Ris-Rez Cuts Death Risk by 54% in Relapsed SCLC: Full Phase III OS Data from GSK
GSK sits 27% above its 52-week low of $39.29.
Summary
Full Phase III data show Ris-Rez reduced death risk by 54% vs topotecan in relapsed SCLC, with median OS of 18.5 vs 10.3 months — the first OS benefit for a B7-H3 ADC in any tumor type.
Key Events · Product Development and Regulatory · GSK
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54% Reduction in Death Risk
Ris-Rez reduced risk of death by 54% vs topotecan (HR 0.46; 95% CI: 0.35-0.62, p<0.0001) in relapsed SCLC — the first Phase III OS benefit for a B7-H3 ADC in any tumor type.
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Median OS Nearly Doubled
Patients on Ris-Rez lived a median of 18.5 months vs 10.3 months on topotecan, an 8.2-month survival advantage after 12.2 months median follow-up.
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Superior Efficacy Across All Endpoints
Median PFS 7.2 vs 3.0 months (HR 0.33), ORR 58.3% vs 12.6%, and DCR 90.4% vs 60.2% — all favoring Ris-Rez.
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Cleaner Safety Profile
Grade 3+ treatment-related adverse events occurred in 60.9% of Ris-Rez patients vs 78.2% for topotecan, with manageable hematologic toxicities.
Analysis · GSK · Life Sciences
Full overall survival data from the pivotal ARTEMIS-008 trial were presented by Hansoh Pharma, GSK's licensor, at WCLC 2026. Ris-Rez reduced the risk of death by 54% versus topotecan (HR 0.46), with median OS of 18.5 months versus 10.3 months — the first Phase III OS benefit ever demonstrated for a B7-H3 ADC in any tumor type. The magnitude of survival benefit, combined with a cleaner safety profile (60.9% vs 78.2% grade 3+ TRAEs), strengthens the case for Ris-Rez as a potential new standard of care in relapsed SCLC. GSK holds ex-China rights and is running the global EMBOLD program, with pivotal data from the phase III EMBOLD SCLC-301 trial expected next year. This data materially de-risks the global development program and supports GSK's ambition to develop Ris-Rez across more than 40 indications by 2040.
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At the time of this filing, GSK was trading at $49.89 on NYSE in the Life Sciences sector, with a market capitalization of approximately $95.9B. The 52-week trading range was $39.29 to $61.70. This filing was assessed with positive market sentiment and an importance score of 8 out of 10.