Immune checkpoint inhibitors (ICIs) can cause inflammatory and immune-related adverse events (irAEs) that might worsen the course of COVID-19. We conducted a systematic review (PROSPERO ID: CRD42022307545) to evaluate the clinical course and complications of COVID-19 in patients with cancer receiving ICI.


We searched Medline and Embase through January 5, 2022. We included studies evaluating patients with cancer who received ICI and developed COVID-19. Outcomes included mortality, severe COVID-19, intensive care unit (ICU) and hospital admissions, irAEs, and serious adverse events. We pooled data with random effects meta-analysis.


Twenty-five studies met study eligibility (n = 36,532 patients: 15,497 had COVID-19 and 3220 received ICI). Most studies (71.4%) had a high risk of comparability bias. There were no significant differences in mortality (relative risk [RR] 1.29; 95% CI 0.62–2.69), ICU admission (RR 1.20; 95% CI 0.71–2.00), and hospital admission (RR 0.91; 95% CI 0.79–1.06) when comparing patients treated with ICI with patients without cancer treatment. When pooling adjusted odds ratios (ORs), no statistically significant differences were observed in mortality (OR 0.95; 95% CI 0.57–1.60), severe COVID-19 (OR 1.05; 95% CI 0.45–2.46), or hospital admission (OR 2.02; 95% CI 0.96–4.27), when comparing patients treated with ICIs versus patients with cancer without ICI therapy. No significant differences were observed when comparing clinical outcomes in patients receiving ICIs versus patients receiving any of the other anticancer therapies.


Although current evidence is limited, COVID-19 clinical outcomes of patients with cancer receiving ICI therapy appear to be similar to those not receiving oncologic treatment or other cancer therapies.

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Author notes

Source of support: This study was supported by the National Cancer Institute (K08 grant CA237619, Maria A. Lopez-Olivo, MD, PhD, Principal Investigator), and the Cancer Survivorship Research Grant at the University of Texas MD Anderson Cancer Center (FP00015598). Partial support was provided through MD Anderson's Cancer Center Support Grant (P30 CA016672). The study sponsors did not play any role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing Interests

Conflict of interest: Dr. Suarez-Almazor has received consultant fees in the past 12 months from Pfizer, Eli Lilly, and Bristol Myers Squibb/Celgene, unrelated to this study.

This work is published under a CC-BY-NC-ND 4.0 International License.

Supplementary data