SAN DIEGO, CA - December 11, 2001 -- Metabasis Therapeutics, Inc., a rapidly growing, clinical stage biopharmaceutical company, announced today that it has completed the formation of its Scientific Advisory Board (SAB). The SAB will help the company to deliver on the promise of its growing pipeline of products for liver-related diseases and its rapidly expanding research programs. Metabasis' product pipeline consists of MB6322, a novel gluconeogenesis inhibitor targeting type 2 diabetes and MB6866, a Hepatitis B drug candidate derived from Metabasis' HepDirect™ liver targeting technology. Sankyo Co., Ltd. is responsible for the development of MB6322, which recently entered Phase 1 human clinical studies. MB6866, the subject of a recently signed agreement with ICN Pharmaceuticals who is funding its development, is expected to enter the clinic in the first half of 2002. A third compound for treatment of primary liver cancer, as yet unnamed and also based on the HepDirect technology, is expected to be recommended for clinical development early in 2002.

Dr. Mark Erion, Executive Vice President of Research and Development, stated "The members of the SAB were carefully chosen based on their scientific expertise as well as their interest in both drug discovery and clinical development. We sought leaders in the scientific community who were conducting cutting-edge research in areas relevant to our research interests in liver-related diseases. Our current R&D efforts are focused on finding novel therapies for hepatitis B and C, primary and metastatic liver cancers, chronic liver disease and metabolic diseases in which the liver plays a central role. We look forward to benefiting from the thoughts and insights of our scientific advisors in the years to come."

Dr. Paul Laikind, Chairman, CEO and President at Metabasis stated, "To have assembled such a world-class scientific advisory board is very exciting for all of us here at Metabasis. We are looking forward to working closely with them individually and as a group. A strong SAB used in an effective manner can help the company make smart and timely strategic decisions on our current products and will also help us to identify new product opportunities."

The Metabasis Scientific Advisory Board includes the following members:

D. Montgomery Bissell, M.D. is Professor of Medicine and Director of both the Division of Gastroenterology at the University of California, San Francisco and the UCSF Liver Center. Dr. Bissell is a world leader in research on liver fibrosis and the past president of the American Association for the Study of Liver Diseases.

Alan D. Cherrington, Ph.D. is Professor and Chair of the Department of Molecular Physiology and Biophysics at Vanderbilt University. Dr. Cherrington's research has focused on the regulation of pathways in the liver controlling glucose production and glucose uptake. Dr. Cherrington has received numerous prestigious awards for his research, including both the Lilly and Banting Awards from the American Diabetes Association.

Anna Mae Diehl, M.D. is a Professor of Medicine at Johns Hopkins University. Dr. Diehl's research has focused on chronic liver diseases including alcohol and non-alcoholic liver steatohepatitis, liver regeneration and the role of cytokines in liver disease.

Jules L. Dienstag, M.D. is an Associate Professor of Medicine at Harvard Medical School and serves as a Physician at Massachusetts General Hospital and as the Executive Director of the Liver-Biliary-Pancreas Center. Dr. Dienstag is recognized worldwide as a leader in pre-clinical and clinic hepatitis research and has been one of the principle investigators for several clinical studies evaluating new antiviral drugs for hepatitis B and C.

Heinz W. Gschwend, Ph.D. is the former head of research at CIBA-GEIGY's US Pharmaceutical Division where he played a leading role in the discovery and development of over 80 pre-clinical and clinical candidates. Dr. Gschwend also helped build the discovery group at Arris Pharmaceuticals. Dr. Gschwend has been a Board member and ad hoc consultant to Metabasis Therapeutics since August 1999.

David J. H. Herzig, Ph.D., LLC. is the former Vice President of Drug Development at Parke-Davis R&D in Ann Arbor, Michigan, where he was responsible for all aspects of the development, registration, and launch support for Rezulinä, FemHRTä, FemPatchä, and Estrostepä. In addition, as head of Scientific Development he was responsible for the identification and evaluation of compounds and technology for Warner-Lambert and for assisting in their acquisition.

Gerald I. Shulman, M.D., Ph.D. is an Investigator of the Howard Hughes Medical Institute and Professor of Medicine and Cellular & Molecular Physiology at Yale University School of Medicine. Dr. Shulman's research has focused on the mechanism of insulin-resistance in type 2 diabetes and on pathways controlling glucose production in the liver. Dr. Shulman has received numerous awards for his research, including the Outstanding Investigator Award of the American Federation for Clinical Research and the Outstanding Scientific Achievement Award of the American Diabetes Association.

Alan P. Venook, M.D. is Professor of Clinical Medicine, Director of the Clinical Research Office in the UCSF Cancer Center and the Clinical Leader of the Gastrointestinal Oncology program at UCSF. His academic focus and clinical interests are in the treatment of GI malignancies and liver tumors, and in the application of new biological agents.

David J. Waxman, Ph.D. is Professor of Cell and Molecular Biology at Boston University and Professor of Medicine at Boston University School of Medicine. He is an internationally recognized authority on cytochrome P450 enzymes and genes, with emphasis on their importance in drug development and on their role in the bioactivation of anti-cancer drugs.

Metabasis Therapeutics, Inc. (www.mbasis.com) is a privately-held, biopharmaceutical company that develops proprietary products for the treatment of human disease with a current focus on diseases that involve the liver. The Company is a leader in the field of nucleoside/nucleotide metabolism and chemistry, and has proprietary expertise in liver biology and organ-specific drug delivery. The Company has developed the HepDirect™ prodrug technology that allows liver-specific delivery of new and existing drugs. The company has also discovered and developed a new class of drugs for treating diabetes that acts to lower liver glucose production in diabetic patients. The first drug from this program is being developed in collaboration with Sankyo Co., Ltd. and is currently undergoing Phase 1 clinical testing. The Company occupies state-of-the-art research facilities in San Diego, California.