Idenix announces updates on HCV and HIV clinical development programs

Idenix Pharmaceuticals, Inc. (Nasdaq: IDIX), a biopharmaceutical company engaged in the discovery and development of drugs for the treatment of human viral diseases, today announced updates to three clinical development programs.

IDX184, a liver-targeted HCV nucleotide prodrug

The U.S. Food and Drug Administration (FDA) has verbally informed Idenix that the full clinical hold for IDX184 has been removed. The program has been placed on partial clinical hold, and Idenix anticipates initiating a Phase IIb12-week trial of IDX184 in combination with pegylated interferon and ribavirin in the second half of 2011.

The clinical hold was issued in September 2010 as a result of three cases of elevated liver function tests observed during a drug-drug interaction study of the combination of IDX184 and IDX320, an HCV protease inhibitor, in healthy volunteers. Idenix reviewed available data and conducted additional preclinical studies. With the help of independent experts and an external safety committee, the company concluded that the observed toxicity was likely caused by IDX320. Idenix submitted a response to the clinical hold to the FDA in January 2011.

IDX320, an HCV protease inhibitor

Based on Idenix's conclusion that the observed toxicity in the drug-drug interaction study was likely caused by IDX320, the company has discontinued the development of IDX320. Next generation protease inhibitors that may potentially avoid the observed hepatotoxicity are in preclinical development at Idenix.

GSK2248761 ('761, formerly IDX899), an HIV non-nucleoside reverse transcriptase inhibitor

Idenix was informed by ViiV Healthcare Company (ViiV), an affiliate of GlaxoSmithKline (GSK), that '761, a non-nucleoside reverse transcriptase inhibitor drug candidate for the treatment of HIV/AIDS licensed by Idenix to GSK, was placed on clinical hold by the FDA. ViiV has full responsibility for the development of '761, including any regulatory interactions.

Under the collaboration arrangement between Idenix and GSK, Idenix has received $60.5 million in license fees, equity investment and milestone payments to date and is eligible to receive up to $390.0 million in additional milestone payments as well as double-digit tiered royalties on worldwide product sales.

SOURCE Idenix Pharmaceuticals, Inc.