Abstract
BACKGROUND: Kidney transplant recipients (KTRs) are most vulnerable to infection in the first year after transplantation. Tixagevimab and cilgavimab are neutralizing monoclonal antibodies directed against different epitopes of the receptor-binding domain of the severe acute respiratory syndrome coronavirus 2 spike protein. The purpose of this study is to report experience with tixagevimab/cilgavimab administered to KTRs who were within 1 year of transplantation. AIM: To describe outcomes of KTRs who received tixagevimab/cilgavimab early posttransplant to prevent coronavirus disease 2019 (COVID-19). METHODS: This is a single-center retrospective cohort study of adult KTRs who underwent kidney transplantation from January 1, 2022 to September 30, 2022 and received tixagevimab/cilgavimab 300 mg/300 mg for prevention of COVID-19. Outcomes of interest were adverse events associated with tixagevimab/cilgavimab, COVID-19 breakthrough infection and COVID-19-associated hospitalization and complications. We also conducted a systematic review of the literature for the use of tixagevimab/cilgavimab as pre-exposure prophylaxis for COVID-19 in solid organ transplant recipients (SOTRs) from inception to December 31, 2023. RESULTS: There were 104 patients included with median age of 50 years (range 21-72 years). Omicron strain of the COVID-19 virus was the predominantly circulating variant at the time of current study. Patients testing positive for COVID-19 were given tixagevimab/cilgavimab for prophylaxis of complications during the median of 3 days (range 0-201 days) after kidney transplant, of whom 97 (93.3%) received the antibodies prior to discharge. No discernable adverse effects attributable to the medication were observed during the time they received prophylaxis. The efficacy of the drug assessed through the absence of breakthrough infections were observed in 91 patients. 13 (12.5%) patients developed COVID-19 breakthrough infections during an overall median follow-up period of 125 days (range 10-257 days) after tixagevimab/cilgavimab. These infections were observed at median 105 days (range 6-211 days) after receiving the prophylactic medication. 5 (4.8%) of overall patients required hospitalization and there were no reported deaths in the cohort. Findings of the systematic review were consistent with our findings wherein tixagevimab/cilgavimab was well tolerated by SOTRs. CONCLUSION: Tixagevimab/cilgavimab has a favorable safety profile when administered in newly transplanted kidney recipients. Although breakthrough infections were not uncommon, there was a low rate of hospitalization and no deaths. This study highlights the need to examine the efficacy of novel monoclonal antibodies administered for COVID-19 prophylaxis in newly transplanted recipients.