Serplulimab Plus Chemotherapy Shows Sustained Survival Benefit in Extensive-Stage Small Cell Lung Cancer
Results from the Phase 3 ASTRUM-005 Trial
Results from the Phase 3 ASTRUM-005 Trial
Clinical Summary:
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Design/Population: The phase 3 ASTRUM-005 trial evaluated serplulimab plus carboplatin and etoposide versus placebo plus chemotherapy in patients with previously untreated extensive-stage small cell lung cancer (ES-SCLC).
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Key Outcomes: Extended follow-up demonstrated sustained overall survival benefit with serplulimab plus chemotherapy, reducing the risk of death by 40% and improving 4-year overall survival rates. No new safety signals were identified, and patient-reported outcomes remained favorable.
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Clinical Relevance: These findings reinforce serplulimab plus platinum-etoposide chemotherapy as a first-line treatment option for ES-SCLC and support its long-term clinical benefit.
Updated results from the phase 3 ASTRUM-005 trial demonstrated that serplulimab plus carboplatin and etoposide continued to improve long-term overall survival (OS) compared with chemotherapy alone in patients with previously untreated extensive-stage small cell lung cancer (ES-SCLC), reinforcing the regimen as a first-line treatment option.
Prior results demonstrated “substantial survival benefit from adding serplulimab to chemotherapy for previously untreated ES-SCLC… However, the long-term outcomes are unclear,” stated Jingjing Liu, MD, Jilin Cancer Hospital, Jilin, China, and coauthors.
In this double-blind trial, 585 patients with previously untreated ES-SCLC were randomized 2:1 to receive either 4.5 mg/kg of intravenous serplulimab (n = 389) or placebo (n = 196) in combination with carboplatin and etoposide every 3 weeks for up to 4 cycles. The primary end point was OS. Secondary end points included safety and patient-reported outcomes.
After a median follow-up of 42.4 months, median OS was 15.8 months in the serplulimab arm compared with 11.1 months in the placebo arm (hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.49 to 0.73; P < .001), representing a 40% reduction in the risk of death. The corresponding 4-year OS rates were 21.9% and 7.2%, respectively.
No new safety signals were identified with extended follow-up. Grade ≥3 serplulimab- or placebo-related treatment-emergent adverse events were reported in 136 patients receiving serplulimab and 57 patients receiving placebo. Patient-reported outcomes demonstrated favorable trends with serplulimab, including improvements in overall health, dyspnea, and pain, as well as faster recovery from alopecia.
“This secondary analysis of a randomized clinical trial demonstrated long-term benefit from adding serplulimab to chemotherapy for previously untreated patients with ES-SCLC, supporting this therapy as a first-line standard of care for this patient population,” concluded Dr Liu and coauthors.
Source:
Liu J, Han L, Wu L, et al. First-line serplulimab in extensive-stage small cell lung cancer. JAMA Oncol. Published online: June 4, 2026. doi: 10.1001/jamaoncol.2026.1645
