At the annual meeting of the American Association for the Study of Liver Diseases (AASLD), Professor Edward Gane of New Zealand presented results from ELECTRON demonstrating viral cure (sustained viral response, SVR) in 40 of 40 (100%) patients with HCV GT2 or GT3. ELECTRON was designed to determine the minimum duration of interferon required to achieve SVR in combination with the nucleotide analog PSI-7977 and RBV. All 40 subjects were treated with PSI-7977/RBV, but were randomized to receive one of four "interferon sparing" or interferon-free regimens: 4, 8, or 12 weekly interferon injections, or no interferon. The early antiviral responses were consistent across all four experimental treatment groups with all 40 subjects achieving "undetectable" HCV RNA by week 4. Importantly, there were no treatment failures or discontinuations due to safety or viral resistance during the 12 weeks of therapy, problems that have limited the effectiveness of other direct-acting antivirals in development for HCV.
Data from PROTON, the Phase 2 dose-ranging trial for PSI-7977, were presented at AASLD by Dr. Eric Lawitz. Initial 12-week safety and on-treatment response rates had been presented in early 2011, with 98% of subjects achieving HCV below limit of detection (<LOD), and no safety or tolerability issues in either cohort receiving PSI-7977 at 200 mg or 400 mg QD with Peg-IFN/RBV for 12 weeks. During the Peg-IFN/RBV dosing from week 13 to 24, three subjects in the 200 mg cohort experienced viral breakthrough and one additional subject experienced relapse within 4 weeks of completing the treatment, for a combined 88% SVR12 for the lower-dose of PSI-7977. In contrast, no viral breakthrough was observed in the PSI-7977 400 mg QD cohort, and only one relapse, for an intent to treat (ITT) SVR12 of 91% (43 of 47). Of the 44 subjects who received at least 8 we
|SOURCE Pharmasset, Inc.|
Copyright©2010 PR Newswire.
All rights reserved