Early administration of SARS-CoV-2 monoclonal antibody reduces the risk of mortality in hematologic malignancy and hematopoietic cell transplant patients with COVID-19

Background Data on severe acute respiratory distress syndrome coronavirus 2 monoclonal antibody (SARS-CoV-2-specific mAb) use in hematologic malignancy and hematopoietic cell transplantation (HM/HCT) patients are limited. Here, we describe our experience with the use of casirivimab-imdevimab or bamlanivimab for the treatment of coronavirus disease 2019 (COVID-19) in HM/HCT patients.Methods This was a retrospective chart review at the University of Miami Hospital and Sylvester Comprehensive Cancer Center for HM/HCT patients with COVID-19 who received casirivimab-imdevimab or bamlanivimab from November 21, 2020, to September 30, 2021. Outcomes measured were mortality, hospital admission, and infusion reaction to SARS-CoV-2-specific mAbs.Results We identified 59 HM/HCT patients with mild to moderate COVID-19 who received casirivimab-imdevimab or bamlanivimab. Median age was 57 years (interquartile range [IQR]: 45-65). Among the 59 patients, 25 (42%) received cellular therapy: 14 (24%) had undergone allogeneic HCT, nine (15%) autologous HCT, and two (3%) received chimeric antigen receptor T-cell therapy. The median time from COVID-19 symptom onset to SARS-CoV-2-specific mAb administration was 4 (IQR: 3-6) days. Forty-six (78%) patients received SARS-CoV-2-specific mAbs as outpatients and 13 (22%) patients received SARS-CoV-2-specific mAbs during hospitalization. Among patients who received SARS-CoV-2-specific mAbs as outpatients, only four (9%) visited the emergency department at days 10, 11, 15, and 35 after SARS-CoV-2-specific mAb administration. None of these four patients required hospital admission. Among the hospitalized patients, five (38%) were admitted to the hospital with neutropenic fever, four (31%) were already hospitalized for transplantation and cellular therapy, three (23%) were admitted for monitoring of COVID-19 symptoms, and one (8%) was admitted with acute kidney injury. Three hospitalized patients (23%) died at 14, 35, and 59 days after SARS-CoV-2-specific mAb administration; two of these three deaths were attributed to COVID-19 infection. One patient developed an immediate infusion reaction to bamlanivimab, and no infusion reactions were reported to casirivimab-imdevimab use.Conclusion During the alpha and delta variant surges, early administration of bamlanivimab or casirivimab-imdevimab prevented hospitalization and death when given in the outpatient setting. Among patients who received mAbs at or after hospital admission, the risk of COVID-19 disease progression and death remains significant. Larger studies of the use of mAb therapy to treat COVID-19 in this population are needed.