IDEAYA Biosciences Inc

Trading Plans

During the three months ended March 31, 2025, no Section 16 officers and directors adopted orterminated contracts, instructions or written plans for the purchase or sale of our securities.

Employment Agreement with Joshua Bleharski, Ph.D.

On February 10, 2025, the Company filed a Current Report on Form 8-K (the “Original Form 8-K”) with the Securities and Exchange Commission announcing the appointment of Joshua Bleharski, Ph.D. as the Company’s Chief Financial Officer. The following description supplements the Original Form 8-K as follows to report the compensation arrangements with Dr. Bleharski pursuant to an employment agreement, effective as of May 1, 2025 (the “Employment Agreement”) by and between the Company and Dr. Bleharski. The Board expects to appoint Dr. Bleharski as the “principal financial officer” of the Company under Section 16(a)-1(f) of the Exchange Act.

The Employment Agreement provides for Dr. Bleharski’s base salary, target cash incentive, benefit plan participation and severance benefits. Pursuant to the Employment Agreement, Dr. Bleharski will receive an annual base salary of $500,000 and a target annual performance bonus amount of 40% of his annual base salary (subject to achievement of certain performance objectives). In the event that Dr. Bleharski’s employment is terminated by the Company without “cause” or he resigns for “good reason” (each, as defined in the Employment Agreement) outside of a Change in Control (as defined in the Employment Agreement), then, subject to timely delivering to us a release of claims, he will be entitled to receive: (i) a lump sum severance payment equal to 75% of his annual base salary; and (ii) payment or reimbursement of continued healthcare coverage for up to 9 months following the date of termination. In the event that Dr. Bleharski’s employment is terminated by the Company without “cause” or he resigns for “good reason” during a period of time that begins three months prior to and ends 12 months following a Change in Control, then, subject to timely delivering to us a release of claims, he will be entitled to receive: (i) a lump sum severance payment equal to his annual base salary and target annual bonus; (ii) payment or reimbursement of continued healthcare coverage for up to 12 months following the date of termination; and (iii) full acceleration of his equity awards.

The foregoing is only a summary description of the terms of the Employment Agreement, does not purpose to be complete and is qualified in its entirety by reference to the Employment Agreement, which will be filed as an exhibit to the Company’s Quarterly Report on Form 10-Q for the fiscal quarter ending June 30, 2025.

Pursuant to the Employment Agreement, the Company expects to grant Dr. Bleharski a stock option to purchase 250,000 shares of the Company’s common stock.

Exhibit Index