Libtayo (cemiplimab-rwlc) injection (Regeneron Pharmaceuticals, Inc.)  is now FDA-approved for intravenous use for the treatment of patients with metastatic cutaneous squamous cell carcinoma (CSCC) or locally advanced CSCC who are not candidates for curative surgery or curative radiation. This is the first FDA approval of a drug specifically for advanced CSCC.

Libtayo works by targeting the cellular pathway known as PD-1 (protein found on the body’s immune cells and some cancer cells). By blocking this pathway, the drug may help the body’s immune system fight the cancer cells.

The safety and efficacy of Libtayo was studied in two open label clinical trials. A total of 108 patients (75 with metastatic disease and 33 with locally-advanced disease) were included in the efficacy evaluation. The study’s primary endpoint was objective response rate, or the percentage of patients who experienced partial shrinkage or complete disappearance of their tumor(s) after treatment. Results showed that 47.2 percent of all patients treated with Libtayo had their tumors shrink or disappear. The majority of these patients had ongoing responses at the time of data analysis.

“We’re continuing to see a shift in oncology toward identifying and developing drugs aimed at a specific molecular target. With the Libtayo approval, the FDA has approved six immune checkpoint inhibitors targeting the the PD-1 / PD-L1 pathway for treating a variety of tumors, from bladder to head and neck cancer, and now advanced CSCC,” said Richard Pazdur, MD, director of the FDA’s Oncology Center of Excellence and acting director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “This type of cancer can be difficult to treat effectively when it is advanced and it is important that we continue to bring new treatment options to patients.”

Common side effects of Libtayo include fatigue, rash and diarrhea. Libtayo must be dispensed with a patient Medication Guide that describes uses of the drug and its serious warnings. Libtayo can cause the immune system to attack normal organs and tissues in any area of the body and can affect the way they work. These reactions can sometimes become severe or life-threatening and can lead to death. These reactions include the risk of immune-mediated adverse reactions including lung problems (pneumonitis), intestinal problems (colitis), liver problems (hepatitis), hormone gland problems (endocrinopathies), skin (dermatologic) problems and kidney problems. Patients should also be monitored for infusion-related reactions.  

Libtayo can cause harm to a developing fetus; women should be advised of the potential risk to the fetus and to use effective contraception. The FDA granted this application Breakthrough Therapy and Priority Review designations.