Guy Macdonald, B.Sc.
President and Chief Executive Officer

Guy Macdonald has served as our President and Chief Executive Officer and a member of our board of directors since January 2008. From August 2003 until January 2008, Mr. Macdonald served as Executive Vice President, Operations, of Idenix Pharmaceuticals, Inc., a biopharmaceutical company. Prior to joining Idenix, he served in various positions at Merck & Co., Inc., a pharmaceutical company, from 1981 to 2003, most recently serving as the Vice President for Anti-Infective and Hospital Products. Mr. Macdonald currently serves as a member of the board of directors of Spring Bank Pharmaceuticals, Inc., a privately held company. Mr. Macdonald received an Honours Degree in biochemistry from Dundee University in Dundee, Scotland. We believe that Mr. Macdonald’s detailed knowledge of our company and his 25 year career in the global pharmaceutical and biotechnology industries, including his roles at Idenix Pharmaceuticals and Merck & Co., provides a critical contribution to our board of directors.

Patrick Horn, M.D., Ph.D.
Chief Medical Officer

Patrick T. Horn, M.D., Ph.D. has served as our Chief Medical Officer since January 2011. From September 2007 until December 2010, he served as Vice President, Clinical & Medical Affairs at Dyax Corporation, a biopharmaceutical company. Prior to joining Dyax, Dr. Horn served in various positions at Abbott Laboratories, a pharmaceutical company, from 2001 to 2006, most recently serving as Medical Director, Head of Clinical Pharmacology. Dr. Horn received a B.S. in Chemistry from the University of Illinois, doctorate in the Pharmacological and Physiological Sciences from the University of Chicago and an M.D. from the University of Chicago, Pritzker School of Medicine.

David Lubner
Senior Vice President and Chief Financial Officer

David C. Lubner has served as our Senior Vice President and Chief Financial Officer since October 2010 and from our inception in 2006 until October 2010 he served on a part-time basis as our Senior Vice President and Chief Operating Officer. Mr. Lubner also served as Chief Financial Officer of Mediphase Venture Partners, a venture capital firm, from 2006 until October 2010. From 1999 to 2005, he served as Vice President and Chief Financial Officer at PharMetrics, Inc., a pharmacy and medical claims data informatics company, until its acquisition by IMS Health in 2005. Prior to joining PharMetrics, Mr. Lubner served as Vice President and Chief Financial Officer of ProScript, Inc., a biotechnology company, from 1996 to 1999. Mr. Lubner is a member of the American Institute of CPAs and is a certified public accountant in the Commonwealth of Massachusetts. Mr. Lubner received a B.S. in business administration from Northeastern University and an M.S. in Taxation from Bentley University.

Magnus Ronn, Ph.D.
Vice President, Chemistry, Manufacturing and Control

Magnus Ronn, Ph.D. has served as our Vice President, Chemistry, Manufacturing and Control since October 2009 and as our Senior Director for Chemistry, Manufacturing and Control since our inception in 2006 until September 2009. From 2001 to 2006, he served as a Scientist at increasing levels of responsibility within Process Chemistry Research & Development at Millennium Pharmaceuticals, Inc. (now a Takeda company), a pharmaceutical company. Prior to joining Millennium, Dr. Ronn was a scientist at Roche Colorado Corporation (now known as Corden Pharma Colorado, Inc.), a pharmaceutical manufacturing company. Dr. Ronn received a B.S. in chemistry and a Ph.D. in organic chemistry from the University of Uppsala, Sweden.

Joyce Sutcliffe, Ph.D.
Senior Vice President, Biology

Joyce Sutcliffe, Ph.D. has served as our Senior Vice President, Biology, since May 2009. From October 2007 until May 2009, Dr. Sutcliffe served as Vice President, Research at NanoBio Corporation, a biopharmaceutical company. From September 2001 until September 2007, Dr. Sutcliffe served as Chief Research Scientist and Vice President, Biology at Rib-X Pharmaceuticals, Inc., a biopharmaceutical company. Prior to joining Rib-X Pharmaceuticals, she held various positions at Pfizer, Inc., a pharmaceutical company, for 16 years. Dr. Sutcliffe received a B.S. in zoology from the University of Florida and a Ph.D. in microbiology from the University of Florida, Gainesville, and has held postdoctoral positions at the University of Massachusetts Medical School and the National Institutes of Health.

Leland Webster, Ph.D.
Vice President, Business Development

Leland Webster, Ph.D. has served as our Vice President, Business Development since January 2009. From August 2007 to January 2009, Dr. Webster served as Vice President, Corporate Development at Surface Logix, Inc., a biomedical development company. Prior to joining Surface Logix, Dr. Webster served in various positions in business development (in-licensing and out-licensing) at ImmunoGen, a biopharmaceutical company, from 2004 to 2007, and at Vertex Pharmaceuticals, a biotechnology company, from 1999 to 2004. Dr. Webster served as a Senior Analyst at MPM Capital L.P., a venture capital firm, from 1994 to 1997. Dr. Webster served as Damon Runyon-Walker Winchell postdoctoral fellow in the Department of Biological Chemistry and Molecular Pharmacology at the Harvard Medical School from 1991 to 1994. Dr. Webster received a B.A. in biological sciences from Northwestern University, a Ph.D. in biochemistry from the University of Pennsylvania and an M.B.A. from the MIT Sloan School of Management.

Xiao-Yi Xiao, Ph.D.
Vice President, Medicinal Chemistry

Xiao-Yi Xiao, Ph.D. has served as our Vice President, Medicinal Chemistry since September 2006. From 2003 to 2006, Dr. Xiao served as Senior Director of Discovery Chemistry at Miikana Therapeutics (now part of EntreMed), a pharmaceutical company. Prior to joining Miikana Therapeutics, Dr. Xiao served as Director of Discovery Chemistry at Syrrx, Inc. (now a Takeda Pharmaceuticals company), a pharmaceutical company, from 2001 to 2003. From 1995 to 2001, he served in various positions at Discovery Partners International (now part of Infinity Pharmaceuticals), a chemical synthesis company. From 1993 to 1995, Dr. Xiao served in various positions at Affymax Research Institute, a biopharmaceutical company. Dr. Xiao has published more than 40 research articles and book chapters as well as over 20 issued patents and patent applications. Dr. Xiao received a B.S. in chemistry from Zhongshan University, China, and a Ph.D. in organic and bio-organic chemistry from State University of New York Stony Brook.