A large scale meta analysis identifies common adverse events with checkpoint inhibitors vs chemotherapy in melanoma patients

Background: A meta-analysis was performed to assess the risk of common adverse events in melanoma patients treated with checkpoint inhibitors. Methods: Eligible studies were downloaded from PubMed, Embase, and Cochrane databases based on an established strategy. Review manager version 5.3 was used to analyze data. Results: After exclusion of ineligible studies, six studies were finally included in the meta-analysis, which comprised of 2136 patients in intervention group and 1773 patients in control group. There was a difference in low grade risk of pruritus (OR 5.63, 95% CI 2.92-10.85, P < 0.00001), diarrhea/colitis (OR 1.51, 95% CI 1.09-2.09, P = 0.01), but not fatigue (low grade, OR 0.96, 95% CI 0.72-1.29, P = 0.80; high grade, OR 0.72, 95% CI 0.23-2.24, P = 0.57) and some high grade risk between the intervention group and control group. Subgroups analysis revealed that low grade risk of pruritus (OR 8.17, 95% CI 4.29-15.55, P < 0.00001) and high grade risk of pruritus (OR 7.08, 95% CI 1.25-40.09, P = 0.03) were significantly different between patients treated with chemotherapy and those treated with checkpoint inhibitors. But fatigue and diarrhea/colitis were not different between the two groups. Conclusion: Checkpoint inhibitors are associated with a higher risk in some side effects than chemotherapy in melanoma patients. Therefore, strategies that reduce the risk of adverse events in patients taking checkpoint inhibitors should be developed.