ANA773 HCV
investigational oral TLR7 agonist prodrug

ANA773 - HCV

ANA773 is our oral inducer of endogenous interferons that acts via the toll-like receptor 7 (TLR7) pathway. In early August, we announced that ANA773 had demonstrated a significant antiviral response in Hepatitis C patients in the final cohort of a Phase I clinical trial. In patients who received 2000 mg of ANA773 every other day (QOD) over 10 days, the mean (± SEM) maximal decline in viral load was 1.3 (± 0.4) log10, compared to a mean maximal decline of 0.3 (± 0.1) log10 in patients who received placebo (p=0.037). Five of the eight patients who received 2000 mg of ANA773 experienced a maximal decline of greater than 1 log, while none of the eight patients who received placebo experienced a decline of greater than 1 log (p<0.001 for the proportion of patients with maximal response greater than 1 log compared to placebo). The mean end-of-treatment decline was 0.6 log10 in patients who received 2000 mg of ANA773 compared to 0.1 log10 in patients who received placebo. ANA773 was well-tolerated in patients in the Phase I study and no serious adverse events were reported. Anadys intends to explore partnership opportunities as a potential path to continue the development of ANA773. Please see Anadys’ press release dated August 11, 2009 for further information.

Anadys intends to present complete results from the Phase I clinical study of ANA773 in HCV at the 2009 Annual Meeting of the American Association for the Study of Liver Diseases (AASLD).

Last Updated 8/20/2009

This description contains certain forward-looking statements within the meaning of the Federal securities laws. Our results could vary, perhaps materially, from our projections or expectations. Please see our SEC filings, including our most recent 10-K, for a discussion of the risk factors that could affect our business.