Pharmasset and Roche to Present R7128 Data at the 14th International Symposium on Hepatitis C Virus and Relat...(boratory abnormalities of clinical ...)

significance were noted.

-- Part 2 is a multiple ascending dose study of R7128 conducted in 40

patients chronically infected with HCV genotype 1 who have previously

failed interferon therapy. The primary objective of Part 2 is to

assess the safety, tolerability and pharmacokinetics of R7128 after

once-daily or twice-daily dosing for 14 days. The secondary objective

is to assess antiviral efficacy by measuring the change in HCV RNA.

About Hepatitis C

Hepatitis C is a blood-borne infectious disease of the liver and is a leading cause of chronic liver disease and liver transplants. The WHO estimates that nearly 180 million people worldwide, or approximately 3% of the world's population, are infected with hepatitis C virus (HCV). The CDC has reported that almost four million people in the United States have been infected with HCV, of whom 2.7 million are chronically infected.

Contact

Alan Roemer, Vice President

Investor Relations & Corporate Communications

alan.roemer@pharmasset.com

Office: (609) 613-4125

Forward-Looking Statements

Pharmasset "Safe Harbor" Statement under the Private Securities Litigation Reform Act of 1995: Statements in this press release regarding our business that are not historical facts are "forward-looking statements" that involve risks and uncertainties, including without limitation the risk that there will be a delay in the presentation of R7128 data at upcoming conferences, the risk that the R7128 data to be presented at upcoming conferences is not accurate or representative, the risk that the preliminary data from the R7128 Phase 1 Study is not accurate or representative, the risk that our collaboration with Roche will not continue or will not be successful, the risk that the on-going or anticipated clinical trials for any one or more o
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