Roche and Pharmasset initiate dosing in Phase IIb hepatitis trial

The trial will evaluate the dose and duration of treatment of R7128 in combination with Roche’s Pegasys (peginterferon alfa-2a) and Copegus (ribavirin) – in hepatitis C virus (HCV) patients who have not been treated previously. The goal of adding R7128 to the existing standard therapy is to improve rates of sustained virological response (SVR) and to shorten the length of treatment for patients.

The Phase IIb trial is anticipated to enroll about 400 HCV-infected patients with genotypes 1 or 4 who have not been treated previously. The primary efficacy endpoint of the trial will be the proportion of patients who achieve an SVR, defined as undetectable levels of HCV 24 weeks after completion of treatment.

According to the study design, 100 patients will be initially enrolled, equally across all five arms. The remaining 300 will be enrolled following a review of the 12-week data by the data safety monitoring board.

R7128 is being developed by Roche and Pharmasset under a partnership agreement entered into in 2004. The first patient dosed in this study triggered a $10 million payment to Pharmasset from Roche.

Rob Mitchell, global head of virology business at Roche, said: “The collaboration with Pharmasset underscores Roche’s commitment to develop new therapies that will meet the needs of a growing population of patients with hepatitis C. We are hopeful that a combination of R7128 and the current gold standard of Pegasys and Copegus can provide a more potent – and potentially shorter – treatment regimen.”