Stock Option Grant to Chief Business Officer of CytomX Therapeutics, Inc.

On October 20, 2025, Rachael Lester, the Chief Business Officer of CytomX Therapeutics, Inc., was granted 650,000 stock options with the right to buy common stock at a price of $3.74 per share. The options vest over four years, with 25% vesting on the first anniversary of the grant date and the remaining shares vesting monthly thereafter. The options expire on October 19, 2035. This transaction was reported in a Form 4 filing with the SEC. The grant is subject to Lester's continued service with the company through each vesting date.