Hero Image

Betty Larson

Executive vice president and chief human resources officer

Betty Larson joined the company in April 2024 as the executive vice president and chief human resources officer. She is responsible for global human resources and diversity, equity and inclusion for the company.

She has extensive domain expertise with more than two decades in the health care industry. She most recently served as chief people officer of GE HealthCare, a leading global medical technology, pharmaceutical diagnostics and digital solutions innovator. She provided strategy and leadership for GE HealthCare’s human resources and corporate marketing and communications teams.

Betty also served as executive vice president and chief human resources officer of BD (Becton, Dickinson and Company) from 2018 to 2022, a global medical technology company, where work responsibilities also included strategy and leadership for communications and social investing. Betty joined BD through the acquisition of C.R. Bard Inc., a medtech company focused on vascular, urology and surgical specialty products. She served as C.R. Bard’s chief human resources officer responsible for human resources and communications from 2014 until the acquisition in 2017.

Betty spent the first 16 years of her career at Baxter International, a global medtech company. She was in human resources leadership roles of increasing responsibility in their pharmaceuticals, renal therapies, vaccines, bio pharmaceuticals and hospital products businesses.

She is on the board of directors for Baxter Credit Union. She has served on the board of Fortrea, contributing as a member of the nominating, corporate governance and compliance committee. Betty also served on the board for the Overlook Foundation, a non-profit organization that raises funds to support the New Jersey-based Overlook Medical Center in its mission to provide high-quality care to patients. She earned a bachelor’s and master’s degree from the University of Illinois, and a master’s degree in business administration from Northwestern University.

Hero Image

Joseph Romanelli

President, Human Health International

Joseph Romanelli is president, Human Health International for MSD. He has P&L responsibility for MSD’s 75-plus markets outside of the U.S. and leads a team of 14,000 colleagues.  

From 2021 to mid-2022, Joseph served as chief executive officer of JiXing Pharmaceuticals, a China-based biopharmaceutical company.

Prior to JiXing, Joseph served in a variety of strategic and operational roles with increasing responsibility at MSD and Schering-Plough for 25 years. He led MSD’s business in China from 2016 through 2021. During his tenure in China, MSD became the second largest multi-national pharmaceutical company by revenue in the market, as well as the second largest subsidiary for the company globally. Joseph’s previous roles at MSD include serving as chief of staff to the president of Human Health and managing the Human Health business for multiple markets in Asia Pacific. In addition, he led the Investor Relations team at MSD.

Joseph received his undergraduate degree from the University of Delaware and his master’s in Business Administration from Fordham University’s Gabelli School of Management.

Hero Image

Chirfi Guindo

Chief marketing officer, Human Health

Chirfi Guindo is chief marketing officer for MSD. He is responsible for leading the development and implementation of the company’s long-term strategy for the Human Health portfolio spanning oncology, vaccines, pharmaceutical and pipeline products.

Prior to this role, Chirfi was executive vice president and head of global product strategy and commercialization at Biogen. 

Before joining Biogen in 2017, Chirfi spent more than 25 years with MSD in positions of increasing responsibility in finance, sales, commercial and marketing. During his time with MSD, he led global marketing for MSD’s HIV portfolio, and also led the company’s Human Health businesses in Canada, the Netherlands and South Africa. Chirfi has been recognized for developing strong talent and forging innovative public-private partnerships that expand access to MSD medicines, while elevating the profile of MSD as a patient-focused company.

Chirfi is a graduate of Ecole Centrale de Paris (France) with a degree in engineering and has a master’s of Business Administration from New York University’s Stern School of Business.

Hero Image

Douglas M. Baker, Jr.

Director since



Download bio

Download photo


Mr. Baker has wide-ranging expertise in corporate governance and general and organizational management, including a deep understanding of global marketing, sales and operations of public companies. Mr. Baker is a Founding Partner of E2SG Partners, a company that invests in environmentally sustainable technologies. Previously, Mr. Baker was Chairman & Chief Executive Officer of Ecolab Inc., a provider of water and hygiene services and technologies for the food, hospitality, industrial and energy markets. Mr. Baker is also a member of the Board of Target Corporation and served as their Lead Independent Director from 2015 to 2021. This directorship along with his experience at Ecolab and his previous directorship at U.S. Bancorp provide him with deep experience on governance issues facing large public companies.

Career highlights

E2SG Partners

  • Founding Partner (2022-Present)

Ecolab Inc.

  • Executive Chairman (2021-2022)
  • Chairman and Chief Executive Officer (2006-2020)
  • Chief Executive Officer (2004-2006)
Hero Image

Jannie Oosthuizen

President, MSD Human Health U.S.

Jannie Oosthuizen leads MSD Human Health U.S., which is MSD’s largest business globally. He is responsible for P&L, strategy, customer engagement and commercialization in the U.S. for MSD’s broad portfolio of human health medicines and vaccines.

Jannie joined the company in 2014 to lead the Human Health oncology business in Asia Pacific and Latin America, then led MSD’s business in Japan from 2016 to 2020, and then led Global Marketing for Oncology. In each of these roles, Jannie successfully created and implemented new strategies and innovative commercial models that delivered strong, leveraged growth and established MSD as a leading business in those markets and therapeutic areas.

Jannie has deep experience in a broad range of global markets and therapeutic areas, and in building and leading high-performing teams. Prior to MSD, Jannie spent 20 years at Eli Lilly in a wide range of commercial and marketing roles with increasing responsibility. He began his career with Eli Lilly in 1993 in his home country of South Africa. Jannie is a pharmacist by training and graduated from North-West University in South Africa. He has lived and worked in six countries spanning five continents with his wife and three children.

Hero Image

Cristal N. Downing

Executive vice president and chief communications & public affairs officer

Cristal Downing joined MSD as executive vice president and chief communications & public affairs officer in 2021. In this role, Cristal leads MSD’s Corporate Affairs organization and is responsible for the development, advancement and execution of the company’s communications, public affairs, and Environmental, Social and Governance (ESG) efforts. Guided by business priorities and dedication to all who depend on the company’s lifesaving and life-changing work, Cristal is focused on fostering a deep understanding of MSD’s scientific contributions and impact on global health, ensuring public policy priorities stay aligned with business priorities, and enabling strategic engagement and impactful outcomes with a broad range of internal and external stakeholders.  

Most recently, Cristal was vice president, Communications & Public Affairs, Medical Devices, at Johnson & Johnson, where she fortified and amplified the strategy that conveys how the business is elevating the standard of patient care. Prior to that, she held the role of vice president, Global Finance Communications at Johnson & Johnson, where she partnered with the chief financial officer to implement communications and public affairs strategies that enabled the CFO and CEO strategic platforms.

Cristal also co-led the development and implementation of “Our Race to Health Equity” — Johnson & Johnson’s Racial & Social Justice strategy. She has more than 20 years of leadership expertise and capabilities, working in dynamic and complex organizations, including American Express, JP Morgan Chase, and Wells Fargo.

Cristal is a member of the board of trustees for the Ronald McDonald House of Central & Northern New Jersey and is affiliated with several key communications associations. Cristal received her bachelor of arts degree in communications from Monmouth University.

Hero Image

Michael A. Klobuchar

Executive vice president and chief strategy officer

Mike Klobuchar serves as the chief strategy officer for MSD, leading the advancement and execution of the company’s strategy. He is also responsible for setting and executing the company's global business development strategies as well as leading the digital, data and IT infrastructure and cybersecurity strategies.

Prior to this role, Mike was senior vice president and finance lead for MSD Research Laboratories, the company’s research and development organization, and led the Global Portfolio and Alliance Management group within the organization.

Previously, Mike was senior vice president, Corporate Strategy and Financial Planning, focused on developing and implementing improvements to the company’s operating model. He was also president, MSD Global Health Innovation Fund, and led key elements related to the integration of MSD Research Laboratories with Schering-Plough R&D following the merger of the two companies.

Mike joined MSD Research Laboratories in 1998 and has held a wide range of positions of increasing responsibility in the company’s research, manufacturing, commercial planning, finance and strategy organizations.

Mike serves on the board of directors for Revvity, a global scientific technology and life science research company. He received his MBA from Villanova University, a master of science degree in chemical engineering from Rutgers University and a bachelor of science degree from Purdue University.

Hero Image

Caroline Litchfield

Executive vice president and chief financial officer

Caroline Litchfield is executive vice president and chief financial officer for MSD, responsible for the company’s finance, procurement and real estate operations. 

Prior to this role, Caroline served as the company’s treasurer, a position that included responsibility for treasury, tax and investor relations. From 2014 to 2018, Caroline led finance for Human Health, the company’s largest business, overseeing financial operations and reporting in approximately 100 markets.

Previously, Caroline was the vice president and finance lead for the company’s Emerging Markets region when it was established in 2009 following the merger of MSD and Schering-Plough and was instrumental in integrating the two companies. She joined MSD in 1990 in its U.K. business and has held a wide range of positions of increasing responsibility in the company’s country, regional and global finance functions.

Caroline received her Bachelor of Science degree in Mathematics from the University of Leicester and is a fellow of the Chartered Institute of Management Accountants.

Hero Image

Stephen L. Mayo, Ph.D.

Director since


Download bio

Download photo


Dr. Mayo has extensive scientific experience relevant to the biopharmaceutical industry, including being the Bren Professor of Biology and Chemistry, Merkin Institute Professor and former Chair of the Division of Biology and Biological Engineering at the California Institute of Technology (“Caltech”) and co-founder of Xencor, a public antibody engineering company. In addition, in his role as the former Vice Provost at Caltech, Dr. Mayo oversaw Caltech’s technology licensing program. Elected to the National Academy of Sciences in 2004 for his pioneering contributions in the field of protein design, Dr. Mayo has also served as a presidential appointee on the National Science Foundation’s National Science Board and as an elected board member for the American Association for the Advancement of Science. Dr. Mayo also serves as a member of the board of directors of Sarepta Therapeutics, Inc. and Allogene Therapeutics, Inc.

Career highlights

California Institute of Technology

  • Merkin Institute Professor (2021-present)
  • Bren Professor of Biology and Chemistry (2007–present)
  • Chair, Division of Biology and Biological Engineering (2010–2020)
  • Vice Provost for Research (2007–2010)

Howard Hughes Medical Institute, non-profit medical research organization

  • Investigator (1994–2007)
Hero Image

Dean Y. Li, M.D., Ph.D.

Executive vice president and president, MSD Research Laboratories

Dean Li serves as executive vice president and president of MSD Research Laboratories. He leads the company’s worldwide human vaccines and therapeutics research and development organization.

Since joining MSD in 2017 Dean has held leadership roles in the Translational Medicine and Discovery functions and was appointed to President, MSD Research Laboratories in January 2021.

Prior to joining MSD, Dean held positions of increasing responsibility in translational medical research at the University of Utah. Most recently he served as the H.A. & Edna Benning Professor of Medicine and Cardiology, chief scientific officer, associate vice president and vice dean at the University of Utah Health System. From 2015 to 2016, he also served as interim CEO of Associated Regional University Pathologists, one of the United States’ largest clinical reference laboratories. During his tenure at the University of Utah, he co-founded several biotechnology companies based upon research conducted in his laboratory, including Recursion Pharmaceuticals, Hydra Biosciences and Navigen Pharmaceuticals.    

Dean received his Bachelor’s degree in Chemistry from the University of Chicago and his graduate and clinical training at Washington University School of Medicine in St. Louis. Dean is a cardiologist, a member of the American Society for Clinical Investigation and the Association of American Physicians.