SARS-CoV-2 Neutralizing Monoclonal Antibodies for the Treatment of COVID-19 in Kidney Transplant Recipients

Morbidity and mortality associated with coronavirus disease 2019 (COVID-19) infection in kidney transplant recipients are high and early outpatient interventions to prevent progression to severe disease are needed. SARS-CoV-2 neutralizing mAbs, including bamlanivimab and casirivimab-imdevimab, received emergency use authorization in the United States in November 2020 for treatment of mild to moderate COVID-19 disease. We performed a retrospective analysis of 27 kidney transplant recipients diagnosed with COVID-19 between July 2020 and February 2021 who were treated with bamlanivimab or casirivimab-imdevimab and immunosuppression reduction. We additionally identified 13 kidney transplant recipients with COVID-19 who had mild to moderate disease at presentation, who did not receive mAbs, and had SARS-CoV-2 serology testing available. There were no deaths or graft failures in either group. Both infusions were well tolerated. Four of the 27 patients treated with mAbs required hospitalization due to COVID-19. Four of 13 patients who did not receive mAbs required hospitalization due to COVID-19. Patients who received mAbs demonstrated measurable anti-SARS-CoV-2 IgG with angiotensin-converting enzyme 2 (ACE2) receptor blocking activity at the highest level detectable at 90 days postinfusion, whereas ACE2 blocking activity acquired from natural immunity in the mAb-untreated group was weak. Bamlanivimab and casirivimab-imdevimab combined with immunosuppression reduction were well tolerated and associated with favorable clinical outcomes in kidney transplant recipients diagnosed with mild to moderate COVID-19.