31 August 2026: IDEAYA Biosciences’ IDE849 advances to a phase 3 registrational trial following a successful FDA type C meeting for ES-SCLC
IDEAYA Biosciences announced a successful FDA Type C meeting supporting the phase 3 registrational trial design for IDE849, a potential DLL3-targeting Topo-I ADC that has progressed from phase 2 to phase 3 in extensive-stage small cell lung cancer, with trial initiation targeted by year-end
Based on FDA feedback, the planned phase 3 study will enroll approximately 400 ES-SCLC patients previously treated with tarlatamab and randomize them 1:1 to IDE849 or investigator’s choice therapy, with ORR by BICR serving as the primary endpoint for potential accelerated approval and median OS as the primary endpoint for potential full approval
The planned development addresses a major unmet need in ES-SCLC, where patients who progress after established therapies such as tarlatamab have limited treatment options, underscoring the need for new therapies capable of delivering durable responses
IDE849 is a DLL3-directed ADC carrying a topoisomerase I inhibitor payload, designed to selectively target DLL3-expressing tumor cells and deliver the cytotoxic payload to the tumor
Strategically, the FDA-aligned phase 3 design positions IDE849 for a potential seamless path toward accelerated and full approval in post-tarlatamab ES-SCLC, while ongoing combination studies with PD-L1 inhibition and IDEAYA’s PARG inhibitor IDE161 are exploring its potential expansion into first-line SCLC