UPDATE 1-Roche has promising results from Hep C trial

* Hepatitis C combination study shows "significant" potency

* No serious adverse effects in study

(Adds further details)

ZURICH, April 27 (Reuters) - Roche Holding AG (ROG.VX) has announced promising results from a study of a combination therapy for patients chronically infected with hepatitis C.

Roche announced the results along with InterMune (ITMN.O) and Pharmasset VRUS.O which they presented on Saturday at the annual meeting of the European Association for the Study of the Liver in Copenhagen.

They said the study, which combined two oral direct-acting antivirals, R7227 and R7128, showed no serious adverse effects during 14 days of dosing and showed "significant" potency in reducing the viral load of hepatitis C patients.

Roche is developing R7227, a protease inhibitor, with InterMune, and R7128, a nucleoside polymerase inhibitor, with Pharmasset. (Reporting by Emma Thomasson; Editing by Greg Mahlich)