FDA approves Keytruda for cutaneous squamous cell carcinoma
The FDA approved pembrolizumab for treatment of recurrent or metastatic cutaneous squamous cell carcinoma that is not curable by surgery or radiation.
The agency based the approval on results of the nonrandomized, open-label KEYNOTE-629 trial, which included 105 patients (median age, 72 years; 76.2% men) with recurrent or metastatic cutaneous squamous cell carcinoma.
Study protocol excluded patients who received prior anti-PD-1, anti-PD-L1 or anti-CTLA-4 antibody therapy, as well as those who had autoimmune disease or medical conditions that required immunosuppression.
Most patients had received at least one line of prior systemic therapy (86.7%) and had undergone radiation (74.3%).
Patients received the anti-PD-1 therapy pembrolizumab (Keytruda, Merck) dosed at 200 mg via IV every 3 weeks. Treatment continued for 24 months, or until disease progression or unacceptable toxicity.
Researchers assessed tumor status every 6 weeks during the first year and every 9 weeks during the second year.
Objective response rate and response duration as assessed by blinded independent central review served as major efficacy outcome measures.
Median follow-up was 9.5 months (range, 0.4-16.3).
Researchers reported an ORR of 34.3% (95% CI, 25.3-44.2). Four patients (3.8%) achieved complete response and 32 patients (30.5%) achieved partial response.
Median duration of response was not reached (range, 2.7-13.1+). Median PFS was 6.9 months (95% CI, 3.1-8.5) and 32.4% of patients remained progression free at 12 months. Median OS had not been reached (95% CI, 10.7-not reached) and 60.3% of patients remained alive at 12 months.
Seventy patients (66.7%) experienced treatment-related adverse events, the most common of which were pruritus (14.3%), asthenia (13.3%) and fatigue (12.4%).
Six patients (5.7%) experienced grade 3 to grade 5 treatment-related adverse events. One patient died of treatment-related cranial nerve neuropathy.
The FDA approval applies to two pembrolizumab dosing options: 200 mg every 3 weeks, or 400 mg every 6 weeks.