SARS-CoV-2 neutralizing antibodies for COVID-19: Outcomes for bamlanivimab versus bamlanivimab-etesevimab combination in a racially diverse cohort of patients with significant comorbidities

What is known and objective: Anti-spike monoclonal antibodies (MAB) including bamlanivimab (BAM) and bamlanivimab/etesevimab (BAM/E) have shown reduced hospitalization rates for non-severe coronavirus disease 2019 (COVID-19) in clinical trials. Recent data have provided real-world hospitalization rates for high-risk patients treated with BAM, however, data on a similar cohort treated with BAM/E are lacking.

Methods: This retrospective cohort study evaluated outpatients ≥18 years with laboratory-confirmed mild/moderate COVID-19 who received MAB from 1 December 2020 to 19 April 2021. Use of BAM monotherapy changed to BAM/E combination on 27 March 2021. Primary outcome was overall rate of COVID-19 related-hospitalization, including comparison of hospitalization rates between MAB-formulation groups. Secondary outcomes were 30-day mortality and length of stay (LOS).

Results and discussion: The population included 643 patients (BAM and BAM/E); median age was 58 years, 43% were male, median BMI was 33 kg/m² , and 24% self-identified as Black. Patients in the BAM/E combination group were significantly younger with higher median BMI and a longer time from symptom onset to infusion. The incidence of 30-day COVID-19 related hospitalization was similar between patients receiving either BAM or BAM/E combination (7.8% and 7.2%, respectively).

What is new and conclusion: This study represents the first such publication of real-world BAM/E hospitalization outcomes. Hospitalization rates utilizing BAM/E were comparable to BAM in our real-world study.