X0508 4 2026-02-02 0001501989 CytomX Therapeutics, Inc. CTMX 0001970752 BELVIN MARCIA C/O CYTOMX THERAPEUTICS, INC. 151 OYSTER POINT BLVD., STE. 400 SOUTH SAN FRANCISCO CA 94080 true SVP, Chief Scientific Officer false Common Stock 2026-02-02 4 A 0 60000 0 A 332252 D Stock Option (Right to Buy) 6.09 2026-02-02 4 A 0 250000 0 A 2036-02-01 Common Stock 250000 250000 D Constitute restricted stock units ("RSUs") for which the Reporting Person is entitled to receive one (1) share of Common Stock for each RSU upon vesting. 1/3rd of the RSUs vest annually on March 15 of each year, with the first 1/3rd vesting on March 15, 2027, subject to the Reporting Person continuing as a service provider through each such date. Includes 218,958 RSUs. 1/48th of the shares subject to the option vest on each monthly anniversary measured from February 2, 2026 (the "Vesting Commencement Date"), such that 100% of the shares subject to the option will be fully vested and exercisable on the fourth anniversary of the Vesting Commencement Date, subject to the Reporting Person's continued service to the Issuer through each such date. /s/ Christopher Ogden, as Attorney-in-Fact for Marcia Belvin 2026-02-04