CEO and Executive Committee


David Johnston, Ph.D.

Executive Vice President, Clinical Development Services

David Johnston, Ph.D., serves as executive vice president and global head of clinical development services at PPD, responsible for all aspects of the company’s early development services and Phase II-III clinical development operations. In addition, he has responsibility for PPD’s Accelerated Enrollment Solutions (AES) business, which provides data-driven patient recruitment for clinical trials and includes a network of dedicated clinical research investigator sites to support sponsored research studies. From 2016 through January 2021, Dr. Johnston served as executive vice president of global clinical development at PPD. Prior to that, he was executive vice president and head of PPD® Laboratories from 2013-2016, where he oversaw significant growth and expansion of the global central laboratories, bioanalytical labs and GMP laboratories, and led the development of a biomarker research laboratory and dedicated vaccine laboratory testing capabilities.

Prior to joining PPD, Dr. Johnston served in a variety of senior leadership roles at LabCorp from 1998-2013, where most recently he was senior vice president and global head of LabCorp’s clinical trials business and was the founding director of the companion diagnostics department. His diverse experience in clinical research includes leadership of R&D teams, multinational laboratory operations, clinical quality assurance, and preclinical and late stage clinical development.

Dr. Johnston earned a bachelor’s degree in biology from the University of North Carolina at Greensboro and a Ph.D. in microbiology and immunology from the University of North Carolina at Chapel Hill School of Medicine.