FDA Approves Libtayo

Regeneron Pharmaceuticals announced 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%.

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."

Libtayo is a fully-human monoclonal antibody targeting the immune checkpoint receptor PD-1 on T-cells. By binding to PD-1, Libtayo has been shown to block cancer cells from using the PD-1 pathway to suppress T-cell activation.

Across all of its approved indications, the recommended dose of Libtayo is 350 mg administered as an intravenous infusion over 30 minutes every three weeks, until disease progression or unacceptable toxicity. Libtayo is available as a single-dose 350 mg vial.

In the U.S., the generic name for Libtayo in its approved indication is cemiplimab-rwlc, with rwlc as the suffix designated in accordance with Nonproprietary Naming of Biological Products Guidance for Industry issued by the FDA. Outside of the U.S., the generic name for Libtayo in its approved indication is cemiplimab.

Libtayo was invented using Regeneron's VelocImmune® technology that utilizes a proprietary genetically-engineered mouse platform endowed with a genetically-humanized immune system to produce optimized fully-human antibodies. When Regeneron's co-Founder, President and Chief Scientific Officer George D. Yancopoulos was a graduate student with his mentor Frederick W. Alt in 1985, they were the first to envision making such a genetically-humanized mouse, and Regeneron has spent decades inventing and developing VelocImmune® and related VelociSuite® technologies. Yancopoulos and his team have used VelocImmune technology to create multiple antibodies including Dupixent® (dupilumab), Praluent® (alirocumab), Kevzara® (sarilumab), Evkeeza™ (evinacumab-dgnb), Inmazeb™ (atoltivimab, maftivimab, and odesivimab-ebgn) and Regeneron's antibody cocktail for COVID-19, which was recently granted Emergency Use Authorization (EUA) in the U.S.