China-based Phase 3 trials reported overall survival wins for B7-H3 antibody-drug conjugates in relapsed small-cell lung cancer. MediLink’s tambotatug pelitecan (tam-peli; YL-201) and risvutatug rezetecan (ris-rez) each hit the OS primary endpoint in their respective studies, according to results discussed in conjunction with the IASLC 2026 World Conference on Lung Cancer. Both programs reported an OS hazard ratio of 0.46 versus topotecan, corresponding to a 54% reduction in the risk of death. The readouts reinforce B7-H3 ADCs as a developing competitive class in relapsed SCLC, where options after first-line immunotherapy and platinum chemotherapy remain limited. For sponsors planning subsequent global studies, the trials also raise the stakes around generalizability given long-standing cross-region differences in patient characteristics and treatment practices.