Pembrolizumab in Asia‐Pacific patients with advanced head and neck squamous cell carcinoma: Analyses from KEYNOTE‐012

KEYNOTE‐012 was a phase Ib, multicohort study designed to investigate efficacy and safety of pembrolizumab in advanced solid tumors. Results from the subset of patients with recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) from the Asia‐Pacific region are reported. Patients with recurrent/metastatic HNSCC, measurable disease (RECIST version 1.1), and ECOG performance status (PS) 0‐1 were eligible for enrollment in the HNSCC expansion cohort. Patients received pembrolizumab 200 mg every 3 weeks. Response was assessed every 8 weeks. Co‐primary end‐points were safety and overall response rate (RECIST version 1.1, central review). Secondary end‐points included overall survival and response duration. Patients enrolled at any of the five centers throughout the Asia‐Pacific region were included in these analyses. Twenty‐six patients with HNSCC from the Asia‐Pacific region received pembrolizumab. The median age was 62 years, 65% of patients had ECOG PS 1, and 62% had received two or more prior therapies for recurrent/metastatic disease. Sixteen (62%) patients experienced a treatment‐related adverse event of any grade, including two (8%) patients who experienced one or more events of grade 3 severity. No treatment‐related deaths occurred. The overall response rate was 19% (95% confidence interval, 7%‐39%). After a median follow‐up of 12 months (range, 2‐21 months), a median response duration was not reached (range, 6 to 17+ months); four of five responses lasted ≥6 months. Median overall survival was 11.6 months (95% confidence interval, 4.7‐17.7 months). Pembrolizumab was well tolerated and had durable antitumor activity in patients with HNSCC from the Asia‐Pacific region. (Trial registration no. NCT01848834.)