Libtayo (cemiplimab) demonstrated clinically meaningful and durable responses in patients with advanced basal cell carcinoma who had progressed on or were intolerant to prior hedgehog pathway inhibitor therapy.
Libtayo is being jointly developed and commercialized by Regeneron and Sanofi under a global collaboration agreement. Regeneron and Sanofi said they plan regulatory submissions in 2020.
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 in 2018.
In the trial phase II, the objective response rate for patients (n=84) with locally advanced disease was 29% (95% CI: 19%-40%), with an estimated duration of response exceeding one year in 85% of responders. The durable disease control rate (DCR–response or stable disease lasting at least six 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.
“These data in advanced BCC provide the third instance where Libtayo monotherapy has demonstrated robust and clinically meaningful outcomes in advanced cancer, and follows last week’s announcement in advanced non-small cell lung cancer where the pivotal trial was stopped early for positive overall survival,” Israel Lowy, senior vice president of Translational and Clinical Sciences, Oncology, Regeneron, said in a statement.
There were no new safety signals in this trial. Among the 132 patients assessed for safety (84 locally advanced and 48 metastatic), 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 nine deaths in the metastatic group; none of the deaths were considered treatment-related.
“While PD-1 inhibitors have transformed the outlook for many patients with melanoma, progress for patients with non-melanoma skin cancers has not been as rapid,” said Peter C. Adamson, global head of Oncology Development at Sanofi. “We are continuing to address this unmet need by first bringing Libtayo to patients with advanced cutaneous squamous cell carcinoma, and now, with this second trial, as a potential therapy for patients with advanced basal cell carcinoma. These important new results further demonstrate Libtayo’s potential in patients with difficult-to-treat, non-melanoma skin cancers.”
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.