The drug, IDX184, was given to 31 patients in combination with the standard hep C treatments pegylated interferon and ribavirin.

Nine patients received the combination therapy for 12 extended weeks and were checked four weeks later for signs of the virus in the blood to determine if there was a sustained virologic response, or SVR.

All four patients in the 100 mg arm and four out of five patients in the 50 mg arm achieved a sustained virologic response four weeks after the completion of treatment.

Patients who did not have undetectable levels of virus at 4 weeks and 12 weeks automatically entered the 36-week combination therapy extended treatment phase which is ongoing, the company said.

Idenix shares rose 12 percent to $10.45 in extended trade, after closing at $9.37 on Tuesday on the Nasdaq.

(Reporting by Shailesh Kuber in Bangalore; Editing by Saumyadeb Chakrabarty)

• A Permanent Economic Emergency