HCV candidate for Anadys

San Diego-based Anadys Pharmaceuticals has selected ANA975, an oral prodrug of isatoribine (ANA245), to be its development candidate for front-line treatment of chronic hepatitis C virus (HCV) infection.

ANA975 builds from Anadys' clinical experience with isatoribine, including knowledge of isatoribine doses that have been shown to be well-tolerated in Phase 1A and Phase 1B trials and that demonstrated a statistically significant reduction of HCV viral load. Anadys expects that this knowledge will facilitate an accelerated and efficient clinical development program for ANA975.

'ANA975 was selected from the ANA97X family of isatoribine prodrug compounds based upon its favorable pharmaceutical properties, which we believe should allow it to become an orally administered front-line treatment for chronic HCV,' said Dr Devron Averett, senior vice president of Drug Development for Anadys.

Prodrugs are distinct chemical entities that are administered as a precursor of the active drug and then are converted into the active drug in the body. Isatoribine and its prodrugs are a new class of drugs being developed by Anadys to regulate innate immunity, the body's first line of defense against viruses and other foreign organisms.

Anadys believes that isatoribine interacts with a specific receptor on certain immune system cells named TLR-7, which assists in regulating innate immune responses against viruses.

'We are very pleased in achieving one of our goals for the second quarter of 2004, by selecting a front-line clinical candidate for the treatment of chronic hepatitis C virus infection,' said Dr Kleanthis Xanthopoulos, president and ceo of Anadys. 'ANA975 broadens our existing pipeline of anti-infective drug candidates, which includes isatoribine and ANA971 for the treatment of HCV, ANA380 for the treatment of hepatitis B virus, and preclinical candidates to treat bacterial infections. We look forward to advancing ANA975 into the clinic.'

About isatoribine (ANA245)

Isatoribine is a nucleoside analog Anadys is evaluating in ongoing clinical trials for the treatment of HCV infections. Isatoribine represents one of a new class of drugs being developed by Anadys to regulate innate immunity, combat HCV infection, and overcome limitations of current anti-HCV therapies.

About hepatitis C

Hepatitis C virus, the most common chronic blood-borne infection in the US, causes inflammation of the liver and may progress to more serious complications such as cirrhosis of the liver, liver cancer and death. Approximately 2.7m people in the US are chronically infected with HCV, and the Centers for Disease Control (CDC) estimates that by the year 2010, the number of deaths attributed annually to HCV could surpass that due to HIV/AIDS. Worldwide sales for anti-infective products were $40bn in 2002, yet current treatments for HCV may be ineffective in up to 50% of patients due to the development of drug-resistant viral strains, and many treatments are associated with serious side effects.