Efficacy of immune checkpoint inhibitor as maintenance therapy for advanced or metastatic cancers: A meta-analysis of randomized controlled trials

This study aimed to evaluate the efficacy of immune checkpoint inhibitors (ICIs) as maintenance therapy for advanced or metastatic cancers. METHODS: The PubMed, Embase, and Cochrane Library databases were searched for eligible randomized controlled trials. A meta-analysis of eligible studies investigating the outcomes including progression-free survival (PFS), overall survival (OS), and objective response rate (ORR) with a significance level set to 0.05 was performed. RESULTS: Five RCTs (n = 2828) were identified in this analysis. The pooled hazard ratios (HRs) of PFS and OS for ICI maintenance therapy were 0.88 (95% CI: 0.68–1.13, P = .31) and 0.82 (95% confidence interval [CI]: 0.74–0.92, P = .0005), respectively; the pooled odds ratio (OR) of ORR was 2.24 (95% CI: 1.23–4.09, P = .0008). Subgroup analysis indicated that anti-PD-L1 antibody significantly improved the OS (P = .0008), while anti-PD-1 and anti-PD-1 plus anti-cytotoxic T lymphocyte antigen 4 antibodies significantly prolonged the PFS of patients. CONCLUSION: ICI maintenance therapy enhanced the survival of patients with advanced or metastatic cancers.