Vertex Pharmaceuticals Announces Initiation of First Human Clinical Trial for an Investigational Oral Protease Inhibitor for the Treatment of Hepatitis C

CAMBRIDGE, Mass. -- Vertex Pharmaceuticals

Incorporated announce the initiation of a Phase I

clinical trial for VX-950, an investigational oral protease inhibitor for the

treatment of hepatitis C virus (HCV) infection. The objective of this trial

is to assess safety, tolerability and pharmacokinetics in escalating single

doses of VX-950 in healthy volunteers. Approximately 35 healthy subjects will

participate in the study, which is being conducted in Europe. Successful

completion of the Phase I clinical trial will enable a first study of VX-950

in HCV-infected patients. Such a study is currently planned to start in the

fourth quarter of 2004.

VX-950 is Vertex's lead oral HCV protease inhibitor and one of a new class

of direct antivirals in development for the treatment of HCV. Preclinical

studies have shown that VX-950 significantly reduces levels of HCV RNA in both

an in vitro replicon system and infectious virus assays. At a scientific

conference in October 2003, Vertex scientists reported that VX-950 reduced HCV

RNA 10,000-fold (4 log 10) in nine days in an in vitro replicon assay.

Preclinical pharmacokinetic studies have indicated that VX-950 is orally

bioavailable and achieves excellent exposure in the liver, the target organ

for HCV treatment. The initiation of clinical testing of VX-950 represents a

first step towards establishing the safety and tolerability in humans.

"Preclinical data to date have indicated that direct antivirals such as

VX-950 may represent a powerful new approach to the treatment of HCV

infection," stated John J. Alam, MD, senior vice president of drug

evaluation and approval at Vertex. "Initiation of human clinical trials for

VX-950 reflects Vertex's commitment to leadership in the development and

commercialization of novel antivirals for the treatment of HCV infection, and

it is one of several important clinical milestones for Vertex's proprietary

development programs in 2004."

Chronic hepatitis C virus (HCV) infection is a serious public health

concern affecting approximately 2.7 million people in the United States. HCV

causes inflammation of the liver, which may lead to fibrosis and cirrhosis,

liver cancer, and ultimately, liver failure. Cirrhosis of the liver resulting

from chronic HCV infection is the leading indication for liver transplantation

in the U.S. Due to the asymptomatic nature of HCV infection, it often goes

undetected for up to 20 years following initial infection. Worldwide, the

disease strikes as many as 185 million people. Each year, 8,000 to 10,000

people in the U.S. die from complications of HCV.

The current standard of care in HCV treatment is a combination of weekly

injections of pegylated interferon alpha (peg-IFN) and daily oral dosing of

ribavirin. This combination therapy provides a sustained viral response for

only 40 to 50 percent of patients chronically infected with genotype 1 HCV,

the most difficult viral strain to treat and the most common form in the U.S.

Vertex's drug development portfolio includes two different approaches for

advancing the future standard-of-care in HCV. In addition to VX-950, Vertex

is developing merimepodib, an IMPDH inhibitor in combination with pegylated

interferon alpha (peg-IFN) and ribavirin. Addition of merimepodib to standard

therapy has the potential to enhance antiviral activity and improve clinical

outcomes for a larger percentage of patients. Vertex owns worldwide

development and commercialization rights for both merimepodib and VX-950.

Source: Vertex Pharmaceuticals Incorporated