GSK’s Ris-Rez cuts death risk by 54% in relapsed small-cell lung cancer trial

At WCLC 2026, GSK and partner Hansoh Pharma reported positive interim Phase III results from ARTEMIS-008 in China.

Risvutatug rezetecan (Ris-Rez), a B7-H3-targeted antibody-drug conjugate, reduced the risk of death by 54% versus topotecan in patients with relapsed small-cell lung cancer after platinum-based therapy. The hazard ratio was 0.46 (95% CI 0.35–0.62; p<0.0001).

Median overall survival was 18.5 months with Ris-Rez versus 10.3 months with topotecan—an 8.2-month difference.

Progression-free survival was also improved:
7.2 versus 3.0 months. Response rates were 58.3% versus 12.6%.

The 461-patient China study met its primary overall-survival endpoint. The findings are described as the first positive Phase III overall-survival result for a B7-H3 ADC in any cancer type.

GSK said the safety profile was consistent with earlier data, with no new safety signals reported. Hansoh plans to use the results for a regulatory submission in China.

The result is important but geographically limited:
it was conducted in China, and regulatory approval and confirmation in broader populations remain pending.