Pre-Exposure Prophylaxis (PrEP)- Gender Affirming Hormone Therapy (GAHT) Interactions in TGW

A Phase I Trial for the Evaluation of the Two-way Pharmacokinetic-pharmacodynamic (PD) Interaction of Gender Affirming Exogenous Estrogen (With Testosterone Suppression) on TDF/FTC PrEP in Transgender Women (TGW)

This is a research study to determine the best way to dose Truvada®, an oral medication licensed to be taken as Pre-Exposure Prophylaxis (PrEP) to prevent HIV infection, in transgender women who are also taking feminizing hormones. The duration of the study is about 4 months, and involves a screening visit, a baseline visit with colon biopsies and kidney function testing, and several outpatient visits, including 5 intensive sampling visits that last about 9 hours and involve colon biopsies, kidney function testing and other blood specimen collections.

After the baseline visit, participants will start on PrEP, daily Truvada® pills, and will continue on the Truvada® for 5 weeks. Participants will then receive either an injection of Lupron, oral low-dose estradiol or oral high-dose estradiol, which will be taken along with the Truvada® PrEP for 1-2 weeks before returning for an intensive sampling visit.

Study Overview

• Status: Completed
• Conditions: HIV; Prophylaxis; Transgender
• Intervention / Treatment: Drug: Truvada alone; Drug: Truvada plus Estradiol 1 mg; Drug: Estradiol 6 mg alone; Drug: Truvada plus Leuprolide 11.25mg intramuscular injection; Drug: Truvada plus Estradiol 6 mg

Detailed Description

The PrEP-GAHT Interactions in TGW protocol is a phase 1, open label study to compare the safety, PK and PD of five sequential phases of PrEP administration in the presence or absence of testosterone-reducing therapies or dose-escalated estrogen therapy. Each participant will undergo a Screening Visit to evaluate eligibility.

Following Baseline evaluation, eligible participants will receive 300 milligrams (mg) TDF/200 mg FTC (Truvada®) once daily for seven days, using direct observation approaches, to achieve steady state drug PrEP concentrations. After one week of therapy, participants will undergo intensive PK analysis as well as collection of colorectal biopsies for PD testing (PK1). During the PK-intensive day, iohexol will be administered intravenously for the empirical determination of renal function and measured glomerular filtration rate (mGFR). While concurrently on PrEP, participants will then be intramuscularly administered depot leuprolide acetate (11.25 mg Lupron®). Two weeks post-injection, when testosterone concentrations are far below the lower limit of normal of total testosterone in men (typically < 200 ng/dL, or < 2 ng/mL), sampling for PK, PD, and renal function will be performed (PK2).

Participants will then immediately begin low-dose oral estrogen therapy (1 mg 17β-estradiol) in conjunction with PrEP for one week, at which time samples will be collected for the analyses described above (PK3). While still on PrEP, participants will then transition to high-dose estrogen therapy (6 mg 17β-estradiol) for the remainder of the study. One week post-high dose estrogen therapy in the presence of PrEP, pharmacologic and renal samples will be collected for analysis (PK4). PrEP will then be discontinued, and two weeks later, samples will be collected to assess renal function and hormonal concentrations, and evaluate the presence of any remaining PrEP in plasma, Peripheral Blood Mononuclear Cells (PBMC), or colorectal tissue (though it should be near undetectable levels for most analytes according to the investigators' prior data)(PK5).

Safety assessments, including history/physical, chemistry/hematology labs at screening and interim history will be performed at each study-intensive visit. Additionally, periodic assessments of gender dysphoria will be conducted at baseline and a convenient time during PK visits throughout the study. To ensure compliance, participants will undergo direct observation of dosing each day of the week prior to PK visits, using the aforementioned strategies.

• Study Type: Interventional
• Enrollment (Actual): 13
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21287
      • Johns Hopkins School of Medicine Drug Development Unit

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. 18 years of age or older
2. Self-identifying as a transgender woman
3. Not currently taking any gender affirming hormonal therapy (GAHT) with a total testosterone concentration of ≥ 200 ng/dL, or willing to abstain from feminizing therapies (including estradiol, spironolactone, progesterone, etc.) until total total testosterone concentrations are ≥ 200 ng/dL. Note: Testosterone may be retested every 2-4 weeks during screening to determine eligibility up to 6 weeks.
4. HIV-1 uninfected at screening as documented by Combo Ag/Ab HIV-1/HIV-2 immunoassay
5. Understand and agree to local STI reporting requirements
6. Able and willing to communicate in English
7. Able and willing to provide written informed consent to take part in the study
8. Able and willing to provide adequate information for locator purposes
9. Able and willing to participate in a directly observed study, which may occur in person, using live streaming or a time stamped video?
10. Availability to return for all study visits, barring unforeseen circumstances
11. Willing to abstain from insertion of anything (drug, enema, penis, or sex toy) in rectum for 72 hours before and 72 hours after each flexible sigmoidoscopy
12. Willing to refrain from aspirin and NSAID use for one week before and after each study biopsy visit
13. Willing and able to use condoms for all Receptive Anal Intercourse (RAI) for the duration of participation
14. Willing and able to participate in a directly observed study, which may occur in person, using live streaming or a time stamped video
15. Has an identified healthcare provider for transgender health management
16. Agree not to participate in other research studies involving drugs and/or medical devices for the duration of the study

Exclusion Criteria:

1. Not currently on any PrEP regimen (e.g., Truvada®, tenofovir alafenamide/ emtricitabine)
2. History of chronic Hepatitis B infection, as documented by positive HBsAg at screening
3. ≥ Grade 2 laboratory abnormality at baseline as defined by Division of AIDS Table for Grading the Severity of Adult and Pediatric Adverse Events, Corrected Version 2.1 - July 2017, and Addendum 3 (Rectal Grading Tables for Use in Microbicide Studies)
4. Significant colorectal symptom(s) as determined by medical history or by participant self- report (including but not limited to presence of any unresolved injury, infectious or inflammatory condition of the local mucosa, history of inflammatory bowel disease, presence of symptomatic hemorrhoids, and presence of any painful anorectal conditions that would be tender to manipulation)
5. At screening or within the past 2 months: participant-reported symptoms and/or clinical or laboratory diagnosis of active rectal infection requiring treatment per current Centers for Disease Control (CDC) guidelines or symptomatic urinary tract infection (UTI). Infections requiring treatment include Chlamydia (CT), gonorrhea (GC), syphilis, active herpes simplex virus (HSV) lesions, chancroid, genital sores or ulcers, and, if clinically indicated, genital warts. Note that HSV seropositivity with no active genital lesions is not an exclusion criterion. (Note: if an Sexually Transmitted Infection (STI) apart from HIV is detected, the participant will be referred for treatment and can be retested in 30 days and rescreened once.)
6. History of an underlying clinically significant cardiac arrhythmia or renal disease (including creatinine clearance < 60 mL/min using Cockcroft-Gault equation)
7. Serum phosphate < 2.3 mg/dL
8. History of severe or recent cardiac or pulmonary event
9. History of significant gastrointestinal bleeding
10. Current use of warfarin or heparin or other anticoagulant medications associated with increased risk for bleeding following mucosal biopsy (e.g., daily high dose aspirin [>81 mg], Non-steroidal anti-inflammatory drug [NSAIDs], or Pradaxa®)
11. Use of systemic or anorectal immunomodulatory medications within 4 weeks of enrollment or planned use at any time during study participation

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Non-Randomized
• Interventional Model: Sequential Assignment
• Masking: None (Open Label)

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Pre-Exposure Prophylaxis (PrEP) only; Truvada one tablet by mouth daily	Drug: Truvada alone; TDF/FTC 300 mg (milligrams) / 200 mg by mouth once daily; Other Names: tenofovir disoproxil fumarate/emtricitabine (TDF/FTC)
Experimental: PrEP plus Gonadotropin Releasing Hormone (GnRH) Agonist; Truvada one tablet by mouth daily Leuprolide 11.25 milligrams (mg) intramuscular (im) injection once	Drug: Truvada plus Leuprolide 11.25mg intramuscular injection; TDF/FTC 300mg/ 200 mg by mouth once daily Leuprolide 11.25 mg intramuscular injection once; Other Names: Truvada plus Lupron
Experimental: PrEP plus Low Dose Estrogen; Truvada one tablet by mouth daily Estradiol 1 milligram by mouth daily x 2 weeks	Drug: Truvada plus Estradiol 1 mg; TDF/FTC 300mg/ 200 mg by mouth once daily Estradiol 1 mg by mouth once daily; Other Names: Truvada plus low dose estrogen
Experimental: PrEP plus High Dose Estrogen; Truvada one tablet by mouth daily Estradiol 6 milligrams (mg) by mouth daily x 2 weeks	Drug: Truvada plus Estradiol 6 mg; TDF/FTC 300mg/ 200 mg by mouth once daily Estradiol 3 mg by mouth twice daily; Other Names: Truvada plus high dose estrogen
Experimental: High Dose Estrogen; Estradiol 6 mg by mouth daily x 2 weeks	Drug: Estradiol 6 mg alone; Estradiol 3 mg by mouth twice daily; Other Names: Estradiol 6 mg

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Maximum Tenofovir Plasma (Cmax) Concentration	Plasma TFV Cmax was defined as the highest observed concentration during the 24 hour (h) dosing interval and determined via non-compartmental analyses. Median maximum concentrations with interquartile ranges (IQR) were determined. Differences in TFV Cmax concentrations were determined for each participant, and each dosing period was compared to the PrEP Only Dosing Period. The median intra-individual difference in TFV Cmax, with IQRs, was calculated.	Days 7-8 for Pre-Exposure Prophylaxis (PrEP) Only, Days 21-22 For PrEP Plus Gonadotropin Releasing Hormone (GnRH) Agonist, Days 28-29 for PrEP Plus Lose-Dose Estrogen, Days 35-36 for PrEP Plus High-Dose Estrogen, and Days 49-50 for High-Dose Estrogen.
Change in Calculated Plasma TFV Area Under the Concentration-Time Curve (AUC0-24h)	The reported AUC is the area under the curve of the concentration-time curve calculated using trapezoidal rule (sum of trapezoids) over a 24h period (AUC0-24h). Median AUCs and IQRs were determined. Changes in AUC0-24h from baseline were based on comparisons between the reported AUC during each dosing period. Differences in the TFV AUC0-24h were determined for each participant, and each dosing period was compared to the PrEP Only Dosing Period. The median intra-individual difference in the TFV AUC0-24h, with IQRs, was calculated.	Days 7-8 for Pre-Exposure Prophylaxis (PrEP) Only, Days 21-22 For PrEP Plus Gonadotropin Releasing Hormone (GnRH) Agonist, Days 28-29 for PrEP Plus Lose-Dose Estrogen, Days 35-36 for PrEP Plus High-Dose Estrogen, and Days 49-50 for High-Dose Estrogen.
Change in PBMC TFV-DP C24 Concentration	The PBMC TFV-DP (fmol/10^6 cells) concentration was measured at 24 hours following a directly observed F/TDF or high-dose estrogen dose. Median PBMC TFV-DP concentrations, normalized to millions of cells analyzed, were measured. Differences in the PBMC TFV-DP concentrations were determined for each participant, and each dosing period was compared to the PrEP Only Dosing Period. The median intra-individual difference in the PBMC TFV-DP Concentrations, with IQRs, was calculated.	Day 8 for Pre-Exposure Prophylaxis (PrEP) Only, Day 22 For PrEP Plus Gonadotropin Releasing Hormone (GnRH) Agonist, Day 29 for PrEP Plus Lose-Dose Estrogen, Day 36 for PrEP Plus High-Dose Estrogen, and Day 50 for High-Dose Estrogen.
Change in TFV-DP Colon Tissue Concentration	The estimated colon TFV-DP was measured from colon biopsies 24 hours following a directly observed F/TDF or high-dose estrogen dose. Median colon tissue TFV-DP concentrations (with IQRs), normalized to weight of tissue biopsy analyzed, were measured. Differences in the colonic tissue TFV-DP concentrations were determined for each participant, and each dosing period was compared to the PrEP Only Dosing Period. The median intra-individual difference in the colonic tissue TFV-DP concentrations, with IQRs, was calculated.	Day 8 for Pre-Exposure Prophylaxis (PrEP) Only, Day 22 For PrEP Plus Gonadotropin Releasing Hormone (GnRH) Agonist, Day 29 for PrEP Plus Lose-Dose Estrogen, Day 36 for PrEP Plus High-Dose Estrogen, and Day 50 for High-Dose Estrogen

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Serum Estradiol Concentration	The measured serum estradiol concentration at the beginning of the intensive PK-sampling visit for the preceding evaluated dosing period. Differences in the serum estradiol concentrations were determined for each participant, and each dosing period was compared to baseline visit (no PrEP and no hormone supplementation). The median intra-individual difference in serum estradiol concentrations, with IQRs, was calculated.	Day 7 for Pre-Exposure Prophylaxis (PrEP) Only, Day 21 For PrEP Plus Gonadotropin Releasing Hormone (GnRH) Agonist, Day 28 for PrEP Plus Lose-Dose Estrogen, Day 35 for PrEP Plus High-Dose Estrogen, and Day 49 for High-Dose Estrogen
Change in Serum Free Testosterone	The measured percent free testosterone at the beginning of the intensive PK-sampling visit for the preceding evaluated dosing period. Median percent free testosterone measurements, with interquartile range, were measured. Differences in the percent free testosterone were determined for each participant, and each dosing period was compared to baseline visit (no PrEP and no hormone supplementation). The median intra-individual difference in percent free testosterone, with IQRs, was calculated.	Day 7 for Pre-Exposure Prophylaxis (PrEP) Only, Day 21 For PrEP Plus Gonadotropin Releasing Hormone (GnRH) Agonist, Day 28 for PrEP Plus Lose-Dose Estrogen, Day 35 for PrEP Plus High-Dose Estrogen, and Day 49 for High-Dose Estrogen
Change in Serum Total Testosterone Concentration	The measured serum total testosterone concentration at the beginning of the intensive PK-sampling visit for the preceding evaluated dosing period. Median serum total testosterone concentrations, with interquartile range, were measured. Differences in serum testosterone concentrations were determined for each participant, and each dosing period was compared to baseline visit (no PrEP and no hormone supplementation). The median intra-individual difference in serum testosterone concentrations, with IQRs, was calculated.	Day 7 for Pre-Exposure Prophylaxis (PrEP) Only, Day 21 For PrEP Plus Gonadotropin Releasing Hormone (GnRH) Agonist, Day 28 for PrEP Plus Lose-Dose Estrogen, Day 35 for PrEP Plus High-Dose Estrogen, and Day 49 for High-Dose Estrogen
Change in Serum Luteinizing Hormone (LH) Concentration	The measured serum LH concentration at the beginning of the intensive PK-sampling visit for the preceding evaluated dosing period. Median serum LH concentrations, with interquartile range, were measured. Differences in serum LH concentrations were determined for each participant, and each dosing period was compared to baseline visit (no PrEP and no hormone supplementation). The median intra-individual difference in serum LH concentrations, with IQRs, was calculated.	Day 7 for Pre-Exposure Prophylaxis (PrEP) Only, Day 21 For PrEP Plus Gonadotropin Releasing Hormone (GnRH) Agonist, Day 28 for PrEP Plus Lose-Dose Estrogen, Day 35 for PrEP Plus High-Dose Estrogen, and Day 49 for High-Dose Estrogen
Change in Serum Follicle Stimulating Hormone (FSH) Concentration	The measured serum FSH concentration at the beginning of the intensive PK-sampling visit for the preceding evaluated dosing period. Median serum FSH concentrations, with interquartile range, were measured. Differences in serum FSH concentrations were determined for each participant, and each dosing period was compared to baseline visit (no PrEP and no hormone supplementation). The median intra-individual difference in serum FSH concentrations, with IQRs, was calculated.	Day 7 for Pre-Exposure Prophylaxis (PrEP) Only, Day 21 For PrEP Plus Gonadotropin Releasing Hormone (GnRH) Agonist, Day 28 for PrEP Plus Lose-Dose Estrogen, Day 35 for PrEP Plus High-Dose Estrogen, and Day 49 for High-Dose Estrogen

Collaborators and Investigators

• Sponsor: Johns Hopkins University
• Collaborators: National Institute of Allergy and Infectious Diseases (NIAID)
• Investigators: Principal Investigator: Mark A Marzinke, PhD, Johns Hopkins School of Medicine

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2021
• Primary Completion (Actual): March 24, 2025
• Study Completion (Actual): March 24, 2025

Study Registration Dates

• First Submitted: February 15, 2021
• First Submitted That Met QC Criteria: February 15, 2021
• First Posted (Actual): February 18, 2021

Study Record Updates

• Last Update Posted (Actual): April 6, 2026
• Last Update Submitted That Met QC Criteria: April 2, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Pituitary Hormone-Releasing Hormones; Hypothalamic Hormones; Peptide Hormones; Neuropeptides; Peptides; Amino Acids, Peptides, and Proteins; Oligopeptides; Nerve Tissue Proteins; Proteins; Organic Chemicals; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Pharmaceutical Preparations; Therapeutics; Drug Administration Routes; Drug Therapy; Nucleic Acids, Nucleotides, and Nucleosides; Pharmacologic Actions; Chemical Actions and Uses; Polycyclic Compounds; Purines; Deoxycytidine; Cytidine; Pyrimidine Nucleosides; Pyrimidines; Steroids; Fused-Ring Compounds; Socioeconomic Factors; Population Characteristics; Organophosphorus Compounds; Nucleosides; Demography; Estrenes; Estranes; Estradiol Congeners; Gonadal Steroid Hormones; Gonadal Hormones; Deoxyribonucleosides; Organophosphonates; Adenine; Drug Combinations; Gonadotropin-Releasing Hormone; Injections; Family Characteristics; Marital Status; Tenofovir; Emtricitabine; Emtricitabine, Tenofovir Disoproxil Fumarate Drug Combination; Leuprolide; Estrogens; Estradiol; Injections, Intramuscular; Single Person
• Other Study ID Numbers: IRB00203162; R01AI145675 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No