SOUTH SAN FRANCISCO, Calif. -- September 01, 2026 -- IDEAYA Biosciences said its FDA Type C meeting on IDE849, a DLL3-targeting antibody drug conjugate, produced agreement on a Phase 3 registrational trial design for extensive stage small cell lung cancer (ES-SCLC). The Nasdaq-listed company (IDYA) plans to enroll roughly 400 patients who have already received tarlatamab, randomizing them 1:1 between IDE849 monotherapy and an investigator's choice control arm of topotecan and amrubicin. IDEAYA is targeting trial initiation by year-end 2026.