Top-line data from a pivotal single-arm, open-label study revealed a statistically significant response rate among patients with basal cell carcinoma (BCC) who received cemiplimab (Libtayo). Most of the patients who responded maintained their response for at least 1 year. 

BCC is the most common cancer worldwide and leads to approximately 2 million new diagnoses every year in the United States. Although many cases are caught early and can be cured with surgery or radiation, a small number of tumors can become advanced and more difficult to treat. Approximately 20,000 patients in the United States have advanced BCC and about 3000 die each year, according to a press release from Sanofi, the maker of cemiplimab. 

A fully human monoclonal antibody, cemiplimab targets the immune checkpoint receptor PD-1 on T cells, blocking cancer cells from using the PD-1 pathway to suppress T-cell activation. It is the first immunotherapy approved in the United States, European Union, and other countries for adults with metastatic or local advanced cutaneous squamous cell carcinoma. 

“[Although] PD-1 inhibitors have transformed the outlook for many patients with melanoma, progress for patients with nonmelanoma skin cancers has not been as rapid,” Peter C. Adamson, MD, global head of oncology development at Sanofi, said in a statement. 

Investigators observed a 29% objective response rate (ORR) among the 84 patients with locally advanced disease, and the estimated duration of response (DOR) exceeded 1 year in 85% of responders. The durable disease control rate (DCR) was 60%. 

In the preliminary analysis of 28 patients with metastatic BCC, the ORR was 21% and the estimated DOR exceeded 1 year in 83% of responders. The durable DCR was 46%. 

The investigators observed no new safety signals. Among the 132 patients assessed for safety, 95% experienced an adverse event (AE), 32% had a serious AE, and 13% discontinued due to an AE. There were 10 deaths in the locally advanced group and 9 in the metastatic group, but none were considered treatment related. 

All patients received 350 mg of cemiplimab intravenously every 3 weeks for up to 93 weeks or until disease progression, unacceptable toxicity, withdrawal of consent, or confirmed complete response. 

The drug is being investigated as monotherapy and as a foundation therapy for combinations with other novel therapeutic approaches, according to Sanofi.