Cemiplimab-rwlc (Libtayo), a monoclonal antibody, is the first drug approved to treat metastatic or locally advanced cutaneous squamous cell carcinoma (CSCC) in patients who are not candidates for curative surgery or curative radiation. CSCC is the second most common skin cancer in the United States, after basal cell cancer. CSCC develops in skin that has been exposed to sun or other ultraviolent radiation. In most cases it is cured with surgical intervention; however, some patients develop a form that becomes resistant to local treatments, including surgery and radiation. Cemiplimab-rwlc is the first drug option for these patients.

The safety and efficacy of the drug was studied in two open-label clinical trials that enrolled 75 patients with metastatic CSCC and 33 patients with locally advanced CSCC. Almost half of the patients treated with cemiplimab-rwlc had their tumors shrink or disappear after treatment.

Common adverse effects of cemiplimab-rwlc are fatigue, rash, and diarrhea. Serious immune-mediated adverse effects, where the immune system attacks healthy organs and tissues, include pneumonitis, colitis, hepatitis, endocrinopathies, dermatologic problems, and kidney problems. Nurses should refer to the drug's labeling for recommended dose modifications if these adverse effects occur.

Cemiplimab-rwlc is administered every three weeks as an intravenous infusion. Nurses should mix the drug by gently inverting the vial; the vial should not be shaken. The drug should be administered at room temperature using an in-line or add-on filter. Patients should be monitored for infusion-related reactions, as these can be severe. Nurses should interrupt or slow the rate of the infusion based on the severity of the reactions (see the drug's labeling for details).

Patients should be taught the signs and symptoms of the major immune-mediated adverse effects. These are listed in the medication guide provided with the prescription. Cemiplimab-rwlc is known to cause embryo-fetal toxicity. Nurses should teach women of childbearing age who use cemiplamab-rwlc to use effective contraception.

For complete prescribing information, see http://www.accessdata.fda.gov/drugsatfda_docs/label/2018/761097s000lbl.pdf.