Bamlanivimab and Casirivimab/Imdevimab Treatment Outcomes: Results from a Large Healthcare System's Structured Implementation Experience

ABSTRACT

Background. Neutralizing antibody therapies targeting SARS-CoV-2 have been released for emergency use authorization by the FDA. Little is published on their real-world experience. In this retrospective study we share the results of our early experience on patient outcomes from use of these neutralizing antibodies within a large healthcare system. Methods. We retrospectively analyzed results of a healthcare system wide program to pro-actively identify and treat COVID-19 patients with neutralizing antibody therapy. Results. The 449 patients identified for SARS-CoV-2 neutralizing antibody therapy during the study period were retrospectively classified as falling in one of the three groups untreated (199), bamlanivimab (87) and casirivimab/indevimab (125) treated patients (Table 1). Reasons identified patients were not treated most commonly were patient declined (n=74), unable to be contacted (n=36), out of treatment window (n=23), asymptomatic and feeling better (n=21) or did not have transportation (n=9). Bamlanivimab infusion did not reduce emergency room (ER) visits or hospitalization compared to untreated patient within 30-days of follow up (Table 2), and among all patients treated with antibody therapy only treatment with bamlanivimab and non-white race were predictors of need for hospitalization (Table 3). Casirivimab/ indevimab did reduce subsequent ER visits or hospitalization within 30 days post-infusion when compared to the untreated group. However, patients treated with either antibody therapy had lower acuity of COVID-19 disease as reflected in need for intensive care unit (ICU) stay, mechanical ventilation or death (Table 2). Conclusion. Either neutralizing antibody therapy appears to markedly reduce acuity of COVID-19 disease even if patients do progress to requiring hospitalization. However, casirivimab/indevimab therapy also decreased ER visits and hospitalization suggesting better efficacy in our experience.