ANA598 Demonstrates Potent Antiviral Activity in an Early Clinical Study in HCV-Infected Patients

Patients treated at the initial dose in an ongoing Phase 1b trial demonstrated a 2.5 log10 median viral load decline after three days

San Diego -- January 8, 2009 -- Anadys Pharmaceuticals, Inc. (Nasdaq: ANDS) today announced results from the first cohort of an ongoing Phase 1b clinical trial of ANA598, the Company's investigational non-nucleoside polymerase inhibitor. ANA598 was very well-tolerated and demonstrated potent antiviral activity in patients infected with chronic Hepatitis C virus (HCV) in this first cohort of the study.

Patients in the first cohort received 200 mg ANA598 (n=8) or placebo (n=2), twice-daily (bid) for three days. At the end of the treatment period, the median viral load decline was 2.5 log10 (>99%), with a range of 1.4-3.4 log10, for the eight patients who received ANA598. Three patients who received ANA598 were genotype 1a and demonstrated a median viral load decline of 1.6 log10, while five patients who received ANA598 were genotype 1b and demonstrated a median viral load decline of 2.6 log10. All eight patients who received ANA598 demonstrated a rapid decline in viral load, and no patients demonstrated viral rebound while on study drug.

In addition to the robust viral load decline, ANA598 was very well-tolerated and there were no serious adverse events in the first dose cohort, although conclusions regarding longer-term safety and tolerability cannot be made until the results of future clinical trials of longer duration in more patients are known. Patients are currently being enrolled in the second cohort (400 mg bid) of the study. Anadys expects to report detailed data from multiple cohorts of the study at an upcoming medical conference.

"We are very pleased with the antiviral activity and safety of ANA598 at this first dose tested in the Phase Ib study," commented James Freddo, MD, Anadys' Senior Vice President, Drug Development and Chief Medical Officer. "We believe this early data continues to position ANA598 as a leading non-nucleoside polymerase inhibitor in development for the treatment of HCV and we look forward to investigating ANA598 in longer-term studies in combination with current standard of care."

"The clinical and preclinical profile of ANA598 observed to date is very impressive," said Steve Worland, PhD, President and CEO of Anadys. "The magnitude of viral load drop reported today for ANA598 is greater than has been reported for any other non-nucleoside HCV inhibitor in a monotherapy study. Furthermore, the rate of initial viral load decline, believed to be associated with direct inhibition of viral replication, is greater than has been reported previously for all classes of HCV polymerase inhibitors, including nucleosides. This demonstrated antiviral potency holds significant promise for the future use of ANA598 in combination with other anti-HCV agents."

About ANA598

Anadys retains worldwide rights to ANA598, which was fully discovered at the company. Preclinical evaluation of ANA598 was completed in the first quarter of 2008, leading to submission of an Investigational New Drug Application (IND) to the U.S. Food and Drug Administration (FDA), subsequent allowance of the IND by the FDA and initiation of clinical investigation in the second quarter of 2008. In December 2008, Anadys announced that the FDA granted fast track designation to ANA598 for the treatment of chronic HCV.

In October 2008, Anadys initiated patient dosing in the Phase 1b study of ANA598 in HCV patients. In the double-blind, randomized placebo-controlled Phase 1b study, treatment-naive genotype 1a and 1b patients are to receive oral capsules of ANA598 over three days at doses of 200 mg bid (twice-a-day), 400 mg bid or 800 mg bid. Ten patients are to be enrolled at each dose level, eight receiving active drug and two receiving placebo.

In a Phase 1 study in healthy volunteers, ANA598 was administered as capsules at single oral doses of 400 mg, 800 mg, 1400 mg, 2000 mg (fed and fasted), and 3000 mg. In addition, a separate cohort received two 800 mg doses 12 hours apart. ANA598 was well tolerated at all doses and there were no serious adverse events or withdrawals from the study. All reported adverse events were classified as mild or moderate, with no apparent dose relationship. The pharmacokinetic profile demonstrated sustained plasma levels of ANA598 consistent with the potential for once-daily or twice-daily oral dosing.

In the preclinical program, ANA598 was well tolerated at all doses tested in 28-day GLP toxicology studies. In September 2008, Anadys initiated long-term, chronic toxicology studies of ANA598.

If ANA598 is successful in early stage development, the Company anticipates completion of the clinical, toxicology and manufacturing activities required to initiate Phase 2 studies of ANA598 in combination with current standard of care in mid-2009.

About Anadys

Anadys Pharmaceuticals, Inc. is a clinical-stage biopharmaceutical company dedicated to improving patient care by developing novel medicines in the areas of hepatitis C and oncology. For the treatment of chronic hepatitis C, the Company is developing two potentially complementary agents, ANA598, a non-nucleoside polymerase inhibitor and ANA773, an oral TLR7 agonist prodrug. The Company is also developing ANA773 for the treatment of cancer.

For more information, visit http://anadyspharma.com.

First Candidate from SCYNEXIS Novel Cyclophilin Inhibitor Platform, SCY-635, Establishes Proof of Concept in HCV-Infected Adults

Research Triangle Park, NC -- January 8, 2009 -- Drug discovery company, SCYNEXIS, Inc., today announced top-line results from a Phase 1b randomized, double-blind, placebo-controlled study of its lead oral antiviral drug candidate, SCY-635, in adult patients with chronic hepatitis C (HCV) infection. Treatment with SCY-635 was well tolerated and produced a clinically relevant reduction in plasma HCV RNA. Full results of the study will be presented in 2009. SCY-635, a cyclophilin inhibitor, represents a new class of drugs for the treatment of HCV infection and is the first candidate from a broad platform of proprietary cyclophilin inhibitors developed by SCYNEXIS.

"These data are very encouraging, demonstrating the therapeutic potential of SCY-635 in patients with HCV as well as validating our core discovery platform which is focused on developing cyclophilin inhibitors for multiple diseases, including serious viral diseases, central nervous system disorders and autoimmune diseases," commented Dr. Yves Ribeill, President and Chief Executive Officer of SCYNEXIS. "Based on these promising results, we are actively planning the clinical and regulatory path forward for the development of SCY-635 and will continue to advance additional novel candidates from the platform for other therapeutic indications."

About the Clinical Trial

The clinical study was conducted as a Phase 1b, randomized, double-blind, placebo-controlled, multi-dose study in adult volunteers with genotype 1 chronic hepatitis C infection. SCY-635 was given as an oral capsule for 15 consecutive days.

About SCY-635 and SCYNEXIS' Cyclophilin Inhibitor Platform

SCY-635 represents a new class of therapeutic agents for the treatment of HCV infection. SCY-635 is the first candidate in a novel class of non-immunosuppressive cyclophilin inhibitors owned by SCYNEXIS. Cyclophilins are a family of enzymatic proteins that assist in the folding and transport of other proteins synthesized within a cell. Cyclophilin inhibitors, such as Cyclosporine A, have been used for decades for the prophylaxis of organ rejection in transplant patients. Scientists at SCYNEXIS have synthesized derivatives of Cyclosporine A in which cyclophilin binding activity is separated from calcineurin binding activity (which mediates immunosuppression). A growing body of scientific evidence indicates that non-immunosuppressive analogs of Cyclosporine A may have applications in multiple therapeutic areas. Cyclophilins play a central role in the pathophysiology of chronic viral infection, neurodegenerative diseases and malignant transformation. Cyclophilin inhibition therefore represents an attractive target for drug discovery and development.

About SCYNEXIS

SCYNEXIS is a premier drug discovery and development company delivering effective and innovative drug pipeline solutions to pharmaceutical and global health partners. The company, which is located in Research Triangle Park, North Carolina, is also focused on developing a proprietary internal pipeline based on cyclophilin inhibitors, a class of drugs that hold significant potential for the treatment of a broad range of diseases.

For more information, visit the website at www.scynexis.com.