A phase II randomized trial of nivolumab with stereotactic body radiotherapy (SBRT) versus nivolumab alone in metastatic (M1) head and neck squamous cell carcinoma (HNSCC).

Abstract

6009Background: A minority of patients with metastatic HNSCC respond to the anti-programmed death (PD-1) monoclonal antibody, Nivolumab (Nivo). We sought to determine whether targeted radiation to a single lesion combined with Nivo would enhance tumor regression in non-irradiated lesions (abscopal response) and improve outcomes. Methods: Patients with M1 HNSCC (including nasopharynx) with at least two RECIST 1.1 measurable lesions were randomized with stratification for viral status (EBV/HPV pos vs. neg) 1:1 to either Nivo alone q 2 weeks or Nivo with SBRT to a single lesion (9 Gy x 3) between the 1st and 2nd doses of Nivo. The primary end-point was objective response rate (ORR) in non-irradiated lesions using RECIST 1.1. Secondary analyses included overall survival (OS), progression free-survival (PFS), and duration-of-response (DOR). We hypothesized that SBRT added to Nivo would increase ORR from 15% to 45%. Enrolling 53 patients thus provides a one-sided alpha of 0.10 and a power of 0.80. Results: 53 p...