A phase 2 open-label study of cemiplimab in patients with advanced cutaneous squamous cell carcinoma (EMPOWER-CSCC-1): Final long-term analysis of Groups 1, 2, and 3, and primary analysis of fixed-dose treatment Group 6

In this phase 2, open-label, observational, non-randomized multi-cohort study (NCT02760498) we report the final analysis of weight-based cemiplimab monotherapy (3 mg/kg intravenous [IV] every 2 weeks) in metastatic cutaneous squamous cell carcinoma (mCSCC, Group 1) and locally advanced cutaneous squamous cell carcinoma (laCSCC, Group 2), fixed-dose (350 mg IV every 3 weeks) cemiplimab in mCSCC (Group 3), and the primary analysis of fixed-dose (350 mg IV every 3 weeks) cemiplimab in mCSCC/laCSCC (Group 6).

The primary efficacy endpoint was objective response rate (ORR; defined as complete response + partial response) per independent central review in each group. Secondary endpoints were estimated ORR per investigator’s assessment; complete response per independent central review; duration of response, progression-free survival, and overall survival by independent central review and investigator’s assessment. Safety assessments included immune-related treatment-emergent adverse events and treatment-emergent adverse events (graded by the National Cancer Institute Common Terminology Criteria for Adverse Events v.4.03).