Libtayo Accepted for FDA Priority Review in NSCLC With PD-L1 Expression

Regeneron’s PD-1 inhibitor Libtayo (cemiplimab-rwlc) was accepted for priority review by the FDA for the treatment of first-line locally advanced or metastatic non–small cell lung cancer (NSCLC) with PD-L1 expression of at least 50%, the company announced in a press release on October 29. The target decision date is February 28, 2021.

The supplemental biologics license application accepted for review is based on results from the EMPOWER-Lung 1 trial of cemiplimab monotherapy vs platinum-doublet chemotherapy. The findings were presented in a late-breaking abstract at the European Society for Medical Oncology (ESMO) Virtual Congress 2020 and expanded on topline results reported in April.

The randomized, phase 3, open-label trial separated 710 patients with advanced NSCLC into 2 cohorts. One group received cemiplimab, a fully-human monoclonal antibody, while the other underwent standard-of-care chemotherapy. The median follow-up time was 13 months, with a range of less than 1 month to 32 months in both groups.

In the cemiplimab cohort, risk of death was 32% lower than in the chemotherapy group. The risk of disease progression on cemiplimab was 41% lower, and the objective response rate was 37% in patients who received cemiplimab vs 21% in patients receiving standard chemotherapy. Median overall survival (OS) was also longer in the cemiplimab group (22.1 months) vs the patients receiving chemotherapy (14.3 months).

The results were also promising in patients with confirmed PD-L1 expression of at least 50%, determined by the PD-L1 IHC 22C3 pharmDx kit. Those patients saw a 43% decrease in risk of death, and their risk of disease progression was 46% lower. The cemiplimab cohort also saw a higher objective response rate than the chemotherapy group (39% vs 20%).

In patients whose tumors had at least 90% PD-L1 expression, the objective response rate with cemiplimab was 46% (range, 36%-56%), the most significant rate seen in the trial. Chemotherapy did not produce similar results in that patient population. Patients were able to cross over to the cemiplimab group if their disease progressed, and 73.9% did so.

Libtayo was the first drug to receive FDA approval for treating patients with metastatic cutaneous squamous cell carcinoma (CSCC) or locally advanced CSCC when ineligible for surgery or radiation. In addition to the FDA review for NSCLC with more than 50% PD-L1, the European Medicines Agency is assessing the drug for the same indication, with a decision anticipated in the second quarter of 2021.