R7128 Demonstrates Safety and Potent Antiviral Activity in HCV-Infecte...( - Phase 1 Study Results in 2.7 log10...),Health

- Phase 1 Study Results in 2.7 log10 (>99%) Mean HCV RNA Decrease with No

Serious Adverse Events -

- Conference Call Scheduled for 8:30AM (ET) Today -

PRINCETON, N.J., Sept. 10 /PRNewswire-FirstCall/ -- Pharmasset, Inc. (Nasdaq: VRUS) reports preliminary safety and potent antiviral activity with R7128 following 14 days of monotherapy in 40 patients chronically infected with hepatitis C virus (HCV) who have failed prior interferon therapy. R7128 is a prodrug of PSI-6130, an oral cytidine nucleoside analog polymerase inhibitor of HCV that is being developed through Pharmasset's collaboration with Roche. The Phase 1 multiple ascending dose study of R7128 was designed to evaluate safety, tolerability, pharmacokinetics and preliminary antiviral activity.

R7128 demonstrated potent, dose-dependent antiviral activity across the four patient cohorts (n=10; 8 active, 2 placebo) receiving 750 mg or 1500 mg administered either once-daily or twice-daily for 14 days as monotherapy. The greatest mean decrease in HCV RNA from baseline was demonstrated in the patient cohort that received 1500 mg twice-daily, the highest dose of R7128 administered in this study. These patients demonstrated a mean 2.7 log10 IU/mL (>99%) decrease in HCV RNA. There was no evidence of viral rebound in any dose cohort during the 14 days of dosing.

R7128 was generally safe and well tolerated in this Phase 1 multiple ascending dose study. There were no serious adverse events, no adverse events requiring dose modification, no dose-related gastrointestinal adverse events and no clinically significant changes in vital signs, electrocardiograms, hematologic, renal or other laboratory parameters.

Base
'/>"/>