squamous cell carcinoma skin

Phase II Study of Pembrolizumab As First-Line, Single-Drug Therapy for Patients With Unresectable Cutaneous Squamous Cell Carcinomas

In the September 10, 2020 edition of Journal of Clinical Oncology, Eve Maubec and colleagues reported on the results of pembrolizumab in advanced SCC.

PURPOSE

The efficacy of first-line pembrolizumab monotherapy in unresectable cutaneous squamous cell carcinomas was assessed in this clinical trial.

PATIENTS AND METHODS

. Patients had to have immunohistochemically determined program cell death like ligand 1 status with tumor proportion score threshold, 1% or higher prior to being treated with pembrolizumab (200 mg every 3 weeks). The primary endpoint was the 39-patient primary cohort’s objective response rate at the 15th week (ORRW15). Secondary endpoints were best ORR, overall survival, progression-free survival , duration of response , safety, ORR according to PD-L1 status and health-related quality of life using Functional Assessment of Cancer Therapy–General (FACT-G) score. An 18-patient expansion cohort was needed, so the study can be powered to evaluate the ORRW15 difference between PD-L1+ and PD-L1– patients, and they were also assessed for ORR, disease control rate, and safety, but not survival.

The median age amongst all treated patients was 79 years old. The primary cohort’s ORRW15 was 41% (95% CI, 26% – 58%), including 13 partial and 3 complete responses. Best responses were 8 partial and 8 complete responses. At a median follow-up of 22.4 months, respective median progression free survival, duration of response, and overall survival were 6.7 months, not reached, and 25.3 months, respectively. Pembrolizumab-related adverse events affected 71% of the patients, and 4 (7%) were grade ≥ 3. One patient died because of rapid disease progression while another died as a result of a fatal second aggressive head and neck squamous cell carcinoma diagnosed 15 weeks after inclusion. ORRW15 for the entire study population was 42%; which was notably higher for PD-L1+ patients (55%) versus PD-L1– patients (17%; P = .02). Responders’ W15 total FACT-G score had improved (P = .025) compared with nonresponders. The authors concluded “first-line pembrolizumab monotherapy exhibited promising anti-CSCC activity, with durable responses and manageable safety. PD-L1 positivity appears to be predictive of pembrolizumab efficacy.”

Reference:

Phase II Study of Pembrolizumab As First-Line, Single-Drug Therapy for Patients With Unresectable Cutaneous Squamous Cell Carcinomas

https://ascopubs.org/doi/full/10.1200/JCO.19.03357

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