Letermovir Prophylaxis in Patients at High Risk for CMV Disease Following Hematopoietic Cell Transplant

Abstract

<h3>Objective</h3> Starting January 2018 all adult HCT recipients at Stanford University who were at high risk (HR) for CMV disease received Letermovir prophylaxis (LET PPX). HR included: (1) ATG containing regimen, (2) an umbilical cord blood (UBC) graft, or (3) a haplo-identical, (4) unrelated (URD) (5) mismatched-related donor (misM-RD). We performed a retrospective analysis of the impact of LET PPX on the impact of CMV compared to historical controls. <h3>Methods</h3> 629 adults HCT patients from Jan 2013 - May 2019 were analyzed. 76 of these patients received LET PPX. Plasma CMV PCR was performed weekly through D+100. Prior to 2018, UCB patients received valacyclovir 2000 mg TID. PET was started if viral load (VL) was > 400 copies/ml (2009-2012) or 400 IU/ml (2013-2019). CMV disease was defined by published criteria. <h3>Results</h3> • LET PPX was well-tolerated without hematopoietic/organ toxicity. • CMV viremia occurred during LET PPX in 71 % of patients which was comparable to 74% in the controls; however, 34% LET PPX (34%) were started on a different CMV-active agent compared to 50% of controls. In 52% of LET PPX patients viremia cleared without change of antiviral or disease. (Table 1) • Although median hospital stays were the same in the LET PPX and control groups, there was a trend to greater number of hospitalizations in the control group. • Median Day post-transplant of first detection of CMV viremia for patients who received PET/change in CMV-active agent was later in the LET PPX group (D+45) than in the controls (D+ 18) • 3 of 76 (3.9%) LET PPX developed disease compared with 48 of 553 controls (8.7%). None of 24 ATG patients on LET PPX developed disease compared to 23/235 controls. (Table 2) <h3>Conclusion</h3> • Compared to controls, LET prophylaxis decreased the burden of CMV. • Other analyses not shown: hospitalizations, transfusions, infections, GHVD, relapse, survival