Below is an excerpt from a Pharmasset press release describing
the new status.
Receives Fast Track Designation from the FDA for the Treatment
of Chronic Hepatitis C Infection
N.J. -- August 12, 2010 -- 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."
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 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 plus
Copegus and is also in the INFORM studies, the first series
of studies designed to assess the potential of combinations
of small molecules without Pegasys and Copegus 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
For more information, see www.pharmasset.com.
Inc. PSI-7977 Receives Fast Track Designation from the FDA for
the Treatment of Chronic Hepatitis C Infection. Press release.
August 12, 2010.