of Sangamo France (the "Subject Free Shares") for cash in four separate tranches beginning May 3, 2019 (the "Free Shares Call Options"). The exercise price per Subject Free Share to be paid by the Issuer upon any exercise of its Free Shares Call Options is equal to the product of 2.58 euros times the quotient of the 20-day volume weighted average price of the Issuer's common stock preceding the date the Issuer notifies the Reporting Person of its exercise of its Free Shares Call Options (as converted to euros) divided by 12.8329. On May 9, 2020, the Free Shares Call Option with respect to the second tranche of Subject Free Shares (or 80,000 Subject Free Shares) expired unexercised. On July 3, 2020, the Free Shares Call Option with respect to the third tranche of Subject Free Shares (or 52,700 Subject Free Shares) expired unexercised. /s/ Matthew Colvin, Attorney-in-Fact for Stephane Boissel 2020-07-31