Use of maintenance therapy and incidence of recurrent Cytomegalovirus DNAemia among allogeneic hematopoietic cell transplant recipients.

Background: Cytomegalovirus (CMV) infection is the most common infection following hematopoietic cell transplantation (HCT). Preemptive antiviral therapy is highly effective at halting viral replication and preventing CMV disease; however, recurrence rates after clearance of CMV DNAemia are high (50-70%). Current treatment guidelines recommend maintenance therapy after initial clearance. Yet, the effectiveness of this intervention to prevent recurrence is not well defined.

Objectives: We aimed to assess the impact of maintenance therapy on the probability of recurrent CMV in allogeneic HCT recipients with early CMV reactivation.

Study Design: Sixty-six patients with an initial episode of early CMV reactivation who achieved viral clearance in response to preemptive therapy were included. We compared the incidence of recurrent CMV DNAemia in patients who received maintenance therapy vs those who underwent early discontinuation of antiviral therapy.

Results: Recurrence occurred in 47/64 (73%) patients, including 11/14 (79%) patients without maintenance therapy and 36/50 (72%) of patients who received maintenance therapy (P = 0.74). The propensity score adjusted risk ratio for the effect of maintenance therapy on recurrence was 0.89 (95% CI 0.64-1.25; P = 0.41). In a time to event analysis using the unweighted cohort, the 90-day probability of CMV recurrence was similar between patient groups independent of maintenance therapy administration (54% vs 64% for maintenance vs non-maintenance groups, respectively; log-rank P = 0.37).

Conclusion: These data suggest that maintenance antiviral therapy does not reduce the incidence of CMV recurrence while off therapy and is of limited value in HCT recipients who have successfully eradicated CMV DNAemia in response to preemptive therapy. Larger studies in this area are needed.