In the phase I study, patients are randomized to receive either oral treatment with R1626 or placebo for 14 days with 14 days of follow-up. Preliminary data were presented at the 41st annual meeting of the European Association for the Study of the Liver (EASL), on the 18 patients who received 500mg or 1,500mg twice daily doses of R1626. The study is still ongoing and higher doses of R1626 are being evaluated.
The study found that, at the 1,500mg twice daily dose, R1626 was associated with clinically significant reductions from baseline in serum HCV RNA (a measure of how much virus is in the blood) of 1.2 log(10) (group mean).
At both 500mg and 1,500mg twice daily, R1626 was well tolerated in patients, with no serious adverse events and no premature withdrawals.
“Data from this study evaluating R1626 are encouraging,” said Frederick Thompson, president and CEO of the American Liver Foundation. “Since genotype 1 patients are the most common in the US and also the most difficult to treat, there is a real need for a product that could potentially improve treatment outcomes.”
Further trials are planned to study how well R1626 works in combination with Pegasys (peginterferon alfa-2a) and Copegus (ribavirin).
Additional data reported at EASL related to partnerships include Vertex Pharmaceutical’s VX-950, a protease inhibitor, which, in combination with Pegasys and Copegus, showed a significantly increased antiviral effect in patients with hepatitis C. Subsequent studies will evaluate whether VX-950, in combination with Pegasys and Copegus, may clear the hepatitis C virus with shortened treatment duration.