Monday, October 10, 2011

Pharmasset expands PSI-7977 ELECTRON trial for treatment of HCV...

Pharmasset expands it's ELECTRON trial by adding two interferon-free arms and modifying another one. The changes include a PSI-7977 monotherapy arm (!!!) for Tx-naive genotype 1 patients; a PSI-7977 + RBV arm in Tx-experienced GT 2/3 patients and modifying a treatment arm for null responders by adding an interferon-free PSI-7977 + RBV arm. This announcement caused investors to flee Vertex Pharmaceuticals, which saw a 7% slide today.

press release

Oct. 10, 2011, 6:45 a.m. EDT

Pharmasset Announces Further Expansion of ELECTRON Trial in Hepatitis C

--**Added PSI-7977 monotherapy arm in treatment-naive patients with HCV GT1
--**Added PSI-7977/RBV arm in treatment experienced patients with HCV GT2/3
--**Modified previously-announced treatment regimen in HCV GT1 prior null responders to explore IFN-free regimen of PSI-7977/RBV


PRINCETON, N.J., Oct. 10, 2011 /PRNewswire via COMTEX/ -- Pharmasset, Inc. announced today the addition of two treatment arms to the ELECTRON trial of PSI-7977, a nucleotide analog polymerase inhibitor, for the treatment of chronic hepatitis C (HCV). The rapid and consistent antiviral effects and high barrier to resistance demonstrated with PSI-7977 to date provided the rationale for additional exploratory regimens in this setting. The protocol amendment adds one arm exploring 12 weeks of PSI-7977 monotherapy in treatment naive patients with HCV genotype 1 (GT1), and one arm of PSI-7977 and ribavirin (RBV) in treatment-experienced patients with HCV genotype 2 (GT2) or genotype 3 (GT3). In addition, the previously announced arm in HCV GT1 patients with a prior "null" response to an interferon (IFN) containing regimen, which was planned to assess PSI-7977/IFN/RBV, has been modified to an IFN-free 12-week regimen of PSI-7977/RBV.

"We look forward to reporting SVR12 results from Part 1 and interim data from the PSI-7977 monotherapy arm of ELECTRON on Sunday, November 6th, 2011 at the upcoming 2011 American Association for the Study of Liver Diseases (AASLD) annual meeting. The preliminary results to be discussed at AASLD led us to expand the study to add an arm of PSI-7977 monotherapy for HCV GT1," said Michelle Berrey, MD, MPH, Pharmasset's Chief Medical Officer. "We and others continue to explore the potential of PSI-7977 for IFN-free and monotherapy treatment regimens in a broader group of individuals living with HCV of all genotypes and regardless of their response to prior treatment."

In addition to previously announced interferon-free studies of PSI-7977 by Bristol Myers Squibb and Tibotec, The National Institute of Health (NIH) recently initiated an interferon-free 24 week study of PSI-7977 400mg QD with and without ribavirin, in 60 treatment naive patients with HCV genotype 1 (GT1) in the US.

About ELECTRON

ELECTRON is an exploratory study of PSI-7977 for the treatment of chronic HCV infection. Part 1 of the trial is evaluating 12-week regimens of interferon-free PSI-7977 400mg QD with ribavirin (RBV), and three abbreviated duration peginterferon (Peg-IFN) regimens of 4, 8, or 12 weeks in treatment-naive patients with HCV GT2 or GT3. The primary endpoint of the trial is the safety and tolerability of PSI-7977 400mg QD and RBV for 12 weeks, administered with or without Peg-IFN. On May 11, 2011, Pharmasset announced the completed enrollment of Part 1 of ELECTRON:

PSI-7977 400 mg with Peg-IFN and RBV for 12 weeks (GT2/3)

PSI-7977 400 mg with RBV for 12 weeks, Peg-IFN weeks 1-8 only (GT2/3)

PSI-7977 400 mg with RBV for 12 weeks; Peg-IFN weeks 1-4 only (GT2/3)

PSI-7977 400 mg with RBV for 12 weeks (GT2/3)

In Part 2 of ELECTRON, a 5th cohort was added to explore PSI-7977 monotherapy in treatment naive patients with HCV GT2 or GT3:

PSI-7977 400 mg monotherapy for 12 weeks (n=10 GT2/3)

Following on the previously reported 100% SVR12 in treatment-naive subjects with HCV GT2/3 (PROTON), a 6th cohort was added to ELECTRON to explore an 8-week duration of PSI-7977Peg-IFN/RBV. The previously announced 7th cohort in HCV GT1 patients with a prior "null" response to Peg-IFN, has been modified to an interferon-free 12-week regimen of PSI-7977/RBV.

PSI-7977 400 mg with Peg-IFN/RBV for 8 weeks (n=10 GT2/3 treatment-naive)

PSI-7977 400 mg with RBV for 12 weeks (n=10 GT1 null)

In Part 3 of ELECTRON, two additional IFN-free regimens will be explored in treatment-naive patients with HCV GT1 and in treatment-experienced patients with HCV GT2 or GT3.

PSI-7977 400 mg monotherapy for 12 weeks (n=25 GT1 treatment-naive)

PSI-7977 400 mg with RBV for 12 weeks (n=25 GT2/3 treatment-experienced)

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 currently under study in five Phase 2b trials, including abbreviated duration interferon and interferon-free regimens, in subjects with all HCV genotypes. Our purine, PSI-938, an unpartnered guanosine nucleotide analog, is in QUANTUM, a Phase 2b interferon-free trial of PSI-7977 and PSI-938 in subjects with all HCV genotypes. Mericitabine (RG7128) continues in three Phase 2b trials and one interferon-free trial being conducted through a strategic collaboration with Roche.

ContactRichard E. T. Smith, Ph.D.VP, Investor Relations and Corporate CommunicationsOffice: +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.

Copyright (C) 2011 PR Newswire. All rights reserved

No comments:

Post a Comment