A Phase II Single Arm Clinical Study of Treprilimab in the Treatment of Local Recurrent/Residual Nasopharyngeal Carcinoma After Re-irradiation

To establish the antitumor activity and safety of the anti-programmed death 1 receptor monoclonal antibody, Treprilimab, in patients with local recurrent/residual nasopharyngeal carcinoma after re-irradiation.Patients with local recurrent/residual NPC after re-irradiation were treated with Treprilimab until disease progression or unacceptable toxicity. The primary end point was objective response rate (ORR) and secondary end points included survival and toxicity.The sample size of this study was estimated on the assumption that response rates (RRs) to Treprilimab should be around 25%,based on a report that was available at the time this study was planned.Furthermore, the RR to noncytotoxic, experimental agents such as pazopanib and cetuximab in similarly pretreated patient cohorts was approximately 5% to 10%. This study's design was based on the modified Simon two-stage optimal design (α=0.05，β=0.2,n1=2/22,n2=7/40). If two responses were observed during the first stage, enrollment was continued until a total of 40 patients was reached. The target lesions had to be measurable by the Response Evaluation Criteria in Solid Tumors (RECIST). Radiologic assessments were performed every 8 weeks for 6 months and then every 12 weeks thereafter. Eligible patients were treated with Treprilimab at a dosage of 240mg intravenously every 3 weeks until they experienced disease progression or unacceptable toxicity. The primary end point of this study was objective response by the RECIST criteria , and the secondary end points were overall survival (OS), progression-free survival (PFS), duration of response and toxicity.