Among patients with advanced non-small cell lung cancer (NSCLC) with programmed cell death-ligand 1 (PD-L1) expression of at least 50%, cemiplimab monotherapy improved overall survival (OS) and progression-free survival (PFS) compared with chemotherapy, according to the phase 3 data from the global EMPOWER-Lung 1 study published in The Lancet.

Although immune checkpoint inhibitors have revolutionized the treatment landscape for advanced NSCLC, there is still an unmet need for new treatment options that improve survival, particularly among patients with high PD-L1 expression who could avoid chemotherapy-associated toxicities, the study authors stated.

In the open-label, randomized trial ( Identifier: NCT03088540), researchers compared the survival benefits of single-agent cemiplimab (a PD-L1 inhibitor) with investigator’s choice of platinum-doublet chemotherapy in the first-line setting for patients with advanced NSCLC whose tumors expressed at least 50% PD-L1. The intention-to-treat population included 710 patients who were enrolled in 138 clinics from 24 countries. Of these, 563 patients had PD-L1 expression of at least 50% or more.

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The participants were randomly assigned to receive either cemiplimab (356 patients) or investigator’s choice of chemotherapy (354 patients). Patients in the chemotherapy arm were allowed to cross over to the cemiplimab arm following disease progression.

Among the 563 patients with PD-L1 expression of at least 50%, the median OS was not reached (95% CI, 17.9-not evaluable) in the cemiplimab arm (283 patients) compared with 14.2 months (95% CI, 11.2-17.5) in the chemotherapy arm (280 patients; hazard ratio [HR], 0.57; 95% CI, 0.42-0.77; P =.0002).

The median PFS for the cemiplimab arm and the chemotherapy arm was 8.2 months (95% CI, 6.1-8.8) and 5.7 months (95% CI, 4.5-6.2), respectively (HR, 0.54; 95% CI, 0.43-0.68; P <.0001). Even though a large proportion of patients (74%) had crossed over to the cemiplimab arm, significant improvements were observed in both OS and PFS with cemiplimab in the intention-to-treat population.  

Grade 3 to 4 treatment-emergent adverse events (TEAEs) were reported in 28% of the patients in the cemiplimab arm. The most commonly occurring TEAEs in the cemiplimab arm were pneumonia (5%), anemia (3%), and hyponatremia (3%). Grade 3 to 4 TEAEs were reported among 39% of the patients in the chemotherapy arm, with the most common being anemia (16%), neutropenia (10%), and thrombocytopenia (8%).

“Results from this study provide a strong rationale for cemiplimab as a new first-line monotherapy option for patients with advanced [NSCLC] with PD-L1 of at least 50%,” the study authors reported.

“The study also included a proportion of patients with locally advanced [NSCLC] who were not candidates for definitive chemoradiation, and those with treated and clinically stable brain metastases [who] are usually under-represented in clinical trials, making the present study more reflective of real-world clinical practice,” they noted.

Disclosure: This research was supported by Regeneron Pharmaceuticals and Sanofi.  Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.


Sezer A, Kilickap S, Gümüş M, et al. Cemiplimab monotherapy for first-line treatment of advanced non-small-cell lung cancer with PD-L1 of at least 50%: a multicentre, open-label, global, phase 3, randomised, controlled trial. Lancet. 2021;397(10274):592-604. doi:10.1016/S0140-6736(21)00228-2