GSK said its China Phase 3 readout for the B7-H3 antibody-drug conjugate risvutatug rezetecan (ris-rez), partnered with Hansoh Pharma, met its primary endpoint of overall survival in advanced or relapsed small cell lung cancer. The company described the result as the first positive Phase 3 overall survival data reported for a B7-H3-targeted ADC in any tumor type. The trial outcome is positioned to support an approval filing in China, while GSK has also continued global development plans for both ris-rez and a related B7-H4 ADC outside Greater China. The company said secondary endpoints showed consistent benefits, including delayed tumor progression and a manageable safety profile. Analysts and investors are likely to focus on the magnitude of benefit once full data are disclosed, but the primary endpoint success is immediately meaningful for the asset’s regulatory trajectory.