144P - First-line cemiplimab monotherapy for advanced non-small cell lung cancer (NSCLC) of squamous histology: Subgroup analysis with 5-year results from EMPOWER-Lung 1

Background

Patients with squamous NSCLC have a poorer prognosis than those with non-squamous histology and fewer treatment options. The phase 3 EMPOWER-Lung 1 study (NCT03088540) has demonstrated significant survival benefits of first-line (1L) cemiplimab monotherapy vs chemotherapy and an acceptable safety profile in patients with treatment-naïve squamous or non-squamous NSCLC with PD-L1 expression ≥50% and no EGFR, ALK or ROS1 aberrations. Here, we report 5-year results of patients with squamous NSCLC from this study.

Methods

In EMPOWER-Lung 1, patients were randomized to cemiplimab 350 mg IV every 3 weeks for 2 years or to investigator’s choice of chemotherapy. Primary endpoints were overall survival (OS) and progression-free survival (PFS) per Blinded Independent Review Committee. In this exploratory subgroup analysis, efficacy and safety were assessed for the subgroup of patients with squamous NSCLC. The data cutoff date was 16 January 2024 (median follow-up of 59.6 months for the overall study population).

Results

Of 565 patients with verified PD-L1 ≥50%, 245 (43%) had squamous NSCLC (cemiplimab: n = 123; chemotherapy: n = 122). Baseline characteristics were similar between treatment groups. At 5-year follow-up, cemiplimab resulted in longer OS (median 22.7 mo vs 13.5 mo; HR=0.51) and PFS (median 8.3 mo vs 5.9 mo; HR=0.44) vs chemotherapy (Table). Estimated 5-year survival probability was 25.5% for cemiplimab vs 6.9% for chemotherapy. Objective response rate (ORR) was significantly improved with cemiplimab (43.9% vs 22.1%). Approximately 42% of patients in both treatment groups had treatment-emergent adverse events (TEAEs) ≥ grade 3 (Table). Table: 144P

^†Subgroup from the PD-L1 ≥50% population. ^‡Safety analysis set for the subgroup: cemiplimab (n=122), chemotherapy (n=118). ^∗P<0.0001

Conclusions

At 5-year follow-up, 1L cemiplimab monotherapy continued to show durable clinical benefits vs chemotherapy in patients with squamous NSCLC.

Clinical trial identification

NCT03088540.

Editorial acknowledgement

Editorial support was provided by Fiona Woodward, of Alpha (a division 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.

Funding

Regeneron Pharmaceuticals, Inc.

Disclosure

A. Baramidze: Financial Interests, Personal, Other, Travel support: Regeneron Pharmaceuticals, Inc. A. Sezer: Financial Interests, Institutional, Research Funding: Roche, Merck Sharp & Dohme, Merck Serono, AstraZeneca, Lilly, Novartis, Johnson & Johnson, Regeneron Pharmaceuticals, Inc., Sanofi. M. Gumus: Financial Interests, Personal, Other, Honoraria: Roche, Merck Sharp & Dohme, Gen İlaç, Novartis. K.D. Penkov: Financial Interests, Personal, Other, Honoraria: AstraZeneca, BeiGene, GSK, H3 Biomedicine, Janssen, Nektar, Novartis, Pfizer, Regeneron Pharmaceuticals, Inc., Sanofi. M. Ozguroglu: Financial Interests, Personal, Other, Honoraria: Novartis, Roche, Janssen, Sanofi, Astellas; Financial Interests, Personal, Advisory Board: Janssen, Sanofi, Astellas; Financial Interests, Personal, Other, Travel support: Bristol Myers Squibb, Janssen, AstraZeneca; Financial Interests, Personal, Speaker, Consultant, Advisor: AstraZeneca. E. Kalinka: Financial Interests, Personal, Other, Travel and accommodation support: Regeneron Pharmaceuticals, Inc. C. Zhu, F. Seebach, E. Kim, H. Magnan, J. Pouliot: 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.