A Step Forward Towards Cytomegalovirus Free Hematopoietic Stem Cell Transplantation

Abstract Introduction: Cytomegalovirus (CMV) reactivation remains one of the most serious complications after allogeneic hematopoietic stem cell transplantation (HSCT) occurring in up to 30-50% of HSCT recipients. CMV reactivation can lead to adverse outcomes including end-organ damage and graft failure. Prevention of CMV infection may improve outcomes of HSCT recipients; however, CMV reactivation can still occur in HSCT recipients despite receiving prophylactic acyclovir. In this study, we used prophylactic ganciclovir pre-transplant to reduce the incidence of CMV reactivation and CMV disease. Methods: To reduce the incidence of CMV reactivation and disease, ganciclovir was administered before transplantation (5 mg/kg twice daily intravenously from day −8 to day −2) for all donor and recipient seropositive allogeneic HSCT. This was followed by high dose valacyclovir or acyclovir starting day 0 until one year post-transplant. Patients were monitored weekly with serum CMV PCR through Day 100 post transplantation. Preemptive therapy was started for an elevated CMV viral load. CMV reactivation was defined as a CMV viral load of more than 135 IU/ml. Over the course of the analysis period, two different PCR methods were used for CMV viral load; since 2015 Roche Cobas AmpliPrep/Cobas TaqMan CMV test was implicated. CMV disease was defined as detection of CMV by one of the following diagnostic tests including: culture, immunohistochemistry staining, or histopathology examination accompanied by documentation of disease signs and symptoms of the affected organ. Statistical analysis was performed using SAS version 9.4. Logistic regression models were explored to assess the association of age, graft source, and disease type on CMV reactivation. We performed a retrospective analysis of all recipient or donor CMV seropositive patients who received their first allogeneic HSCT at the University of Virginia between 2012 and 2017. Results: Seventy-nine consecutive patients were treated. The median age was 58 years (range 20 to 72). The most common diagnoses were acute myeloid leukemia (n=39, 49%) and acute lymphocytic leukemia (n=11, 14% ). Graft sources were matched related donor, (n=24, 30%), matched unrelated donor, (n=28, 35%), haploidentical (n=4, 5%) and cord blood (n=23, 29%). 43 patients (55%) received myeloablative (CyTBI, BuCy and FluBu) conditioning. 36 patients (45%) received reduced intensity/nonmyeloablative conditioning (Flu/Cy/TBI+/- ATG, Flu/Cy/ATG ,Flu Mel, Flu Bu and Cy ATG). All patients received calcineurin inhibitor based prophylactic immunosuppressive therapy for GVHD prevention. 24 patients (30%) had CMV reactivation with median time of reactivation of 47 days post-transplant (range 27 to 229). 22 out of the 24 (88%) patients required treatment for CMV reactivation with a median treatment duration of 37 days (range 14 to 315). Patients were treated with either ganciclovir or foscarnet, as clinically indicated. The cumulative incidence of CMV reactivation at day 100 post-transplant was 27% with a 95% CI (18%-37%). The median highest viral load was 2130 copies/ml (range 151 to 3,250,000 copies/ml). There were no patients with biopsy proven CMV disease. There were no deaths attributed to CMV reactivation or disease. The median time-to neutrophil recovery (ANC > 500 k/uL) was 18 days and the median time to platelet count greater than 20,000 k/ul unsupported was 19 days. The incidence of acute GVHD (Grades II-IV) was 25 %. The incidence of significant acute kidney injury defined by serum creatinine of more than 2.5 mg/dL was 2.4 %. 1 year overall survival estimate was 54% with 95% CI (42-65%). In multivariate analysis, patients who received cord blood transplants, were approximately 4 times more likely to have a CMV reactivation (Odds Ratio 3.9 with a 95% CI(1.4-10.9)), p= 0.01, than those who did not. Conclusions: The incidence of CMV reactivation by day 100 of 27% with pre-transplant ganciclovir may be improved compared to historical controls of 30-50%. The use of pre-transplant ganciclovir was associated with no CMV disease, in this single center study. The use of pre-transplant ganciclovir is safe, with low incidence of kidney damage. These data suggest that pre-transplant ganciclovir with Preemptive therapy for viral reactivation should be considered regardless of graft source. Future prospective randomized trials are needed to evaluate strategies for CMV prophylactic regimens. Disclosures No relevant conflicts of interest to declare.