Gilead Sciences has announced interim data from a phase 2 trial ( ATOMIC ) examining a 12-week course of treatment with the once-daily nucleotide GS-7977 plus Pegylated interferon ( Peg-IFN ) and Ribavirin ( RBV ) in treatment-naïve patients with genotype 1 chronic hepatitis C virus ( HCV ) infection. The study found that 90% of patients ( n=47/52, missing data equals failure analysis ) achieved a 12-week sustained virologic response ( SVR12 ), defined as maintaining undetectable viral load ( HCV RNA less than 25 IU/mL ) 12 weeks after the completion of therapy.

These data suggest that GS-7977-based regimen could offer most patients with genotype 1 a simple, short, three-month course of treatment with very high cure rates.

In this study, 52 patients were randomized to the 12-week treatment arm. One patient was lost to follow up during the course of treatment. At the end of treatment, 51/51 patients ( 100% ) were HCV RNA undetectable. At the 12-week, post-treatment time period, data were available for 50/51 patients, as one patient was lost to follow up during the post-treatment time period. Of the 50 patients, 47 ( 94% ) remained HCV RNA undetectable. Three patients experienced viral relapse after the end of treatment.

Overall, GS-7977 was well tolerated. The frequency and severity of adverse events were consistent with the historical safety profile of Peg-Interferon and Ribavirin and included fatigue, headache, nausea, chills and insomnia.

ATOMIC is an ongoing phase 2 randomized open-label clinical trial evaluating the efficacy, safety and tolerability of a regimen containing GS-7977 ( 400 mg once daily ), Peg-Interferon ( 180 microg weekly injection ) and Ribavirin ( 500 mg twice daily ) for the treatment of chronic HCV infection in treatment-naïve patients.
Patients with genotype 1 HCV ( n=316 ) who were non-cirrhotic and had HCV RNA of at least 50,000 IU/mL were randomized ( 1:2:3 ) to receive the regimen for 12 weeks ( n=52 ), 24 weeks ( n=109 ) or 12 weeks, followed by re-randomization ( 1:1 ) to receive an additional 12 weeks of either GS-7977 alone or GS-7977 plus Ribavirin ( n=155 ). Additionally, 16 patients with HCV genotypes 4 and 6 received the 24-week regimen of GS-7977, Peg-Interferon and Ribavirin.

Source: 47th Annual Meeting of the European Association for the Study of the Liver ( EASL ), 2012

XagenaMedicine2012