Fresh Phase 2 data are adding weight to Ideaya Biosciences’ case for a targeted therapy it believes could be a first-in-class treatment option for certain types of urothelial cancer and lung cancer.
In a study with 18 evaluable patients, Ideaya’s drug helped seven of them shrink their tumors — translating to an overall response rate of 39%, including one complete response. Factoring in the 10 patients who achieved stable disease, Ideaya said the disease control rate comes in at 94%.
The data update comes almost two years after GSK passed on an option to license that drug, IDE397, and related compounds. While the Phase 2 study looked at monotherapy, it’s also being tested in combination with drugs from Amgen and Gilead — and the new results offer “important clinical proof-of-concept,” Ideaya CEO Yujiro Hata said in a press release.
Shares of Ideaya $IDYA went up by as much as 20% in premarket trading Monday, rising above $41.
Like other programs in Ideaya’s pipeline, IDE397 was designed on the concept of synthetic lethality, where tumors with certain genetic aberrations become dependent on another cellular pathway — and thus vulnerable to drugs hitting that pathway. Specifically, IDE397 blocks MAT2A to treat patients with MTAP-deletion solid tumors.
Ideaya estimates around 48,000 cases of urothelial cancer and non-small cell lung cancer each year are MTAP-deleted, and there are currently no FDA-approved therapies for this specific group. While it’s prioritizing these two tumor types in initial development, MTAP deletion is also found across a range of other cancers.
IDE397 is the second-most advanced program at Ideaya, after lead asset darovasertib. In a Monday note, Mizuho analysts pegged peak sales at $1.2 billion.
Median duration of response and median progression-free survival have not yet been reached, Ideaya said in its release, but 11 of 18 patients are still on treatment, according to the company.
It reported no drug-related adverse events leading to discontinuations. At the expansion dose — a 30 mg tablet given once a day — only around 5.6% experienced grade 3 or higher drug-related adverse events, a safety profile that Ideaya said bodes well for long-term dosing and combination development.