Estradiol Therapy In Transgender Women to Research Interactions With HIV Therapy

Transgender women (TW) are a key population and priority for HIV treatment. More research is needed to develop evidence-based clinical guidance when it comes to choosing antiretroviral treatment (ART) regimens for TW on feminizing hormonal therapy (FHT). Concerns about ART interacting with FHT and decreasing its effectiveness can lead to decreased ART adherence and increased viral loads.

The GET IT RiGHT trial aims to address concerns about drug-drug interactions (DDIs) between ART and FHT while providing access to hormonal therapy to TW living with HIV. Data suggest that access to FHT improves adherence to HIV treatment and decreases treatment interruptions.

This is an open-label, non-randomized, 3-group trial of adult TW and other individuals identifying as female or transfeminine but with male sex assigned at birth living with HIV. Participants will be on ART at entry and receive study-supplied 17-β estradiol for FHT for 48 weeks.

The primary objectives of the study are to 1) assess whether TW continue to achieve therapeutic concentrations of ART while receiving FHT for 48 weeks and 2) assess whether serum estradiol concentrations on FHT (across a range of estradiol doses) vary between boosted and un-boosted ART regimens.

A5403 is a phase IIb, 48-week, open-label, non-randomized, 3-group trial, of 90 adult (≥18 years) transgender women and other individuals identifying as female or transfeminine but with male sex assigned at birth (TW) living with HIV on suppressive antiretroviral therapy (ART) and not currently on FHT. The trial will target at least 50% enrollment of participants identifying as non-white or Latine.

The trial consists of three groups, a BIC-treated group (BIC/TAF/FTC; n=30) (Group 1), a DTG-treated group (DTG/TDF/FTC or 3TC; n=30) (Group 2), and a boosted DRV-treated group (DRV/c; n=30) (Group 3), for a total of 90 participants.

All participants will continue on ART (not provided by the trial) and receive study-supplied 17-β estradiol for weeks 0-48. At entry, participants will be assigned to one of the three analysis groups based on their current ART regimen. Participants on other ART regimens at screening who are willing to switch to one of the regimens above, may also be enrolled.

All participants will receive study supplied 17-β estradiol for weeks 0-48. Oral 17-β estradiol 2 mg once daily will be initiated at study entry. At weeks 4, 12, 24, and 36, study clinicians may titrate 17-β estradiol in 2 mg increments as described in the protocol.

Intensive PK subgroup (n=15 per ART group): At entry (week 0), an 8-hour intensive PK sampling will assess ART exposure prior to FHT initiation. At week 24, intensive sampling will be repeated to assess 17-β estradiol and ART exposure. A final intensive PK visit will occur at week 48 to assess 17-β estradiol and ART exposure at the maximal FHT dosing achieved during the study period.

Sparse PK sampling: all participants not participating in an intensive PK sampling visit on the same day will have timed, sparse PK sampling collected at each visit to characterize the trough plasma (BIC, DTG, and DRV) and intracellular ART (TFV-DP, FTC-TP, 3TC-TP) concentrations to evaluate the relationship of ART PK exposure across a range of 17-β estradiol doses.

FHT satisfaction and acceptability:

To measure acceptability, participants will be asked to self-report the degree to which they find the intervention appropriate and useful using Likert-type agreement scales at three study time points: entry, 24 weeks, and 48 weeks. To measure satisfaction, the 12-question Transgender Congruence Scale (TCS) will be used, which will assess associations between gender-affirming treatments, perceived gender congruence, and satisfaction at three study time points: entry, 24 weeks, and 48 weeks. In addition, brief, 20-minute, semi-structured interviews will be conducted with 30 purposively sampled participants across English- or Spanish-speaking sites to provide an opportunity for more in-depth (open-ended) feedback on intervention satisfaction and acceptability at three time points: entry, 24 weeks, and 48 weeks.

Other assessments throughout the study include: anthropometric measurements (including weight, height, minimum waist circumference, and maximum hip circumference), routine chemistry and hematology labs, HIV-1 RNA, CD4+ and CD8+ T cell counts and percentages, lipids, glucose and insulin, non-estradiol hormone concentrations, stored PBMC, plasma, and serum, and ART and FHT adherence assessments.