Meta-Analysis of the Risk of Immune-Related Adverse Events With Anticytotoxic T-Lymphocyte-Associated Antigen 4 and Antiprogrammed Death 1 Therapies.

We assessed the risks of immune-related adverse events with anticytotoxic T-lymphocyte-associated antigen 4 (CTLA4) and antiprogrammed death 1 (PD1) therapies by meta-analysis. Twenty-one studies including 11,144 patients were found. Anti-CTLA4 therapy was associated with a significantly higher risk of overall immune-related adverse events: diarrhea, immune-related colitis, pruritus, and rash compared to control therapies (relative risk (RR) = 2.43, 2.10, 11.39, 3.88, 3.87, 95% confidence interval (CI) = 1.77-3.34, 1.52-2.45, 6.30-20.59, 2.37-6.37, 2.39-6.27, P < 0.001 for all outcomes). Anti-PD1 therapy was associated with a significantly higher risk of pruritus (RR = 4.01, 95% CI = 1.97 to 8.17, P < 0.001); however, it did not increase the risks of other adverse events. Anti-CTLA4 and anti-PD1 therapies have distinct features of immune-related adverse events. The results of our study would aid the surveillance and management of immune-related adverse events in patients receiving these therapies.