• Based on early safety and efficacy results, a Phase 1/2 study is expanding to assess IDE397, IDEAYA’s MAT2A inhibitor, combined with Gilead’s Trop-2 directed ADC, Trodelvy^®, for urothelial cancer with MTAP-deletion.
• Approximately 26% of urothelial cancers are estimated to have MTAP-deletion.

SOUTH SAN FRANCISCO, Calif., April 10, 2025 — IDEAYA Biosciences, Inc. (Nasdaq:IDYA), a company focused on precision medicine oncology for discovering and creating targeted therapies, has begun a Phase 1/2 expansion in its clinical trial. The trial is testing IDE397, a potential first-in-class, small molecule methionine adenosyltransferase 2a (MAT2A) inhibitor, along with Gilead’s Trodelvy® (sacituzumab govitecan-hziy), a Trop-2 directed antibody-drug conjugate (ADC). This combination is being evaluated in urothelial cancer (UC) patients with methylthioadenosine phosphorylase (MTAP)-deletion, informed by initial safety and efficacy findings.

IDE397 is a selective and potent small molecule inhibitor that targets MAT2A in patients who have solid tumors and MTAP-deletion. It is estimated that about 26% of UC cases have MTAP-deletion.

“We are excited to advance the possible first-in-class combination of IDE397 and Trodelvy into an early Phase 1/2 expansion for UC with MTAP-deletion due to the encouraging preliminary safety and efficacy data. There’s a significant unmet medical need, as there are currently no approved treatments specifically for UC with MTAP-deletion, and we look forward to further exploring this innovative combination,” stated Darrin Beaupre, M.D., Ph.D., Chief Medical Officer, IDEAYA Biosciences.

Trodelvy is approved in over 50 countries for second-line or later metastatic triple-negative breast cancer (TNBC) and in over 40 countries for select pre-treated HR+/HER2- metastatic breast cancer patients. The use of Trodelvy for MTAP-deletion UC is experimental, and its safety and efficacy have not been confirmed for this use.

An update on the clinical program for the IDE397 and Trodelvy combination is expected in 2025. In addition to the trial assessing IDE397 with Trodelvy, IDEAYA has a monotherapy expansion study underway in MTAP-deletion NSCLC and UC. They also plan to begin a wholly-owned clinical combination trial in the latter half of 2025, combining IDE397 with IDE892, their potential best-in-class, MTA-cooperative PRMT5 inhibitor.

According to the clinical study collaboration and supply agreement, IDEAYA and Gilead will retain commercial rights to their respective compounds, both as single therapies and in combinations. IDEAYA is sponsoring the study, and Gilead will supply Trodelvy to IDEAYA.

No regulatory agency has approved IDE397, either alone or with Trodelvy, and its efficacy and safety have not been proven.

Trodelvy and Gilead are trademarks belonging to Gilead Sciences, Inc., or its affiliates.

About IDEAYA Biosciences
IDEAYA is an oncology company focused on precision medicine that is dedicated to discovering and developing targeted treatments for patient groups selected using molecular diagnostics. IDEAYA uses its capabilities in identifying and validating translational biomarkers along with drug discovery to select patient populations most likely to respond positively to its targeted treatments. IDEAYA is using its research and drug discovery capabilities for synthetic lethality, an emerging class of precision medicine targets.  

Forward-Looking Statements
This press release contains forward-looking statements regarding (i) the prevalence of MTAP-deletion and (ii) the potential therapeutic advantages of combining IDE397 and Trodelvy, among other things. These forward-looking statements are subject to significant risks and uncertainties, which could cause IDEAYA’s preclinical and clinical development programs, future performance, results, or achievements to be materially different from those expressed or implied. These risks and uncertainties include, among other things, the inherent uncertainties of drug development, including the early stage of IDEAYA’s programs, the design and execution of preclinical and clinical trials, regulatory approval processes, the timing of regulatory filings, the challenges of drug product manufacturing, IDEAYA’s ability to successfully establish, protect, and defend its intellectual property, and other issues that may affect the sufficiency of existing cash to fund operations. IDEAYA is not obligated to update or revise any forward-looking statements. More information about the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks related to IDEAYA’s business in general, can be found in IDEAYA’s Annual Report on Form 10-K dated February 18, 2025, and any current and periodic reports filed with the U.S. Securities and Exchange Commission.

Investor and Media Contact
IDEAYA Biosciences
Andres Ruiz Briseno
Chief Accounting Officer
 

SOURCE IDEAYA Biosciences, Inc.

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