Maribavir

Maribavir is an orally bioavailable benzimidazole l-riboside antiviral drug, with a spectrum of activity essentially limited to human cytomegalovirus (CMV) and Epstein-Barr virus (EBV). It is a potent and specific inhibitor of the CMV UL97 kinase. Maribavir is the generic name for 5,6-dichloro-2- (isopropylamino)-1-beta-l-ribofuranosylbenzimidazole, with the chemical structure as shown in Figure 223.1. The molecular weight is 376.24. Investigational drug code names include (BW)1263W94, GW257406X, VP41263, and SHP620 reflecting sequential changes in corporate ownership. Over the past 20 years, maribavir has undergone various clinical trials as an experimental CMV antiviral drug. Earlier phase I and II trials showed anti-CMV activity with an acceptable adverse effect profile. Unsuccessful phase III trials of low-dose maribavir for prevention of CMV infection in transplant patient populations ended in 2009, followed a few years later by phase II CMV treatment trials at higher doses, which were announced as successful in 2015. There is continued clinical interest in this compound because of its distinct antiviral target, oral bioavailability and favorable toxicity profile, although its optimal therapeutic role remains to be determined.