Ideaya Biosciences received FDA alignment on a Phase 3 study for IDE-849, a DLL3-targeted antibody-drug conjugate in extensive-stage small-cell lung cancer (ES-SCLC). The U.S. FDA type C meeting supported launching a randomized Phase 3 trial for IDE-849 monotherapy in patients previously treated with tarlatamab, positioning the asset in a late-stage competitive ADC sequence. IDE-849 enters the DLL3 ADC “horse race” ahead of Zai Lab’s zocilurtatug pelitecan (zoci; ZL-1310; YL-212). Ideaya had previously reported positive Phase 1 data in small-cell lung cancer about a year before the FDA alignment. With the Phase 3 path now cleared, IDE-849 becomes one of the key next readouts for DLL3-driven therapeutic strategies in post-tarlatamab ES-SCLC.