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Regeneron Pharmaceuticals, Inc.,  (NASDAQ: REGN) and Sanofi today announced that the U.S. Food and Drug Administration (FDA) has approved the PD-1 inhibitor Libtayo^® (cemiplimab-rwlc) for the first-line treatment of patients with advanced non-small cell lung cancer (NSCLC) whose tumors have high PD-L1 expression (tumor proportion score ≥50%), as determined by an FDA-approved test. Patients must either have metastatic or locally advanced tumors that are not candidates for surgical resection or definitive chemoradiation, and the tumors must not have EGFR, ALK, or ROS1 aberrations.

"The approval of Libtayo to treat first-line advanced non-small cell lung cancer with high PD-L1 expression means physicians and patients have a potent new treatment option against this deadly disease," said Naiyer Rizvi, M.D., Price Family Professor of Medicine, Director of Thoracic Oncology and Co-director of Cancer Immunotherapy at Columbia University Irving Medical Center, as well as a steering committee member of the trial. "Notably, Libtayo was approved based on a pivotal trial where most chemotherapy patients crossed over to Libtayo following disease progression, and that allowed for frequently underrepresented patients who had pretreated and clinically stable brain metastases, or who had locally advanced disease and were not candidates for definitive chemoradiation. This gives doctors important new data when considering Libtayo for the varied patients and situations they treat in daily clinical practice."

This is the third approval for Libtayo and follows a Priority Review by the FDA, which is reserved for medicines that represent significant improvements in safety or efficacy in treating serious conditions. Earlier this month, Libtayo was approved as the first immunotherapy indicated for patients with advanced basal cell carcinoma (BCC) previously treated with a hedgehog pathway inhibitor (HHI) or for whom an HHI is not appropriate, with full approval granted for locally advanced disease and accelerated approval granted for metastatic disease. In 2018, Libtayo was the first systemic treatment approved for adults with advanced cutaneous squamous cell carcinoma (CSCC) that is locally advanced or metastatic and who are not candidates for curative surgery or curative radiation. Immune-mediated adverse reactions, which may be severe or fatal, can occur in any organ system or tissue during or after treatment with Libtayo.

"Libtayo has demonstrated an impressive level of efficacy in advanced NSCLC with at least 50% PD-L1 expression in its pivotal trial," said Ahmet Sezer, M.D., Professor in the Department of Medical Oncology at Başkent University in Adana, Turkey and a trial investigator. "As published in The Lancet, in a prespecified analysis in the subset of patients proven to have PD-L1 expression of at least 50%, Libtayo reduced the risk of death by 43% compared to chemotherapy. This was achieved with a greater than 70% crossover rate to Libtayo following disease progression on chemotherapy, as well as the largest population of patients with pretreated and clinically stable brain metastases among advanced NSCLC pivotal trials to date."

The data supporting the Libtayo approval are based on an analysis of 710 patients who were randomized to receive treatment in a Phase 3 trial; eligible patients were intended to have PD-L1 expression of ≥50%. In this patient population, Libtayo reduced the risk of death by 32% compared to chemotherapy, with additional efficacy results as follows:

a Based on Kaplan-Meier method
b Based on stratified proportional hazards model

Due to PD-L1 testing issues, an additional prespecified analysis was performed in 563 patients with proven PD-L1 expression of ≥50%, according to the FDA-approved assay, and is described in the updated labeling of the FDA-approved assay (and also recently published in The Lancet). This analysis showed that Libtayo reduced the risk of death by 43% compared to chemotherapy, with additional efficacy results as follows:

NOTE: The analysis was conducted in a subset of the randomized population that excluded 147 patients whose tumors could not be retested or were later found to have <50% PD-L1 expression.
a Based on Kaplan-Meier method
b Based on stratified proportional hazards model

Safety was assessed in 355 patients in the Libtayo group (median duration of exposure: 27 weeks; range: 9 days to 115 weeks) and 342 patients in the chemotherapy group (median duration of exposure: 18 weeks; range: 18 days to 87 weeks). Adverse reactions that occurred more commonly in the Libtayo group and in at least 10% of patients were rash (15% Libtayo, 6% chemotherapy) and cough (11% Libtayo, 8% chemotherapy). The most frequent serious adverse reactions in at least 2% of patients were pneumonia (5% Libtayo, 6% chemotherapy) and pneumonitis (2% Libtayo, 0% chemotherapy). Treatment was permanently discontinued due to adverse reactions in 6% of Libtayo patients; adverse reactions resulting in permanent discontinuation in at least 2 patients were pneumonitis, pneumonia, ischemic stroke, and increased aspartate aminotransferase. No new Libtayo safety signals were observed.

"We developed Libtayo to deliver clinically meaningful benefits to patients suffering from a diverse range of cancers and to establish a foundation for potential future immunotherapy combinations. Today's approval continues to support this vision," said Israel Lowy, M.D., Ph.D., Senior Vice President, Translational and Clinical Sciences, Oncology at Regeneron. "Libtayo has already changed the treatment paradigm for certain patients with advanced cutaneous squamous cell carcinoma and is poised to do the same for advanced basal cell carcinoma. Now, Libtayo has the opportunity to make a meaningful difference for the many U.S. patients battling advanced non-small cell lung cancer. Libtayo is being investigated in a variety of settings, and we hope to share updates later this year on our pivotal trials in cervical cancer and in combination with chemotherapy in advanced non-small cell lung cancer."

Lung cancer is the leading cause of cancer death worldwide. In 2020, an estimated 2.2 million and 225,000 new cases were diagnosed worldwide and in the U.S, respectively. Approximately 84% of all lung cancers are NSCLC, with 75% of these cases diagnosed in advanced stages and an estimated 25% to 30% of cases expected to test positive for PD-L1 in ≥50% of tumor cells.

"With this third approval for Libtayo, we are proud to deliver on our ambition to bring our PD-1 inhibitor to patients in need with difficult-to-treat cancers, such as advanced non-small cell lung cancer," said Peter C. Adamson, M.D., Global Development Head, Oncology and Pediatric Innovation at Sanofi. "As the leading cause of cancer deaths globally, the need for additional therapeutic options in advanced NSCLC is clear. Libtayo allows physicians to further optimize treatment of these patients whose tumors have high expression of PD-L1. We thank all of the trial investigators, patients, and their caregivers who helped make this milestone possible."

About the Phase 3 Trial Supporting Approval
The open-label, randomized, multi-center Phase 3 trial, called EMPOWER-Lung 1, was designed to investigate the first-line treatment of Libtayo monotherapy compared to platinum-doublet chemotherapy in patients with advanced NSCLC who tested positive for PD-L1 in ≥50% of tumor cells and without EGFR, ALK, or ROS1 aberrations. PD-L1 expression was confirmed using the Agilent Dako PD-L1 IHC 22C3 pharmDx kit. The primary endpoints were OS and PFS, and secondary endpoints included overall response rate, duration of response, and quality of life.

The trial randomized 710 patients with either previously untreated metastatic NSCLC (Stage IV) or locally advanced NSCLC (Stage IIIB/C) who were not candidates for surgical resection or definitive chemoradiation or who had progressed after treatment with definitive chemoradiation. Enrolled patients included those with disease characteristics frequently underrepresented in pivotal advanced NSCLC trials. Among them, 12% had pre-treated and clinically stable brain metastases, and 16% had locally advanced NSCLC that was not a candidate for definitive chemoradiation.

Importantly, patients whose disease progressed in the trial were able to change their therapy: those assigned to chemotherapy were allowed to crossover to Libtayo treatment following disease progression, while those assigned to Libtayo monotherapy were allowed to combine Libtayo treatment with 4 to 6 cycles of chemotherapy following disease progression. There was a >70% crossover rate to Libtayo following disease progression on chemotherapy.