Evaluation of Monoclonal Antibodies in Preventing Hospitalizations, Emergency Department Visits, and Mortality in High-Risk COVID-19 Patients.

Background: The coronavirus disease 2019 (COVID-19) is a novel coronavirus that has caused an unprecedented global pandemic, with few treatment options currently available. Neutralizing monoclonal antibodies (mAbs) are a promising treatment approach to reduce hospitalizations in high-risk patients with mild-to-moderate COVID-19 infections.

Objective: The primary objective is to compare hospitalization rates of high-risk patients who tested positive for COVID-19 within 28 days between those who received mAb infusions versus those who did not. Secondary objectives were emergency department (ED) visits and mortality within 28 days of a positive test.

Methods: This single-center, institutional review board-approved, retrospective, observational cohort study included patients aged 19 years and older who tested positive for COVID-19 between December 2, 2020 and February 28, 2021. Patients who received the mAbs bamlanivimab or casirivimab/imdevimab were compared with patients who did not receive mAb infusions to examine hospitalization rates, ED visits, and mortality within 28 days of the positive COVID-19 test.

Results: A total of 2780 patients were evaluated for inclusion using electronic chart review via Cerner. Of the 1612 patients who met inclusion criteria, 568 received an mAb infusion (mAb group) and 1044 did not (non-mAb group). Baseline characteristics were similar between the 2 groups. Of the patients in the mAb group, 34 (6%) were hospitalized versus 397 (38%) in the non-mAb group. Patients with ED visits included 111 (20%) and 672 (64%) in the mAb and non-mAb groups, respectively. Finally, 5 patients in the mAb group experienced mortality (0.9%) versus 83 (8%) in the non-mAb group. Each endpoint achieved statistical significance with a P value of <0.0001.

Conclusion: Monoclonal antibody infusions are effective in preventing hospitalization, ED visits, and mortality in high-risk patients with mild-to-moderate COVID-19.