Durvalumab in combination with chemoradiotherapy in patients with head and neck squamous cell carcinoma: Results from the Phase 1 CLOVER study

Background: The Phase 1 CLOVER study (NCT03509012) assessed durvalumab in combination with concurrent chemoradiotherapy (cCRT) in patients with advanced solid tumors; we report results from the head and neck squamous cell carcinoma (HNSCC) cohort. Methods: Patients with histologically/cytologically confirmed locally advanced HNSCC, eligible for definitive cCRT and not considered for primary surgery, received durvalumab plus cisplatin and concurrent external beam radiation. Objectives were to assess safety/tolerability and preliminary efficacy. Results: Eight patients were enrolled. The most frequent any-cause adverse events (AEs) were nausea and radiation skin injury (each n = 5); most frequent grade 3/4 AEs were lymphopenia and stomatitis (each n = 3). No patients had dose-limiting toxicities. Objective response rate was 71.4% (5/7 patients; four complete responses, one partial response); disease control rate was 85.7% at 18 weeks and 83.3% at 48 weeks. Conclusions: Durvalumab plus cCRT was tolerable and active in patients with unresected, locally advanced HNSCC.