cemiplimab

Cemiplimab is a human monoclonal antibody that inhibits the PD-1 receptor, part of the class of drugs known as immune checkpoint inhibitors. It is marketed under the brand name Libtayo and was developed by Regeneron and Sanofi. Cemiplimab is administered by intravenous infusion and is used in oncology to help the immune system recognize and attack cancer cells.

Mechanism of action: Cemiplimab binds to PD-1 on T cells, blocking its interaction with the ligands PD-L1 and PD-L2. This releases the inhibition on T cells, enhancing anti-tumor immune responses. As with other PD-1 inhibitors, responses can be durable in some patients, but the therapy can also trigger immune-related adverse events affecting various organs.

Clinical use: In the United States and many other regions, cemiplimab was first approved for adults with metastatic or locally advanced cutaneous squamous cell carcinoma (CSCC). Regulatory approvals have expanded over time to include additional indications in some regions, such as other skin cancers and certain non-skin tumors, with dosing schedules varying by indication. Treatment decisions are based on disease type, prior therapies, and patient factors.

Safety and monitoring: Cemiplimab can cause immune-related adverse events, including effects on the skin, colon, liver, endocrine glands, lungs, and other organs. Common side effects include fatigue, rash, diarrhea, and nausea. Patients require regular monitoring and management of irAEs per clinical guidelines, which may involve temporary or permanent treatment modification and, in some cases, immunosuppressive therapy.

See also: Other PD-1 inhibitors such as nivolumab and pembrolizumab, and the broader class of immune checkpoint inhibitors.

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