Clin Infect Dis. 2021 Apr 8:ciab298. doi: 10.1093/cid/ciab298. Online ahead of print.
BACKGROUND: Cytomegalovirus (CMV) reactivation is one of the most common infectious complications after allogeneic hematopoietic cell transplant (HCT) and may result in significant morbidity and mortality. Primary prophylaxis with letermovir demonstrated a reduction in clinically significant CMV infections (CS-CMVi) in clinical trials of CMV-seropositive HCT recipients. This study aims at exploring the effect of primary letermovir prophylaxis in this population on the incidence and outcomes of refractory or resistant CMV infections.
METHODS: This is a single-center, retrospective cohort study of 537 consecutive CMV-seropositive allogeneic HCT recipients cared for during March 2016 to October 2018. Baseline demographics, HCT characteristics, CMV infections, treatment and mortality data were collected from the electronic medical record. CMV outcomes were defined according to the recently standardized definitions for clinical trials. Characteristics and outcomes were assessed according to receipt of primary letermovir prophylaxis.
RESULTS: Of 537 patients identified, 123 received letermovir for primary prophylaxis during the first 100 days after HCT, and 414 did not. In a multivariate analysis, primary prophylaxis with letermovir was associated with reductions in CS-CMVi (hazard ratio [HR] 0.26, 95% CI 0.16-0.41), CMV end-organ disease (HR 0.23, 95% CI 0.10-0.52), refractory or resistant CMV infection (HR 0.15, 95% CI 0.04-0.52), and non-relapse mortality at week 48 (HR 0.55, 95% CI 0.32-0.93). There was neither resistant CMV nor CMV-related mortality in the primary letermovir prophylaxis group.
CONCLUSIONS: Primary letermovir prophylaxis effectively prevents refractory or resistant CMV infections and decreases non-relapse mortality at week 48, as well as CS-CMVi and CMV disease after allogeneic HCT.