Oral Versus Intravenous Anti-CMV Preemptive Strategies in Allogeneic Stem Cell Transplant Patients with CMV Reactivation: Experience from the National Center of Bone Marrow Transplantation, Tunis, Tunisia

Cytomegalovirus (CMV) infection is a common and severe complication following allogeneic stem cell transplantation (ASCT) and requires effective preemptive antiviral therapy. Both oral and intravenous (IV) antiviral agents effectively reduce CMV viral load and achieve viral clearance. Studies comparing oral and IV anti-CMV preemptive treatment in ASCT patients with CMV reactivation showed a potential difference in treatment response and safety profiles between the two administration routes. We retrospectively compared the efficacy and safety of oral with intravenous (IV) anti-CMV preemptive therapy in ASCT recipients with CMV reactivation. A descriptive retrospective study included patients who received their first ASCT between January 2018 and June 2022. The monitoring oral load was assessed weekly using a quantitative polymerase chain reaction in plasma. Fifty-five patients developing 72 CMV reactivations were included. The median age was 29 years (range, 6-50). The main underlying diseases were acute leukemia and aplastic anemia. Before ASCT, 96% of patients were at high risk of CMV reactivation. CMV reactivations were observed at a median of 43 days (range, 16-270) post-ASCT. The median viral load at CMV reactivation was 248 copies/mL (range, 150-4800). The first-line preemptive treatment was oral in 51 (71%) of the episodes (Valganciclovir, n = 40; Leflunomide, n = 11) and IV in 21 (29%) of the episodes (Foscarnet, n = 16; Ganciclovir, n = 5). Response to first-line therapy was not statistically significant between the two groups (74% vs 76%, p = 0.88). Thirteen (25%) and 5 (24%) episodes needed second or subsequent-line therapy in the oral and IV groups, respectively. The hematological toxicity was significantly higher in the oral group (61% vs 29%, p = 0.01). The mean duration of hospital stay per patient in the oral and IV groups was 7 days and 49 days (p < 10^-3), respectively. More non-CMV documented infections were observed in the IV group (38% vs 4%, p = 0.001). After a median follow-up of 18 months (range, 2-55), the 2-year-overall survival, event-free survival and cumulative incidence of non-relapse mortality were 85%, 75% and 6%, respectively. Our results showed that the oral preemptive therapy for CMV reactivations after ASCT was as effective as IV formulations and needed less hospital stay time. However, it is associated with more hematological toxicity.