Sanofi and Regeneron’s imunotherapy Libtayo has been cleared in the US to treat patients with certain forms of cutaneous squamous cell carcinoma (CSCC).

The decision, which follows a priority review, allows physicians to prescribe the drug to patients with metastatic CSCC or for those with locally advanced CSCC who are not candidates for curative surgery or radiation.

Advanced CSCC is the deadliest non-melanoma skin cancer, responsible for around 7,000 deaths in the US each year. There are currently no FDA-approved treatments for the condition.

Libtayo (cemiplimab) is an investigational human monoclonal antibody that targets the checkpoint inhibitor PD-1, and was granted Breakthrough Therapy designation status in the US last year.

Approval follows a combined analysis of data from the Phase II EMPOWER-CSCC-1 and two advanced CSCC expansion cohorts from a the Phase I Study 1423.

Efficacy endpoints included objective response rate, showing 47% in metastatic CSCC and 49% in locally advanced CSCC, and a duration of response of 3-15+ months and 1-13+ months, respectively.

On the safety side, the most common adverse reactions reported were fatigue (29%), rash (25%) and diarrhea (22%), and the drug was permanently discontinued due to adverse reactions in 5% of patients.

Michael Migden, a lead investigator in the pivotal CSCC clinical programme and Professor in the Departments of Dermatology and Head and Neck Surgery at The University of Texas MD Anderson Cancer Center, hailed FDA approval of Libtayo as “great news for patients with advanced CSCC, who previously had no approved treatment options”.

“This is especially true because these patients are no longer candidates for curative surgery or radiation," he added.

European regulators are also currently reviewing the drug in this setting, a decision on which is anticipated in the first half of next year.