On June 26, Anadys Pharmaceuticals announced that it would suspend dosing of its investigation hepatitis C candidate, ANA975, in an ongoing Phase 1b trial, pending further assessment of data from preclinical toxicology studies. The company called the move a "precautionary measure."

ANA975 is an oral pro-drug of isatoribine, a toll-like receptor-7 agonist. Toll-like receptors are known to play a role in immune system activation. To date, ANA975 has been administered to more than 90 healthy volunteers in three completed Phase I trials.

Preliminary analysis of data from animal studies revealed new information suggesting that ANA975 causes intense immune stimulation.

"Although we have not seen any serious adverse events in clinical experience with ANA975, the health and safety of patients are our first and overriding concern," said Anadys president and CEO Kleanthis Xanthopoulos, PhD. "Consequently, we are suspending this trial for appropriate reasons of precaution while we gain a greater understanding of this recently obtained information."

Anadys and its collaborator, Novartis, are currently evaluating how best to proceed. Steve Worland, PhD, Anadys President of Pharmaceuticals, said that the latest data might lead to modifications of the current clinical trial design.

"We continue to believe that ANA975 is an effective immunomodulator and therefore a potentially promising agent for patients infected with hepatitis C virus," Worland added.

Another toll-like receptor agonist, Coley Pharmaceutical Group's CPG 10101 (Actilon), is also under development, and so far has not been linked to serious adverse events.

6/30/06

Source
PRNewswire. Anadys Pharmaceuticals Suspends Dosing of ANA975 in Hepatitis C Clinical Trial Pending Further Assessment of 13-Week Pre-Clinical Toxicology Studies. June 28, 2006.

FDA-approved Monotherapies for HCV

Intron A Roferon Infergen Pegasys PEG-Intron

FDA-approved Combination Therapies for HCV

Pegasys + Copegus PEG-Intron + Rebetol Intron A + Rebetol Roferon A + Ribavirin