OBJECTIVES: COVID-19 treatment guidelines, particularly for monoclonal antibody (mAb) therapies, have changed over time, as new variants have emerged and new treatments have been authorized. However, limited research exists on mAb utilization and the characteristics of patients who receive this treatment. Commissioned by the FDA, this study aims to describe mAb utilization and the characteristics of patients who utilized mAb therapy in the outpatient setting.

METHODS: This retrospective cohort study was conducted using closed claims from Komodo’s Healthcare Map from January 1, 2019 to March 31, 2022 (study period). The sample included patients >18 years of age with >1 COVID-19 diagnosis and their first mAb therapy in the outpatient setting between January 1, 2020 and March 1, 2022 (index date). Patient characteristics were assessed during the 365 days before or on the index date, and mAb utilization was assessed on or after the index date through the end of continuous enrollment or the study period.

RESULTS: 397,818 patients (mean age 50.5; 56.1% female) were identified. Of the patients with race and ethnicity information (46.0% and 40.4%, respectively), 82.6% were white and 90.8% were non-Hispanic or Latino. Most patients (78.9%) had at least one pre-existing condition; the most common pre-existing conditions were heart and mental health conditions. The most common mAb index therapy overall was casirivimab+imdevimab; however, the most common mAb therapy was bamlanivimab before the Delta variant vs. casirivimab+imdevimab after the Delta variant. Most patients (98.5%) received only one mAb therapy.

CONCLUSIONS: mAb utilization varied over time possibly due to changes in the most prevalent variant, supply chain issues, and current recommendations and regulations. Most patients who received mAb therapy had pre-existing conditions or were white or non-Hispanic or Latino. Additional research is needed to better understand a potential disparity in access and clinical outcomes associated with outpatient mAb utilization.