Board of Directors

David F. Hale, Chairman of the Board - Mr. Hale has served as Chairman of our Board of Directors since September 2006 and as a director since April 1997. Mr. Hale is currently Executive Chairman and Interim Chief Executive Officer of Somaxon Pharmaceuticals and Chairman of Hale BioPharma Ventures. He served as President and Chief Executive Officer and a Director of CancerVax Corporation from October 2000 to May 2006 when CancerVax merged with Micromet AG to form Micromet, Inc., of which he is Chairman. Prior to joining CancerVax, he was President and Chief Executive Officer of Women First HealthCare, Inc. from January 1998 to May 2000. Mr. Hale served as President, Chief Executive Officer and Chairman of Gensia from May 1987 to November 1997. Prior to joining Gensia, Mr. Hale was President and Chief Executive Officer of Hybritech Inc. Mr. Hale serves as Chairman of the board of directors of the publicly-held biopharmaceutical companies Santarus, Inc. He also serves as Executive Chairman of the privately-held specialty pharma company, SkinMedica, Inc., and on the boards of privately-held Verus Pharmaceuticals, Inc. and Conatus Pharmaceuticals, Inc. Mr. Hale also serves on the boards of the Biotechnology Industry Organization (BIO), BIOCOM/San Diego, CONNECT, the Biotechnology Institute, Children's Hospital and The Burnham Institute. Mr. Hale received a B.A. in biology and chemistry from Jacksonville State University.

Daniel D. Burgess, Director - Mr. Burgess has served on our Board of Directors since March 2004. Mr. Burgess is currently President and Chief Executive Officer and a director of Mpex Pharmaceuticals, Inc., a privately held pharmaceutical company. Prior to joining Mpex, Mr. Burgess was Chief Operating Officer and Chief Financial Officer of Hollis-Eden Pharmaceuticals, Inc., where he was employed from 1999 to 2007. Mr. Burgess was also Chief Financial Officer of Nanogen, Inc. from 1998 to 1999 and previously spent ten years with Gensia, including with Gensia Automedics, Inc., a partially owned subsidiary of Gensia. He served as President and a director of Gensia Automedics, where he was responsible for all functional areas of this medical products company. In addition, he was Vice President and Chief Financial Officer of Gensia, where he was responsible for finance, investor relations, business development and other administrative functions. Prior to joining Gensia, Mr. Burgess held positions at Castle & Cooke, Inc. and Smith Barney, Harris Upham and Company. He received a degree in economics from Stanford University and an M.B.A. from Harvard Business School.

Mark D. Erion, Ph.D., Director, President, CEO & CSO - Dr. Erion is one of the founders and has served as executive vice president of research and development since April 1997 and on the board of directors since June 1999. In November 2005, Dr. Erion was appointed chief scientific officer of Metabasis. At Metabasis, Dr. Erion has been responsible for building the research and development teams that advanced five candidates into clinical development and for discovering the company’s HepDirect and NuMimetic technologies. Prior to Metabasis, Dr. Erion was at Gensia where he became vice president of research in 1996 after serving as their head of chemistry and biochemistry. Prior to Gensia, Dr. Erion was a research scientist and group leader at Ciba-Geigy Pharmaceutical Company. Dr. Erion received a B.S. with honors in mathematics and chemistry from the University of Oregon, a Ph.D. in Chemistry from Cornell University and was a National Institutes of Health postdoctoral fellow at Massachusetts Institute of Technology. Dr. Erion has authored over 112 publications and is named as an inventor on 36 U.S. patents.

Luke B. Evnin, Ph.D., Director - Dr. Evnin has served on our board of directors since September 2000. Dr. Evnin is a General Partner at MPM Capital, a venture capital firm focusing on global healthcare investments. Before joining MPM Capital in 1998, Dr. Evnin was affiliated with Accel Partners for seven years, including four years as a General Partner. He was involved in biopharmaceutical, pharmaceutical, medical device and healthcare service companies for Accel Partners' funds III, IV, and V. He was responsible for overall investment strategy, deal orientation, analyses, investment and gain realization. Dr. Evnin serves on the board of directors of several privately-held healthcare companies including BioValve Technologies, Inc. and Genesoft, Inc. He also serves on the board of directors of Medical Portfolio Management, L.P., an investment management firm, and is chairman of the Scleroderma Research Foundation. Dr. Evnin holds a Ph.D. in biochemistry from the University of California at San Francisco, and an A.B. in Molecular Biology from Princeton University.

Paul K. Laikind, Ph.D., Director - Dr. Laikind was one of the founders of Metabasis and was with the company from its inception in April 1997 until December 2008. He joined the company as president and served on the board of directors. He was appointed chief executive officer in April 1998 and his role was expanded to include president and secretary in June 1999. He served as chairman of the board of directors from April 1998 until September 2006. Prior to joining Metabasis, Dr. Laikind founded Gensia, Inc. in 1986 where he served as vice president of business development. He was responsible for establishing major research and development corporate partnerships with leading U.S. and European companies. While at Gensia, Dr. Laikind also founded Viagene, Inc., a biotechnology company acquired by Chiron, Inc. in 1995. Dr. Laikind currently serves on the Boards of BIOCOM and the San Diego Chapter of the American Liver Foundation and is a member of the BIO Emerging Companies Section Governing Body. Dr. Laikind holds a Ph.D. in chemistry from the University of California at San Diego and has served as a research faculty member at the UCSD School of Medicine.

Arnold L. Oronsky, Ph.D., Director - Dr. Oronsky has served on our board of directors since September 2000. Dr. Oronsky is a General Partner at InterWest Partners, a venture capital firm focusing on investments in life sciences and information technology. Dr. Oronsky joined InterWest Partners in a full-time capacity in 1994 after serving as a special limited partner since 1989. He also serves as a senior lecturer in the Department of Medicine at Johns Hopkins Medical School. From 1980 to 1993, Dr. Oronsky was Vice President for Discovery Research at the Lederle Laboratories division of American Cynamid Company, a pharmaceutical company. From 1973 to 1976, Dr. Oronsky was Head of Inflammation, Allergy and Immunology Research at Ciba-Geigy. From 1970 to 1972, he was an assistant professor at Harvard Medical School, where he also served as a research fellow from 1968 to 1970. Dr. Oronsky serves on the board of directors the publicly-held biotechnology companies Aresiva, Inc. and Dynavax Technologies Corporation. He holds a Ph.D. from Columbia University, College of Physicians and Surgeons and a B.S. degree from University College, New York University.

William R. Rohn, Director - Mr. Rohn has served on our Board of Directors since December 2004. Mr. Rohn has over 30 years of management experience in the biotechnology and pharmaceutical industry including more than 10 years in executive management positions at IDEC Pharmaceuticals Inc. and, more recently, Biogen Idec where he served as Chief Operating Officer until his retirement in 2005. He joined IDEC in August 1993 as Senior Vice President, Commercial and Corporate Development, was appointed Senior Vice President, Commercial Operations in April 1996 and was promoted to Chief Operating Officer in May 1998. In January 2002, he became President, responsible for Sales, Marketing, Business Development, Manufacturing, Quality, Medical Affairs and CMC Regulatory Affairs. Prior to joining IDEC, Mr. Rohn was employed for approximately nine years by Adria Laboratories, now part of Pfizer, most recently as Senior Vice President of Sales and Marketing. Prior to Adria, Mr. Rohn held marketing and sales management positions at Abbott Laboratories, Warren-Teed Pharmaceuticals, Miles Laboratories and Mead Johnson Laboratories. Mr. Rohn serves on the Board of Directors of Elan Corporation, plc, Pharmacyclics, Inc., Cerus Corporation, and Raven Biotechnologies. Mr. Rohn received a B.A. in Marketing from Michigan State University.

George F. Schreiner, M.D., Ph.D., Director - Dr. Schreiner has served on our Board of Directors since June 2007. Dr. Schreiner is currently Chief Executive Officer and a director of Raven Biotechnologies, Inc., a privately-held biotechnology company. Prior to joining Raven Biotechnologies in May 2006, he was President of Research and Development and Chief Scientific Officer at Scios Inc., a biopharmaceutical company and member of the Johnson & Johnson Family of Companies, from April 2003 to May 2006, and held the positions of Chief Scientific Officer, Chief Medical Officer and Senior Vice President of Research and Development of Scios from January 1997 to April 2003. Prior to joining Scios, Dr. Schreiner was Vice President, Medical Science and Preclinical Research at CV Therapeutics, Inc., a publicly-held biopharmaceutical company, from 1993 to January 1997. Dr. Schreiner received his M.D. from Harvard Medical School and his Ph.D. in Immunology from Harvard University. He trained in Internal Medicine and Nephrology at the Brigham and Women's Hospital in Boston. He held joint appointments on the faculties of the Department of Medicine and Pathology at Harvard Medical School and the Washington University School of Medicine, where he received tenure.

Elizabeth Stoner, M.D., Director - Dr. Stoner has served on our Board of Directors since April 2008. Dr. Stoner is a managing member of MPM Capital, a venture capital firm focusing on global healthcare investments. From 1985 to 2007, Dr. Stoner held various key executive roles while at Merck Research Laboratories, most recently as Senior Vice President for Global Clinical Development Operations. In that role, she was responsible for the Merck's clinical development activity in over 40 countries, as well as the clinical development activities for Merck's Japanese partner Banyu and the Merck/Schering-Plough Joint Venture for Zetia/Vytorin. Dr. Stoner's other roles at Merck included Endocrine Therapeutic Head, Senior Vice President of Clinical Sciences and Product Development, Chair of the Cholesterol Development Committee, and Vice President of Clinical Research for the Endocrine/Metabolism clinical research programs. In addition to her work in clinical research and development at Merck, Dr. Stoner maintained a medical practice from 1985 to 2006 as an Assistant Attending Physician of Pediatrics at New York Hospital. Prior to 1985, she was an Assistant Professor of Pediatrics at Cornell University Medical College. Dr. Stoner serves on the board of directors of publicly-held Momenta Pharmaceuticals, a biotechnology company specializing in the characterization and engineering of complex drugs. She is the recipient of numerous distinguished honors. Dr. Stoner has also authored over 50 publications as well as 13 U.S. patents. Dr. Stoner received a B.S. in Chemistry from Ottawa University, KS, an M.S. in Chemistry from the State University of New York at Stony Brook, and an M.D. from Albert Einstein College of Medicine.