IDEAYA Biosciences, Inc. announced clinical program updates for IDE397, a potential first-in-class Phase 2 MAT2A inhibitor targeting MTAP-deletion solid tumors. The Company is now targeting an IDE397 clinical data update for the IDE397 Phase 2 monotherapy expansion dose in MTAP-deletion bladder and lung cancer in over approximately 15 evaluable patients in the second half of 2024. The clinical data update is anticipated to include a clinical efficacy summary, including a RECIST 1.1 clinical efficacy waterfall, swim-lane plot, and ctDNA molecular response analysis.

In addition, at this update the Company also anticipates providing an adverse event, pharmacokinetics and pharmacodynamics summary at the IDE397 Phase 2 monotherapy expansion dose. Next, the Company is initiating an IDE397 Phase 2 monotherapy expansion in MTAP-deletion bladder cancer, in addition to the earlier reported Phase 2 expansion in MTAP-deletion squamous lung cancer. The Company has activated over 35 clinical trial sites globally in the U.S., Canada, Europe, and Asia Pacific to enable potential rapid enrollment for the IDE397 Phase 2 monotherapy expansion in MTAP-deletion lung and bladder cancer, and for the IDEAYA sponsored clinical combination.

IDE397 is a potential first-in-class potent and selective small molecule inhibitor targeting methionine adenosyltransferase 2 alpha (MAT2A) in patients having solid tumors with methylthioadenosine phosphorylase deletion. There is an ongoing Phase 2 expansion of IDE397 monotherapy in MTAP-deletion solid tumors, and an Amgen-sponsored Phase 1/2 trial of IDE397 and AMG 193 combination in MTAP-Deletion NSCLC for which the companies intend to develop a joint publication strategy in 2024. Next, there is a Phase 1 clinical trial that will evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics and efficacy of IDE397 in combination with Trodelvy.

IDEAYA is also advancing multiple preclinical stage MTAP-deletion programs to enable wholly-owned combinations with IDE397, including a program targeting a Development Candidate nomination in the second half of 2024.