Abstract
BACKGROUND: Recurrent and/or metastatic (R/M) disease develops in approximately 65% of patients with squamous cell carcinoma of the head and neck (SCCHN) and is associated with a poor prognosis. Immune checkpoint inhibitors have proven effective in multiple tumor types, including R/M SCCHN. We report the efficacy and safety of avelumab (antiprogrammed death ligand 1 antibody) in an expansion cohort of patients with platinum-refractory/ineligible R/M SCCHN enrolled in the phase I JAVELIN Solid Tumor trial (NCT01772004). METHODS: Eligible patients with R/M SCCHN were aged ≥18 years and had received ≥1 line of platinum-based chemotherapy with disease progression or recurrence within 6 months of the last dose or were ineligible for platinum-based chemotherapy. All patients received avelumab 10 mg/kg every 2 weeks. Tumor assessments were carried out by a blinded independent review committee (IRC) and investigators according to Response Evaluation Criteria in Solid Tumors V.1.1 (RECIST 1.1). Key endpoints included best overall response, duration of response (DOR) and progression-free survival (PFS) assessed by IRC and investigator per RECIST 1.1, overall survival (OS), and safety. RESULTS: Between April 24, 2015, and November 13, 2015, 153 patients were enrolled. Patients had a median of two prior lines of therapy for metastatic or locally advanced disease (range 0-6); 12 patients (7.8%) were not eligible for platinum-based chemotherapy. At data cut-off (December 31, 2017), the confirmed objective response rate was 9.2% (95% CI 5.1% to 14.9%) assessed by IRC and 13.1% (95% CI 8.2% to 19.5%) assessed by investigator. Median DOR was not reached (95% CI 4.2 to not estimable) based on IRC assessment. Median PFS was 1.4 months (95% CI 1.4 to 2.6) assessed by IRC and 1.8 months (95% CI 1.4 to 2.7) assessed by investigator; median OS was 8.0 months (95% CI 6.5 to 10.2). Any-grade treatment-related adverse events (TRAEs) occurred in 83 patients (54.2%) and were grade ≥3 in 10 patients (6.5%). The most common TRAEs were fatigue (n=19, 12.4%), fever (n=14, 9.2%), pruritus (n=12, 7.8%), and chills (n=11, 7.2%), and there were no treatment-related deaths. CONCLUSION: Avelumab showed clinical activity and was associated with a low rate of grade ≥3 TRAEs in heavily pretreated patients with platinum-refractory/ineligible R/M SCCHN.