NEW YORK – Ideaya Biosciences said on Monday it will begin a Phase I study of its MAT2A inhibitor, IDE397, in solid cancers with MTAP gene deletions after its investigational new drug application was accepted by the US Food and Drug Administration.
IDE397 is the lead candidate in Ideaya's synthetic lethality program. The San Francisco-based firm will begin enrolling patients in the Phase I trial in the first quarter of 2021 and will evaluate IDE397 as a monotherapy. In the study, patients' tumors will be molecularly tested using next-generation sequencing panels, and their MTAP protein levels will be confirmed through an immunohistochemistry assay the company developed in collaboration with Roche subsidiary Ventana.
Ideaya presented updated preclinical data on IDE397 at the JP Morgan Healthcare Conference last month, showing that in more than 50 percent of patient-derived xenograft models the drug led to 75 percent or greater tumor regression. Preclinical studies also suggested IDE397 had advantages over other MAT2A inhibitors, including greater solubility and none of the liver effects of Agios' AG-270.
MTAP gene deletions occur in about 15 percent of all solid tumors. The company is seeking to develop the drug in combination with GlaxoSmithKline's PRMT inhibitor GSK3368715, among other drugs.
GSK and Ideaya began a collaboration last year to co-develop synthetic lethality drugs. GSK paid $100 million in cash and bought $20 million of Ideaya common stock upfront for the option to license its synthetic lethality candidates, including IDE397.