Sanofi and Regeneron Pharmaceuticals has announced that the US Food and Drug Administration (FDA) has granted Breakthrough Therapy designation status to cemiplimab (REGN2810) for the treatment of adults with metastatic cutaneous squamous cell carcinoma (CSCC) and adults with locally advanced and unresectable CSCC, the second deadliest skin cancer after melanoma. Cemiplimab is an investigational human, monoclonal antibody targeting PD-1.

Sanofi and Regeneron previously reported positive, preliminary results for cemiplimab from two expansion cohorts involving 26 advanced CSCC patients in a Phase 1 study of nearly 400 patients, at the American Society of Clinical Oncology (ASCO) Annual Meeting in June 2017. EMPOWER-CSCC 1, a Phase 2, potentially pivotal, single-arm, open label clinical trial of cemiplimab is currently enrolling patients for metastatic CSCC and locally advanced and unresectable CSCC. Cemiplimab is being jointly developed by Sanofi and Regeneron under a global collaboration agreement.  Pending data results, the companies anticipate submitting a biologics license application for cemiplimab with the FDA in the first quarter of 2018.

CSCC is the second most common type of skin cancer in the United States. Although CSCC has a good prognosis when caught early, it can prove especially difficult to treat when it progresses to advanced stages. Patients at this stage can be disfigured due to multiple surgeries to remove CSCC tumors on the head, neck and other parts of the body. CSCC is responsible for the most deaths among non-melanoma skin cancer patients.

Breakthrough Therapy designation serves to expedite the development and review of drugs that target serious or life-threatening conditions. Drugs qualifying for this designation must show credible evidence of a substantial improvement on a clinically significant endpoint over available therapies, or over placebo if there is no available therapy. The designation includes all of the Fast Track program features, as well as more intensive FDA guidance and discussion. The Breakthrough Therapy designation is distinct from both accelerated approval and priority review, which can also be granted to the same drug if relevant criteria are met.

Cemiplimab is currently under clinical development, and its safety and efficacy has not been fully evaluated by any regulatory authority.