Updated on 4 November 2013
Of those who were either ineligible for or intolerant of treatment with interferon, the cure rate was 87.4 percent, while 80.5 percent of past nonresponders to the older drugs were deemed cured.
"The Phase III study results of daclatasvir plus asunaprevir are exciting to see, especially in this difficult-to-treat patient population," Kazuaki Chayama, the study's lead investigator from Hiroshima University said in a statement.
It further said that twenty-eight patients dropped out of the study - a 12.6 percent discontinuation rate and about 6 percent, or 13 patients, reported serious side effects, primarily elevated liver enzymes, an indication of inflammation.
About 1.2 million people in Japan suffer from hepatitis C. The patients tend to be older than those in other developed countries and about 70 percent have Genotype 1b, a form of the virus with very low response rates to the older treatments.
A Reuters report said that several other companies are also developing all-oral hepatitis C treatments, including AbbVie Inc, Merck & Co and Johnson & Johnson, and expect to be able to shorten treatment duration to 12 weeks from the current 24 or 48 week regimens.