Multicenter phase 3 trial of first-line serplulimab in extensive-stage small cell lung cancer: long-term outcomes from ASTRUM-005

The phase 3 ASTRUM-005 trial in China and five countries in Eastern Europe showed substantial survival benefit from adding serplulimab to chemotherapy for previously untreated extensive-stage small cell lung cancer (ES-SCLC). Results from the trial after median follow-up of 42.4 months (additional 22.6 months follow-up since the latest analysis) have now been published. Patients were randomized 2:1 to receive intravenous serplulimab (n=389) or placebo (n=196) combined with up to 4 cycles of carboplatin and etoposide every 3 weeks. Primary endpoint was overall survival (OS). At data cutoff, 280 OS events (72.0%) in the serplulimab group versus 166 (84.7%) in the placebo group had occurred, with a median OS of 15.8 months versus 11.1 months (HR 0.60; p<0.001) and 4-year OS rates of 21.9% versus 7.2%. Grade 3 or higher treatment-emergent adverse events occurred in 35.0% of patients in the serplulimab group and 29.1% of patients in the placebo group. Patient-reported outcomes analysis revealed consistent trends of improved overall health, dyspnea, and pain in both groups and faster recovery from alopecia in the serplulimab group. The authors conclude that adding serplulimab to chemotherapy resulted in long-term benefit among previously untreated ES-SCLC patients.