Management Team

Harith Rajagopalan, M.D., Ph.D., is Co-founder and CEO of Fractyl Health, having started the company while serving as an Entrepreneur-in-Residence at General Catalyst Partners.

Prior to founding Fractyl Health, Harith was an academic cardiologist and physician-scientist. He received his B.S. in chemistry from Stanford University and went on to obtain M.D. and Ph.D. degrees from Johns Hopkins School of Medicine. At Johns Hopkins, Harith did groundbreaking and award-winning research on intestinal cancers that was published in top medical journals including Nature and Science.

After medical school, Harith trained in internal medicine and clinical cardiology at Brigham and Women’s Hospital and completed a research fellowship at the Harvard Stem Cell Institute at Harvard Medical School.

Jay Caplan is Co-Founder, President, and Chief Product Officer of Fractyl Health and has held leadership positions in the medical device field for more than 20 years.

Prior to founding Fractyl Health, Jay was the Chief Operating Officer of the Candela Corporation, a world leader in aesthetic devices. Previously, he was Chief Technology Officer and Vice President of Research and Development at InfraReDx, Inc. a venture-backed startup developing a novel cardiovascular imaging system to identify lipid-rich coronary plaques.

Prior to InfraReDx, Jay was Vice President of Operations for Thermo Cardiosystems, where he led the team developing the HeartMate II left ventricular assist device. Jay holds a B.S. in electrical engineering from M.I.T. and an MBA from The Wharton School of the University of Pennsylvania.

Lisa Davidson is Chief Financial Officer of Fractyl Health.

Lisa has more than 25 years of broad corporate finance experience encompassing treasury management, strategic planning, operations finance, and controllership.

She served as Vice President of Finance & Administration at Flexion Therapeutics, Inc. Prior to Flexion, Lisa served as Director of Finance at OmniSonics Medical Technologies, Inc.

She previously served in various finance, strategy, and administration positions at PerkinElmer Inc., Pepsi Bottling Group, and Fisher Scientific International, Inc. (now part of ThermoFisher Scientific). Lisa has been involved in a number of M&A transactions, venture debt and equity financings, and numerous product launches. She holds both a B.A. and an MBA from the University of New Hampshire.

Timothy Kieffer is Chief Scientific Officer of Fractyl Health. Tim has co-authored more than 200 publications on incretin hormones, islet biology, and gene therapies, and has been cited over 20,000 times.

He is a Professor of Medicine, Department of Cellular & Physiological Sciences and Department of Surgery, School of Biomedical Engineering, and Life Sciences Institute at the University of British Columbia, where his laboratory focuses on islet biology and the development of novel gene and cell therapy approaches to treat diabetes.

In 2021, Tim joined ViaCyte, a leader in stem cell therapies for Type 1 Diabetes, as its Chief Scientific Officer until ViaCyte’s acquisition by Vertex. He obtained his PhD at the University of British Columbia and completed a postdoctoral research fellowship at Massachusetts General Hospital.

Sarah Toomey, Esq., is General Counsel and Corporate Secretary of Fractyl Health.

Sarah brings nearly 20 years of legal and strategic advisory experience to Fractyl and has expertise in managing legal matters pertaining to intellectual property, debt and equity financing, clinical operations, regulatory compliance, quality assurance, corporate governance, and operations.

Sarah most recently served as the Senior Vice President of Operations and General Counsel at BERG LLC. She formerly held the roles of General Counsel at Metamark Genetics and Senior Vice President and General Counsel at IntellligentMDx. Before IntelligentMDx, Sarah worked as a patent attorney in two boutique patent law firms and as a research scientist at Merck.

Sarah holds a B.S. in bacteriology from University of Wisconsin-Madison and a J.D., intellectual property concentration, from Suffolk University Law School.

Jon Fitzgerald is Vice President of Quality Assurance and Regulatory Affairs of Fractyl Health.

Jon brings more than 20 years of medical device start-up experience to Fractyl Health.

He has developed and scaled multiple quality systems and has a successful track record of regulatory agency engagement. In addition to his experience in quality, he has successfully conducted recalls, led vigilance activities, and played a pivotal role in global regulatory filings resulting in device clearances and approvals, including the U.S., E.U., Middle East, and Japan.

Previously, Jon held quality engineering and management positions at Neuronetics, Animas (a Johnson & Johnson Company), and Kensey Nash (now DSM Biomedical). His expertise encompasses microbiology, quality management, electronic system implementation, as well as technical file and design dossier development. After serving as an air traffic controller in the U.S. Navy, Jon studied mechanical engineering at Northeastern University.

Len Rosberg is Vice President of Manufacturing of Fractyl Health.

He brings more than 20 years of experience in supply chain management and manufacturing engineering roles for major medical device firms. With more than a decade of senior management expertise, Len most recently served as Vice President of Operations for Candela Corporation, and his industry tenure includes positions at Boston Scientific, Thoratec, and Baxter International.

His technical expertise encompasses reliability engineering, design for manufacturability, and implementation of scalable manufacturing processes. Len holds a B.S. in electrical engineering from Wentworth Institute of Technology.

Jessica Cotrone is Vice President of Corporate Communications at Fractyl Health, where she leads strategic communications across corporate, clinical, and commercial milestones. With more than 20 years of experience in healthcare communications, she plays a key role in shaping the Company’s narrative as it pioneers a new era in the treatment of metabolic disease.

Prior to joining Fractyl, Jessica was Head of Corporate Communications at BeiGene. She has also held senior communications roles at Evelo Biosciences, Alexion Pharmaceuticals, and Shire, where she built and scaled communications platforms that supported major moments—including product launches, IPOs, and strategic transformations. Her expertise lies in connecting science to strategy and driving visibility for mission-driven teams.

Jessica holds a B.A. in English from Providence College and an M.A. in Communications from Suffolk University.