Topline data for Libtayo to treat advanced basal cell carcinoma.- Sanofi + Regeneron

Topline data for a pivotal, single-arm, open-label trial for Sanofi and Regeneron’s PD-1 inhibitor Libtayo (cemiplimab) in patients with advanced basal cell carcinoma (BCC) who had progressed on or were intolerant to prior hedgehog pathway inhibitor (HHI) therapy were announced .

Libtayo demonstrated clinically meaningful and durable responses in this group of patients for whom there are no approved treatments. Sanofi and Regeneron plan regulatory submissions in 2020. In the trial, the objective response rate (ORR) for patients (n=84) with locally advanced disease was 29% (95% CI: 19%-40%), with an estimated duration of response (DOR) exceeding one year in 85% of responders. The durable disease control rate (DCR —response or stable disease lasting at least 6 months) was 60% (95% CI: 48%-70%). In a preliminary analysis of patients (n=28) with metastatic disease, the ORR was 21% (95% CI: 8%-41%), with an estimated DOR exceeding one year in 83% of responders. The durable DCR was 46% (95% CI: 28%-66%). All data were assessed by an independent central review. Data are expected to continue to evolve with further follow-up across both patient groups.

There were no new safety signals in this trial. Among the 132 patients assessed for safety (84 locally advanced and 48 metastatic), 95% of patients 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 nine deaths in the metastatic group; none of the deaths were considered treatment-related. Sanofi and Regeneron will present additional trial findings at an upcoming medical meeting. .

In this ongoing global Phase II trial, patients received Libtayo 350 mg intravenously every three weeks for up to 93 weeks or until disease progression, unacceptable toxicity, withdrawal of consent or confirmed complete response. ORR is the primary endpoint and key secondary endpoints include overall survival, progression-free survival, duration of response, safety and quality of life.

Basal Cell Carcinoma is a skin cancer and is the most common cancer worldwide, with approximately two million new cases diagnosed every year in the U.S. alone. While the vast majority of BCCs are caught early and cured with surgery or radiation, a small proportion of tumors can become advanced and penetrate deeper into surrounding tissues (locally advanced), which is more difficult to treat. Approximately 20,000 U.S. patients have advanced BCC and it is estimated that about 3,000 die each year. BCC marks the second non-melanoma skin cancer for which Libtayo has demonstrated first-in-class data and follows its initial U.S. approval in advanced cutaneous squamous cell carcinoma (CSCC) in 2018.