John F. Milligan, PhD
President and Chief Executive Officer
Dr. Milligan joined Gilead Sciences in 1990 and was appointed Chief Executive Officer in March 2016. He began his career at Gilead as a research scientist, and subsequently held leadership positions in project management and corporate development before being named Chief Financial Officer in 2002. He was appointed Chief Operating Officer in 2007 and President in 2008.

During his tenure at Gilead, Dr. Milligan has led teams that have developed, manufactured and commercialized more than 20 new therapies for significant unmet needs. He has managed multiple transformative acquisitions, licensing agreements and financings, helping the company grow into a worldwide organization reaching more than 10 million patients. He is a member of the board of Pacific Biosciences of California, Inc. and a Trustee of Ohio Wesleyan University.

Dr. Milligan received his BA from Ohio Wesleyan University, his PhD in biochemistry from the University of Illinois and was an American Cancer Society postdoctoral fellow at the University of California at San Francisco.

Gregg H. Alton
Executive Vice President, International Operations and Corporate Affairs
Mr. Alton joined Gilead Sciences in 1999 and served as General Counsel from 2000 to 2009. In his current role, Mr. Alton is responsible for commercial and access operations in Africa, Asia, Europe, Latin America and the Middle East, government affairs and policy and public affairs. Prior to joining Gilead, Mr. Alton was an attorney at the law firm of Cooley Godward, LLP, where he specialized in mergers and acquisitions, corporate partnerships and corporate finance transactions for healthcare and information technology companies.

Mr. Alton is a member of the boards of the AIDS Institute and the Boys and Girls Clubs of Oakland. He is also a member of the U.S. Government's Industry Trade Advisory Committee on Intellectual Property Rights, the advisory boards of UCSF Global Health Group, USC Schaeffer Center for Health Policy and Economics, Pharmozyme, Inc., and the UC Berkeley College of Letters & Science Advisory Board. In addition, he serves on Partners In Health’s Board of Trustees. Mr. Alton received a bachelor's degree in legal studies from the University of California at Berkeley, and holds a JD from Stanford University.

Andrew Cheng, MD, PhD
Chief Medical Officer, Executive Vice President
Dr. Cheng joined Gilead Sciences in 1999 and was appointed to the role of Chief Medical Officer in April 2018. In this role, he is responsible for leading the company’s Medical Affairs organization, as well as overseeing clinical development for the company’s programs in HIV/AIDS. Dr. Cheng is board certified in internal medicine and trained at the University of California, Los Angeles.

Dr. Cheng is a member of the board of the Global Virus Network, based in Baltimore, Maryland. He received his bachelor’s degree from the Johns Hopkins University and his medical degree and PhD in Cellular and Molecular Biology from Columbia University College of Physicians and Surgeons.

Andrew Dickinson
Executive Vice President, Corporate Development and Strategy
Mr. Dickinson joined Gilead in 2016 and is responsible for overseeing the company’s corporate development, alliance management, competitive intelligence, and corporate strategy and planning groups. He helped engineer the company’s 2017 acquisition of Kite Pharma Inc.

Prior to joining Gilead, Mr. Dickinson served as Global Co-Head of Healthcare Investment Banking for Lazard. At Lazard, he advised on numerous, industry-defining merger and acquisition transactions, as well as many other strategic matters across the biopharmaceutical industry. Mr. Dickinson received his bachelor’s degree in molecular, cellular and developmental biology from the University of Colorado and his law degree from Loyola University Chicago.

William A. Lee, PhD
Executive Vice President Research
Dr. Lee joined Gilead Sciences in 1991 as Director, Pharmaceutical Product Development. In 2015, he was appointed Executive Vice President, Research and has been responsible for the expansion of the company’s research and preclinical activities across a range of therapeutic areas, including HIV, liver diseases, hematology and oncology, inflammation and respiratory diseases and cardiovascular conditions. Prior to joining Gilead, Dr. Lee was head of Drug Delivery at California Biotechnology, Inc. and began his career as a research scientist at Syntex Research in Palo Alto, California.

Dr. Lee received his BS in Chemistry from the University of Massachusetts, PhD in Chemistry from the University of California at San Diego and performed postdoctoral work at the Ecole Polytech Federal Lausanne with Dr. Michael Graetzel and the University of California at Santa Barbara with Dr. Tom Bruice.

John McHutchison, MD
Chief Scientific Officer, Head of Research and Development
Chief Scientific Officer, Head of Research and Development

Dr. McHutchison joined Gilead in 2010, and was appointed Chief Scientific Officer in March 2018. Prior to joining Gilead, Dr. McHutchison worked at Duke University Medical Center, where he served as Associate Director of the Duke Clinical Research Institute. He also held the positions of Professor of Medicine in the Division of Gastroenterology at Duke University Medical Center, Associate Director at Duke Clinical Research Institute and Co-Director of the Duke Clinical and Translational Science Award. Prior to his positions at Duke, Dr. McHutchison spent nearly 10 years at Scripps Clinic, most recently as Medical Director, Liver Transplantation. He also previously held an Assistant Professorship in Medicine at the University of Southern California.

In June 2018, Dr. McHutchison was appointed an Officer of the Order of Australia in recognition of his distinguished service to medical research in gastroenterology and hepatology.

Dr. McHutchison has undergraduate degrees in medicine and surgery from the University of Melbourne in Australia and completed his residency in internal medicine and fellowship in gastroenterology at the Royal Melbourne Hospital. He is a member of the Royal Australasian College of Physicians.

Brett A. Pletcher
Executive Vice President, General Counsel and Chief Compliance Officer
Brett Pletcher joined Gilead Sciences in 2005 and is currently Executive Vice President, General Counsel and Chief Compliance Officer overseeing the legal organization and compliance efforts associated with the promotion of our products and interactions with healthcare professionals and payers. Mr. Pletcher also serves as Corporate Secretary. Prior to joining Gilead, Mr. Pletcher was a partner in the law firm of Gunderson Dettmer, LLP, where he focused on providing corporate and securities services to emerging growth public and private companies and venture capital investors.

Mr. Pletcher received his bachelor’s degree in economics and political science from the University of California, Riverside and his law degree from the University of California, Berkeley’s Boalt Hall School of Law. He is a member of the California State Bar and a former member of the Nasdaq Listing and Hearing Review Council and serves on the Advisory Board for the East Bay Community Law Center.

Alessandro Riva, MD
Executive Vice President, Oncology Therapeutics
Dr. Riva joined Gilead in January 2017 as Senior Vice President, Hematology and Oncology Therapeutic Area Head. He was instrumental in expanding Gilead’s oncology program with the acquisition of Kite Pharma, establishing the company as a leader in the field of cellular therapy. He has also guided the strategy and development of Gilead’s broader oncology pipeline during his tenure.

Prior to joining Gilead, Dr. Riva served as Head, Global Oncology Development at Novartis, where he oversaw the development and worldwide regulatory approval of multiple compounds in a variety of tumor types. He received his bachelor’s degree in Medicine and a Certificate Board in Oncology/Hematology from the School of Medicine of Milan. Earlier in his career, he worked as a physician, treating patients with hematological malignancies at the University Hospital of Milan.

Martin B. Silverstein, MD
Executive Vice President, Strategy
Dr. Silverstein joined Gilead in 2016 to oversee the company’s corporate development, commercial planning and alliance management functions. Prior to this, he held the role of Executive Vice President and Chief Strategy Officer at Anthem, and spent 28 years in roles of increasing responsibility at The Boston Consulting Group, where he was a Senior Partner and Managing Director and served as the Global Leader of its Health Care Practice.

Dr. Silverstein received a medical degree from Yale University, an MBA from Harvard Business School and a bachelor’s degree from the University of Pennsylvania. He completed his internal medicine residency at Boston's Beth Israel Hospital and is board certified in Internal Medicine. Dr. Silverstein is a board member of the Vagelos Program in Life Sciences and Management at the University of Pennsylvania.

Robin  L.  Washington
Executive Vice President and Chief Financial Officer
Ms. Washington joined Gilead in 2008 as Senior Vice President and Chief Financial Officer where she oversees the Global Finance and Information Technology organizations. Ms. Washington was promoted to Executive Vice President in 2014. Ms. Washington was previously Chief Financial Officer of Hyperion Solutions, which was acquired by Oracle Corporation in March 2007. Prior to that, Ms. Washington served in a number of executive positions with PeopleSoft, most recently in the role of Senior Vice President and Corporate Controller. Ms. Washington previously served on the Board of Directors of Tektronix, Inc. (acquired by Danaher), the Board of Directors of MIPS Technologies Inc. (acquired by Imagination), and currently is a member of the Board of Directors of Honeywell International, the Board of Directors of, and the Board of Visitors, Graziadio School of Business and Management, Pepperdine University.

Ms. Washington is a certified public accountant and holds a bachelor's degree in business administration from the University of Michigan and a MBA from Pepperdine University.

Katie L. Watson
Senior Vice President, Human Resources
Ms. Watson joined Gilead in February 2003 to manage compensation and HR information systems. In 2006 she was promoted to Senior Director of Total Rewards, and was appointed to Vice President of Employee Development and Rewards in 2012. In 2013 she was promoted to lead the worldwide HR function as Senior Vice President, and now serves as Executive Vice President, Human Resources. Before joining Gilead she was Manager of Compensation for Applied Biosystems of Applera Corporation, led the HR consulting practice for TriNet, and worked as an HR Business Partner for D.E. Shaw & Co.

Ms. Watson holds a degree in Psychology from the University of California at San Diego and a master's in Organizational Psychology from Columbia University.

Taiyin Yang, PhD
Executive Vice President, Pharmaceutical Development and Manufacturing
Dr. Yang joined Gilead in 1993 and was appointed to her current role of Executive Vice President, Pharmaceutical Development and Manufacturing in January 2015. She is responsible for the chemistry, manufacturing and control operations of small molecules and biologics encompassing process development, production, supply chain management, analytical operations, laboratory information and quality assurance for Gilead’s investigational and commercial products. Prior to joining Gilead, Dr. Yang was Director of Analytical Chemistry at Syntex.

She received her bachelor’s degree in Chemistry from National Taiwan University and her PhD in Organic Chemistry from the University of Southern California.