Abstract
OBJECTIVES: Metastatic nasopharyngeal carcinoma (mNPC) following palliative chemotherapy has high incidence and mortality rates. While maintenance therapy shows promising potential, the optimal strategy remains undefined. This study aimed to evaluate the therapeutic efficacy of immunochemotherapy maintenance in patients with mNPC. METHODS: This cohort study evaluated the therapeutic efficacy of combined maintenance therapy with capecitabine and anti-PD-1 antibodies in mNPC patients, using a prospectively maintained database. The primary endpoint was progression-free survival (PFS), and secondary endpoints included overall survival and safety profile. Furthermore, stratification analysis and sensitivity analysis were performed. RESULTS: The study included 300 mNPC patients treated at Sun Yat-sen University Cancer Center from 2018 to 2023. Two hundred and thirty-four patients (78.0%) were male, and the median age was 45 years [interquartile range (IQR): 36-54]. At median follow-up of 43.6 months (IQR: 31.8-57.8), combination maintenance significantly improved PFS compared to single-drug maintenance [weighted hazard ratio (HR) 0.580, 95% confidence interval (95% CI) 0.387-0.872, P = 0.009; E-value, 2.27]. Stratification analysis revealed enhanced efficacy of immunochemotherapy maintenance in patients without prior local treatment (HR 0.414, 95% CI 0.224-0.767, P = 0.005) or with elevated premaintenance Epstein-Barr virus (EBV) DNA levels (HR 0.063, 95% CI 0.007-0.548, P = 0.012). No significant difference in PFS was observed between the capecitabine and anti-PD-1 single-agent groups. Notably, combination therapy yielded significantly longer PFS than either single-drug regimen. The safety profile was similar between combination maintenance and single-drug groups. CONCLUSIONS: Combined maintenance therapy with anti-PD-1 antibodies and capecitabine may be a feasible treatment strategy for mNPC patients.