Eight, 12 or 16 weeks of Merck’s investigational triple-combination treatment MK3682B (MK-3682/grazoprevir/ruzasvir) boasted generally high hepatitis C virus (HCV) cure rates in recent Phase II trials. The treatment is informally known as MK3.

Researchers presented findings from Part B of the ongoing open-label C-CREST 1 & 2 trials at the Annual Meeting of the American Association for the Study of Liver Diseases (AASLD) in Boston.

The trials included 90 people with genotype 1a of hep C, 86 with genotype 1b, 151 people with genotype 2 and 337 people with genotype 3. Some of the participants had cirrhosis. Some of those with genotypes 2 or 3 received ribavirin in addition to MK3. All of those with genotypes 1 or 3 were being treated for hep C for the first time. Fifty-six percent of those with genotype 3 had not been treated before, and 44 percent were previously treated with interferon and ribavirin.

Among those treated for eight weeks, a respective 95 percent, 86 percent and 95 percent of those with genotypes 1, 2 and 3 achieved a sustained virologic response 12 weeks after completing therapy (SVR12, considered a cure). Those treated for 12 weeks saw respective cure rates of 99 percent, 97 percent and 97 percent. Having cirrhosis did not significantly impact the chance of a cure.

The most common side effects reported by participants were headache (22 percent), fatigue (19 percent) and nausea (13 percent). Two people experienced drug-related serious adverse health events, as a result of taking ribavirin. Nine people stopped treatment because of adverse health events, with four of them stopping only ribavirin.

To read a press release about the study, click here.