Clinical data being presented at the 56th American Association for the Study of Liver Diseases (AASLD) annual meeting confirm that VX-950, an investigational oral Hepatitis C protease inhibitor developed by Vertex Pharmaceuticals Incorporated was well-tolerated and possessed potent antiviral activity in a 14-day study in patients with Hepatitis C virus (HCV) infection.

The rapid decline in plasma HCV-RNA levels observed in HCV patients taking VX-950, together with a viral kinetic analysis that projects the potential duration of treatment required to achieve sustained virologic response (SVR), support the evaluation of VX-950 in a novel, three-month combination treatment paradigm. Vertex has filed an investigational new drug application (IND) with the US Food and Drug Administration to support Phase II clinical development of VX-950, claims a company release.

"The clinical data demonstrate a swift and dramatic decline in viral levels with VX-950, and provide insight into VX-950's potential to transform future HCV treatment. Our clinical development effort is gaining momentum, as indicated by our recent IND submission with the FDA to support the planned initiation before year-end of the first clinical study in what we expect will be a broad Phase II programme," said Joshua Boger, chairman, president and chief executive officer of Vertex

Further, the researchers analysed the viral kinetics to estimate the treatment duration required to achieve viral eradication. In this analysis, researchers projected the continued slope of viral decline that could be expected with dosing beyond 14 days in the patients who achieved HCV-RNA levels below the limit of quantitation at the end of dosing in the Phase Ib study.

"The complete data set for the Phase Ib study suggests that VX-950 is well-tolerated and can substantially reduce virus in a 14-day study. The results of the blood-concentration versus antiviral effect analysis are encouraging because they indicate that optimal antiviral response could be maintained if certain trough concentrations are achieved. Moreover, the viral kinetic analysis supports the evaluation of VX-950, at doses that maintain the target trough concentration, in a novel treatment paradigm of 12 weeks duration," said Henk W. Reesink, associate professor of medicine at Academic Medical Center in Amsterdam

Hepatitis C is a liver disease caused by the Hepatitis C virus, which is found in the blood of people with the disease. HCV, a serious public health concern affecting 3.4 million individuals in the United States, is spread through direct contact with the blood of infected people.

VX-950 is an oral inhibitor of Hepatitis C virus protease, an enzyme essential for viral replication. Vertex researchers were the first to solve the three-dimensional crystal structure of HCV protease, and have used structural insights to enable the design of small molecule HCV protease inhibitors, including VX-950.

Vertex Pharmaceuticals Incorporated is a global biotechnology company committed to the discovery and development of breakthrough small molecule drugs for serious diseases.