Nov 11, 2012
Merck announced that 96% of trial patients achieved SVR12 with it's protease inhibitor (MK-5172) combined with Interferon and Ribavirin. Merck plans to begin other Phase 2 studies soon.
AASLD-Merck MK-5172 Hepatitis C Drug Shows Promise in Study
Merck Hepatitis C Drug Shows Promise in Study
Published: November 10, 2012
Dow Jones Newswires
A regimen containing an experimental Merck & Co. (MRK) drug suppressed the hepatitis C virus in most patients in a new clinical trial, and appears to be more potent than the company's Victrelis treatment.
The mid-stage study included the injectable drug interferon that Merck and its rivals hope to drop from future regimens. Merck now plans to conduct new studies of its drug, MK-5172, as part of a potential all-oral hepatitis C regimen that eliminates interferon, which can be difficult for patients to tolerate.
Merck is among a pack of drug companies--including Gilead Sciences Inc. (GILD) and Abbott Laboratories (ABT)--racing to tap what's expected to be a multibillion-dollar market for all-oral regimens. Current standard therapies, including Merck's Victrelis, are typically given with interferon.
Hepatitis C is a viral disease that attacks the liver, and is believed to afflict about 180 million people world-wide, with more than four million in the U.S., according to the National Institute of Allergy and Infectious Diseases. At-risk groups include people who had blood transfusions before 1992, when a screening test for the virus was developed.
Merck is presenting clinical data for MK-5172 at the annual meeting of the American Association for the Study of Liver Diseases in Boston, which began Friday.
MK-5172 is a so-called protease inhibitor, the same class of drug as Victrelis, which went on sale last year and generated $387 million in sales for the first nine months of 2012. But MK-5172 is designed to be more potent and to carry a higher barrier to treatment resistance than Victrelis, said Eliav Barr, vice president of infectious diseases with Merck's research arm.
In a phase 2, or mid-stage, clinical trial of about 330 patients with hepatitis C, patients were given various dose levels of MK-5172 in combination with the drugs ribavirin and interferon for 12 weeks. One group of patients received Victrelis plus ribavirin and interferon--which is now a standard treatment.
The study found that 96% of patients who received the 100-milligram dose of MK-5172 had sustained virologic response 12 weeks after treatment ended, the highest response rate of the various treatment groups. Sustained virologic response is roughly equivalent to being virus-free or having nearly undetectable viral levels.
Higher doses of MK-5172 were associated with liver toxicities, said Dr. Barr.
Because the study contained interferon, additional studies are needed to test whether MK-5172 is efficacious without interferon.
Merck plans to conduct phase 2 studies of MK-5172 in combination with another experimental oral drug, MK-8742, plus ribavirin, which is also an oral drug. If testing goes well, Merck may consider removing ribavirin from the regimen and pursuing a combination of MK-5172 and MK-8742, he said. Ideally, they could be combined in a once-daily tablet.
"We're looking for something highly efficacious, short duration, well-tolerated and all-oral," he said.
Dr. Barr declined to provide a timeline for when Merck might be in a position to submit a new hepatitis C regimen for regulatory approval.