This is a multicenter, open-label, randomized phase II clinical trial designed to evaluate the optimal timing of toripalimab administration during neoadjuvant chemotherapy in patients with locoregionally advanced nasopharyngeal carcinoma. Participants will receive gemcitabine and cisplatin (GP) chemotherapy combined with toripalimab administered on different days (Day 1, Day 5, or Day 9) to compare treatment responses. The neoadjuvant phase includes 3 cycles of 21 days each, followed by concurrent chemoradiotherapy. The estimated enrollment period is from March 2026 to March 2028.