318P - EMPOWER-Lung 3: Cemiplimab in combination with platinum doublet chemotherapy for first-line (1L) treatment of advanced non-small cell lung cancer (NSCLC)

Background

EMPOWER-Lung 3 is a randomised, 2-part, Phase 3 study of 1L treatment of patients (pts) with advanced (Stage III/IV) squamous (SQ) or non-squamous (NSQ) NSCLC without actionable mutations (NCT03409614). The double-blind Part 2 of the study enrolled pts irrespective of PD-L1 levels and compared clinical activity and safety of cemiplimab, an anti-PD-1, plus (+) platinum-based chemo, versus (vs) placebo (PBO)+chemo.

Methods

Pts were randomised (2:1; stratified by histology and PD-L1 expression) to receive cemiplimab 350 mg once every 3 weeks (Q3W) or PBO Q3W for 108 weeks (or until progression), plus up to 4 cycles of chemo (followed by mandatory pemetrexed maintenance for NSQ pts assigned to a pemetrexed-containing regimen). Primary endpoint was overall survival (OS). Key secondary endpoints include progression-free survival (PFS) and objective response rate (ORR) per blinded independent central review. Here we report Part 2 results from the prespecified 2 interim analysis. Data cut-off was 14 June 2021.

Results

Overall, 466 pts were eligible and randomised to cemiplimab+chemo (n=312) or PBO+chemo (n=154). Median (range) age was 63.0 (25-84) years; 57.1% had NSQ NSCLC; and 85.2% had Stage IV disease. Median OS was 21.9 months with cemiplimab+chemo vs 13.0 months with PBO+chemo (HR, 0.71; P=0.014). Cemiplimab+chemo was associated with superior median PFS (8.2 vs 5.0 months; HR, 0.56), higher ORR (43.3% vs 22.7%), and longer median duration of response (DOR) (15.6 months vs 7.3 months) vs PBO+chemo (Table). Incidence of Grade ≥3 adverse events was 43.6% in cemiplimab+chemo arm and 31.4% in PBO+chemo arm. Table: 318P

Conclusions

In pts with advanced NSCLC, 1L cemiplimab+chemo demonstrated clinically meaningful and statistically significant improvement in OS, PFS, ORR and DOR vs chemo alone, with a safety profile consistent with cemiplimab monotherapy and platinum-based chemo.

Clinical trial identification

NCT03409614.

Editorial acknowledgement

Medical writing support was provided by Jenna Lee, MS of Prime, Knutsford, UK, funded by Regeneron Pharmaceuticals, Inc., and Sanofi. Responsibility for all opinions, conclusions, and data interpretation lies with the authors.

Legal entity responsible for the study

Regeneron Pharmaceuticals, Inc., and Sanofi.

Funding

Regeneron Pharmaceuticals, Inc., and Sanofi.

Disclosure

K.D. Penkov: Financial Interests, Personal, Advisory Role: AstraZeneca, Merck Sharp & Dohme, Nektar, Pfizer, Regeneron Pharmaceuticals, Inc., and Roche. E. Kalinka: Financial Interests, Personal, Advisory Role: Amgen, AstraZeneca, Bristol Myers Squibb, Merck Sharp & Dohme, Nektar, Pfizer, Roche, and Regeneron Pharmaceuticals, Inc. C. Gessner: Financial Interests, Personal, Advisory Board: AstraZeneca, Berlin-Chemie, Boehringer Ingelheim, Bristol Myers Squibb, Chiesi, GlaxoSmithKline, Merck Sharp & Dohme, Novartis, Pfizer, Roche, Sanofi. R. Passalacqua: Financial Interests, Personal, Advisory Board: Astellas, Bristol Myers Squibb, Ipsen, Janssen, Merck Sharp & Dohme, Roche, and Sanofi-Aventis; Financial Interests, Institutional, Research Grant: Amgen, AstraZeneca, Novartis, and Pierre-Fabre. S. Li, K. McGuire, R.G. Quek, G. Gullo, P. Rietschel: Financial Interests, Personal, Full or part-time Employment: Regeneron Pharmaceuticals, Inc.; Financial Interests, Personal, Stocks/Shares: Regeneron Pharmaceuticals, Inc. All other authors have declared no conflicts of interest.