Transgender women on oral HIV pre-exposure prophylaxis have significantly lower tenofovir and emtricitabine concentrations when also taking oestrogen when compared to cisgender men

Protocol of a drug-drug interaction study between bictegravir/emtricitabine/tenofovir alafenamide and feminizing hormones in trans women living with HIV

AIMS

Trans/transfeminine women are disproportionally affected by HIV. Concerns regarding negative drug-drug interactions (DDIs) between ART drugs and gender-affirming hormone therapy (GAHT), specifically feminizing hormone therapy (FHT), may contribute to the lower ART uptake by trans women with HIV compared with their cis counterparts. The aim of this study is to investigate the bidirectional pharmacokinetic effects of components of FHT regimens (oral oestradiol and androgen-suppressing medications) with the ART regimen (bictegravir/emtricitabine/tenofovir alafenamide [B/F/TAF)].

METHODS

We present a protocol for a three-armed, parallel-group, longitudinal (6-month), DDI study. Group 1 includes 15 3trans women with HIV taking FHT and ART; group 2 includes 15 premenopausal cis women with HIV taking ART; group 3 includes 15 trans women without HIV taking FHT. Women with HIV must be on or switch to B/F/TAF at baseline and be virally suppressed for ≥3 months. Trans women must be taking a stable regimen of ≥2 mg daily oral oestradiol and an anti-androgen (pharmaceutical, and/or surgical, and/or medical) for ≥3 months. Plasma ART drug concentrations will be sampled at Month 2 and compared between groups 1 and 2. Serum oestradiol concentrations will be sampled at baseline and Month 2 visits and compared between groups 1 and 3. The primary outcomes are B/F/TAF pharmacokinetic parameters (Cmin, Cmax and AUC) and oestradiol concentrations (Cmin, C4h, Cmax and AUC) at month 2.

DISCUSSION

This study is of global importance as it provides critical information regarding safe coadministration of B/F/TAF and FHT, both of which are life-saving therapies for trans women with HIV.

Drug-drug interactions between gender-affirming hormone therapy and antiretrovirals for treatment/prevention of HIV

Transgender persons face a greater burden of HIV compared to cisgender counterparts. Concerns around drug-drug interactions (DDIs) have been cited as reasons for lower engagement in HIV care and lower pre-exposure prophylaxis (PrEP) uptake among transgender populations. It is therefore imperative for hormone therapy, PrEP and antiretroviral therapy providers to understand the DDI potential between these therapies. Studies of tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) PrEP with feminizing hormone therapies (FHTs) show reduced plasma tenofovir concentrations, but intracellular concentrations of tenofovir-diphosphate are not reduced. Efficacy of PrEP is expected to be maintained despite this interaction. Masculinizing hormone therapies have no effect on tenofovir concentrations but may increase FTC to a nonclinically relevant extent. No interactions between FHT and cabotegravir or tenofovir alafenamide have been demonstrated. Administration of TDF/FTC PrEP has no effect on hormone levels in transmen or transwomen. PrEP is expected to be effective and safe in transpersons and should be provided to high-risk individuals regardless of gender affirming hormone use. Enzyme inducing/inhibiting antiretroviral therapy may decrease or increase, respectively, the concentrations of FHT and masculinizing hormone therapy. Unboosted integrase inhibitors or enzyme neutral non-nucleoside reverse transcriptase inhibitors are not expected to affect and are not affected by gender affirming hormones and can be considered in transmen and transwomen. Overlapping toxicities including weight gain, dyslipidaemia, cardiovascular disease and bone density effects should be considered, and antiretroviral modifications can be made to minimize toxicities. Interactions between supportive care medications should be assessed to avoid chelation interactions and hyperkalaemia.

No observed bidirectional effect between tenofovir diphosphate concentrations and gender-affirming hormone concentrations among transgender persons switching from tenofovir disoproxil fumarate/emtricitabine to tenofovir alafenamide/emtricitabine for HIV pre-exposure prophylaxis

AIMS

Many transgender and gender diverse (TGD) individuals have expressed concerns about the potential for oral pre-exposure prophylaxis to affect hormonal concentrations achieved from taking gender-affirming hormone therapy (GAHT). The purpose of this study was to understand the bidirectional effects between hormone and intraerythrocytic tenofovir diphosphate concentrations when switching from tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) to tenofovir alafenamide/emtricitabine (TAF/FTC) in TGD users/nonusers of GAHT.

METHODS

The study evaluated stored blood samples and dried blood spot cards from TGD adults without HIV who took ≥12 weeks of TDF/FTC and then switched to ≥12 weeks of TAF/FTC for pre-exposure prophylaxis.

RESULTS

Thirty-nine individuals met the study inclusion criteria. Regardless of sex assigned at birth and the use of GAHT, there were no significant differences in hormone concentrations when individuals taking GAHT were taking TDF/FTC and then switched to TAF/FTC. Further, there was no significant difference in intraerythrocytic tenofovir diphosphate concentrations between users and nonusers of GAHT.

CONCLUSION

There are no bidirectional effects between hormone and intraerythocytic tenofovir diphosphate concentrations when switching from TDF/FTC to TAF/FTC in TGD users/nonusers of GAHT.

Perceived Feasibility and Acceptability of HIV Prevention Research With Daily Oral PrEP Among Young Transgender Women (YTGW) Who Sell or Trade Sex in Bangkok and Pattaya, Thailand

Young transgender women (YTGW) who sell or trade sex have among the highest HIV incidence rates in Thailand. Using qualitative methods, we assessed perceived acceptability, feasibility, and optimal design of a combination HIV prevention intervention including PrEP for YTGW. Key informant interviews were conducted during July 2016-July 2018 with 21 YTGW, aged 18-26 years, who sold sex and resided in Bangkok or Pattaya, Thailand. Grounded theory and content analysis were used for data analysis. Most YTGW interviewed reported high interest in HIV prevention research and believed participation in it supported sexual health. However, participants perceived HIV studies as complicated and time-consuming. Regarding PrEP, participants suggested more PrEP options beyond daily oral PrEP and expressed concerns related to perceived side effects of PrEP, including interaction with gender-affirming hormone therapy. Improving PrEP knowledge, being able to self-assess HIV risk, and reducing HIV/PrEP stigma could increase interest in research and PrEP uptake among YTGW.

Social, economic, and physical side effects impact PrEP uptake and persistence among transgender women in Peru

INTRODUCTION

Oral pre-exposure prophylaxis (PrEP) for HIV-1 infection is over 99% effective in protecting against HIV acquisition when used consistently and appropriately. However, PrEP uptake and persistent use remains suboptimal, with a substantial gap in utilization among key populations who could most benefit from PrEP. In Latin America specifically, there is poor understanding of barriers to PrEP uptake and persistence among transgender (trans) women.

METHODS

In April-May 2018, we conducted qualitative interviews lasting 25-45 min as part of an end-of-project evaluation of TransPrEP, a pilot RCT that examined the impact of a social network-based peer support intervention on PrEP adherence among trans women in Lima, Peru. Participants in the qualitative evaluation, all adult trans women, included individuals who either (1) screened eligible to participate in the TransPrEP pilot, but opted not to enroll (n = 8), (2) enrolled, but later withdrew (n = 6), (3) were still actively enrolled at the time of interview and/or successfully completed the study (n = 16), or (4) were study staff (n = 4). Interviews were audio recorded and transcribed verbatim. Codebook development followed an immersion/crystallization approach, and coding was completed using Dedoose.

RESULTS

Evaluation participants had a mean age of 28.2 years (range 19-47). When describing experiences taking PrEP, participant narratives highlighted side effects that spanned three domains: physical side effects, such as prolonged symptoms of gastrointestinal distress or somnolence; economic challenges, including lost income due to inability to work; and social concerns, including interpersonal conflicts due to HIV-related stigma. Participants described PrEP use within a broader context of social and economic marginalization, with a focus on daily survival, and how PrEP side effects negatively contributed to these stressors. Persistence was, in some cases, supported through the intervention's educational workshops.

CONCLUSION

This research highlights the ways that physical, economic, and social side effects of PrEP can impact acceptability and persistence among trans women in Peru, amplifying and layering onto existing stressors including economic precarity. Understanding the unique experiences of trans women taking PrEP is crucial to informing tailored interventions to improve uptake and persistence.

Tenofovir Douche as HIV Preexposure Prophylaxis for Receptive Anal Intercourse: Safety, Acceptability, Pharmacokinetics, and Pharmacodynamics (DREAM 01)

BACKGROUND

Despite highly effective HIV preexposure prophylaxis (PrEP) options, no options provide on-demand, nonsystemic, behaviorally congruent PrEP that many desire. A tenofovir-medicated rectal douche before receptive anal intercourse may provide this option.

METHODS

Three tenofovir rectal douches-220 mg iso-osmolar product A, 660 mg iso-osmolar product B, and 660 mg hypo-osmolar product C-were studied in 21 HIV-negative men who have sex with men. We sampled blood and colorectal tissue to assess safety, acceptability, pharmacokinetics, and pharmacodynamics.

RESULTS

The douches had high acceptability without toxicity. Median plasma tenofovir peak concentrations for all products were several-fold below trough concentrations associated with oral tenofovir disoproxil fumarate (TDF). Median colon tissue mucosal mononuclear cell (MMC) tenofovir-diphosphate concentrations exceeded target concentrations from 1 hour through 3 to 7 days after dosing. For 6-7 days after a single product C dose, MMC tenofovir-diphosphate exceeded concentrations expected with steady-state oral TDF 300 mg on-demand 2-1-1 dosing. Compared to predrug baseline, HIV replication after ex vivo colon tissue HIV challenge demonstrated a concentration-response relationship with 1.9 log10 maximal effect.

CONCLUSIONS

All 3 tenofovir douches achieved tissue tenofovir-diphosphate concentrations and colorectal antiviral effect exceeding oral TDF and with lower systemic tenofovir. Tenofovir douches may provide a single-dose, on-demand, behaviorally congruent PrEP option, and warrant continued development. Clinical Trials Registration . NCT02750540.

Bidirectional pharmacokinetics of doravirine, tenofovir, and feminizing hormones in transgender women (IDentify): A randomized crossover trial

Transgender women may have concerns of drug interactions between feminizing hormone therapy (FHT) and antiretrovirals, leading to nonadherence. This randomized, three-period crossover, open-label, phase I trial assessed the effects of doravirine (DOR) and tenofovir disoproxil fumarate (TDF) on the pharmacokinetics (PKs) of estradiol, spironolactone, and total testosterone and vice versa in healthy transgender women. Volunteers were randomized 1:1 into two sequences containing three treatment groups (DOR, lamivudine [3TC], and TDF alone; estradiol, spironolactone, and placebo; and DOR/3TC/TDF, estradiol, and spironolactone). Eight subjects enrolled in the study and six had completed all study periods. The geometric mean ratios for DOR area under the concentration-time curve from zero to last measured concentration (AUC0-last ), maximum concentration (Cmax ), and concentration at 24 h (C24 ) were similar. However, tenofovir (TFV) AUC0-last , Cmax , and C24 moderately increased by 14%-38%. Last, estradiol AUC0-last , Cmax , and C24 were increased by 10%-13%. Whereas most 90% confidence intervals did not meet the bioequivalence bounds of 80%-125%, the point estimates fell within the intervals. Log-transformed DOR, TFV, and estradiol PK parameters computed with and without co-administration were not statistically different (p > 0.05). There were no serious adverse events. There is not a clinically significant impact of FHT on DOR/TFV PKs. Similarly, there is no observed impact on estradiol PKs and total testosterone following use of DOR/3TC/TDF.

Gender Affirming Hormones Do Not Affect the Exposure and Efficacy of F/TDF or F/TAF for HIV Preexposure Prophylaxis: A Subgroup Analysis from the DISCOVER Trial

Purpose

Transgender women are disproportionately affected by HIV and are underutilizing preexposure prophylaxis (PrEP). The lower uptake of PrEP by transgender women may be, in part, owing to the perception that taking PrEP may lower the efficacy of gender-affirming hormone therapy (GAHT) or to provider concerns that GAHT may lower the efficacy of PrEP.

Methods

DISCOVER was a randomized, double-blind, noninferiority trial comparing emtricitabine (FTC, F) and tenofovir alafenamide (F/TAF) versus emtricitabine and tenofovir disoproxil fumarate (F/TDF) as PrEP among transgender women and cisgender men who have sex with men (MSM). This nested substudy of the DISCOVER trial compared the exposure of the active intracellular metabolites of FTC and tenofovir (TFV), FTC triphosphate (FTC-TP) and TFV diphosphate (TFV-DP), in peripheral blood mononuclear cells (PBMC) among transgender women receiving GAHT versus MSM within the F/TAF and F/TDF groups.

Results

Our results demonstrate that TFV-DP and FTC-TP levels in PBMC were comparable between transgender women on GAHT and MSM receiving F/TAF, and between transgender women on GAHT and MSM receiving F/TDF. TFV-DP concentrations remained above the EC90 of 40 fmol/106 cells across all groups. No clinically significant drug-drug interactions of GAHT were observed with either F/TAF or F/TDF in this subanalysis.

Conclusions

These findings are consistent with the clinical pharmacology of GAHT, FTC, TDF, and TAF reported in previous studies, and support the continued use of F/TAF and F/TDF for PrEP in transgender women.

Clinicaltrials.gov registration number: NCT02842086.

Model-based predictions of protective HIV pre-exposure prophylaxis adherence levels in cisgender women

Most human immunodeficiency virus (HIV) infections occur in cisgender women in resource-limited settings. In women, self-protection with emtricitabine/tenofovir disoproxil fumarate pre-exposure prophylaxis (FTC/TDF-PrEP) constitutes a major pillar of HIV prevention. However, clinical trials in women had inconsistent outcomes, sparking uncertainty about adherence requirements and reluctance in evaluating on-demand regimens. We analyzed data from published FTC/TDF-PrEP trials to establish efficacy ranges in cisgender women. In a 'bottom-up' approach, we modeled hypotheses in the context of risk-group-specific, adherence-efficacy profiles and challenged those hypotheses with clinical data. We found that different clinical outcomes were related to the proportion of women taking the product, allowing coherent interpretation of the data. Our analysis showed that 90% protection was achieved when women took some product. We found that hypotheses of putative male/female differences were either not impactful or statistically inconsistent with clinical data. We propose that differing clinical outcomes could arise from pill-taking behavior rather than biological factors driving specific adherence requirements in cisgender women.

Clinical Relevance of Drug Interactions in People Living with Human Immunodeficiency Virus on Antiretroviral Therapy-Update 2022: Systematic Review

BACKGROUND

The clinical outcomes of antiretroviral drugs may be modified through drug interactions; thus, it is important to update the drug interactions in people living with HIV (PLHIV).

AIM

To update clinically relevant drug interactions in PLHIV on antiretroviral therapy with novel drug interactions published from 2017 to 2022.

METHODS

A systematic review in Medline/PubMed database from July 2017 to December 2022 using the Mesh terms antiretroviral agents and drug interactions or herb-drug interactions or food-drug interactions. Publications with drug interactions in humans, in English or Spanish, and with full-text access were retrieved. The clinical relevance of drug interactions was grouped into five levels according to the gravity and probability of occurrence.

RESULTS

A total of 366 articles were identified, with 219 (including 87 citation lists) were included, which allowed for the identification of 471 drug interaction pairs; among them, 291 were systematically reported for the first time. In total 42 (14.4%) and 137 (47.1%) were level one and two, respectively, and 233 (80.1%) pairs were explained with the pharmacokinetic mechanism. Among these 291 pairs, protease inhibitors (PIs) and ritonavir/cobicistat-boosted PIs, as well as integrase strand transfer inhibitors (InSTIs), with 70 (24.1%) and 65 (22.3%) drug interaction pairs of levels one and two, respectively, were more frequent.

CONCLUSIONS

In PLHIV on antiretroviral therapy, we identify 291 drug interaction pairs systematically reported for the first time, with 179 (61.5%) being assessed as clinically relevant (levels one and two). The pharmacokinetic mechanism was the most frequently identified. PIs, ritonavir/cobicistat-boosted PIs, and InSTIs were the antiretroviral groups with the highest number of clinically relevant drug interaction pairs (levels one and two).

Estradiol and Spironolactone Plasma Pharmacokinetics Among Brazilian Transgender Women Using HIV Pre-Exposure Prophylaxis: Analysis of Potential Interactions

BACKGROUND AND OBJECTIVE

An important barrier to HIV prevention among transgender women (TGW) is the concern that oral pre-exposure prophylaxis (PrEP) negatively affects the efficacy of feminizing hormone therapy (FHT). We aimed to assess the impact of PrEP on FHT pharmacokinetics (PK) among TGW from Brazil.

METHODS

We performed a drug-drug interaction sub-study among TGW enrolled in a daily oral PrEP demonstration study (PrEParadas, NCT03220152). Participants had a first PK assessment (PK1) 15 days after FHT (estradiol valerate 2-6 mg plus spironolactone 100-200 mg) initiation and then started PrEP (tenofovir disoproxil fumarate 300 mg/emtricitabine 200 mg). A second PK evaluation was performed 12 weeks later (PK2). Blood samples were collected prior and after the directly observed dosing (0, 0.5, 1, 2, 4, 6, 8, and 24 hours). Pharmacokinetic parameters of estradiol, spironolactone, and metabolites were estimated by non-compartmental analysis (Monolix 2021R2, Lixoft®) and compared as geometric mean ratios (GMRs, 90% confidence interval [CI]).

RESULTS

Among 19 TGW who completed the substudy, median age was 26 years (interquartile range: 23-27.5). Estradiol area under the plasma concentration-time curve (AUCτ) and trough concentrations did not differ between PK1 and PK2 evaluations (GMR [90% CI]: 0.89 [0.76-1.04] and 1.06 [0.94-1.20], respectively). Spironolactone and canrenone AUCτ were statistically lower at PK2 than PK1 (0.76 [0.65-0.89] and 0.85 [0.78-0.94], respectively). Canrenone maximum concentration was also lower at PK2 than PK1 (0.82 [0.74-0.91]).

CONCLUSION

Estradiol PK was not influenced by PrEP concomitant use. The small differences observed in some spironolactone and canrenone PK parameters should not prevent the concomitant use of estradiol-based FHT and PrEP.

TRIAL REGISTRATION

This trial (NCT03220152) was registered on July 18, 2017.

Synthesis of protective oral PrEP adherence levels in cisgender women using convergent clinical- and bottom-up modeling

Globally, most HIV infections occur in heterosexual women in resource-limited settings. In these settings, female self-protection with generic emtricitabine/tenofovir disoproxil fumarate pre-exposure prophylaxis (FTC/TDF-PrEP) may constitute a major pillar of the HIV prevention portfolio. However, clinical trials in women had inconsistent outcomes, sparking uncertainty regarding risk-group specific adherence requirements and causing reluctance in testing and recommending on-demand regimen in women. We analyzed all FTC/TDF-PrEP trials to establish PrEP efficacy ranges in women. In a 'bottom-up' approach, we modeled hypotheses corroborating risk-group specific adherence-efficacy profiles. Finally, we used the clinical efficacy ranges to (in-)validate hypotheses. We found that different clinical outcomes could solely be explained by the proportion of enrolled participants not taking the product, allowing, for the first time, to unify clinical observations. This analysis showed that 90% protection was achieved, when women took some of the product. Using 'bottom-up' modelling, we found that hypotheses of putative male/female differences were either irrelevant, or statistically inconsistent with clinical data. Furthermore, our multiscale modelling indicated that 90% protection was achieved if oral FTC/TDF was taken at least twice weekly.

Inclusion of Transgender and Gender Diverse People in Phase III Trials: Examples from HIV Pharmacologic Prevention Studies

Although at least 25 million adults are transgender worldwide, few phase III clinical trials have enrolled transgender and gender diverse (TGD) people. HIV is the only therapeutic area to include TGD people intentionally in phase III randomized clinical trials during the development of certain newer HIV pharmacologic prevention interventions. Pharmacologic assessments for HIV prevention efficacy in TGD populations are important, as there may be specific considerations for product use and potential interactions with hormone therapies. Herein, we summarize ongoing and completed phase III HIV trials that included TGD people as part of the study population, we examine investigators' strategies for recruiting and engaging TGD priority populations in these phase III trials, and we comment on the implications of these studies for prioritizing TGD populations in clinical pharmacology research within the phase III clinical trial landscape.

Cell and Tissue Specific Metabolism of Nucleoside and Nucleotide Drugs: Case Studies and Implications for Precision Medicine

Many clinically used antiviral drugs are nucleoside or nucleotide analog drugs, which have a unique mechanism of action that requires intracellular phosphorylation. This dependence on intracellular activation presents novel challenges for the discovery and development of nucleoside/nucleotide analog drugs. Contrary to many small molecule drug development programs that rely on plasma pharmacokinetics and systemic exposures, the precise mechanisms that result in efficacious intracellular nucleoside triphosphate concentrations must be understood in the process of nucleoside/nucleotide drug development. The importance is highlighted here, using the following as case studies: the herpes treatment acyclovir, the cytomegalovirus therapy ganciclovir, and human immunodeficiency virus (HIV) treatments based on tenofovir, which are also in use for HIV prophylaxis. For each drug, the specificity of metabolism that results in its activation in different cells or tissues is discussed, and the implications explored. Acyclovir's dependence on a viral enzyme for activation provides selective pressure for resistance mutations. Ganciclovir is also dependent on a viral enzyme for activation, and suicide gene therapy capitalizes on that for a novel oncology treatment. The tissue of most relevance for tenofovir activation depends on its use as treatment or as prophylaxis, and the pharmacogenomics and drug-drug interactions in those tissues must be considered. Finally, differential metabolism of different tenofovir prodrugs and its effects on toxicity risk are explored. Taken together, these examples highlight the importance of understanding tissue specific metabolism for optimal use of nucleoside/nucleotide drugs in the clinic. SIGNIFICANCE STATEMENT: Nucleoside and nucleotide analogue drugs are cornerstones in current antiviral therapy and prevention efforts that require intracellular phosphorylation for activity. Understanding their cell and tissue specific metabolism enables their rational, precision use for maximum efficacy.

PrEP Use and Adherence among Transgender Persons in Chicago, IL (SHIPP Study, 2014-2018, USA)

Few studies investigating daily oral preexposure prophylaxis (PrEP) focus on transgender persons. The Sustainable Health Center Implementation PrEP Pilot (SHIPP) Study included a large observational cohort of transgender persons with implications for PrEP in the United States. We examined data from SHIPP's observational cohort and its Medication Adherence Substudy (MAS) to understand adherence among transgender participants in Chicago, IL. We assessed adherence by the proportion of days covered (PDC) for PrEP medication prescriptions, self-reported interview data, and concentrations of intracellular tenofovir diphosphate (TFV-DP) in dried blood spot (DBS) samples. Between 2014 and 2018, there were 510 transgender participants, 349 (68.4%) transgender women and 152 (29.8%) transgender men. Forty-five of these participants were enrolled in the MAS, 31 (68.9%) transgender women and 9 (20.0%) transgender men. By the 3-month follow up, 100% of MAS participants who completed an interview reported taking 4 or more doses of PrEP in the previous week. At 6, 9, and 12 months, taking 4 or more doses in the past week was reported by 81.0%, 94.1%, and 83.3% of participants, respectively. Results from TFV-DP DBS indicated that fewer participants reached the same level of adherence (4 or more doses/week) at clinical visits compared to self-report and even fewer participants reached this level of adherence based on the calculated PDC. Among participants who remained on PrEP throughout the study, DBS adherence levels declined after the first three months. There remains a critical need to develop strategies to address barriers and interventions that support PrEP adherence among transgender people.

Barriers to uptake of PrEP across the continuum among transgender women: A global scoping review

BACKGROUND

Although preexposure prophylaxis (PrEP) has demonstrated high efficacy for HIV prevention, rates of PrEP uptake remain low among the transgender population, especially in transgender women (TGW). We conducted this scoping review to assess and characterize barriers to PrEP use along the PrEP care continuum among TGW.

METHODS

We conducted this scoping review by searching studies in Embase, PubMed, Scopus, and Web of Science. Eligibility criteria included: reporting a PrEP related quantitative result among TGW; peer-reviewed and published in English between 2010-2021.

RESULTS

Globally, high willingness (80%) to use PrEP was found, yet uptake and adherence (35.4%) were low. TGW experiencing hardship, including poverty, incarceration, and substance use, were associated with higher odds of PrEP awareness but lower odds of PrEP use. Structural and social barriers such as stigma, medical mistrust, and perceived racism can be important barriers for PrEP continuation. High social cohesion and hormone replacement therapy were associated with greater odds of awareness. In addition, our study confirmed prior research showing that PrEP does not lower feminizing hormone levels in TGW.

CONCLUSIONS

Significant demographic factors among TGW that are associated with PrEP engagement. It is imperative to focus on TGW as a population with independent needs, requiring specific PrEP care guidelines and tailored resource allocation, that fully considers individual-, provider-, and community/structural-level barriers and facilitators. The present review also indicates that combining PrEP care with GAHT or broader gender-affirmation care may facilitate PrEP use.

Interaction of Depot Medroxyprogesterone Acetate and Tenofovir Disoproxil Fumarate/Emtricitabine on Peripheral Blood Mononuclear Cells and Cervical Tissue Susceptibility to HIV Infection and Pharmacokinetics

BACKGROUND

Depot medroxyprogesterone acetate (DMPA) is a widely used contraceptive method. HIV pre-exposure prophylaxis with emtricitabine and tenofovir disoproxil fumarate (F/TDF) is highly effective in reducing HIV acquisition in women. We sought to determine the impact of DMPA on F/TDF pharmacokinetics and pharmacodynamics.

METHODS

Twelve healthy premenopausal cisgender women were enrolled and each completed 4 sequential conditions: (1) baseline, (2) steady-state F/TDF alone, (3) steady-state F/TDF + DMPA, and (4) DMPA alone. Assessments included clinical, pharmacokinetic, viral infectivity (ex vivo challenge of peripheral blood mononuclear cells by X4- and R5-tropic green fluorescent protein pseudoviruses and cervical tissue by HIV BaL ), endocrine, immune cell phenotyping, and renal function.

RESULTS

Compared with baseline, F/TDF (± DMPA) significantly decreased both %R5- and X4-infected CD4 T cells and F/TDF + DMPA decreased cervical explant p24 (all P < 0.05). The %R5- and X4-infected CD4 T cells were higher during DMPA alone than during F/TDF periods and lower than baseline (not statistically significant). Cervical explant p24 fell between baseline and F/TDF values (not statistically significant). There were neither statistically significant differences in F/TDF pharmacokinetics, including total or renal clearance of either antiviral drug, nor changes in glomerular filtration rate with the addition of DMPA. There were few immune cell phenotypic differences across conditions.

CONCLUSIONS

F/TDF decreased HIV infection in both challenge assays, whereas DMPA alone did not enhance HIV infection in either challenge assay. DMPA did not alter F/TDF pharmacokinetics or renal function.

Gender-Affirming Hormone Pharmacokinetics Among Adolescent and Young Adult Transgender Persons Receiving Daily Emtricitabine/Tenofovir Disoproxil Fumarate

Transgender persons have an increased vulnerability to HIV infection yet have not been well-represented in past clinical trials for pre-exposure prophylaxis (PrEP). Because of this, there are few data available to understand whether gender-affirming hormone concentrations are influenced by PrEP agents in transgender men (TM) and transgender women (TW). The objective of this study was to compare gender-affirming hormone concentrations with versus without emtricitabine (F, FTC)-tenofovir disoproxil fumarate (TDF). TM and TW without HIV, aged 15-24 years, were enrolled for 1 month of directly observed daily F/TDF. Participants were required to be receiving a stable hormone dose (estradiol or testosterone) for at least 1 month or three consecutive doses, whichever was longer, before enrollment and willing to continue the same dose. Intensive pharmacokinetic (PK) sampling for gender-affirming hormones was collected before and 2-3 weeks after daily F/TDF. Serum estradiol and total testosterone were determined by liquid chromatography-tandem mass spectrometry; free testosterone by equilibrium dialysis. Maximum concentrations (Cmax) and area under the curve (AUClast) were log-transformed and compared between baseline and on F/TDF using geometric mean ratios (GMRs) with 95% confidence intervals (CIs). Twenty-five TW and 24 TM were enrolled (median age: 20 and 21 years, respectively). In TW, estradiol Cmax (GMR [95% CI]: 0.85 [0.65-1.11]) and AUClast (GMR [95% CI]: 0.87 [0.73-1.03]) were comparable on F/TDF versus baseline. In TM, similar comparability was observed for PrEP versus baseline including total testosterone Cmax (GMR [95% CI]: 0.91 [0.80-1.03]) and AUClast (GMR [95% CI]: 0.91 [0.81-1.04]) and free testosterone Cmax (GMR [95% CI]: 0.89 [0.74-1.07]) and AUClast (GMR [95% CI]: 0.88 [0.74-1.03]). Estradiol and testosterone exposures in young TW and TM did not significantly differ on F/TDF versus baseline. These findings should reassure patients and providers that F/TDF can be used as PrEP without concern for altering gender-affirming hormone PK. ClinicalTrials.gov (NCT03652623).

MTN-033: a Phase 1 Study Comparing Applicator versus "as Lubricant" Delivery of Rectal Dapivirine Gel

Data to inform behaviorally congruent delivery of rectal microbicides as lubricants are scant. Dapivirine (DPV) is a nonnucleoside reverse transcriptase inhibitor which has been demonstrated to be well-tolerated and efficacious in multiple clinical trials when used in a vaginal ring formulation. DPV gel administered rectally with an applicator was found to be well-tolerated in a phase 1 clinical trial. MTN-033, a single site, open label, sequence randomized, crossover study, enrolled HIV-negative men to receive 0.05% DPV gel intrarectally using an applicator (2.5 g) and self-administered on an artificial phallus as lubricant (up to 10 g). The study evaluated the pharmacokinetics (in plasma, rectal fluid, and mucosal rectal tissue), safety, acceptability, and pharmacodynamics of DPV gel when applied rectally. Statistical comparisons between methods of application were performed using mixed effects models or Wilcoxon's signed rank tests. Sixteen participants used DPV gel by applicator and 15/16 participants used gel as lubricant (mean, 1.8 g; SD, 0.8). DPV plasma AUC0-24h after use as lubricant was estimated to be 0.41 times the AUC0-24h (95% CI 0.24, 0.88) after use with applicator. While DPV was quantifiable in plasma and luminal fluid, it was not quantifiable in tissue for both applicator and as lubricant administration. No related adverse events (AE) were reported, and 15/15 participants felt the gel was easy to use. Evidence of local delivery and systemic absorption of DPV when dosed as an anal lubricant supports the feasibility and potential for development of lubricant-delivered rectal microbicides. There were no safety concerns associated with use of DPV gel and participants reported finding it easy to use. However, lower DPV exposure in plasma and lack of quantifiable DPV in rectal tissue indicate that higher potency, concentration, and longer half-life antiretrovirals with optimized formulations will be needed to achieve protective tissue concentrations.

Pharmacokinetics of Emtricitabine/Tenofovir Disoproxil Fumarate Among Transgender Adolescents and Young Adults Without HIV Receiving Gender Affirming Hormones

The transgender community has expressed concerns regarding drug-drug interactions between HIV-pre-exposure prophylaxis (PrEP) and gender-affirming hormones. In this study, we evaluated emtricitabine (F, FTC)/tenofovir (TFV) disoporoxil fumarate (TDF) pharmacokinetics (PK) among adolescent and young adult transgender persons receiving gender-affirming hormone therapy (GAHT). This was a prospective, observational study among transgender women (TW) and men (TM) without HIV, 15-24 years of age, receiving GAHT (estradiol with/without spironolactone, or testosterone). Participants received 1 month of directly observed daily F/TDF. Weekly convenience blood samples were collected for plasma TFV and FTC, and intracellular TFV-diphosphate (TFV-DP) and FTC-triphosphate (FTC-TP) in peripheral blood mononuclear cells (PBMC) and dried blood spots (DBS). After 2-3 weeks of F/TDF dosing, intensive PK sampling was conducted. PK parameters were estimated using noncompartmental methods. Data were log-transformed and compared between TM and TW, and to historical data among cisgender adults. Plasma TFV exposures were similar between TM and TW [geometric mean ratio (GMR); confidence interval (95% CI): 1.06 (0.89-1.28)], whereas FTC plasma exposures were 21% higher in TM versus TW (95% CI: 1.07-1.38). TFV-DP in PBMC and DBS and FTC-TP in DBS did not differ between TM versus TW after controlling for creatinine clearance (CrCl), but FTC-TP in PBMC remained 46% (95% CI: 1.15-1.86) higher in TM versus TW. All PK exposures were within expected ranges based on historical studies. TM had higher FTC exposures compared with TW, but overall plasma and intracellular exposures for both drugs were within the range of historical studies, suggesting high PrEP efficacy will be retained in adolescent and young adult transgender persons. Registered at ClinicalTrials.gov (NCT03652623).

Factors associated with long-term HIV pre-exposure prophylaxis engagement and adherence among transgender women in Brazil, Mexico and Peru: results from the ImPrEP study

Introduction

The HIV epidemic continues to disproportionately impact Latin‐American transgender women (TGW). We assessed factors associated with long‐term pre‐exposure prophylaxis (PrEP) engagement and adherence among TGW enrolled in the Implementation of PrEP (ImPrEP) study, the largest PrEP demonstration study in Latin America.

Methods

HIV‐negative TGW aged ≥18 years reporting 1+eligibility criteria in the 6 months prior to enrolment (e.g. sex partner known to be living with HIV, condomless anal sex [CAS], transactional sex or having a sexually transmitted infection [STI]) who could safely take PrEP were enrolled. Follow‐up visits were conducted at 4 weeks and then quarterly. We conducted logistic regression to identify factors associated with long‐term PrEP engagement (3+ follow‐up visits in 52 weeks) and complete self‐reported adherence (no missed pills in the past 30 days) during follow‐up. For both outcomes, we constructed multivariable models controlling for country, socio‐demographics, sexual behaviour, substance use, STIs and self‐reported adherence at 4 weeks (long‐term engagement outcome only).

Results

From March 2018 to June 2021, ImPrEP screened 519 TGW, enrolled 494 (Brazil: 190, Mexico: 66 and Peru: 238) and followed them for 52 weeks. At baseline, 27.5% of TGW were aged 18–24 years, 67.8% were mixed‐race and 31.6% had >secondary education. Most, 89.9% reported CAS, 61.9% had >10 sex partners and 71.9% reported transactional sex. HIV incidence was 1.82 cases per 100 person‐years (95% confidence interval [CI]: 0.76–4.38). Almost half of TGW (48.6%) had long‐term PrEP engagement, which was positively associated with reporting complete adherence at week 4 (aOR:2.94 [95%CI:1.88–4.63]) and was inversely associated with reporting CAS with unknown‐HIV partner (aOR:0.52 [95%CI:0.34–0.81]), migration (aOR:0.54 [95%CI:0.34–0.84]), and being from Mexico (aOR:0.28 [95%CI:0.14–0.53]). Self‐reported adherence was associated with TGW aged >34 (aOR:1.61 [95%CI:1.10–2.34]) compared to those aged 25–34 and those with >secondary education (aOR:1.55 [95%CI:1.10–2.19]) and was lower among TGW from Peru (aOR:0.29 [95%CI:0.21–0.41]) or reporting PrEP‐related adverse effects (aOR:0.63 [95%CI:0.42–0.92]).

Conclusions

Although TGW were willing to enrol in ImPrEP, long‐term PrEP engagement and complete self‐reported adherence were limited, and HIV incidence remained relatively high. A successful HIV prevention agenda should include trans‐specific interventions supporting oral PrEP and exploring long‐acting PrEP strategies for TGW.

Impact of feminizing hormone therapy on tenofovir and emtricitabine plasma pharmacokinetics: a nested drug-drug interaction study in a cohort of Brazilian transgender women using HIV pre-exposure prophylaxis

OBJECTIVES

Potential interactions between feminizing hormone therapy (FHT) and pre-exposure prophylaxis (PrEP) may be a barrier to PrEP use among transgender women (TGW). We aimed to assess the impact of FHT on PrEP plasma pharmacokinetics (PK) among TGW.

METHODS

This was a PK substudy of the effects of FHT on tenofovir disoproxil fumarate/emtricitabine nested to a trans-specific PrEP demonstration study (NCT03220152). Participants were assigned to receive PrEP only (noFHT) or standardized FHT (sFHT; oestradiol valerate 2-6 mg plus spironolactone 100-300 mg) plus PrEP for 12 weeks, after which they could start any FHT (aFHT). Short- and long-term PK assessment occurred at Weeks 12 and 30-48, respectively (plasma samples prior and 0.5, 1, 2, 4, 6, 8 and 24 h after dose). Non-compartmental PK parameters of tenofovir and emtricitabine were compared as geometric mean ratios (GMRs) between noFHT and PrEP and FHT (sFHT at short-term PK; aFHT at long-term PK) participants.

RESULTS

No differences in tenofovir and emtricitabine plasma PK parameters were observed between the short-term PK of noFHT (n = 12) and sFHT participants (n = 18), except for emtricitabine Cmax [GMR: 1.15 (95% CI: 1.01-1.32)], or between noFHT short-term PK and aFHT long-term PK (n = 13). Most participants were on oestradiol valerate 2 mg at the short-term PK (56%) and 4 mg at the long-term PK (54%). Median (IQR) oestradiol levels were 56.8 (43.2-65.4) pg/mL at short-term PK (sFHT) and 44.8 (24.70-57.30) pg/mL at long-term PK (aFHT). No participants in this analysis seroconverted during the study.

CONCLUSIONS

Our results indicate no interaction of FHT on tenofovir levels, further supporting PrEP use among TGW using FHT.

Standards of Care for the Health of Transgender and Gender Diverse People, Version 8

Background: Transgender healthcare is a rapidly evolving interdisciplinary field. In the last decade, there has been an unprecedented increase in the number and visibility of transgender and gender diverse (TGD) people seeking support and gender-affirming medical treatment in parallel with a significant rise in the scientific literature in this area. The World Professional Association for Transgender Health (WPATH) is an international, multidisciplinary, professional association whose mission is to promote evidence-based care, education, research, public policy, and respect in transgender health. One of the main functions of WPATH is to promote the highest standards of health care for TGD people through the Standards of Care (SOC). The SOC was initially developed in 1979 and the last version (SOC-7) was published in 2012. In view of the increasing scientific evidence, WPATH commissioned a new version of the Standards of Care, the SOC-8. Aim: The overall goal of SOC-8 is to provide health care professionals (HCPs) with clinical guidance to assist TGD people in accessing safe and effective pathways to achieving lasting personal comfort with their gendered selves with the aim of optimizing their overall physical health, psychological well-being, and self-fulfillment. Methods: The SOC-8 is based on the best available science and expert professional consensus in transgender health. International professionals and stakeholders were selected to serve on the SOC-8 committee. Recommendation statements were developed based on data derived from independent systematic literature reviews, where available, background reviews and expert opinions. Grading of recommendations was based on the available evidence supporting interventions, a discussion of risks and harms, as well as the feasibility and acceptability within different contexts and country settings. Results: A total of 18 chapters were developed as part of the SOC-8. They contain recommendations for health care professionals who provide care and treatment for TGD people. Each of the recommendations is followed by explanatory text with relevant references. General areas related to transgender health are covered in the chapters Terminology, Global Applicability, Population Estimates, and Education. The chapters developed for the diverse population of TGD people include Assessment of Adults, Adolescents, Children, Nonbinary, Eunuchs, and Intersex Individuals, and people living in Institutional Environments. Finally, the chapters related to gender-affirming treatment are Hormone Therapy, Surgery and Postoperative Care, Voice and Communication, Primary Care, Reproductive Health, Sexual Health, and Mental Health. Conclusions: The SOC-8 guidelines are intended to be flexible to meet the diverse health care needs of TGD people globally. While adaptable, they offer standards for promoting optimal health care and guidance for the treatment of people experiencing gender incongruence. As in all previous versions of the SOC, the criteria set forth in this document for gender-affirming medical interventions are clinical guidelines; individual health care professionals and programs may modify these in consultation with the TGD person.

The Effect of Gender-Affirming Hormone Therapy on Measures of Kidney Function: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Gender-affirming hormone therapy modifies body composition and lean muscle mass in transgender persons. We sought to characterize the change in serum creatinine, other kidney function biomarkers, and GFR in transgender persons initiating masculinizing and feminizing gender-affirming hormone therapy.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We searched PubMed, EMBASE, the Cochrane Library, and ClinicalTrials.gov from inception to September 16, 2020 for randomized controlled trials, observational studies, and case series that evaluated the change in serum creatinine, other kidney function biomarkers, and GFR before and after the initiation of gender-affirming hormone therapy in adult transgender persons. Two reviewers independently screened and abstracted data, and disagreements were resolved by a third reviewer. A random effects meta-analysis was performed to determine the change in outcomes over follow-up of 3, 6, and 12 months.

RESULTS

Of the 4758 eligible studies, 26 met the inclusion criteria, including nine studies that recruited 488 transgender men and 593 women in which data were meta-analyzed. There was heterogeneity in study design, populations, gender-affirming hormone therapy routes, and dosing. At 12 months after initiating gender-affirming hormone therapy, serum creatinine increased by 0.15 mg/dl (95% confidence interval, 0.00 to 0.29) in 370 transgender men and decreased by -0.05 mg/dl (95% confidence interval, -0.16 to 0.05) in 361 transgender women. No study reported the effect of gender-affirming hormone therapy on albuminuria, proteinuria, cystatin C, or measured GFR.

CONCLUSIONS

Gender-affirming hormone therapy increases serum creatinine in transgender men and does not affect serum creatinine in transgender women. The effect on gender-affirming hormone therapy on other kidney function biomarkers and measured GFR is unknown.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Change in Kidney Function Biomarkers in Transgender Persons on Gender Affirmation Hormone Therapy-A Systematic Review and Meta-Analysis, CRD42020214248.

Exploring Pre-Exposure Prophylaxis (PrEP) and Post-Exposure Prophylaxis (PEP) Knowledge in Incarcerated Men

People who are incarcerated have a disproportionately high risk of contracting human immunodeficiency virus (HIV). While there is no known cure for HIV, there are biomedical approaches that can successfully manage the virus and prevent its transmission. A total of 267 men who are incarcerated completed a cross-sectional survey focused on cancer health, HIV prevention, and mental health in three state prisons. The mean age was 39 years. The majority had an annual income of US$10,000 or less, self-identified as heterosexual, not married, had children, did not have any military status, and identified as African American/Black. Less than 4% indicated that they had heard about Pre-Exposure Prophylaxis (PrEP), and only 3% had heard of Post-Exposure Prophylaxis (PEP). PrEP and PEP effectively prevent HIV infection, but little attention has focused on increasing the knowledge and awareness of these HIV prevention interventions in the incarcerated population.

One in ten virally suppressed persons with HIV in the Netherlands experiences ≥10% weight gain after switching to TAF and/or INSTI

Background

We determined the frequency of and factors associated with ≥10% weight gain and its metabolic effects in virally suppressed people with HIV (PWH) from the Dutch national ATHENA cohort switching to TAF and/or INSTI.

Methods

We identified ART-experienced, but TAF/INSTI-naïve PWH, who switched to a TAF and/or INSTI-containing regimen whilst virally suppressed for &gt;12 months. Individuals with comorbidities/co-medication associated with weight change were excluded. Analyses were stratified by switch to only TAF, only INSTI or combined TAF + INSTI. Factors associated with ≥10% weight gain were assessed using parametric survival models. Changes in glucose, lipids and blood pressure post-switch were modelled using mixed-effect linear regression and compared between those with and without ≥10% weight gain.

Results

Among 1,544 PWH who switched to only TAF, 2,629 to only INSTI and 918 to combined TAF + INSTI, ≥10% weight gain was observed in 8.8%, 10.6% and 14.4%, respectively. Across these groups, weight gain was more frequent in Western and Sub-Saharan African females than Western males. Weight gain was also more frequent in those with weight loss ≥1 kg/yr before switching, age &lt; 40 years, and those discontinuing efavirenz. In those with ≥10% weight gain, 53.7% remained in the same BMI category, whilst a BMI change from normal/overweight at baseline to obesity at 24 months post-switch was seen in 13.9%, 11.7% and 15.2% of those switching to only TAF, only INSTI and combined TAF + INSTI respectively. PWH with ≥10% weight gain showed significantly larger, but small increases in glucose, blood pressure and lipid levels. Lipid increases were limited to those whose switch included TAF, whereas lipids decreased after switching to only INSTI.

Conclusions

Weight gain of ≥10% after switch to TAF and/or INSTI was common in virally suppressed PWH, particularly in females and those starting both drugs simultaneously. Consequent changes in metabolic parameters were however modest.

Barriers and Facilitators to HIV Pre-Exposure Prophylaxis Uptake, Adherence, and Persistence Among Transgender Populations in the United States: A Systematic Review

HIV pre-exposure prophylaxis (PrEP) is highly effective at preventing HIV; however, PrEP use among transgender individuals remains low. We conducted a systematic review to identify barriers and facilitators to PrEP uptake, adherence, and persistence among transgender individuals in the United States. We conducted a literature search in PubMed and CINAHL databases in March 2021 and followed PRISMA guidelines. Studies were eligible if they were published in a peer-reviewed journal and reported interest, uptake, adherence, and/or persistence of PrEP use among transgender individuals. Articles that did not disaggregate results for transgender participants were excluded. Data from included articles were coded using content analysis and narratively synthesized using a framework matrix. We screened 254 unique articles published after US Food and Drug Administration approval of PrEP, and 33 articles were included in the review. Five themes were identified in the literature, including (1) PrEP concentrations were lower among individuals taking feminizing hormones, but the difference did not appear clinically significant; (2) concerns regarding interactions between gender-affirming hormone therapy and PrEP remain a large barrier; (3) PrEP initiation may facilitate increased self-advocacy and self-acceptance; (4) lack of trust in medical institutions impacts PrEP uptake; and (5) social networks have a significant influence on PrEP knowledge, interest, and adherence. Additional research is needed involving transgender men and nonbinary persons, and efforts to improve PrEP persistence among the transgender community are needed. Training health care providers to provide inclusive and affirming care is perhaps one of the strongest areas for intervention to increase PrEP uptake and persistence.

Improving access to pre-exposure prophylaxis for HIV prescribing in a primary care setting

Although emtricitabine-tenofovir was approved for HIV pre-exposure prophylaxis (PrEP) in 2012, use by persons at risk of acquiring HIV has been limited. Because many primary care providers lacked familiarity and comfort prescribing PrEP, at our institution PrEP prescribing was concentrated among the infectious disease specialists, effectively limiting access. This project sought to increase the number of patients receiving new prescriptions for PrEP. The interventions targeted primary care providers (including internal medicine and family medicine), and were designed to increase the number of unique providers offering PrEP to their patients. The overall strategy was to expand the clinical scope of practice for primary care providers through education and provision of detailed care templates in the electronic health record. These initiatives were implemented through a series of informal Plan-Do-Study-Act cycles, then generalised throughout the medical system. To evaluate the success of the project, we queried the electronic medical record for all new prescriptions for PrEP, with provider name and specialty, for all outpatients 18 years of age and older from 2012 through 2020. In 2015, prior to the intervention, only 78 patients received new prescriptions for PrEP at our institution, and only 38% (30 of 78) of these were from primary care clinicians. After the intervention, the number of patients receiving PrEP increased to 190 in 2019, with 85% (162 of 190) prescribed by primary care providers. In addition, the number of primary care providers making a new prescription for PrEP increased from 20 in 2015 to 73 in 2019. We conclude that targeted clinical education, combined with electronic health record templates, was associated with a significant increase in PrEP prescribing.

Navigating Human Immunodeficiency Virus and Primary Care Concerns Specific to the Transgender and Gender-Nonbinary Population

Human immunodeficiency virus (HIV) prevention and treatment remain critically important to outpatient care among transgender and gender-nonbinary individuals. Epidemiologically, trans men and trans women are significantly more likely to have HIV compared with all adults of reproductive age. Here, we provide an overview of unique primary care considerations affecting transgender and gender-nonbinary individuals, including screening and treatment of HIV and other sexually transmitted infections as well as cancer screening and fertility preservation options. We also seek to review current literature and clinical practice guidelines related to drug–drug interactions between antiretroviral therapy (ART) and gender-affirming hormonal therapy (GAHT). In short, integrase strand transfer inhibitor–based therapy is not expected to have significant drug interactions with most GAHT and is preferred in most transgender individuals, including those on GAHT. Clinicians should also remain aware of current GAHT regimens and consider tailoring ART and GAHT to reduce cardiovascular and other risk factors.

Population pharmacokinetics of tenofovir, emtricitabine and intracellular metabolites in transgender women

Aims

Transgender women (TGW) have been underrepresented in trials and use gender‐affirming hormonal therapies (GAHT) that may alter renal function by significantly increasing creatinine clearance. Population pharmacokinetic (popPK) models and simulations would aid in understanding potential differences in emtricitabine/tenofovir disproxil fumarate (F/TDF) parent–metabolite concentrations in TGW on GAHT when compared to cisgender men (CGM) not exposed to GAHT.

Methods

Pharmacokinetic (PK) data from a Phase 1, open‐label clinical trial with directly observed therapy of daily F/TDF consisting of 8 TGW and 8 CGM was utilized for model building. PopPK analysis was performed using nonlinear mixed effects modelling (NONMEM 7.5.0). Covariates of body weight, creatinine clearance, and gender were evaluated. Final models were subjected to Monte Carlo simulations to compare drug exposure following once daily and on‐demand (IPERGAY 2 + 1 + 1) dosing of F/TDF.

Results

Tenofovir (TFV) and emtricitabine PK were best described by a 2‐compartment model, first‐order absorption/elimination with absorption lag time. Parent models were linked to their metabolites by first order formation and elimination. Creatinine clearance was a significant covariate influencing clearance in both models. Simulations demonstrated that at least 2, weekly 2 + 1 + 1 cycles of on‐demand dosing in TGW on GAHT is necessary for TFV‐diphosphate to reach similar exposure after the initial week of on‐demand dosing in CGM not on GAHT.

Conclusion

PopPK models of TFV, emtricitabine and intracellular metabolites in TGW were established. Dose simulations revealed that TGW should be treated for at least 2 weeks to have comparable exposures to CGM.

Vaginal Microbiota and Mucosal Pharmacokinetics of Tenofovir in Healthy Women Using a 90-Day Tenofovir/Levonorgestrel Vaginal Ring

Background

A relationship between the vaginal microbiota and tenofovir (TFV) concentrations and activity after topical administration has been previously reported.

Objective

CONRAD A15-138 was a randomized, placebo-controlled Phase I study aimed at characterizing the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of TFV and levonorgestrel (LNG) administered through a vaginal ring (IVR) for 90 days. Herein, we describe changes from baseline in the vaginal microbiota with IVR use and the impact of the vaginal microbiota on mucosal TFV PK.

Methods

The study screened 68 participants and randomized 47 (37 TFV/LNG, 10 placebo), assessing the vaginal microbiota by sequencing the V3-V4 regions of 16S rRNA genes prior to IVR insertion and monthly for 3 months. Concentrations of TFV in vaginal fluid (VF), and TFV and TFV-diphosphate (TFV-DP) in vaginal tissue, and modeled PD against HIV-1 in vitro were measured before and after treatment.

Results

There were no clinically significant changes in relative abundance of vaginal bacterial phylotypes from pre-insertion baseline at any month among active and placebo IVR users. There were no significant changes in community state type (CST) with IVR use. Participants with diverse, anaerobic CST IVA/B microbiota had higher in vivo release of TFV from the IVR compared to women with Lactobacillus-dominated (LbD) microbiota, who had expected in vivo TFV release rates. Median VF TFV concentrations were significantly higher among women with CST IVA/B microbiota in months 1 (3,135 ng/mg VF) and 2 (3,800 ng/mg). Women with LbD microbiota had significantly higher median VF TFV concentration (1,423 ng/mg) and median TFV (103 ng/mg) and TFV-DP (5,877 fmol/mg) tissue concentrations versus women with CST IVA/B microbiota at month 3. All women demonstrated a significant increase from pre-insertion baseline of in vitro HIV-1 inhibition by VF (p values <0.05). PD differences in tissue according to CST, however, were not statistically significant.

Conclusion

TFV/LNG IVR use did not change the vaginal microbiota nor increase the incidence of CST IVA/B. Vaginal microbiota, and in particular CST IVA/B, possibly through increased vaginal pH, impacted in vivo TFV release and cervicovaginal (CV) PK, but both PK and PD data suggest CV protection against HIV-1.

Clinical Trial Registration

ClinicalTrials.gov (#NCT03279120).

Similar Sexual Behaviour yet Different Outcomes: Comparing Trans and Gender Diverse and Cis PrEP Users in Germany Based on the Outcomes of the PrApp Study

Little knowledge about pre-exposure prophylaxis (PrEP) use in trans and gender diverse (TGD) communities in Germany exists. The PrApp Study collected data on PrEP use and sexual behaviour among PrEP users in Germany. Descriptive methods and logistic regression were used to describe PrEP use among TGD and cis persons. A total of 4350 PrEP users in Germany were included, with 65 (1.5%) identified as TGD. Compared to cis participants, TGD participants were younger (median age 29 vs. 37 years) and more likely to have a lower income (adjusted odds ratio (aOR) = 4.4; 95% confidence interval (CI) = 2.4–8.2) and be born outside Germany (aOR = 2.5; 95% CI = 1.3–4.5). On-demand PrEP use was higher in TGD participants (aOR = 1.9; 95% CI = 1.0–3.5) and numerically more TGD obtained PrEP from informal sources (aOR = 1.8; 95% CI = 0.9–3.5). Testing behaviour, condom use, and number of sexual partners were comparable between both groups. Socioeconomic disparities may constitute structural barriers for TGD people to access PrEP, leading to more informal and on-demand use. PrEP providers need to reduce access barriers for TGD PrEP users and provide information on safe PrEP use for this population.

“It’s behaviors, not identity”: Attitudes and beliefs related to HIV risk and pre-exposure prophylaxis among transgender women in the Southeastern United States

HIV prevalence is high among transgender women (TGW) in the Southeastern U.S. Uptake of HIV Pre-Exposure Prophylaxis (PrEP) is low among TGW nationwide. We aimed to explore beliefs associated with PrEP among TGW in the Southeastern U.S., framed by the Health Belief Model. HIV-negative TGW ≥18 years old in Alabama participated in virtual focus group discussions. Authors coded and amended transcripts to explore emerging themes. Between July-December 2020, 17 TGW participated in 4 sessions. Mean age was 28.1±8.5 years. Several themes were identified: frustration with conflation of transgender identity and HIV risk, inappropriate transgender representation in PrEP advertising, concerns for interactions between PrEP and hormone therapy, perception that PrEP is meant for cisgender men who have sex with men and limited trans-affirming healthcare. Nuanced messaging is necessary to properly educate and engage TGW in HIV prevention strategies including PrEP given the diversity of this population.

Cardiovascular Disease Risk Among Transgender People with HIV

PURPOSE OF REVIEW

Transgender individuals are at disproportionate risk for HIV infection, with prevalence rates highest among transgender women of color. Antiretroviral therapy (ART)-treated people with HIV (PWH) are at increased risk for cardiovascular disease (CVD), in relation to persistent systemic immune activation and metabolic dysregulation. The purpose of this review is to examine parameters which may affect CVD risk among transgender PWH.

RECENT FINDINGS

Among transgender women and men, prospective longitudinal studies have shown that gender-affirming hormonal therapy (GAHT) is associated with select deleterious cardiometabolic effects such as increases in visceral adipose tissue. Retrospective studies among transgender women and men suggest an increase in CVD risk, such as venous thromboembolism, cerebrovascular accidents, and myocardial infarction. Studies among transgender PWH adhering to GAHT and ART suggest heightened systemic immune activation/inflammation. Prospective longitudinal studies assessing factors associated with increased CVD events among transgender PWH are needed to guide the development of CVD prevention strategies in this at-risk population.

Sex Hormone Therapy and Tenofovir Diphosphate Concentration in Dried Blood Spots: Primary Results of the Interactions Between Antiretrovirals And Transgender Hormones Study

BACKGROUND

Sex hormone and preexposure prophylaxis (PrEP) drug interactions among transgender women (TGW), transgender men (TGM), and cisgender men (CGM) are not fully understood.

METHODS

TGM and TGW on at least 6 months of stable sex hormone therapy containing testosterone or estradiol (respectively) were enrolled in a 4-week study of directly observed dosing of daily oral coformulated emtricitabine and tenofovir disoproxil fumarate (FTC/TDF). TFV-DP in dried blood spots and sex hormones in serum were measured at weekly intervals. TFV-DP was compared with 2- and 4-week samples from Directly Observed Therapy Dried Blood Spots (DOT-DBS) Study (NCT02022657).

RESULTS

From May 2017 to June 2018, 24 TGM and 24 TGW were enrolled. Testosterone (total and free) and estradiol concentrations were comparable before and after 4 weeks of PrEP use in TGM and TGW, respectively. Historical controls included 17 cisgender women (CGW) and 15 CGM. TFV-DP concentrations at week 4 were comparable between TGW and TGM (mean difference, -6%; 95% confidence interval [CI], -21% to 12%; P = .47), comparable between TGW and CGM (mean difference, -12%; 95% CI, -27% to 7%; P = .21) and were lower among TGM compared with CGW (mean difference, -23%; 95% CI, -36% to -7%; P = .007). All persons in all groups were projected to reach the TFV-DP threshold that has been associated with high protection from human immunodeficiency virus.

CONCLUSIONS

CGM, TGM, and TGW had comparable TFV-DP concentrations in dried blood spots after 4 weeks of directly observed daily FTC/TDF PrEP use. Serum hormone concentrations were not affected by FTC/TDF PrEP use.

CLINICAL TRIALS REGISTRATION

NCT04050371.

Global scoping review of HIV prevention research with transgender people: Transcending from trans-subsumed to trans-centred research

INTRODUCTION

Globally, transgender populations are disproportionally impacted by HIV and effective HIV prevention interventions targeting these populations are critically needed. Such interventions require research focused on the specific needs and experiences of transgender people. This methodological review aims to determine the extent to which HIV prevention research has included transgender participants by subsuming them into non-transgender populations, or by centring them either in comparison with other groups or as the sole focus of research.

METHODS

We searched five electronic databases (e.g. SCOPUS) for empirical studies that focused on HIV prevention and included transgender participants, published through 31 December 2020. For each study, we extracted information on: (a) types of inclusion of transgender participants; (b) total sample size and number/percentage of transgender participants; (c) country(ies) where study was conducted; (d) HIV research topics; (e) methods (i.e. quantitative, qualitative or mixed-methods research) and (f) gender identity of transgender participants.

RESULTS AND DISCUSSION

Of 667 HIV prevention studies included in the review, 38.5% subsumed transgender participants into cisgender populations (most frequently combining transgender women with cisgender men who have sex with men), 20.4% compared transgender and cisgender participants and 41.1% focused exclusively on transgender populations. Our global scoping review also revealed that these three types of transgender inclusion in HIV prevention research vary greatly over time, place and thematic areas. Transgender women are the focus of the majority of reviewed studies, whereas transgender men and gender expansive people are rarely included as participants.

CONCLUSIONS

Inclusion of transgender persons as participants in HIV prevention research has significantly increased, particularly in the last decade. Further research centred on transgender participants and their experiences are needed to develop effective HIV prevention interventions for transgender populations. We advocate for HIV prevention research to move from subsuming transgender people, to trans-centred research that asks questions that focus on their specific needs and experiences. We provide recommendations to move from trans-subsumed to trans-centred HIV prevention research.

Higher colorectal tissue HIV infectivity in cisgender women compared with MSM before and during oral preexposure prophylaxis

OBJECTIVE

The objective of this study was to compare HIV-negative cisgender women (CGW) with MSM for mucosal tissue differences in pharmacokinetics, HIV infectivity and cell phenotype.

DESIGN

A substudy of HPTN 069/ACTG A5305, 48-week study of three oral candidate preexposure prophylaxis regimens: maraviroc, maraviroc/emtricitabine and maraviroc/tenofovir disoproxil fumarate (TDF) compared with a TDF/emtricitabine control group.

METHODS

Plasma, peripheral blood mononuclear cells and cervical and colorectal tissue biopsies were collected at Baseline (no drug), Week 24 and 48 (on drug), and Week 49 (1-week postdrug). Drug concentrations were assessed in all matrices. HIV infectivity was assessed using tissue biopsy 'explants' challenged with HIV ex vivo followed by HIV p24 measurement. Flow cytometry evaluated colorectal cell phenotype.

RESULTS

Thirty-seven CGW and 54 MSM participated. CGW's colorectal explant p24 was higher than MSM before (0.31 log10, P = 0.046), during (1.01-1.19 log10, P = 0.016) and one week after (0.61 log10, P = 0.011) study drug dosing. Pooling regimens, cervical explant p24 did not differ among visits. CGW had higher plasma maraviroc and colorectal tissue tenofovir diphosphate and lower colorectal tissue emtricitabine (all P < 0.005) compared with MSM. Each study drug's cervical tissue concentrations were more than 10-fold below paired colorectal concentrations (P < 0.001). Cell phenotype sex differences included 4% higher CD38+/CD8+ cells at baseline and 3-7% higher CD69+/CD8+ cells throughout Weeks 24-49 in CGW compared with MSM (P < 0.05).

CONCLUSION

Colorectal explants in CGW demonstrated greater HIV infectivity than MSM with and without study drugs. Small differences in adherence, drug concentration and colorectal tissue flow cytometry cannot fully explain this difference.

Plasma and intracellular pharmacokinetics of tenofovir disoproxil fumarate and emtricitabine in transgender women receiving feminizing hormone therapy

BACKGROUND

Transwomen have an increased risk of HIV acquisition compared with other adults. Drug-drug interactions between pre-exposure prophylaxis (PrEP) and gender-affirming therapy are cited as a reason for poor PrEP uptake among transwomen. We evaluated plasma tenofovir and emtricitabine pharmacokinetics and their active intracellular anabolites, tenofovir-diphosphate and emtricitabine-triphosphate, in transwomen receiving feminizing hormones.

METHODS

We enrolled HIV-negative transwomen (≥19 years) not receiving PrEP. Participants took oral tenofovir disoproxil fumarate/emtricitabine 300/200 mg daily for 14 days. Plasma was collected at 0 h (pre-dose), 0.5, 1, 2, 3, 4, 6, 8 and 12 h on day 14 post-tenofovir disoproxil fumarate/emtricitabine dose. The plasma AUC0-24 was calculated using the trapezoidal rule and compared with historical HIV-negative cisgender adults as geometric mean ratios (GMRs, 90% CI). Secondarily, tenofovir-diphosphate and emtricitabine-triphosphate from PBMCs collected at 0 h and 12 h were reported descriptively as geometric means (90% CI). Clinical trials registration: NCT03270969.

RESULTS

Among 15 transwomen (mean age 32 years), geometric mean tenofovir and emtricitabine plasma AUC0-24 were lower compared with controls: tenofovir, 2.10 versus 2.76 mg·h/L, GMR 0.76 (0.65-0.90), P = 0.01; emtricitabine, 9.15 versus 10.64 mg·h/L, GMR 0.86 (0.75-0.98), P = 0.07. Tenofovir-diphosphate and emtricitabine-triphosphate concentrations were higher than previously reported in the literature: 167.1 (146.6-190.5) fmol/106 cells and 15.4 (13.8-17.3) pmol/106 cells, respectively.

CONCLUSIONS

We observed lower plasma tenofovir and emtricitabine concentrations in transwomen compared with historical cisgender adults, yet intracellular tenofovir-diphosphate and emtricitabine-triphosphate concentrations were higher than previously reported in PBMCs. Understanding the differences of PrEP pharmacokinetics in plasma and tissue compartments and the resultant impact on efficacy remains important for transwomen.

HIV Pre-exposure Prophylaxis in the LGBTQ Community: A Review of Practice and Places

One in six bisexual and gay men will be diagnosed with HIV in their lifetime (Human Rights Campaign, 2017). Without a vaccine or cure, prevention may be the best tool to control the HIV pandemic. Since 2012, the World Health Organization (WHO) recommends HIV pre-exposure prophylaxis (PrEP) for a high-risk population. To this day, in the United States (U.S.), the group with the highest risk is MSM (men who have sex with other men) that have condom-less sexual intercourse (Center for Disease Control and Prevention, 2019). In fact, in 2018, over 50% of all HIV infections occurred in MSM and members of the LGBT community. A systematic review was conducted using PubMed, Google Scholar, and Cochrane Library. The inclusive criteria were articles published from 2015-2020, focusing specifically on HIV PrEP among the members of the LGBTQ+ community. The keywords for our search were "Pre-exposure prophylaxis," "HIV," "men who have sex with other men" (MSM), "Bisexual," "transgender." A total of 25 articles met the inclusion criteria. About 50% of the articles focused on MSM while others highlighted bisexual and transgender women. Globally, PrEP is a priority. Programs to educate and promote its use are being developed, but challenges are present regarding access to PrEP and its maintenance for longer than 12 months. In the U.S., PrEP programs started in 2012, intending to promote and educate. Research shows that more than 60% of the high-risk patients are willing to try PrEP if they are correctly educated, showing that physicians were not doing a thorough job educating their patients. PrEP is essential for preventing the transmission of HIV among the LGBTQ+ subpopulation. Existing gaps need to be bridged to create or improve to educate high-risk populations and physicians on HIV PrEP.

TransPrEP: Results from the Pilot Study of a Social Network-Based Intervention to Support PrEP Adherence Among Transgender Women in Lima, Peru

We conducted a pilot randomized controlled trial of a social network-based intervention to promote PrEP adherence among transgender women (TW) in Lima, Peru. We enrolled 89 TW from six social networks and cluster-randomized them 1:1 to standard of care (n = 44) or the TransPrEP intervention (n = 45). Core workshops discussed strategies to support PrEP adherence and defined group adherence objectives. Maintenance workshops discussed participants' experiences taking PrEP and collective adherence goals. At 3-month follow-up, we evaluated 40 participants and obtained 29 hair samples for tenofovir level measurements. Though no significant differences were observed, 36.4% (4/11) of participants of TransPrEP participants and 10.0% (1/10) of control participants had tenofovir levels > 0.023 ng/mg, consistent with ≥ 4 doses per week. 81.8% (9/11) of intervention and 40.0% (4/10) of control participants had any detectable tenofovir in their hair. Pilot assessment of our network-based intervention suggested a trend towards improved PrEP adherence, measured objectively, for TW in Peru.

A Review of Recent HIV Prevention Interventions and Future Considerations for Nursing Science

ABSTRACT

As our knowledge of HIV evolved over the decades, so have the approaches taken to prevent its transmission. Public health scholars and practitioners have engaged in four key strategies for HIV prevention: behavioral-, technological-, biomedical-, and structural/community-level interventions. We reviewed recent literature in these areas to provide an overview of current advances in HIV prevention science in the United States. Building on classical approaches, current HIV prevention models leverage intimate partners, families, social media, emerging technologies, medication therapy, and policy modifications to effect change. Although much progress has been made, additional work is needed to achieve the national goal of ending the HIV epidemic by 2030. Nurses are in a prime position to advance HIV prevention science in partnership with transdisciplinary experts from other fields (e.g., psychology, informatics, and social work). Future considerations for nursing science include leveraging transdisciplinary collaborations and consider social and structural challenges for individual-level interventions.

Conference proceedings from the 23rd Bangkok International Symposium on HIV Medicine

The Bangkok International Symposium on HIV Medicine is the longest running HIV conference in the Asia-Pacific, that provides professional healthcare workers with the latest information on HIV and related fields. For the first time, this event was held as a virtual symposium due to the COVID-19 pandemic and registration was free to everyone. More than 1800 people viewed the symposium from 41 countries. The first sessions reviewed COVID-19 and had a panel representing physicians from Australia, Myanmar, Indonesia and Thailand, who shared experiences in managing HIV care during the pandemic. For the first time, we had sessions on the WHO’s vision for integrating HIV care delivery models, and a number of physicians shared the innovative models that have been developed in their clinics.

Preventive efficacy of a tenofovir alafenamide fumarate nanofluidic implant in SHIV-challenged nonhuman primates

Pre-exposure prophylaxis (PrEP) using antiretroviral oral drugs is effective at preventing HIV transmission when individuals adhere to the dosing regimen. Tenofovir alafenamide (TAF) is a potent antiretroviral drug, with numerous long-acting (LA) delivery systems under development to improve PrEP adherence. However, none has undergone preventive efficacy assessment. Here we show that LA TAF using a novel subcutaneous nanofluidic implant (nTAF) confers partial protection from HIV transmission. We demonstrate that sustained subcutaneous delivery through nTAF in rhesus macaques maintained tenofovir diphosphate concentration at a median of 390.00 fmol/106 peripheral blood mononuclear cells, 9 times above clinically protective levels. In a non-blinded, placebo-controlled rhesus macaque study with repeated low-dose rectal SHIVSF162P3 challenge, the nTAF cohort had a 62.50% reduction (95% CI: 1.72% to 85.69%; p=0.068) in risk of infection per exposure compared to the control. Our finding mirrors that of tenofovir disoproxil fumarate (TDF) monotherapy, where 60.00% protective efficacy was observed in macaques, and clinically, 67.00% reduction in risk with 86.00% preventive efficacy in individuals with detectable drug in the plasma. Overall, our nanofluidic technology shows potential as a subcutaneous delivery platform for long-term PrEP and provides insights for clinical implementation of LA TAF for HIV prevention.

Pharmacotherapy considerations in transgender individuals living with human immunodeficiency virus

Pharmacotherapy considerations are often a concern for transgender individuals who are living with human immunodeficiency virus (HIV) due to concerns for drug-drug interactions between their hormone and antiretroviral therapies. Many of the first-line therapies offered to patients for the management of HIV have reduced concerns for safety, resistance, and drug-drug interactions. In this review, we highlight common medications and important considerations for caring for transgender people living with HIV.

Endocrine Management of Transgender Adults: A Clinical Approach

The attention to transgender medicine has changed over the last decade and the interest is most likely going to increase in the future due to the fact that gender-affirming treatments are now being requested by an increasing number of transgender people. Even if gender-affirming hormone therapy (GAHT) is based on a multidisciplinary approach, this review is going to focus on the procedures adopted by the endocrinologist in an out-clinic setting once an adult patient is referred by another specialist for ‘gender affirming’ therapy. Before commencing this latter treatment, several background information on unmet needs regarding medical and surgical outcomes should be investigated. We summarized our endocrinological clinical and therapeutic approaches to adult transgender individuals before and during GAHT based on a non-systematic review. Moreover, the possible relationships between GAHT, gender-related pharmacology, and COVID-19 are also reported.

Management and Prevention of HIV Among Transgender Adults

Transgender individuals face discrimination, violence, social exclusion, and other social, political, and economic factors that result in increased vulnerability to HIV. Rates of viral suppression and uptake of preexposure prophylaxis are lower among transgender individuals than the general population. HIV clinics can help improve these rates by promoting inclusivity and tailoring care to the specific needs of transgender patients. This article summarizes an International Antiviral Society-USA (IAS-USA) webinar presented by Asa E. Radix, MD, PhD, MPH, on August 18, 2020. This webinar is available on demand at https://www.iasusa.org/courses/on-demand-webinar-2020-radix/.