The efficacy and safety of programmed cell death 1 and programmed cell death 1 ligand inhibitors for advanced melanoma: A meta-analysis of clinical trials following the PRISMA guidelines

The purpose of this study was to investigate the efficacy and safety of programmed cell death 1 (PD-1) and programmed cell death 1 ligand (PD-L1) inhibitors using a meta-analysis of present trials for advanced melanoma. A fully recursive literature search of the primary electronic databases for available trials was performed. The objective response rate (ORR) and the median progression-free survival (PFS) of clinical responses were considered the main endpoints to evaluate the efficacy, whereas Grade 3-4 adverse effects (AEs) were analyzed to evaluate safety. The ORR of PD-1 and PD-L1 inhibitors was 30% (95% CI: 25- 35%). No significant difference in the ORR was observed after the comparisons of low-dose, median-dose, and high-dose cohorts. In addition, the rate of Grade 3-4 AEs was 9% (95% CI: 6-12%). According to the 3 randomized controlled trials that compared PD-1 inhibitors with chemotherapy, the difference between these 2 groups was found to be statistically significant with respect to the ORR, PFS and the incidence of Grade 3-4 AEs; that is, the relative risk (RR) of the ORR was 3.42 (95% CI: 2.49-4.69, P<0.001), the hazard ratio (HR) of the PFS was 0.50 (95% CI: 0.44-0.58, P<0.001), and the RR of Grade 3-4 AEs was 0.45 (95% CI: 0.31-0.65, P<0.001). According to a meta-analysis of limited concurrent studies, PD-1 and PD-L1 inhibitors appear to be associated with improved response rates, superior response durability and tolerable toxicity in patients with advanced melanoma.