A single-center review of pre-exposure prophylaxis with tixagevimab–cilgavimab in solid organ transplant recipients

Background

Coronavirus disease 2019 (COVID-19) continues to negatively impact solid organ transplant recipients (SOTr). Data on the use of tixagevimab–cilgavimab (tix-cil) in vaccinated SOTr during circulation of Omicron and its subvariants are limited. Therefore, this single-center review was conducted to evaluate tix-cil efficacy in multiple organ transplant groups during a study period where Omicron B.1.1.529, BA.2.12.1, and BA.5 predominated.

Methods

In this single-center retrospective study, we evaluated the incidence of COVID-19 infection in adult SOTr who did or did not receive pre-exposure prophylaxis (PrEP) with tix-cil. SOTr were included if they were at least 18 years of age and met emergency use authorization criteria for tix-cil use. The primary outcome analyzed was the incidence of COVID-19 infection.

Results

Ninety SOTr met inclusion criteria and comprised of two groups, tix-cil PrEP (n = 45) and no tix-cil PrEP (n = 45). Of SOTr who received tix-cil PrEP, three (6.7%) developed COVID-19 infection, compared to eight (17.8%) in the no tix-cil PrEP group (p = .20). Of the 11 SOTr diagnosed with COVID-19, 15 (82.2%) were fully vaccinated against COVID-19 prior to transplantation. Moreover, 18.2% and 81.8% of the COVID-19 cases observed were asymptomatic and mild-to-moderate, respectively.

Discussion

Our study results, which included months when BA.5 was in increased circulation, suggest no significant difference in COVID-19 infection with or without use of tix-cil PrEP in our solid organ transplant groups. As the COVID-19 pandemic continues to evolve, clinical utility of tix-cil should be evaluated against new, emerging strains.