GSK reported that its B7-H3 antibody-drug conjugate risvutatug rezetecan (ris-rez) met a primary endpoint in a Phase 3 trial in advanced or relapsed small cell lung cancer in China. The study compared ris-rez against standard-of-care topotecan and showed statistically significant, clinically meaningful survival improvements, with benefits also reflected across secondary measures. GSK said the results represent the first clear Phase 3 survival extension attributed to an ADC in any tumor type, and that the data will support a regulatory filing in China through partner Hansoh, which holds commercial rights in the region. GSK also noted that a global study in extensive-stage small cell lung cancer is ongoing with results expected next year. The update matters for oncology pipeline prioritization, particularly as ADC competition increases and B7-H3 expands beyond earlier-generation signals.