GP Combined with Toripalimab Versus GP Induction Chemotherapy for Advanced Childhood Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) has a low incidence rate in children, accounting for only 1-2% of pediatric tumors. However, it is prone to metastasis, and most patients are already in advanced stages at the time of diagnosis. Chemoradiotherapy has been shown to effectively improve prognosis. Induction chemotherapy combined with concurrent chemoradiotherapy with adjusted radiation doses has demonstrated good efficacy in children and adolescents with locally advanced NPC. Nevertheless, 10-15% of patients still experience treatment failure, and 15-20% of patients respond poorly to induction chemotherapy, necessitating higher doses of radiation, which in turn increases the incidence of treatment-related sequelae. Therefore, it is crucial to explore further treatment strategies that can enhance response rates, reduce acute and long-term treatment toxicities, and improve overall efficacy on the basis of induction chemotherapy followed by adjusted concurrent chemoradiotherapy. The combination of gemcitabine and cisplatin (GP regimen) has been identified as the highest level of evidence-based induction chemotherapy regimen (Class 1A). However, the complete response rate of only 10% after three cycles of GP regimen induction chemotherapy in adults with locoregionally advanced NPC indicates the need for intensified induction treatment. PD-1 inhibitors combined with chemotherapy have demonstrated synergistic tumor-killing effects, providing additional curative opportunities for patients with locally advanced disease. Toripalimab, with its dual-blocking mechanism, is an ideal PD-1 monoclonal antibody model that can fully relieve T-cell-mediated antitumor immune suppression. Previous clinical trials have confirmed the efficacy and safety of toripalimab in treating nasopharyngeal carcinoma. This study aims to conduct the first single-center, phase II randomized controlled clinical trial in children and adolescents with nasopharyngeal carcinoma, comparing the GP regimen combined