Reuters (04.02.12) - Friday, April 06, 2012

A combination of oral hepatitis C drugs being developed by Abbott Laboratories realized cure rates exceeding 90 percent in treatment-naive patients, according to a small, mid-stage study. The results, released Wednesday, will be presented later this month in Barcelona at a meeting of the European Association for the Study of the Liver.

For 12 weeks, patients in the Phase II trial, known as "Co- Pilot," received Abbott's protease inhibitor ABT-450, boosted by the antiviral drug ritonavir with its polymerase inhibitor ABT-333, and ribavirin, which is used in all current hepatitis C regimens. Patients' blood virus levels were checked 24 weeks later for a sustained virologic response. Those achieving SVR were considered cured.

Eighteen of the 19 patients (95 percent) given 250 milligram doses of ABT-450 in their combination achieved SVR. Thirteen of 14 patients (93 percent) given 150 mg doses of ABT-450 achieved SVR.

"This demonstrates unprecedented cure rates for the most common form of hepatitis C infection," said Scott Brun, Abbott's divisional vice president for infectious disease development. Although confirming the effectiveness and safety of the drugs requires much larger trials, Abbot maintains it is on track to embark on Phase III testing early next year.

In a third portion of the study concentrating on patients unresponsive to the standard regimen of interferon and ribavirin, 8 of 17 (47 percent) achieved SVR. Abbott is hopeful an NS5A inhibitor it is testing in several all-oral combinations will boost SVR rates of previous non-responders.