Study to Determine Interaction Between the Use of Feminizing Hormone Therapy and Antiretroviral Agents Concomitantly Among Transgender Women

The Thai Red Cross AIDS Research Centre

Objective

1. To determine pharmacokinetic (PK) DDI between GAHT and ARVs used as PrEP and ART among TGW
2. To evaluate ARV adherence among TGW

GAHT will be initiated on week 0. ARVs, either PrEP or ART, will be initiated on week 3. GAHT will then be withheld on week 5, and restart at week 8.

GAHT: Oral estradiol valerate 2 mg once daily and cyproterone acetate 25 mg once daily, which are the treatment of choice for GAHT in the TRC-ARC's Tangerine Community Health Center, will be provided to all participants.

PrEP and ART regimen: Generic fixed-dose combination of TDF 300 mg and FTC 200 mg will be used for PrEP and a generic fixed-dose combination of TDF 300 mg, FTC 200 mg and efavirenz 600 mg will be used for ART as recommended in the 2017 Thailand National Guidelines on HIV/AIDS Treatment and Prevention.

Inclusion Criteria:

1. Thai nationality
2. Age 18-40 years old
3. Male-to-female transgender individual
4. PrEP/ART naïve
5. Body mass index 18.5-25 kg/m2
6. Calculated creatinine clearance (CrCl) ≥60 mL/min, as estimated by the Cockcroft- Gault equation
7. Alanine aminotransferase (ALT) ≤2.5 x ULN
8. Have signed the informed consent form

Exclusion Criteria:

1. Known history of allergy to hormonal or ARV component to be used in the study

2. Male-to-female transgender who underwent orchiectomy

3. Any of the following in HIV-infected participants

   • CD4 < 350 cells/mm3
   • History of psychiatric disorder that may be worsening by taking EFV

4. Previous use of injectable GAHT in the past 6 months

5. Current use of any of the following medication:

   • Anticonvulsant: Phenytoin, carbamazepine or phenobarbitol
   • Ergot-containing agents: dihydroergotamine, ergotamine or other ergot derivatives
   • Sedatives: Midazolam or triazolam
   • Herbs: Gingko biloba, St John's wort or milk thistle
   • Anti-infective agents: Erythromycin, clarithromycin, ketoconazole, itraconazole, rifampicin or rifabutin

6. Alcohol or drug use that, in the opinion of the investigator, would interfere with completion of study procedures