Roche said Friday that in a phase IIa study a triple-drug combination for treatment of hepatitis C showed a robust virological response and subsequently will proceed to a phase IIb study. Presenting results at the American Association of the Study of Liver Diseases (AASLD) meeting in Boston, the Swiss drugmaker said its investigational hepatitis C drug R1626 showed promising antiviral activity in the phase IIa trial when given with Pegasys (peginterferon alfa-2a) and Copegus. The aforementioned Roche drugs are used together to treat adults with chronic hepatitis C whose liver still works normally and who haven't been previously treated with an interferon alpha. After four weeks of treatment with the three-drug combination, the virus couldn't be detected in 81% of patients with a mean decrease in viral load of 5.2 log10 from the baseline, and Roche said most adverse events were mild to moderate. Also, no resistance to R1626 was identified following intensive testing for either two weeks of treatment with R1626 as monotherapy or in patients treated with R1626 for four weeks in combination with the standard of care. The phase IIb study, called POLI 1, which will further investigate R1626 in combination with standard or lower dose of Pegasys and standard dose of Copegus, is now open and enrolling patients in eight countries, including the U.S.