Abstract
Objective: This study aimed to compare the efficacy and safety of maribavir and valganciclovir in the treatment of asymptomatic cytomegalovirus (CMV) infection in hematopoietic stem cell transplant (HSCT) recipients. Methods: In this phase 3, multicenter, randomized, double-blind, positive-controlled study, subjects with first episode of asymptomatic CMV infection post-HSCT were randomly assigned in a 1∶1 ratio to receive maribavir (400 mg, twice daily) or valganciclovir (dose-adjusted for renal clearance) for 8 weeks with a follow-up period spanned from 8 to week 20. The primary efficacy endpoint includes confirmed CMV viremia clearance at 8 weeks. Safety assessment included treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs) . Results: The Chinese population subgroup included 18 subjects, comprising 9 subjects each in the maribavir and valganciclovir arms. At 8 weeks, 77.8% of the subjects in both arms achieved confirmed CMV viremia clearance, with an unadjusted difference (maribavir vs valganciclovir) of 0.0% (95% CI: -38.4% to 38.4% ). The proportions of responders who achieved CMV viremia clearance at 8 weeks and maintained it until 16 weeks were 44.4% and 55.6% in the maribavir and valganciclovir arms, respectively, with an unadjusted difference of -11.1% (95% CI: -57.0% to 34.8% ). During the treatment observation period, 100% of subjects in both the maribavir and valganciclovir arms experienced at least one TEAE, causing 11.1% and 33.3% of subjects, respectively, to discontinue the study drug. The incidence of treatment-related SAEs was 0 and 22.2% in the maribavir and valganciclovir arms, respectively. Further, the incidence of neutropenia during the treatment observation period was lower in the maribavir arm than in the valganciclovir arm (22.2% vs 55.6% ) . Conclusion: In the Chinese population, maribavir may be comparable to valganciclovir in clearing CMV viremia to treat HSCT recipients with asymptomatic CMV infection, with acceptable safety and good tolerability, especially being numerically lower than valganciclovir in terms of neutropenia.