Merck & Co.'s Four-Week Hep C Regimen With Gilead Sciences, Inc.'s Sovaldi Fails To Deliver

Published: Nov 11, 2014

Merck & Co's Four-Week Hep C Regimen With Gilead Sciences, Inc.'s Sovaldi Fails To Deliver

November 10, 2014

By Jessica Wilson, Breaking News Staff

Merck & Co. today announced interim results of its clinical trial of a triple-therapy regimen consisting of the fixed-dose combination of grazoprevir/elbasvir (MK-5172/MK-8742, MK-5172A) and Gilead Sciences, Inc. ’s Sovaldi for the treatment of chronic hepatitis C virus (HCV) infection which showed that the drug combination failed to meet its efficacy endpoint for a four-week treatment.

The results of the study, known as C-SWIFT, which were presented at the 65th Annual Meeting of the American Association for the Study of Liver Diseases (AASLD). The drug cocktail did show success in a six-week and an eight-week treatment.

In the C-SWIFT study, the 102 participants received Merck’s experimental drugs grazoprevir and elbasvir, along with Gilead’s Sovaldi for as little as four weeks. According to an article in Businessweek, “In patients whose livers weren’t already badly damaged by the virus, 38.7 percent were cured in four weeks and 86.7 percent were cured in six weeks….That’s well below the 90 percent-plus cure rates seen with longer treatments.” Based on these results, Merck will not move forward in clinical testing with the four-week treatment.

“These interim data provide a compelling proof-of-concept for the potential of an eight- or six-week triple therapy course in treatment-naive patients with genotype 1 disease, including cirrhotic patients,” Eric Lawitz, vice president of scientific and research development at The Texas Liver Institute and C-SWIFT lead investigator, said in a statement. “These findings will inform the design of larger studies aimed at understanding the potential of short-duration triple therapy across multiple patient types.”

Merck’s Vice President of Infectious Diseases Eliav Barr, told Businessweek, “The key thing for me was having a clear road map. I was afraid it’d be a pastiche of results difficult to interpret, whereas this clearly shows the Achilles’ heel in terms of duration.”

Now that Merck has decided not to pursue the four-week treatment in clinical trials, the company has decided to begin testing a new combination therapy that will involve both grazoprevir and elbasvir as well the investigational drug MK-3682. Merck acquired MK-3682 with its $3.85 billion purchase of Idenix Pharmaceuticals Inc. The new study, called C-CREST, is scheduled to begin in in the first quarter of 2015 and will begin at the Phase II stage.

According to an article in Business Insider, the Hepatitis C research field is “moving at lightning pace.” A few years ago, patients had to go through an approximately one-year long treatment that had severe side effects and efficacy as low as 40 percent. The most effective treatment today is Gilead’s Harvoni, a combination of Sovaldi and a second drug, which has shown cure rates as high as 99 percent after 12 weeks of treatment.

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