The risk of rash for cancer patients treated with PD-1/PD-L1 inhibitors: An updated systematic review and meta-analysis

Background: This study was designed to assess the risk of programmed cell death-1 (PD-1) or programmed cell death ligand 1 (PD-L1) related rash in various situations. Methods: Guided by Preferred Reporting Items for Systematic Reviews and Meta-Analyses, data on rash in clinical trials related to PD-1 or PD-L1 were collected to comprehensively evaluate its incidence risk in various situations. Results: Ninety-five clinical trials, divided into 12 groups according to treatment regimens, were enrolled for the final comprehensive assessments and analyses. Compared with chemotherapy or placebo alone, both PD-1 and PD-L1 inhibitors increased the risk of developing rashes for all grades (odds ratio [OR] = 1.61, P = .0003; OR = 2.94, P < .00001). Whether used in combination with chemotherapy or other types of immunosuppressants, similar risk trends were observed (OR = 2.42, P < .00001; OR = 2.11, P = .0007; OR = 4.49, P < .00001; OR = 5.15, P = .0006; OR = 3.16, P = .0002). Conclusion: Both PD-1 and PD-L1 increased the risk of rash occurrence, especially when used in combination with other immunosuppressive antitumor drugs.