PSI-7977 Receives Fast Track Designation from the FDA for the Treatment of Chronic Hepatitis C Infection

PRINCETON, N.J., Aug 12, 2010 /PRNewswire via COMTEX News Network/ -- Pharmasset, Inc. (Nasdaq: VRUS) has received fast track designation from the U.S. Food and Drug Administration (FDA) for PSI-7977 for the treatment of chronic hepatitis C virus (HCV) infection. PSI-7977 is an oral uridine nucleotide analog polymerase inhibitor of HCV. Pharmasset recently completed dosing in a 28 day Phase 2a trial to evaluate PSI-7977 in combination with Pegasys (pegylated interferon) plus Copegus (ribavirin) in treatment-naive patients chronically infected with HCV genotype 1. Pharmasset expects to initiate a 12-week Phase 2b study of PSI-7977 in the fourth quarter of 2010.

Under the FDA Modernization Act of 1997, fast track designation may facilitate the development and expedite the review of a drug candidate that is intended for the treatment of a serious and life-threatening condition and demonstrates the potential to address an unmet medical need for such a condition. PSI-7977 was granted the fast track designation primarily due to the need for HCV treatments with novel mechanisms of action, oral administration, different resistance profiles and improved safety and efficacy over the existing standard of care for both treatment-naive and treatment-experienced patients.

"The FDA's fast track designation for PSI-7977 acknowledges the urgent need for new HCV drugs," stated Dr. Michael Rogers, Pharmasset's Chief Development Officer. "Currently, there are no HCV nucleoside/tide inhibitors approved for the treatment of chronic HCV infection. We continue to work closely with the FDA on the development and regulatory review of PSI-7977, which has demonstrated compelling antiviral activity, a high barrier to resistance and has been generally well-tolerated in clinical trials to date."

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 on the development of oral therapeutics for the treatment of hepatitis C virus (HCV) and, secondarily, on the development of Racivir(TM) for the treatment of human immunodeficiency virus (HIV). Our research and development efforts focus on nucleoside/tide analogs, a class of compounds which act as alternative substrates for the viral polymerase, thus inhibiting viral replication. We currently have four clinical-stage product candidates. RG7128, a cytosine nucleoside analog for chronic HCV infection, is in two Phase 2b clinical studies in combination with Pegasys(R) plus Copegus(R) and is also in the INFORM studies, the first series of studies designed to assess the potential of combinations of small molecules without Pegasys(R) and Copegus(R) to treat chronic HCV. These clinical studies are being conducted through a strategic collaboration with Roche. Our other clinical stage HCV candidates include PSI-7977, an unpartnered uracil nucleotide analog that has recently completed 28 days of dosing in a Phase 2a study, and PSI-938, an unpartnered guanosine nucleotide analog in a Phase 1 study. We also have in our pipeline an additional purine nucleotide analog, PSI-661, in advanced preclinical development. Racivir, for the treatment of HIV, has completed a Phase 2 clinical study.

Pegasys(R) and Copegus(R) are registered trademarks of Roche.

[viaduk]

This is good news. There are many reasons to be hopeful for those who can wait to treat.  It would be great if tx could be shortened to 12 weeks.  

[copyman]

I wish "fast track" really meant that but unfortunately with the FDA this is not the case. It still takes 5+ years for new drugs to make it to market. I think this "slow track" with FDA is because of the drugs like vioxx that they approved to soon which ended hurting people.
Just wish they would stop tap dancing and approve the drugs like Telaprevir & Boceprevir that have proven to work and be safe. These new drugs have been thoroughly tested and can help people NOW !!!

[22hamilton]

Couldnt agree more copyman !!! Some people need treatment NOW, 5yrs 10 yrs is a waste of time for some, we wont be here !