Management Team


Robert Booth PhD
Founder and Chief Executive Officer

Robert Booth PhD
Chief Executive Officer, Virobay

Robert F. Booth, Ph.D. has served as our Chief Executive Officer, President, Secretary and a member of our board of directors since May 2010 and he was previously our Executive Chairman and a member of our board of directors from July 2006 to May 2010. From July 2006 to May 2010, Dr. Booth served as an Operating Partner and Senior Advisor at TPG Biotechnology Partners, LP, a venture capital company. From December 2006 to July 2007, Dr. Booth served as the acting Chief Scientific Officer of Galleon Pharmaceuticals, Inc., a company which is developing new therapeutics for diseases of the respiratory system. From 2002 to 2006, Dr. Booth was the Chief Scientific Officer at Celera Genomics Corporation, or Celera, a drug discovery and development company. Dr. Booth served as Senior Vice President at Roche Bioscience, a part of F. Hoffmann-La Roche Ltd, or Roche, from 1996 to 2002, where he was responsible for research and early development activities in the therapeutic areas of inflammation, autoimmunity, respiratory diseases, transplantation, bone diseases and viral diseases. Dr. Booth was a member of the Global Research Management Team and a member of the Business Development Committee, which oversaw licensing opportunities for Roche. From 1989 to December 1995, Dr. Booth served as Director of Biology for Roche Products Ltd, a part of Roche’s research operation, which was located in the United Kingdom. Dr. Booth currently serves on the boards of directors of Pharmacyclics, Inc., Galleon Pharmaceuticals, Inc. and Glialogix, Inc., and is Chairman of the Scientific Advisory Board at Galleon Pharmaceuticals, Inc. Dr. Booth also serves as a member of the Scientific Advisory Boards of ShangPharma Corporation, Elcelyx Therapeutics, Inc. and NaZura Biohealth, Inc. Dr. Booth received a B.Sc. and a Ph.D. from the University of London in biochemistry.

James H. Welch
Senior Vice President, CFO

James H. Welch
Senior Vice President, Chief Financial Officer

James H. Welch has served as our Chief Financial and Accounting Officer since June 2014. From October 2010 to March 2014, Mr. Welch served as Chief Financial Officer of Acelrx Pharmaceuticals, Inc. From June 2006 to September 2010, Mr. Welch served as Chief Financial Officer and Corporate Secretary at Cerimon Pharmaceuticals, Inc., a biopharmaceutical company. Mr. Welch served as Vice President, Chief Financial Officer and Corporate Secretary at Rigel Pharmaceuticals, Inc., a drug development company from October 2000 to May 2006, and as its Vice President, Finance and Administration from May 1999 to October 2000. From June 1998 to May 1999, Mr. Welch served as an independent consultant at various companies. Mr. Welch served as Chief Financial Officer of Biocircuits Corporation, a company focused on developing immunodiagnostic testing systems, from February 1997 to June 1998, and from June 1992 to February 1997, he served as its Corporate Controller. Mr. Welch received a B.A. in Business Administration from Whitworth College and an M.B.A. from Washington State University.

David B. Karpf MD
Chief Medical Officer

David B. Karpf MD
Chief Medical Officer

David B. Karpf, M.D. has served as our Chief Medical Officer since October 2011. From December 2010 to October 2011, Dr. Karpf served as a life sciences consultant. From January 2004 to December 2010, Dr. Karpf served as Chief Medical Officer and Vice President of Clinical Affairs at Metabolex, Inc., now CymaBay Therapeutics, Inc., where he oversaw the development of clinical programs in various diseases, including type 2 diabetes, gout and dyslipdemia. From May 2001 to January 2004, Dr. Karpf served as Executive Director of Clinical Research and Regulatory Affairs at Geron Corporation, or Geron, a clinical stage biopharmaceutical company, where he oversaw early clinical programs in cancer and regenerative medicine. From May 2000 to May 2001, Dr. Karpf served as Vice President, Clinical and Regulatory Affairs at Calydon, Inc., a company that developed oncolytic virus cancer treatments, which was acquired by Cell Genesis, Inc. in September 2001. From October 1996 to May 2000, Dr. Karpf served as Executive Director of Clinical Research at Roche, where he was responsible for clinical development activities in endocrinology and metabolic bone disease. From August 1991 to December 1996, Dr. Karpf served as Director of Clinical Research at Merck Research Laboratories, where he played a pivotal role in the successful New Drug Application and launch of Fosamax™. Dr. Karpf has also held several academic positions and is currently an adjunct clinical professor of endocrinology at Stanford University School of Medicine. Dr. Karpf received a B.A. in Psychology and Biology from University of California, Berkeley and an M.D. from University of California, San Diego. He completed a residency in Internal Medicine and a fellowship in Endocrinology, Diabetes and Metabolism at University of California, Los Angeles School of Medicine and Cedars-Sinai Medical Center, and a post-doctoral fellowship in the Endocrine Unit at University of California, San Francisco School of Medicine.

Kyle Elrod
Senior Vice President, Project Management and Operations

Kyle Elrod
Senior Vice President, Project Management and Operations

Kyle C. Elrod has served as our Senior Vice President of Project Management and Operations since June 2014. From March 2012 to June 2014, Mr. Elrod served as our Vice President of Project Management and Operations. From January 2010 to March 2012, Mr. Elrod served as a Research & Development Leader and Product Manager at Life Technologies Corporation, where he oversaw the SOLiD next generation genomic sequencing platform. From June 2006 to January 2010, Mr. Elrod served as our Vice President of Project Management and was responsible for overseeing our initial new drug filings. From January 1994 to May 2006, Mr. Elrod served in several positions in the field of project management, including the Director of Research and Development Projects at Celera, where he was the project manager for all of Celera’s preclinical and clinical programs. Mr. Elrod received a B.A. in immunology and microbiology from University of California, Berkeley.

Leslie Holsinger PhD
Vice President, Biology

Leslie Holsinger PhD
Vice President, Biology

Leslie J. Holsinger, Ph.D. has served as our Vice President of Biology since October 2010. From July 2006 to September 2010, Dr. Holsinger served as our Director of Biology. From November 2003 to June 2006, Dr. Holsinger served as Associate Director of Cell Biology at Celera, where she was responsible for translational and discovery biology. From December 1997 to August 2003, Dr. Holsinger served as Group Leader in discovery research at Sugen, Inc., a Pfizer company, where she assisted in drug discovery programs focused on kinase and phosphatase inhibitor drug development in multiple therapeutic areas. Dr. Holsinger received a B.A. in biochemistry from Occidental College and a Ph.D. in molecular and cellular biology from Northwestern University. She also completed post-doctoral studies at Stanford University School of Medicine.

Anantha Sudhakar PhD MBA
Vice President, Chemistry, Manufacturing and Controls

Anantha Sudhakar PhD MBA
Vice President, Chemistry, Manufacturing and Controls

Anantha R. Sudhakar, Ph.D. has served as our Vice President of Chemistry and Manufacturing and Controls, or CMC, since June 2012. From December 2009 to June 2012, Dr. Sudhakar served as Senior Director of CMC at Achaogen, Inc., where he was responsible for the process research, formulation development and manufacturing of both active pharmaceutical ingredients, or API, and drug products, or DP. From May 2006 to December 2009, Dr. Sudhakar served as Senior Director of CMC at Sunesis Pharmaceuticals, Inc., an emerging pharmaceutical company, where he was responsible for all CMC activities related to API and DP development. From July 2004 to May 2006, Dr. Sudhakar was Senior Director, Process Chemistry at Celera Genomics where he was responsible for API process research and manufacturing. From October 1989 to July 2004, Dr. Sudhakar served in several capacities at Schering Plough Corporation, including Senior Scientist and Associate Director, where he developed commercial processes for multiple drugs. Dr. Sudhakar received a M.Sc. in Chemistry from Indian Institute of Technology, Chennai, India, an M.B.A. in finance and management from New York University Stern School of Business and a Ph.D. in organic chemistry from Columbia University. He also completed post-doctoral studies at University of Wisconsin-Madison and Stanford University.

Jeff Dener PhD
Senior Director, Chemical Development

Jeff Dener PhD
Senior Director, Chemical Development

Jeffrey M. Dener, Ph.D., has served as our Senior Director of Chemical Development since November 2006. From July 2006 to November 2006, Dr. Dener served as served as a life sciences consultant. From March 2002 to July 2006, Dr. Dener served as a Scientific Fellow at Celera. From February 2001 to March 2002, Dr. Dener served as Director of Research and Development in the ChemRx Division at Discovery Partners International, LLC. From March 1996 to March 2001, Dr. Dener served as a Staff Scientist at Axys Advanced Technologies Inc. From March 1994 to March 1996, Dr. Dener served as a Scientist in Medicinal Chemistry at Arris Pharmaceutical Corp. From July 1993 to March 1994, Dr. Dener served as Senior Scientist at Shaman Pharmaceuticals, Inc. From December 1990 to June 1993, Dr. Dener served as Research Scientist at Rhône-Poulenc Rorer, Inc., now Sanofi S.A. Dr. Dener received a B.S. in chemistry from Bucknell University and a Ph.D. in organic chemistry from Ohio State University. He also completed post-doctoral studies at University of California, Berkeley.

Elizabeth Shigezumi MPA
Clinical Trial Manager, Clinical Operations

Elizabeth Shigezumi MPA
Clinical Trial Manager, Clinical Operations

Elizabeth G. Shigezumi has served as our Clinical Trial Manager and head of Clinical Operations since May 2013. From October 2007 to April 2013, Ms. Shigezumi served as a Clinical Program Manager, where she was responsible for multiple studies from phases I to III. From March 2011 to September 2011, Ms. Shigezumi served as Clinical Research Manager at Theravance, Inc., where she oversaw two phase II national gastroenterology trials. From May 2010 to February 2011, Ms. Shigezumi served as Clinical Trial Manager at S*Bio Pte. LTD, where she managed a team of clinical research associates in several phase I and II oncology trials. From August 2009 to February 2010, Ms. Shigezumi served as Clinical Trial Manager at OxiGENE, Inc., where she was responsible for five phase I, II and III oncology and ophthalmology trials. From October 1995 to April 2007, Ms. Shigezumi served as Senior Professional Healthcare Representative at Pfizer, Inc., where she served as lead project liaison for a number of phase III and IV studies on various diseases. Ms. Shigezumi received a B.A. in human physiology and an M.P.A. from San Francisco State University.