PGY2 Oncology Pharmacy Resident University of North Carolina Medical Center Chapel Hill, North Carolina, United States
Poster Abstract: Background/Rationale: Cytomegalovirus (CMV) infection is one of the most common clinically significant infections following allogeneic stem cell transplant.1 Letermovir, an orally-administered CMV DNA terminase complex inhibitor, is approved by the Food and Drug Administration for prophylaxis of CMV infection and disease in adult CMV-seropositive allogeneic stem cell transplant recipients.2 Letermovir is the standard of care for CMV prophylaxis, however, the optimal time of initiation within the initial 28 days post-transplant remains unclear. Standard practice at the University of North Carolina (UNC) Medical Center is to initiate letermovir prophylaxis on Day +15 and to continue through Day +100 for CMV-seropositive allogeneic transplant recipients. Letermovir has been shown to be more effective when initiated prior to detectable CMV DNA, even if not meeting criteria deemed clinically significant.3 Internal quality data found the median time to detectable, low-level CMV DNA at UNC was 18 days post-transplant. Previous studies have noted a median start time of 9 days post-transplant, but no additional data has been published to determine the most effective letermovir start date. Our study seeks to examine if the delayed letermovir start could avoid unnecessary medication administration while maintaining effective CMV prevention.
Objective(s): The objective of this study was to determine if initiation of letermovir prophylaxis on Day +15 following allogeneic stem cell transplant impacts CMV reactivation rates and adequately prevents clinically significant CMV infection.
Methods: This single center, retrospective cohort study included adult patients who received an allogeneic stem cell transplant at UNC Medical Center between May 2015 and April 2023, regardless of CMV serostatus. The primary outcome was the number of patients with clinically significant CMV infection, which was defined as CMV disease or CMV viremia which requires preemptive treatment. Secondary outcomes included time to CMV reactivation, time to start of preemptive treatment, steroid use, the number of patients with CMV viremia/disease, and the CMV preemptive therapy utilized.
Results: Results pending.
Conclusions/
Discussion: Results pending.
References (must also be included in final poster): 1. Teira P, Battiwalla M, Ramanathan M, et al. Early cytomegalovirus reactivation remains associated with increased transplant-related mortality in the current era: a CIBMTR analysis. Blood. 2016;127(20):2427-2438. doi:10.1182/blood-2015-11-679639 2. Marty FM, Ljungman P, Chemaly RF, et al. Letermovir Prophylaxis for Cytomegalovirus in Hematopoietic-Cell Transplantation. N Engl J Med. 2017;377(25):2433-2444. doi:10.1056/NEJMoa1706640 3. Marty FM, Ljungman PT, Chemaly RF, et al. Outcomes of patients with detectable CMV DNA at randomization in the phase III trial of letermovir for the prevention of CMV infection in allogeneic hematopoietic cell transplantation. Am J Transplant. 2020;20(6):1703-1711. doi:10.1111/ajt.15764
