Vertex Pharmaceuticals Incorporated announced that it has entered into a nonexclusive licensing agreement with Chiron Corporation granting Vertex a license to discover, develop and commercialize small molecule therapeutic agents against certain hepatitis C drug targets. The financial terms and other details of the license were not disclosed.

"Vertex has been a pioneer in linking structural and molecular biology with medicinal chemistry to design novel drugs targeting the hepatitis C protease enzyme. We remain on track to initiate clinical development of our lead oral HCV protease inhibitor, VX-950, in early 2004," said Vicki Sato, Ph.D, President of Vertex. "As a direct antiviral, VX-950 holds the potential as a new avenue for the treatment of hepatitis C, and underscores Vertex's commitment to the development of innovative treatments in this important therapeutic area."

As part of the licensing agreement, Chiron and Vertex have settled litigation relating to a patent infringement suit Chiron had brought against Vertex in 1998. Under the terms of the current agreement with Vertex, Chiron has agreed to withdraw the lawsuit against Vertex. In addition, Chiron was granted limited rights to review VX-950 for potential licensing.

VX-950 is an oral, small molecule protease inhibitor being developed by Vertex Pharmaceuticals. Vertex was the first to solve the structure of the hepatitis C NS3-4A protease domain, an enzyme that is essential for HCV viral replication. In addition to potent activity observed in vitro, preclinical testing conducted to date shows that VX-950 achieves good exposure in the liver, the target organ for HCV treatment, good oral bioavailability and favorable pharmacokinetic properties.

Chronic hepatitis C infection afflicts approximately 2.7 million people in the U.S., many of whom are unaware of the infection, which is often undetected for up to 20 years following initial infection. Worldwide, the disease strikes as many as 185 million people. HCV causes inflammation of the liver, which may lead to fibrosis and cirrhosis, liver cancer, and ultimately, liver failure. Each year, 8,000 to 10,000 people in the U.S. die from complications of HCV. Current treatments have been effective for only 40 to 60 per cent of chronically infected HCV patients and are associated with significant side effects. At the present time, there are no direct antiviral therapies available for the treatment of HCV infection.