Background It is unclear whether treatment with immune checkpoint inhibitors (ICIs) is a risk factor for contracting COVID-19. We investigated whether patients prescribed ICIs were more or less likely to contract COVID-19 than matched controls in a collaboration between a large academic healthcare system and the Massachusetts Department of Health.

Methods We performed a retrospective study of 1,577 cancer patients prescribed ICI and 26,241 matched controls. We included all patients infused with an ICI in the Mass General Brigham (MGB) network between 7/1/19 and 2/29/20 and generated an exact match of control patients from the MGB database on age, sex, and Charlson comorbidity index. For both groups, we cross referenced COVID-19 infection data through June 19, 2020 from the Massachusetts Department of Public Health using date of birth, last name, and first four letters of the first name. We calculated odds ratios (OR) for COVID-19 diagnosis using a multivariate logistic regression adjusting for age, sex, race, CCI, zip code income, and local infection rate.

Results Twenty-one patients (1.3%) prescribed ICIs and 527 controls (2.0%) were identified as COVID positive in the Massachusetts department of health database. When controlling for local infection rate, age, sex, race, CCI, and zip code income, there were no significant differences in COVID infection between ICI recipients and matched controls (OR: 0.7, 95% CI: 0.45 – 1.09, p=0.1; table 1).

Conclusions In our experience, patients who were prescribed ICI were not more likely to contract COVID-19 than matched controls, which may assist in decision-making around continuation of therapy during the pandemic. More research needs to be conducted to determine potential behavioral and testing factors that may affect COVID-19 diagnosis.