Schering hep C drug promising in Phase II study

* Boceprevir rapid responders reach 82 pct SVR

* 55 pct SVR in null responders after 48-week regimen

By Bill Berkrot

NEW YORK, Nov 1 (Reuters) - The addition of Schering-Plough Corp'sSGP.N experimental hepatitis C drug boceprevir after four weeks of treatment with standard medicines led to highly encouraging sustained response rates in a mid-stage study.

The triple combination of boceprevir and the current treatments of pegylated-interferon and ribavirin appeared to knock out the virus at double the rate of the standard drugs alone, according to researchers.

Among patients who had a rapid response to the combination therapy, the cure rate, or those in whom the virus remained undetectable after completing treatment, exceeded 80 percent, according to data to be presented at the American Association for the Study of Liver Diseases (AASLD) meeting in Boston.

Boceprevir is in a race with Vertex Pharmaceuticals Inc's (VRTX.O: Quote, Profile, Research) telaprevir to become the first of a next generation of antiviral hepatitis C medicines called protease inhibitors. Both appear to be highly promising advances in the treatment of the serious liver disease based on early clinical results.

"The next decade for hepatitis C not only holds substantial promise for those who have not been treated, but those who have already been treated with standard of care also look like they are going to derive substantial benefits from this new generation of therapies," Dr Paul Kwo, lead investigator of the boceprevir study, said in an interview.

The 595-patient boceprevir study was designed to test the triple combination in a response guided therapy. The idea is to enable physicians to tailor duration of therapy -- either 28 or 48 weeks -- based on a patient's early response to treatment, and to help cut the risk of developing resistance to the drug.