GSK/Hansoh: Ris‑Rez halves death risk vs topotecan in relapsed SCLC in China

Primary outcome

Ris‑Rez (risvutatug rezetecan) reduced the risk of death by 54% versus topotecan (HR 0.46; 95% CI: 0.35–0.62; p<0.0001) after a median follow‑up of 12.2 months. Median overall survival was 18.5 months (n=230) with Ris‑Rez versus 10.3 months (n=231). These are the first Phase III data to demonstrate an overall survival benefit for a B7‑H3‑targeted ADC in any tumour type; results were presented at the 2026 World Conference on Lung Cancer in Seoul.

Secondary endpoints

Key secondary endpoints showed consistent benefits: IRC‑assessed median progression‑free survival was 7.2 months for Ris‑Rez versus 3.0 months for topotecan (HR 0.33; 95% CI: 0.25–0.42). IRC‑assessed objective response rate was 58.3% versus 12.6%, and disease control rate was 90.4% versus 60.2% for Ris‑Rez and topotecan, respectively.

Safety

Grade 3 or higher treatment‑related adverse events occurred in 60.9% of patients receiving Ris‑Rez versus 78.2% with topotecan. The most common grade ≥3 TRAEs with Ris‑Rez were decreased neutrophils, decreased white blood cells, anaemia, decreased lymphocytes and decreased platelets; these haematologic events were reported as manageable and consistent with the class profile.

Trial design and development plans

ARTEMIS‑008 is a multicentre, randomised, open‑label phase III trial in China comparing Ris‑Rez 8.0 mg/kg every three weeks to topotecan 1.2 mg/m² on days 1–5 every 21 days in patients with limited‑ or extensive‑stage SCLC progressing after platinum‑based first‑line therapy. GSK holds exclusive rights to develop and commercialise Ris‑Rez outside mainland China, Hong Kong, Macau and Taiwan and is advancing a global programme, including the phase III EMBOLD SCLC‑301 trial with pivotal data expected next year.