Toripalimab plus concurrent chemoradiotherapy for recurrent nasopharyngeal carcinoma: A single‐arm, phase 2 clinical trial

BACKGROUND: Improving the efficacy of retreatment for locally recurrent nasopharyngeal carcinoma (rNPC) and extending patient survival are urgently required for the clinical prevention and treatment of NPC. This study explored the efficacy and safety of toripalimab in combination with concurrent chemoradiotherapy (CCRT) for the treatment of rNPC. METHODS: This single-arm, Phase 2 trial included patients with rNPC who met the inclusion criteria as confirmed by pathology or imaging. The patients received toripalimab combined with CCRT. The primary end point was the objective response rate (ORR) of the patients. Secondary end points included disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety profile. RESULTS: Between April 2020 and September 2023, 40 patients with rNPC were recruited. The best response of ORR after radiotherapy was 87.5% (95% confidence interval [CI]: 72.0-95.0), with a DCR of 100%. The median PFS for rNPC was 18.1 months (95% CI, 15.2-28.8). The 1-year, 2-year, and 3-year PFS rates were 68.2%, 41.3%, and 15.5%, respectively. The median OS for rNPC was 28.3 months (95% CI, 18.6-Not Available [NA]). The 1-year, 2-year, and 3-year OS rates were 69.7%, 53.9%, 44.8%. The most common acute toxicities were hematological toxicities, including lymphopenia (100%) and anemia (92.5%), whereas the most common late toxicities were dry mouth (60.0%) and nasopharyngeal wall necrosis (40.0%). Fatal epistaxis was the cause of death in 22.5% of patients. CONCLUSION: Toripalimab plus CCRT demonstrates antitumor efficacy in rNPC. The observed 22.5% rate of fatal epistaxis indicates that its potential benefits must be carefully weighed against this serious treatment-related risk.