Background: The association between immune checkpoint inhibitor (ICI) and outcomes of cancer patients with coronavirus disease 2019 (COVID-19) infection has yet to be systematically evaluated. This meta-analysis aims to investigate the effects of ICI treatment on COVID-19 prognosis, including mortality, severity, and any other prognosis-related outcomes. Methods: Eligible studies published up to 27 February 2021 were included and assessed for risk of bias using the Quality in Prognosis Studies tool. A random-effects meta-analysis was conducted to estimate the pooled effect size along with its 95% confidence intervals. The quality of body evidence was evaluated using the modified Grading of Recommendations Assessment, Development, and Evaluation framework. Results: Eleven studies involving a total of 2826 COVID-19-infected cancer patients were included in the systematic review. We discovered a moderate-to-high quality of evidence that ICI was not associated with a higher mortality risk, while the other outcomes yielded a very low-to-low-evidence quality. Although our findings indicated that ICI did not result in a higher risk of severity and hospitalization, further evidence is required to confirm our findings. In addition, we discovered that prior exposure to chemoimmunotherapy may be linked with a higher risk of COVID-19 severity (OR 8.19 [95% CI: 2.67–25.08]; I2 = 0%), albeit with small sample size. Conclusion: Our findings indicated that ICI treatment should not be adjourned nor terminated during the current pandemic. Rather, COVID-19 vigilance should be increased in such patients. Further studies with larger cohorts and higher quality of evidence are required to substantiate our findings. Trial registration number: This project has been prospectively registered at PROSPERO (registration ID: CRD42020202142) on 4 August 2020.
- Checkpoint inhibitor
- Programmed cell death 1 receptor