UPDATE: 52% of unresponsive HCV patients achieve SVR12 with telaprevir

Telaprevir was once again the star of the annual meeting of the American Association for the Study of Liver Diseases. At this year's conference, held in San Francisco, the protease inhibitor originated by Vertex Pharmaceuticals achieved sustained virologic response for 12 weeks in 52% of patients who had previously failed standard treatment.

Before the SVR12 data in difficult-to-treat patients were announced, Susquehanna Financial Group analyst Jason Kolbert told Reuters that, "if Vertex can deliver anything north of 35% in HCV failure patients that's a huge leap. If they come close to 50%, then it's a home run."

The PROVE 3 study tested the agent, which is being co-developed with US health care major Johnson & Johnson, in 435 patients that failed treatment with pegylated-interferon and ribavirin. Of the 52% of subjects that responded to the novel drug, 41% had undetectable viral load and 73% had relapsed after previous treatment.