Impact of early versus late administration of bamlanivimab on readmissions in patients with high-risk COVID-19

Background: Recombinant monoclonal antibody therapies have been utilized under emergency use authorization (EUA) for the prevention of clinical decompensation in high-risk COVID-19 positive patients for up to 10 days from symptom onset. The purpose of this study was to determine the impact of the timing of the monoclonal an-tibody, bamlanivimab, on clinical outcomes in high-risk COVID-19 positive patients. Methods: This was an IRB-approved, retrospective evaluation of adult patients who received bamlanivimab per EUA criteria in the emergency department (ED). Patients were dichotomized into two groups- 3 days of symp-toms or less (early) versus 4 to 10 days (late). The primary outcome was hospitalization for COVID-related illness at 28 days (or treatment failure). Secondary outcomes were COVID-related ED visits at 28 days, hospital and in-tensive care unit (ICU) length of stay (LOS), and in-hospital mortality at 28 days. Results: A total of 839 patients were included in the analysis. There was no difference observed in COVID-related hospitalization rates within 28 days between the early and late bamlanivimab administration groups (7.5% vs. 8.2%, p = 0.71). There was no difference in COVID-related ED visits within 28 days with 13% of patients returning to the ED. Conclusions: In conclusion, there were no differences in the rates of hospitalization at 28 days when bamlanivimab was administered in the first 3 days of illness versus days 4 to 10. Future prospective studies are warranted to expand upon the characteristics of patients that may or may not benefit from monoclonal an-tibody therapy. (c) 2021 Elsevier Inc. All rights reserved.