icon-folder.gif   Conference Reports for NATAP  
  EASL 46th Annual Meeting
March 30th - April 3rd 2011
Berlin, Germany
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PSI-7977 QD Plus PEG/RBV In HCV GT1: 98% Rapid Virologic Response, Complete Early Virologic Response: The PROTON Study
  Reported by Jules Levin
Presented at the 46th Annual Meeting of the European Association for the Study of the Liver, EASL, March 30-April 3, 2011 Berlin, Germany
DR Nelson1*, J Lalezari2, E Lawitz3, T Hassanein4, K Kowdley5, F Poordad6, A Sheikh7, N Afdhal8, D Bernstein9, E Dejesus10, B Freilich11, D Dieterich12, I Jacobson13, D Jensen14, GA Abrams15, J Darling16, M Rodriguez-Torres17, R Reddy18, M Sulkowski19, N Bzowej20, M Demicco21, J Strohecker22, R Hyland23, M Mader23, E Albanis23, WT Symonds23, MM Berrey23 1UFL, Gainesville, FL, 2Quest Clinical Research, San Francisco, CA, 3Alamo Medical Research, San Antonio, TX, 4UCSD, Coronado, CA, 5VMMC, Seattle, WA, 6CSMC, Los Angeles, CA, 7GI Specialists GA, Marietta, GA, 8Beth Israel Deaconess, Boston, MA, 9Digestive Diseases Institute, Manhasset, NY, 10OIC, Orlando, FL, 11Kansas City Gastroenterology & Hepatology, LLCG, Kansas City, KS, 12Mount Sinai, New York, 13Cornell Univ, NY, NY, 14Univ of CH, Chicago, IL, 15AL Liver and Digestive Specialists, Montgomery, AL, 16UNC, Chapel Hill, NC, 17Fundacion de Investigacion De Diego, Santurce, PR, 18U. of PA, Philadelphia, PA, 19JHU, Lutherville, MD, 20California Pacific Med Ctr, San Francisco, CA 21Advanced Clinical Research Institute, Anaheim, CA, 22Columbia Gastroenterology, Columbia, SC, 23Pharmasset, Inc, Princeton, NJ


PSI-7977 is a novel uridine nucleotide analog in Phase 2b development for the treatment of chronic HCV. Consistent antiviral activity, high barrier to resistance, and broad HCV genotype activity of PSI-7977 has supported 12 week regimens with ribavirin (RBV) +/- pegylated interferon alfa-2a (PEG) in treatment-na´ve patients with HCV genotypes 1, 2, and 3.
This planned 12-week interim analysis provides preliminary safety and efficacy for PSI-7977 with PEG/RBV in subjects with HCV GT1 in PROTON. PSI-7977 400 mg QD + PEG/RBV has been administered for 12 weeks to patients with HCV GT2 or GT3 (PROTON, EASL oral presentation, Lalezari) with 24/24 achieving RVR, cEVR/EOT, and no post-therapy relapse.
Reported Antiviral Data
PSI-7977 200mg or 400mg QD with PEG/RBV previously demonstrated 93-94% RVR in a 28-day Phase 2a study (AASLD 2010 #806). These high on-treatment response rates were explored in an analysis of potential synergy of PSI-7851 with IFN (AASLD 2010 #1861). The recent conduct of a 7-day monotherapy regimen of PSI-7977 (EASL LB#1370) demonstrated a -4.7 log10 IU/mL median antiviral response.