Pharmacokinetics of Oral Maribavir, a Novel Anti-Cytomegalovirus Agent, in Subjects with Renal Impairment.

Maribavir (MBV) is an oral antiviral drug with a unique mechanism of action against cytomegalovirus (CMV). Maribavir is currently in clinical development for use in recipients of stem cell or solid organ transplants, who are vulnerable to renal impairment caused by a variety of drugs or post-transplant complications. Characterization of the pharmacokinetic (PK) profile of maribavir in patients with renal impairment was needed to determine if dose adjustment is indicated. The effect of renal function on the PK of a single 400 mg dose of maribavir was evaluated in adults with normal renal function (creatinine clearance >80 mL/min) and adults with renal impairment classified as mild, moderate, or severe, as measured by creatinine clearance 50–80, 30–<50, and <30 mL/min, respectively. Subjects requiring dialysis were not included. PK results, based on total (bound and unbound) plasma concentrations are shown in the table. Analyses of PK parameters estimated from unbound plasma concentrations of maribavir also did not show statistically significant differences between groups. Renal impairment was associated higher AUC and Cmax values as well as with reductions in the oral clearance and terminal-phase volume of distribution of VP 44469, an inactive metabolite of maribavir. Results were consistent with those of previous studies, which showed that very little maribavir was excreted unchanged in urine while about 22% of an oral dose of maribavir is recovered in urine as VP 44469. In conclusion, renal impairment does not affect the pharmacokinetics of maribavir, although plasma concentrations of the metabolite VP 44469 tended to increase with decreasing creatinine clearance. No dose adjustment of maribavir is indicated in subjects with renal impairment as classified in this study.