Safety and efficacy of immune checkpoint inhibitors in nasopharyngeal carcinoma patients with chronic hepatitis B virus infection

Purpose: To explore the safety and efficacy of immune checkpoint inhibitors in nasopharyngeal carcinoma patients with chronic hepatitis B virus (HBV) infection. Methods: We conducted a retrospective study of nasopharyngeal carcinoma patients with HBV infection who received immune checkpoint inhibitors at our medical centre from 1 February 2017, to 30 November 2021. The primary endpoint was treatment-related adverse events and the secondary endpoint was tumour response and survival outcome. Results: Nineteen eligible patients were selected and all patients tested positive for hepatitis B surface antigen. Five patients received Sintilimab, four received Nivolumab, three received Camrelizumab, three received Toripalimab, three received Penpulimab and only one received Pembrolizumab. None of the patients in the study experienced HBV reactivation or treatment-related deaths. The adverse reactions were mild in general, primarily grade 1; only leukopenia, lymphocytopenia, thrombocytopenia, neutrophilia, ALT increase and AST increase were grade 3. The objective response rate was 77.8% and the disease control rate was 88.9%. The median overall survival (OS) of all patients was 14.4 months and the median progression-free survival (PFS) was 10.4 months. The 1-year PFS and 1-year OS were 47.4% and 52.6%, respectively. Subgroup analysis revealed that immunotherapy as a first-line treatment improved patient OS. Conclusion: Immunotherapy is safe and effective for nasopharyngeal carcinoma patients with HBV infection. Regular monitoring of HBV biomarkers and anti-viral prophylaxis should not exclude this particular population from receiving immunotherapy indications in clinical practice or clinical trials.