Cemiplimab (PD-1) monotherapy doubles OS vs chemo in PD-L1≥50% 1L NSCLC at 5 years

Cemiplimab is an anti–PD-1 checkpoint inhibitor given as monotherapy for up to 2 years; EMPOWER-Lung 1 was a randomized Phase 3 trial comparing cemiplimab 350mg IV Q3W vs investigator’s-choice platinum-doublet chemotherapy in previously untreated advanced NSCLC with no EGFR/ALK/ROS1 alterations. At a January 16, 2024 cutoff with median follow-up 59.6 months, the PD-L1≥50% “verified” population (n=565) showed mOS 26.1 vs 13.3 months (HR 0.59, 95%CI 0.48–0.72), mPFS 8.1 vs 5.3 months (HR 0.50, 95%CI 0.41–0.61), ORR 46.5% vs 20.6%, and 5-year OS 29.0% vs 15.0%; grade ≥3 TRAEs were 18.3% vs 39.9%. Clinically, efficacy and durability look broadly in-family with other 1L PD-(L)1 monotherapy benchmarks in PD-L1≥50% disease (e.g., pembrolizumab in KEYNOTE-024 reported ~26-month mOS and ~32% 5-year OS), while the safety profile appears meaningfully lighter than chemotherapy and consistent with PD-1-class expectations.