Ligand Pharma Announces Preclinical Data for LG-7501

Ligand Pharmaceuticals Incorporated

announced that data from preclinical studies evaluating LG-7501 were featured in a poster presentation today at the 63^rd Annual Meeting of the American Association for the Study of Liver Diseases in Boston. Ligand is developing novel small molecule inhibitors of NS5B polymerase for the treatment of hepatitis C virus infection (HCV) using its HepDirect^™ liver-targeting technology platform. LG-7501 is a HepDirect prodrug designed for increased liver targeting, potentially improving clinical efficacy and safety. In preclinical studies, Ligand evaluated the pharmacokinetics and liver targeting of LG-7501. LG-7501 is a HepDirect prodrug of 2'-C methylguanosine, a clinically validated NS5B polymerase inhibitor. HepDirect liver targeting of 2'-C methylguanosine and other active nucleosides may be an effective method to improve efficacy while reducing systemic side effects in HCV treatment. LG-7501 efficiently targeted the liver with reduced systemic distribution in preclinical models, providing proof-of-concept with a clinically validated HCV treatment. The key findings include: * LG-7501 has good oral bioavailability in two species. * LG-7501 is rapidly metabolized to the active drug. * LG-7501 converts to the active drug in the liver, resulting in greatly increased liver concentrations of the active drug while greatly reducing systemic distribution.