IDEAYA and Amgen Achieve First-Patient-In for Clinical Evaluation of IDE397 (MAT2A) and AMG 193 (PRMT5(MTA)) Combination in MTAP(-/-) Tumors

-­ First patient dosed with combination of IDE397, the IDEAYA MAT2A inhibitor, and AMG 193, the Amgen MTA-cooperative PRMT5 inhibitor, in Amgen-sponsored Phase 1/2 clinical trial

­- Global clinical trial will evaluate IDE397 and AMG 193 combination as potential first-in-class synthetic lethality combination in MTAP-deletion patients with planned expansion in NSCLC

­- Earlier reported unconfirmed partial response for IDE397 monotherapy has confirmed with -47% tumor shrinkage by RECIST 1.1 in a high-priority MTAP-deletion solid tumor type

SOUTH SAN FRANCISCO, Calif., Aug. 2, 2023 /PRNewswire/ -- IDEAYA Biosciences, Inc. (Nasdaq:IDYA), a precision medicine oncology company committed to the discovery and development of targeted therapeutics, announced achievement of First-Patient-In for the Amgen-sponsored Phase 1/2 clinical trial evaluating the combination of IDE397, the IDEAYA investigational MAT2A inhibitor, and AMG 193, the Amgen investigational MTA-cooperative PRMT5 inhibitor, in patients having tumors with MTAP deletion, with an expansion focus in NSCLC.

"We are excited to pursue this potential first-in-class synthetic lethality combination therapy targeting mechanistically complementary nodes of the MTAP methylation pathway – MAT2A and PRMT5. The clinical strategy is supported by preliminary signals of monotherapy activity and by compelling preclinical efficacy, tolerability and selectivity for the combination," said Dr. Darrin M. Beaupre, M.D., Ph.D., Chief Medical Officer, IDEAYA Biosciences.

IDE397 is IDEAYA's potent and selective small molecule inhibitor targeting methionine adenosyltransferase 2a (MAT2A). IDEAYA observed clinical efficacy for IDE397 as monotherapy in multiple MTAP-deletion high-priority tumor types based on its experience across several patients in early dose expansion, including an earlier-reported unconfirmed partial response which has confirmed by RECIST 1.1 (~47% tumor reduction). 

AMG 193 is the Amgen investigational methylthioadenosine- (MTA-) cooperative protein arginine methyltransferase 5 (PRMT5) inhibitor. 

IDEAYA and Amgen are collaborating to clinically evaluate the IDE397 and AMG 193 combination in patients having tumors with MTAP deletion in an Amgen-sponsored clinical trial pursuant to a Clinical Trial Collaboration and Supply Agreement, or CTCSA. The global Phase 1/2 clinical trial will evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics and efficacy of IDE397 in combination with AMG 193, with an initial expansion focus in NSCLC patients with MTAP-deletion. 

Pursuant to the mutually non-exclusive CTCSA, Amgen is the sponsor of the IDE397 and AMG 193 combination clinical trial and each of IDEAYA and Amgen will supply their respective compounds, IDE397 and AMG 193. Each party will pay fifty percent (50%) of the external third-party costs for conducting the clinical trial and be wholly responsible for their respective own internal costs and expenses in support of the clinical trial. The companies will jointly own clinical data and all intellectual property, if any, relating to the combined use of IDE397 and AMG 193 from the clinical trial. Each party retains commercial rights to its respective compounds, including with respect to use as a monotherapy or combination agent. The companies have formed a joint oversight committee responsible for coordinating all regulatory and other activities in support of the clinical trial. 

About IDEAYA Biosciences

IDEAYA is a precision medicine oncology company committed to the discovery and development of targeted therapeutics for patient populations selected using molecular diagnostics. IDEAYA's approach integrates capabilities in identifying and validating translational biomarkers with drug discovery to select patient populations most likely to benefit from its targeted therapies. IDEAYA is applying its early research and drug discovery capabilities to precision medicine targets, including synthetic lethality – which represents an emerging class of precision medicine targets. 

Forward-Looking Statements

This press release contains forward-looking statements, including, but not limited to, statements related to potential first-in-class nature of the combination therapy. IDEAYA undertakes no obligation to update or revise any forward-looking statements. For a further description of the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks relating to the business of IDEAYA in general, see IDEAYA's Quarterly Report on Form 10-Q filed on May 9, 2023 and any current and periodic reports filed with the U.S. Securities and Exchange Commission.

Investor and Media Contact
IDEAYA Biosciences
Paul A. Stone
Chief Financial Officer
investor@ideayabio.com

SOURCE IDEAYA Biosciences, Inc.