Pharmasset and Roche Obtain FDA Consent to Start a Phase 2b Study With R7128 in Treatment Naive HC...( PRINCETON N.J. Jan. 12 /- Pharmasset ...)

PRINCETON, N.J., Jan. 12 /PRNewswire-FirstCall/ -- Pharmasset, Inc. (Nasdaq: VRUS) announced today that they and their development partner, Roche, have agreed with the FDA on the final design for a phase 2b trial with R7128, a nucleoside inhibitor of hepatitis C (HCV), slated to initiate in the first quarter of this year.

"We are pleased that R7128 is advancing into a large phase 2b trial," stated Michelle Berrey, MD, MPH, Pharmasset's Chief Medical Officer. "R7128 is the most advanced nucleoside polymerase inhibitor in development and we believe this class of drug brings a number of advantages to HCV-infected patients. R7128's higher barrier to resistance and activity across multiple viral genotypes, as well as the promising short-term safety and tolerability, may bring patients a new option for therapy. We look for this trial to better define the optimal treatment duration with R7128 in combination with the standard of care."

The phase 2b trial is anticipated to enroll about 400 treatment naive, genotype-1 or genotype 4 HCV-infected patients. The trial will evaluate the dose and duration of treatment of R7128 in combination with Pegasys(R) plus Copegus(R). The primary efficacy endpoint of the trial will be the proportion of patients that achieve a sustained virologic response (SVR), defined as undetectable (measured by Roche TaqMan assay) HCV RNA 24 weeks after completion of treatment. Patients will be enrolled into one of 5 arms:

• 24 weeks of total treatment, with R7128 500mg bid in combination with pegylated interferon and ribavirin for 12 weeks, followed by 12 weeks of pegylated interferon and ribavirin
• 24 weeks of total treatment, with R7128 1000mg bid in combination with pegylated interferon and ribavirin for 12 weeks, followed by 12 weeks of pegylated interferon
  '/>"/>