Charles Williams Flexner MD

Professor of Medicine, Johns Hopkins University School of Medicine; Director, AIDS Clinical Trials Unit; Deputy Director, Institute for Clinical and Translational Research

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1800 Orleans StreetBaltimore, MD 21287
Phone+1 410-955-5000
Fax+1 410-955-5001

Summary

Dr. Charles Flexner is an infectious disease specialist based in Baltimore, MD. He completed his medical education at Johns Hopkins University School of Medicine, followed by a residency in Internal Medicine at Stanford Health Care and fellowships in Infectious Disease at the National Institutes of Health Clinical Center and Johns Hopkins University. He is experienced in emerging infectious diseases and has published on topics such as the effectiveness of double-dose dolutegravir in tuberculosis treatment and long-acting antiretroviral therapies. Dr. Flexner has also been involved in several clinical trials, including studies on contraceptive implants, hepatitis C virus treatment, and HIV treatment regimens. He is the founding director of the Long-Acting/Extended-Release Antiretroviral Research Resource Program (LEAP), www.longactinghiv.org.

Education & Training

Johns Hopkins UniversityFellowship, Infectious Disease, 1988 - 1989
National Institutes of Health Clinical CenterFellowship, Infectious Disease, 1985 - 1987
Stanford Health Care-Sponsored Stanford UniversityResidency, Internal Medicine, 1982 - 1985
Johns Hopkins University School of MedicineClass of 1982

Certifications & Licensure

CA State Medical License 1983 - Present
MD State Medical License 1985 - 2026
American Board of Internal Medicine Internal Medicine

Clinical Trials

Continuous High-Dose Intravenous Dextran Sulfate in Human Immunodeficiency Virus-Infected Individuals
Completed
Not Applicable
A Phase I Randomized Dose/Formulation Comparison Study of SC-52151
Completed
Phase 1
Study of How Indinavir (an Anti-HIV Drug) and Rifabutin (a Drug Used to Treat MAC, an HIV-Associated Disease) Interact in HIV-Positive and HIV-Negative Adults
Completed
Phase 1

Publications & Presentations

PubMed

Subscription-Based Pricing for Lenacapavir-Learning From Hepatitis C and Cabotegravir.
Michael R Rose, Charles Flexner, Victor Roy
JAMA. 2026-01-07
Virological and drug-resistance outcomes for people living with HIV initiating or switching to tenofovir, lamivudine, and dolutegravir in six PEPFAR-supported countrie...
Jean Bernard Marc, Caitlyn McCarthy, Carole L Wallis, Cissy Kityo, Michael D Hughes
The Lancet. HIV. 2025-12-01
1 citations
The Promises and Prospects of Long-Acting Therapeutics for Treatment and Prevention of Infectious Diseases.
Adeniyi Olagunju, Simone Perazzolo, Zachary R Stephen, Mark Ryan, Xiaolin Xu
Annual Review of Pharmacology and Toxicology. 2025-09-16

Journal Articles

Effect of Antiretroviral Therapy on Plasma Concentrations of Chloroquine and Desethyl-Chloroquine
Charles Flexner, Michael M Lederman, Theresa A Shapiro, Clinical Infectious Diseases

Lectures

Modern HIV Therapy: Progress and Prospects
Virology Education B.V, Baltimore, Maryland - 11/5/2012

Other

Modern HIV Therapy: Progress and Prospects
Charles Flexner, MD, Clinical Pharmacology & Therapeutics
https://www.doximity.com/articles/d00fecdd-81cc-4143-b68b-e4c067729426
UpToDate, Wolters Kluwer Health - 2012-08-16

Press Mentions

Management of Patients with HIV, Limited Treatment OptionsOctober 26th, 2022
New Approaches to HIV Prevention, Management of Patients with HIVOctober 25th, 2022
Forty Years on, Black Americans Disproportionately Hit by HIVMay 6th, 2021

Grant Support

The Long-Acting/Extended Release Antiretroviral Resource Program (LEAP)JOHNS HOPKINS UNIVERSITY2015–2030
Johns Hopkins University Baltimore India Clinical Trail Unit (JHUBI CTU)JOHNS HOPKINS UNIVERSITY2007–2027
Johns Hopkins AIDS Clinical Trials UnitNational Institute Of Allergy And Infectious Diseases2007–2012
ACTG A5128National Center For Research Resources2005–2007
ACTG A5191National Center For Research Resources2004–2007