IDEAYA Clears Path for Phase 3 Trial of DLL3-Targeting ADC IDE849

The proposed study will enroll approximately 400 patients previously treated with tarlatamab, utilizing a 1:1 randomization against investigator-choice therapies, such as topotecan and amrubicin. IDEAYA has structured the trial to pursue accelerated approval based on overall response rate, while targeting median overall survival as the primary endpoint for full regulatory clearance.

Currently, the company is refining the dosing regimen for IDE849, testing 2.4 mg/kg and 3.5 mg/kg levels to establish the recommended Phase 3 dose. Beyond monotherapy, IDEAYA is exploring combination strategies with AstraZeneca’s PDL1 inhibitor Imfinzi and its own PARG inhibitor, IDE161. Data updates from ongoing trials are expected at the ESMO 2026 conference and in the fourth quarter of the same year, which the company expects will solidify the drug's standing as a best-in-class candidate in the DLL3-targeting landscape.