PD-1 blockade with camrelizumab after chemoradiotherapy in nasopharyngeal carcinoma.

129 Background: Approximately 30% of locoregionally advanced nasopharyngeal carcinoma (NPC) experience disease relapse despite definitive chemoradiotherapy. The programmed death-1 (PD-1) blockade camrelizumab has demonstrated considerable value in recurrent/metastatic NPC, while its role in locoregionally advanced NPC is worth exploring. Methods: We conducted a randomized, open-label, phase 3 trial to evaluate adjuvant camrelizumab in locoregionally advanced NPC after definitive chemoradiotherapy. Patients with T4N1M0 or T1-4N2-3M0 NPC who have undergone induction chemotherapy and concurrent chemoradiotherapy were randomized in a 1:1 ratio to receive adjuvant camrelizumab (200mg intravenously once every 3 weeks for up to 12 cycles; Camrelizumab group) or observation ( Standard-therapy group). The primary endpoint was event-free survival (freedom from randomization to locoregional recurrence, distant metastasis, or death from any cause). The secondary endpoint included locoregional recurrence-free survival, distant metastasis-free survival, overall survival, safety, and quality of life. Results: A total of 226 patients were randomized to the Camrelizumab group and 224 to Standard-therapy group. At a median follow-up of 37 months, the 3-year event-free survival was 86.9% in the Camrelizumab group and 77.4% in the Standard-therapy groups (stratified hazard ratio, 0.61; 95% confidence interval [CI], 0.38 to 0.96; P = 0.03). Grade 3 or 4 adverse events were reported in 11.2% patients in the Camrelizumab group and 3.2% of those in the Standard-therapy group. The most common adverse event of grade 3 or 4 was leukopenia (4.9% and 1.4%, respectively). There was no meaningful deterioration in quality of life associated with the use of adjuvant camrelizumab. Conclusions: Adjuvant PD-1 blockade with camrelizumab significantly improved event-free survival, with mild toxicity, highlighting its compelling role in the management of locoregionally advanced NPC. (DIPPER,ClinicalTrials.gov numberNCT03427827). Clinical trial information: NCT03427827 . [Table: see text]