Pharmasset to Webcast an Investor Event from the AASLD Meeting

PRINCETON, N.J., Nov. 4, 2011 /PRNewswire/ -- Pharmasset, Inc. (Nasdaq: VRUS) today announced that it will webcast an investor event from the American Association for the Study of Liver Diseases (AASLD) on Sunday, November 6, 2011 starting at 6:30pm PT. During this webcast, management will review Pharmasset's progress on the programs that are the subject of presentations at AASLD.

To download a slide presentation and access a simultaneous webcast of this event via the internet, log on to the "Events & Presentations" section of the Investor Center on Pharmasset's website at http://investor.pharmasset.com/events.cfm . Please connect to the website at least ten minutes prior to the start of the presentation to ensure adequate time for a reliable connection and any software download that may be necessary for the webcast.

The following abstracts are available on the AASLD website (AASLD.org).

PSI-7977

Abstract 372

"Lack of Effect of the Nucleotide Analog Polymerase Inhibitor PSI-7977 on Methadone Pharmacokinetics and Pharmacodynamics" will be presented in a poster session on Saturday, November 5. Authors of the study are J. M. Denning et al.

Abstract 391

"PSI-7977 Has No Effect on QTcF Intervals at Therapeutic or Supratherapeutic Doses" will be presented in a poster session on Saturday, November 5. Authors of the study are M. Cornpropst et al.

Abstract 34

"Once Daily PSI-7977 plus RBV: Pegylated interferon-ALFA not required for Complete Rapid viral response in Treatment-naive Patients with HCV GT2 or GT3" will be presented in the HCV: Refining the use of Direct-Acting Antivirals session on Sunday, November 6 at 3:45pm PT. Authors of the study are E. J. Gane et al.

Abstract 225

"Once-Daily PSI-7977 Plus Peg/RBV in Treatment-naive Patients with HCV GT1: Robust End of Treatment Response Rates are Sustained Post-treatment" will be presented in the Presidential Plenary III: Viral Hepatitis session on Tuesday, November 8 at 8:30pm PT. Authors of the study are E. Lawitz et al.

About Pharmasset

Pharmasset is a clinical-stage pharmaceutical company committed to discovering, developing, and commercializing novel drugs to treat viral infections. Pharmasset's primary focus is the development of oral therapeutics for the treatment of hepatitis C virus (HCV) infection. Our research and development efforts are focused on nucleoside/tide analogs, a class of compounds which act as alternative substrates for the viral polymerase, thus inhibiting viral replication. We currently have three clinical-stage product candidates advancing in trials in various populations. Our pyrimidine, PSI-7977, an unpartnered uracil nucleotide analog, is initiating an interferon-free, Phase 3 program in patients with HCV genotypes 1, 2 and 3 and continues to be evaluated in five Phase 2b trials in patients with all HCV genotypes. Our purine, PSI-938, an unpartnered guanosine nucleotide analog, is being studied in QUANTUM, a Phase 2b interferon-free trial of PSI-7977 and/or PSI-938 in patients with all HCV genotypes. Mericitabine (RG7128) continues in development through a strategic collaboration with Roche.

    Contact
         Richard E. T. Smith, Ph.D.
         VP, Investor Relations and Corporate Communications
         Office+1 (609) 865-0693

Forward-Looking Statements
Pharmasset "Safe Harbor" Statement under the Private Securities Litigation Reform Act of 1995: Statements in this press release that are not historical facts are "forward-looking statements," that involve risks, uncertainties, and other important factors, including, without limitation, the risk of cessation or delay of any of the ongoing or planned clinical trials and/or our development of our product candidates, the risk that the results of previously conducted studies involving our product candidates will not be repeated or observed in ongoing or future studies involving our product candidates, the risk that our collaboration with Roche will not continue or will not be successful, and the risk that any one or more of our product candidates will not be successfully developed and commercialized. For a discussion of risks, uncertainties, and other important factors, any of which could cause our actual results to differ from those contained in the forward-looking statements, see the section entitled "Risk Factors" in our Annual Report on Form 10-K for the fiscal year ended September 30, 2010 and our Quarterly Reports on Form 10-Q filed with the Securities and Exchange Commission and discussions of potential risks, uncertainties, and other important factors in our subsequent filings with the Securities and Exchange Commission.

SOURCE Pharmasset, Inc.