BACKGROUND AND PURPOSE: To report on the anti-tumor activity of a novel combination in high-risk locally advanced head and neck squamous cell carcinoma. MATERIALS AND METHODS: At a fixed dose of 1500 mg every 28 days, anti PD-L1 Durvalumab was given concomitantly to Radiotherapy and Cetuximab starting from the first week of combined treatment, followed by adjuvant Durvalumab to a maximum of 6 months after completion of radiation. The primary endpoint of the study was 2-year progression-free survival (PFS). A safety run-in was planned. Due to regulatory issues which prevented from opening multiple centers, COVID-19 pandemic and withdrawal of Durvalumab from supporting company, the study was prematurely terminated in April 2021 RESULTS: Between July 2019 and August 2020, 9 patients were enrolled in the study. All tumors had a PD-L1 Combined Positive Score > 1. Optimal drug exposure was observed, with mean relative dose intensity of 85.5% and 87.5% for Cetuximab and Durvalumab, respectively. No radiation breaks were necessary. A grade 4 mucositis lasting for 14 days corresponded to the only dose limiting toxicity we reported. At a median follow-up of 11.5 months (IQR 7.7-16.7) all surviving patients (6 out of 9) are disease-free, with 1 and 2-year PFS rates of 77.7% and 58.3%, respectively. A selective sparing of node levels in the elective volume was performed in all cases, yielding a cumulative mean dose of 37.6 Gy (SD 8.4). CONCLUSION: Albeit limited by the small sample size, our preliminary observation of anti-tumor activity and tolerability of Durvalumab in addition to Cetuximab and radiation may warrant further investigations.
Durvalumab with cetuximab and radiotherapy for locally advanced squamous cell carcinoma of the head and neck: a phase 1/2 trial