Real-World Use of Maribavir for Refractory CMV Infection and Intolerance to Conventional Anti-CMV Agents After Allogeneic Hematopoietic Cell Transplantation.

Maribavir (MBV) is approved for refractory or resistant cytomegalovirus (CMV) infection after transplantation. However, real-world data on allogeneic hematopoietic cell transplantation (allo-HCT) recipients remain limited. This study aimed to evaluate the real-world efficacy and safety of MBV in allo-HCT recipients with CMV infection or disease refractory or intolerant to conventional anti-CMV agents. This single-center study retrospectively evaluated consecutive adult allo-HCT recipients treated with an initial course of MBV for refractory CMV infection or disease or intolerance to conventional anti-CMV agents between June 2024 and December 2025. Refractory infection was defined as persistent CMV viremia despite ≥2 wk of prior antiviral therapy. The primary endpoint was CMV viremia clearance. Among 33 patients, 30 presented with CMV viremia and 4 with gastrointestinal CMV disease, including 1 patient with both. MBV was initiated mainly due to intolerance to prior antiviral agents. The median MBV therapy duration was 20 (range: 5 to 147) days, reflecting a monitoring-guided, intermittent treatment approach rather than a fixed-duration strategy. In total, 27 (90%) of 30 patients achieved CMV viremia clearance, with a median time to clearance of 11 (range: 5 to 42) days. During a median follow-up of 9.7 mo, 19 (70%) of 27 patients exhibited recurrent CMV viremia, with a median time of 31 days after MBV discontinuation. Most patients (14/16) responded to subsequent therapy, including MBV retreatment. MBV was well tolerated, with no significant hematologic or renal toxicity. MBV achieved high rates of initial CMV viremia clearance with acceptable tolerability in this real-world allo-HCT cohort. Although recurrent CMV viremia after treatment discontinuation was common, most recurrent cases remained clinically manageable with retreatment or alternative anti-CMV therapy. Further studies are needed to define the optimal treatment duration and post-treatment monitoring strategy.