Senti Biosciences, Inc.

(a) Termination of Amended and Restated ChEF Purchase Agreement

On March 17, 2025, Chardan acknowledged and accepted our written notice to terminate the A&R Purchase Agreement, waived its right to prior written notice and mutually agreed to terminate the A&R Purchase Agreement, effective immediately.

(b) Director and Executive Officer Trading Arrangements

During the year ended December 31, 2025, none of our directors or officers adopted, modified orterminated any contract, instruction or written plan for the purchase or sale of our securities intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act or any “non-Rule 10b5-1 trading arrangement” (as defined in Item 408(c) of Regulation S-K).

On May 6, 2025, Kanya Rajangam, our President and Chief Medical Officer, adopted a Rule 10b5-1 trading plan for the sale of our common stock that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act (the “Rajangam Trading Plan”). The Rajangam Trading Plan provides for potential sales beginning on August 5, 2025 of up to an aggregate of 12,628 shares to be sold pursuant to limit orders. The Rajangam Trading Plan will expire upon the date all sales contemplated by the Rajangam Trading Plan have been executed.