Anti-programmed cell death-1 receptor (anti-PD-1) antibodies demonstrate response rates of nearly 50% in both locally advanced and metastatic cutaneous squamous cell carcinoma (cSCC) according to study data published in Dermatologic Therapy.
Studies of immune checkpoint inhibitors (ICI), specifically anti-PD-1 antibodies such as cemiplimab and pembrolizumab, have shown promising results in patients with phase 2 locally advanced and/or metastatic sCCC. In 2 separate studies, patients with locally advanced or metastatic cSCC were treated with cemiplimab 3 mg/kg every 2 weeks. In a phase 2 study of 78 patients treat with cemplimab with locally advanced cSCC, an objective response in 44% of patients (95% CI, 32-35) was observed, with 13% of patients achieving a complete response and 31% demonstrating a partial response. In 29% of patients serious treatment-related adverse events occurred. In a separate phase 2 study of 59 patients with metastatic cSCC who were treated with cemplimab, an overall response rate of 49.2% (95% CI. 35.9-62.5) was seen, with a median progression-free survival (PFS) of 18.4 months.
The most common treatment-related adverse events observed were diarrhea, fatigue and nausea. Grade ≥3 immune-related adverse events were observed in 13.6% of patients. A French phase 2 trial ofpembrolizumab in patients with unresectable sCCC with no prior systemic therapy revealed similar positive results. At week 15, of 39 patients there were 2 complete and 13 partial responses for an objective response rate of 38.5%. Severe treatment-related adverse events occurred in 8% of patients.
Limitations of the study include a focus on a selected patient population and therefore the results may not be generalizable to all patient populations.
The author concluded that anti-PD-1 antibodies demonstrated clinical effectiveness of ICI treatment in patients with unresectable, locally advanced or metastatic cSCC and may be a more favorable treatment strategy than chemotherapy.
Benzaquen M. Update on the anti-programmed cell death-1 receptor antibodies in advanced cutaneous squamous-cell carcinoma (published online March 24, 2020). Dermatol Ther. doi: 10.1111/dth.13325