Single-center, open-label, randomized controlled trial comparing the tolerability of maribavir 400 mg twice daily versus standard-dose valganciclovir for cytomegalovirus prophylaxis in high-risk kidney transplant recipients.

Cytomegalovirus (CMV) remains a major contributor to morbidity after a kidney transplant. Although valganciclovir (VGC) prophylaxis is effective, its use is limited by leukopenia. Maribavir's (MAR) role in primary CMV prophylaxis is not established. We conducted a 12-month, single-center, open-label, randomized controlled trial including 70 adult recipients at high CMV risk randomized 1:1 to MAR 400 mg twice daily or VGC 900 mg daily. The incidence of clinically significant leukopenia during prophylaxis did not differ between arms (22.9% vs 5.7%, P = .084). For the secondary endpoint, VGC recipients spent a greater proportion of prophylaxis days below white blood cell thresholds (<3000/μL: 12.2% vs 2.4%, P < .001; <2000/μL: 3.0% vs 0.2%, P < .001; <1000/μL: 0.3% vs 0.1%, P = .027). As an exploratory endpoint, CMV outcomes appeared similar between arms, including any viremia (37% vs 43%, P = .626), polymerase chain reaction >1000 IU/mL (23% vs 31%, P = .420), and refractory infection (15% vs 17%, P = .743). No cases of CMV breakthrough, disease, or resistance occurred. Hospitalizations, rejection, graft loss, and mortality did not differ. In summary, as compared to VGC, MAR had a similar incidence of clinically significant leukopenia with reduced overall leukopenia burden. These findings should be confirmed in larger multicenter studies.