Jason M. Broderick
The Food and Drug Administration (FDA) granted a priority review to a biologics license application (BLA) for an immunotherapy agent – cemiplimab – to be used to treat metastatic cutaneous squamous cell carcinoma (a type of skin cancer; CSCC) or patients with locally advanced CSCC who are not eligible for surgery.
The BLA was submitted based on data from the phase 2 EMPOWER-CSCC 1 study (NCT02760498
), in which the overall response rate (ORR) was 46.3 percent in patients with advanced CSCC. Regeneron and Sanofi, the codevelopers of cemiplimab, also submitted supporting data from two phase 1 expansion cohorts of patients with advanced CSCC. The companies reported in a statement that updated data from these phase I and II studies will be presented at the 2018 ASCO Annual Meeting.
Cemiplimab previously received an FDA breakthrough therapy designation in CSCC. The FDA is scheduled to make its decision on the BLA by Oct. 28, 2018.
The ORR data reported from the ongoing, single-arm, open-label EMPOWER-CSCC 1 study were for 82 patients. Approximately two-thirds of the patients had progressed following systemic chemotherapy or radiation.
Patients on the study were divided into three cohorts. At the data cutoff, there was one fully enrolled cohort, which included patients with metastatic CSCC who received 3 mg/kg of cemiplimab every two weeks. The other two arms, which are still enrolling, include a group of patients with metastatic CSCC assigned to a 350-mg flat dose of cemiplimab every three weeks, and a group with locally advanced and unresectable CSCC receiving 3 mg/kg of cemiplimab every two weeks.
At the data cutoff, 32 of 38 responses were ongoing and the median duration of response had not been reached. The minimum follow-up was six months. Safety data for cemiplimab were similar to other approved PD-1 inhibitors.
Phase 1 data for cemiplimab in advanced CSCC were reported at the 2017 ASCO Annual Meeting. The results were for 26 patients enrolled across two expansion cohorts of a phase 1 study. Patients in the expansion cohorts were assigned to 3 mg/kg of cemiplimab every two weeks for 48 weeks. Ten patients had metastatic disease and 16 had locally advanced disease.
The investigator-assessed preliminary ORR was 46.2 percent at the data cutoff date of April 27, 2017. Two patients (7.7 percent), both with locally advanced disease, had a complete response. Ten patients (38.5 percent), six in the metastatic group and four in the locally advanced group, had partial response, including one unconfirmed partial complete response. A total of 6 patients (23.1 percent) had stable disease and six others had progressive disease. The disease control rate was 69.2 percent.
Fatigue (23.1 percent) was the most common (at least 10 percent) any-grade treatment-emergent adverse event (TEAE). Incidence of grade 3 or higher TEAEs was low. Investigators recorded single incidences of arthralgia, maculopapular rash, asthenia, AST elevation and ALT elevation.
Toxicity led to treatment discontinuation for two patients: an 88-year-old woman who developed grade 3 rash after three doses and an 86-year-old man who withdrew consent after experiencing grade 3 transaminase elevation and grade 2 fatigue after six doses.
Two patients died within 30 days of the final dose, but these were not attributed to cemiplimab.