A protocol for a randomized trial evaluating the role of carbon‐ion radiation therapy plus camrelizumab for patients with locoregionally recurrent nasopharyngeal carcinoma

Abstract

Abstract Purpose Management of locoregionally recurrent nasopharyngeal carcinoma (LR NPC) is difficult. Although carbon‐ion radiation therapy (CIRT) could substantially improve the overall survival (OS) of those patients, around 40% of the patients may still develop local failure. Further improvement of the disease control is necessary. Immunotherapy, such as immune checkpoint inhibitors (ICIs) becomes a promising antitumor treatment. The role of ICIs was proved in head and neck cancers including recurrent/metastatic NPC. Preclinical studies indicated potential synergistic effects between radiation therapy and ICIs. Therefore, we conduct a randomized phase 2 trial to evaluate the efficacy and safety of camrelizumab, an anti‐PD‐1 monoclonal antibody, along with CIRT in patients with LR NPC. Methods Patients will be randomly assigned at 1:1 to receive either standard CIRT with 63 Gy (relatively biological effectiveness, [RBE]) in 21 fractions, or standard CIRT plus concurrent camrelizumab. Camrelizumab will be administered intravenously with a dose of 200 mg, every 2 week, for a maximum of 1 year. We estimate addition of camrelizumab will improve the 2‐year progression‐free survival (PFS) from 45% to 60%. A total of 146 patients (with a 5% lost to follow‐up rate) is required to yield a type I error of 0.2, and a power of 0.8. Results and Conclusion The results of the trial may shed insights on the combined therapy with ICIs and CIRT.

Keywords

• camrelizumab
• carbon ion
• radiotherapy (RT)
• randomized trial
• recurrent nasopharyngeal carcinoma