Anadys Pharmaceuticals Resumes Clinical Investigation of TLR7 Mechan...(t few weeks and inHCV patients early in ...),Health

About ANA773 and TLR Pharmacology

ANA773 is an orally administered prodrug of a novel TLR7-specific agonist. Results from pre-clinical pharmacology studies have shown that ANA773 can elicit desired immune responses and that the profile of response can be modulated by both dose and schedule of administration. Results of recently completed 13-week GLP toxicology studies have shown that with every-other-day dosing of ANA773, immune stimulation of a magnitude believed to confer therapeutic potential can be achieved without adverse toxicology findings. The immune stimulation observed with every-other-day dosing of ANA773 in monkeys included induction of interferon-alpha and interferon dependent responses at levels that are sustained over 13 weeks of dosing.

The recently obtained results with every-other-day dosing of ANA773 over 13 weeks contrast with results from prior 13-week animal toxicology studies that utilized daily dosing of ANA975, a TLR7 agonist prodrug previously in development by the Company for the treatment of chronic hepatitis C. In initial 13-week animal toxicology studies of ANA975 dosed daily, unexpected findings associated with intense immune stimulation were observed. When lower daily doses of ANA975 were then explored in a subsequent 13-week animal toxicology study, it was determined that adverse findings were present even at dose levels where desired immunostimulatory effects were not measurable, following which the decision was made in 2007 to discontinue development of ANA975.

Webcast of Conference Call

Anadys will host a conference call today, July 7, 2008 at 2:00 p.m. Pacific Daylight Time to discuss Anadys' plans to resume clinical investigation of the TLR7 mechanism in HCV. A live webcast of the call will be available online at http://www.anadyspharma.com. A telephone replay will also b
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