X0206 3 2015-10-07 0 0001501989 CytomX Therapeutics, Inc. CTMX 0001184126 GLUCK FREDERICK W 743 SAN YSIDRO ROAD SANTA BARBARA CA 93108 1 0 0 0 Common Stock 137791 D Common Stock 3200 I By spouse Stock Option (right to buy) 1.1339 2021-03-23 Common Stock 31767 D Stock Option (right to buy) 0.9450 2023-02-25 Common Stock 16612 D Stock Option (right to buy) 1.4489 2024-05-23 Common Stock 27606 D Stock Option (right to buy) 1.5749 2025-02-08 Common Stock 17139 D This option vested 25% on September 22, 2011, and the remaining 75% vested in 36 substantially equal monthly installments thereafter. This option vested in 24 substantially equal monthly installments starting on the last day of February 2013. This option vests in 24 substantially equal monthly installments starting on the last day of April 2014. This option vests in 12 substantially equal monthly installments starting on the last day of January 2015. Exhibit 24.1 - Power of Attorney /s/ Cynthia J. Ladd, attorney-in-fact 2015-10-07