Pradefovir Mesylate
Pradefovir mesilate (previously known as MB-06886, Hepavir B and remofovir mesylate) is an orally administered small molecule compound that belongs to a novel series of phosphate and phosphonate prodrugs of adefovir. [Adefovir] (Hepsera) is an acyclic phosphonate analogue of adenine that is used to treat hepatitis B virus. As adefovir is poorly absorbed and associated with a high level of nephrotoxicity, pradefovir mesilate was designed to specifically target the liver and reduce risks to external tissue, especially the kidneys, while improving results of adefovir.  Pradefovir is activated through oxidation that is mediated by cytochrome P-450 (CYP) 3A4, which is predominantly expressed in the liver. The novel prodrug is highly stable in both plasma and tissues and demonstrated potent preclinical and clinical anti-HBV activity. Pradefovir is undergoing phase II development for the treatment of chronic hepatitis B.