UPDATE 2-Idenix hepatitis C drug mixes safely with others

(Recasts; adds details, CEO comment, share price)

BOSTON, June 12 (Reuters) - Idenix Pharmaceuticals Inc. (IDIX.O) said on Tuesday a trial of its experimental hepatitis C drug valopicitabine, in combination with two other drugs, did not cause any adverse drug interactions.

The 12-week trial evaluated the drug in combination with pegylated interferon and ribavirin, the current standard of care, in patients infected with the genotype-1 strain of the hepatitis C virus.

"While the lack of a drug-drug interaction is positive, we believe the path forward for valopicitabine remains windy with further optimization before Phase III trials commence," said Richard Smith, an analyst at JP Morgan, referring to late-stage trials. "We believe investors can still afford to be patient before revisiting the story."

Shares of Idenix fell nearly 2 percent to $7.09 in early-afternoon trading on Nasdaq.

Cambridge, Massachusetts-based Idenix is developing the drug in collaboration with Swiss drugmaker Novartis AG (NOVN.VX). It said it now plans to test the drug to measure its efficacy compared to the standard of care regime.

Analysts at Bear Stearns cut their rating on Idenix to "peer perform" from "outperform," saying the triple combination may not prove more effective than the standard of care.

Idenix Chief Executive Jean-Pierre Sommadossi said the company also is considering testing a four-drug cocktail. "Ultimately we expect to see treatment with combinations of four or five drugs," he said.

(Additional reporting by Jennifer Robin Raj in Bangalore)

((Reporting by Toni Clarke, editing by Richard Chang; Reuters Messaging, toni.clarke.reuters.com@reuters.net, 617-367-4165)) Keywords: IDENIX TRIALS/

(C) Reuters 2007. All rights reserved. Republication or redistribution ofReuters content, including by caching, framing or similar means, is expresslyprohibited without the prior written consent of Reuters. Reuters and the Reuterssphere logo are registered trademarks and trademarks of the Reuters group ofcompanies around the world.nN12271909