Management Team


Robert Booth PhD
Founder and Chief Executive Officer

Robert Booth PhD
Chief Executive Officer, Virobay

Robert Booth was the driving force behind the creation of Virobay in 2006. While he was the Executive Chairman of Virobay, Inc. from 2006 to 2010, he concurrently served as an Operating Partner and Senior Advisor at TPG Biotech, a venture capital company.

Previously, he was Chief Scientific Officer at Celera Genomics, responsible for integrating and leading Celera's therapeutic discovery and development activities. The therapeutic areas pursued by Celera included oncology, autoimmunity, respiratory diseases and thrombosis.

Robert also served in a series of executive positions at Roche for over 13 years, including Senior Vice President responsible for research and early development in the therapeutic areas of inflammation, autoimmunity, virology, respiratory diseases, transplantation and bone disease products. Robert was a member of the Global Research Management Team and a member of the Business Development Committee, which oversaw licensing opportunities for Roche. During his time at Roche, Robert managed R&D organizations in both the US and Europe.

Robert serves on the board of Pharmacyclics Inc. He is a board member of Glialogix, Inc and he is a board observer and Chairman of the Science Advisory Board of Galleon Pharmaceuticals. He is also a member of the Science Advisory Boards of ShangPharma ChemPartner and Elcelyx. Additionally, he serves as a consultant to a number of biotech and venture capital groups.

Robert obtained his B.Sc. and Ph.D. from the University of London in the field of biochemistry.

James H. Welch
Senior Vice President, CFO

James H. Welch
Senior Vice President, Chief Financial Officer

Jim Welch has more than 20 years of experience in financial and operational management at life science and high technology firms. Jim is responsible for the financial and administrative operations within Virobay.

Prior to joining Virobay, Jim was Chief Financial Officer at AcelRx Pharmaceuticals, a publicly held pharmaceutical company dedicated to the development and commercialization of innovative products for the treatment of painful conditions.

Previously, Jim was Chief Financial Officer at Cerimon Pharmaceuticals, a privately held pharmaceutical company focusing on developing pain and autoimmune disease products.

Before Cerimon, Jim was Chief Financial Officer at Rigel Pharmaceuticals.

Earlier in his career, Jim was Chief Financial Officer of Biocircuits Corporation, a publicly held medical diagnostic company, and held various financial and operational management positions at technology firms in Silicon Valley, including NeXT Computer and Avantek.

David B. Karpf MD
Chief Medical Officer

David B. Karpf MD
Chief Medical Officer

David B. Karpf has more than 20 years of experience in guiding the clinical development of novel therapeutics, both at growing biotechnology firms and within large pharmaceutical companies. David is responsible for all clinical, regulatory and medical affairs functions related to advancing Virobay’s growing pipeline of novel product candidates.

Before joining Virobay, David served as Chief Medical Officer and Vice President, Clinical Affairs at Metabolex. At Metabolex, he oversaw the development of clinical programs in type 2 diabetes, dyslipidemia, and gout, including 2 INDs, 7 Phase 1 trials and 6 Phase 2 trials.

Prior to Metabolex, David was Executive Director of Clinical Research and Regulatory Affairs at Geron where he provided oversight for Geron’s early clinical programs in cancer and regenerative medicine. Prior to Geron, David was Vice President, Clinical and Regulatory Affairs at Calydon, Inc. Prior to his tenure at Calydon, David was Executive Director of Clinical Research at Roche Global Development in Palo Alto and was responsible for clinical development activities in metabolic bone disease and endocrinology, including managing the Phase 3 pivotal program for Boniva™. David was previously Director of Clinical Research at Merck Research Laboratories in Rahway, New Jersey, where he played a pivotal role in the successful NDA and launch of Fosamax™.

In addition to his industry experience, David has held several academic positions and is currently an adjunct clinical professor of endocrinology with the Stanford University School of Medicine, where he directs one of the endocrine subspecialty clinics. He received his M.D. degree from University of California, San Diego, and served on the faculty at UCSF School of Medicine.

Leslie Holsinger PhD
Vice President, Biology

Leslie Holsinger PhD
Vice President, Biology

Leslie Holsinger is responsible for biology and translational medicine at Virobay having joined the company from Celera Genomics where she served as Head of Cell Biology.

At Virobay, Leslie is responsible for all of the biology studies associated with our programs, including compound screening, cell biology, and pharmacology studies in preclinical and clinical studies.

Previously, Leslie was a Group Leader in biology at Sugen, where she was involved in drug discovery programs focused on kinase and phosphatase biology in multiple therapeutic areas.

She completed her post-doctoral studies at the Stanford Medical School having earned her PhD in virology from Northwestern University.

Kyle Elrod
Vice President, Project Management and Operations

Kyle Elrod
Vice President, Project Management and Operations

Kyle is responsible for company operations, project planning and coordinating IND-enabling studies for Virobay’s programs.

Kyle joined Virobay in 2006 from Celera Genomics where he was the Director of Project Management. In this position, he coordinated all Celera small molecule projects from research through to Phase II.

His work experience also includes leadership positions at Life Technologies where he managed several Next Generation Sequencing products.

Kyle has over 20 years experience in pharmaceutical and diagnostic research. Prior to entering the project management field, Kyle was a senior scientist in Enzymology at Arris and Axys Pharmaceuticals where he co-authored over 20 peer reviewed publications and was a named inventor on four issued patents.

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

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

Anantha Sudhakar ("Sudhakar") joined Virobay in June 2012 as Vice President, Chemistry, Manufacturing and Controls (CMC). In this capacity, he is responsible for Chemical, Pharmaceutical and Analytical Development activities for Virobay's clinical and preclinical candidates.

Sudhakar has over 20 years experience working in the CMC area including 15 years at Schering Plough developing commercial processes for multiple drugs. He also led Process Chemistry functions at Celera Genomics and was most recently Senior Director, CMC for Sunesis Pharmaceuticals and Achaogen.

Sudhakar obtained his Ph.D. in Organic Chemistry from Columbia University in New York and an MBA in Finance and Management from New York University Stern School of business. 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

Jeff Dener manages many of the strategic partnerships that Virobay has established with leading contract manufacturers around the world, including suppliers in Europe, Asia and North America.  He is an expert in the outsourcing of medicinal and process chemistry for therapeutic areas including inflammation, pain, cardiovascular, oncology, and virology.

Before joining Virobay, Jeff was Scientific Fellow at Celera Genomics where he held an active role in both the development of process chemistry for, and management of, contract manufacturing activities for two molecules, which subsequently entered clinical trials. Prior to Celera, he was a key contributor to drug discovery and development programs at Axys Pharmaceuticals, Shaman Pharmaceuticals and Rhône-Poulenc Rorer, now part of Sanofi-Aventis.

Jeff received a BS in Chemistry from Bucknell University and obtained his PhD in Organic Chemistry from The Ohio State University under the direction of Professor David J. Hart. Subsequently, he was a Post-Doctoral Research Associate in the research group of Professor Henry Rapoport at the University of California, Berkeley.

Elizabeth Shigezumi MPA
Clinical Trial Manager, Clinical Operations

Elizabeth Shigezumi MPA
Clinical Trial Manager, Clinical Operations

Elizabeth (“Liz”) Shigezumi joined Virobay in May of 2013 as the lead in Clinical Operations. She collaborates with Virobay’s Chief Medical Officer in development of operating procedures in clinical development while assuring good clinical practices in management of all clinical studies.

Liz has over 20 years of experience in the pharmaceutical industry including 15 years at Pfizer and the recent 5 years consulting in clinical operations for multiple biotech companies in the San Francisco Bay Area.

Liz received an undergraduate degree in Biology (Human Physiology) and a Master in Public Administration (Healthcare Policies) from San Francisco State University.

Petra Kempf
Office Management and Web Design

Petra Kempf
Office Management and Web Design

At Virobay, Petra is responsible for office management, web design and communication.

Petra has 20 years of pharmaceutical industry experience working for Roche, in both Europe and in the US, where she held various positions in pharmaceutical marketing, research, communication and public affairs, as well as site informatics.

Petra holds a degree in Business Administration.