On August 29, 2025, IDEAYA Biosciences, Inc. (the "Company") entered into a License Agreement (the "Agreement") with Les Laboratoires Servier ("Servier") pursuant to which the Company granted to Servier an exclusive license under certain intellectual property rights controlled by the Company relating to darovasertib to develop and commercialize products in all countries worldwide except for the United States for all diagnostic, prophylactic and therapeutic uses in humans.

Pursuant to the Agreement, Servier has agreed to provide the Company an upfront payment of $210 million. The Company is also eligible to receive development and regulatory milestone payments of up to an aggregate of $100 million, commercial milestone payments of up to an aggregate of $220 million, clinical trial cost sharing and clinical trial cost reimbursement, and royalties on net sales of products outside of the United States ranging from mid-teensto low-twentiespercentages. The upfront payment, plus expected cost savings, are expected to provide the Company with a cash runway extension of at least twelve months. The Company anticipates that its cash, cash equivalents, and marketable securities, together with the upfront payment and expected cost saving from the Agreement will fund planned operations into 2030 based on its current operating plan.

The Agreement will remain in effect on a product-by-product, country-by-countrybasis until expiration of royalty obligations. Either party may terminate for uncured material breach or insolvency of the other. The Company may terminate if (i) Servier ceases development or commercialization in certain countries for a specified period, or (ii) Servier, its affiliates, or its sublicensees challenge licensed patents, subject to certain exceptions. Servier may terminate at will upon specified prior notice. The Agreement contains various representations, warranties, covenants, dispute resolution mechanisms, indemnities and other provisions customary for transactions of this nature.

The foregoing is only a summary description of the terms of the Agreement, does not purport to be complete and is qualified in its entirety by reference to the Agreement, which will be filed in a redacted form as an exhibit to the Company's Quarterly Report on Form 10-Qfor the quarter ending September 30, 2025.