Efficacy of immune checkpoint inhibitors (ICIs) in locoregionally advanced nasopharyngeal carcinoma (LA NPC): A meta-analysis of phase II and III randomized controlled trials.

Abstract

e18068 Background: Locoregionally advanced nasopharyngeal carcinoma (LA NPC) is primarily managed with definitive chemoradiotherapy, with induction chemotherapy improving disease control in higher-risk patients. However, distant metastasis remains an issue, with suboptimal long-term survival outcomes. While immune checkpoint inhibitors (ICIs) have demonstrated clinical activity in recurrent or metastatic NPC, their role in earlier-stage, curative-intent settings remains under active investigation. We conducted a meta-analysis of randomized controlled trials to evaluate the efficacy of ICIs in patients with LA NPC. Methods: We performed a comprehensive literature search using EMBASE and MEDLINE databases, from inception through January 9th, 2026. Eligible studies were randomized controlled trials, phase II and III, involving ICIs in patients with LA NPC. Studies reporting overall survival (OS), progression/event-free survival (PFS), recurrence-free survival (RFS), and distant metastasis-free survival (DMFS) were included in the analysis. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using random-effects models for PFS/EFS and OS due to some inter-study heterogeneity. Heterogeneity was assessed using Cochran’s Q test and the I² statistic. Results: A total of four trials, two phase III (CONTINUUM and DIPPER) and two phase II (Liu S et al. 2024 and Li W et al. 2025), were included in the analysis. CONTINUUM examined the addition of sintilimab to induction-concurrent chemotherapy. DIPPER compared adjuvant camrelizumab to observation after induction-concurrent chemotherapy. Liu S et al. 2024 compared neoadjuvant and adjuvant toripalimab to standard of care chemotherapy. Li W et al. 2025 examined the addition of adjuvant tislelizumab after endoscopic surgery. Patients receiving ICIs were associated with a significant improvement in PFS compared to standard therapy (HR 0.48; 95% CI 0.33-0.69; p<0.0001). Overall survival did not differ significantly between ICI and standard therapy arms (HR 0.64; 95% CI 0.33-1.23; p=0.18). Among studies reporting secondary efficacy endpoints, ICIs were associated with significant improvements in DMFS (HR 0.52; 95% CI 0.36–0.75; p=0.0005) and RFS (HR 0.47; 95% CI 0.31–0.71; p=0.0003). Conclusions: This meta-analysis demonstrated that ICI-based regimens were associated with significantly improved PFS, RFS, and DMFS. No statistically significant difference in overall survival was observed, though OS data remain immature. Longer follow-up and additional randomized studies are warranted to clarify the durability of benefit and define the impact of ICIs on long-term survival outcomes in LA NPC.