Charles W. Flexner, MD, is the Principal Investigator of the Long Acting/Extended Release Antiretroviral Resource Program (LEAP). He is Professor of Medicine in the Divisions of Clinical Pharmacology and Infectious Diseases, and Professor of Pharmacology and Molecular Sciences in the Johns Hopkins University School of Medicine. He is also Professor of International Health in the Johns Hopkins University Bloomberg School of Public Health. Dr. Flexner is an expert on the basic and clinical pharmacology of drugs for HIV/AIDS and related infections, including viral hepatitis and tuberculosis. He is Co-PI of the Johns Hopkins University Baltimore-India Clinical Trials Unit. His scientific contributions include work on the important roles of pharmacokinetic enhancement, adherence, and dosing frequency in the long-term management of HIV/AIDS. He has published extensively on anti-infective drug transport and metabolism, and metabolic drug interactions. His current research includes the discovery and development of new molecules and formulations for long-acting parenteral administration for treatment and prevention of HIV infection.