Amgen and Ideaya Biosciences are winding down their cancer combination study, closing off one way the Big Biotech was looking to dial up the efficacy of its PRMT5 inhibitor AMG 193.
The combination study was set in motion by a 2022 deal that positioned the partners to test AMG 193 with Ideaya’s MAT2A inhibitor IDE397. MAT2A inhibition is linked to PRMT5 activity, leading the biotechs to identify the combination as a way to improve outcomes in certain solid tumors. BeiGene bought itself a place in the MAT2A-PRMT5 combination race late last year.
Thursday, Ideaya scratched the combination of IDE397 and AMG 193 off the list of drug cocktails that BeiGene is going up against. The biotech said it and Amgen mutually agreed to wind the current study down and drop plans to start dose expansion.
While Ideaya is letting Amgen go, it is retaining an interest in MAT2A-PRMT5 combinations. Ideaya has a PRMT5 inhibitor, IDE892, that it plans to test with IDE397 in people with MTAP-deletion non-small cell lung cancer in the second half of the year.
The biotech unveiled IDE892 at an R&D event in December. At the event, Ideaya CEO Yujiro Hata hailed the drug candidate as a potential best-in-class PRMT5 inhibitor that was “handpicked to be combined with IDE397.” Yet, while Ideaya trumpeted the merits of its combination, the biotech also professed its ongoing commitment to the Amgen pact.
Back then, Hata said the “partnership with Amgen continues to be a significant priority for us,” adding that the plan at that time was “to push both opportunities forward.” Two months later, Ideaya has decided to focus squarely on pushing its in-house opportunity forward.
The mutually agreed destruction of the collaboration leaves Amgen without a MAT2A inhibitor to pair with AMG 193. The PRMT5 inhibitor has underwhelmed as a monotherapy, racking up an 11% response rate in phase 1/2 data shared last year, but Amgen still moved the candidate into phase 2 late last year. If the trial shows lackluster efficacy, the biotech may still be able to salvage the asset using combinations.
AMG 193 faces competition, though. IDE892 is the latest entrant to a field that includes candidates from AstraZeneca, BeiGene, Bristol Myers Squibb, Servier and Tango Therapeutics. BeiGene and Servier sit alongside Ideaya on the list of companies with inhibitors of PRMT5 and MAT2A.