A randomized trial of safety, acceptability and adherence of three rectal microbicide placebo formulations among young sexual and gender minorities who engage in receptive anal intercourse (MTN-035)

A Phase 1 Clinical Trial to Assess the Safety and Pharmacokinetics of a Tenofovir Alafenamide/Elvitegravir Insert Administered Rectally for HIV Prevention

BACKGROUND

On-demand topical products could be an important tool for human immunodeficiency virus (HIV) prevention. We evaluated the safety, pharmacokinetics, and ex vivo pharmacodynamics of a tenofovir alafenamide/elvitegravir (TAF/EVG, 20 mg/16 mg) insert administered rectally.

METHODS

MTN-039 was a phase 1, open-label, single-arm, 2-dose study. Blood, rectal fluid, and rectal tissue were collected over 72 hours following rectal administration of 1 and 2 TAF/EVG inserts for each participant.

RESULTS

TAF/EVG inserts were safe and well tolerated. EVG and tenofovir (TFV) were detected in blood plasma at low concentrations: median peak concentrations after 2 inserts were EVG 2.4 ng/mL and TFV 4.4 ng/mL. Rectal tissue EVG peaked at 2 hours (median, 2 inserts = 9 ng/mg) but declined to below limit of quantification in the majority of samples at 24 hours, whereas tenofovir diphosphate (TFV-DP) remained high >2000 fmol/million cells for 72 hours with 2 inserts. Compared to baseline, median cumulative log10 HIV p24 antigen of ex vivo rectal tissue HIV infection was reduced at each time point for both 1 and 2 inserts (P < .065 and P < .039, respectively).

DISCUSSION

Rectal administration of TAF/EVG inserts achieved high rectal tissue concentrations of EVG and TFV-DP with low systemic drug exposure and demonstrable ex vivo inhibition of HIV infection for 72 hours. Clinical Trials Registration . NCT04047420.

Acceptability of a rectal microbicide douche for HIV prevention: a mixed-methods analysis of a first-in-human formulation pilot study

OBJECTIVES

DREAM-01 was an open label, dose-escalation and variable osmolarity study to identify a tenofovir HIV-prevention douche/enema that could achieve protective colon tissue cell concentrations and high acceptability. To assess impact on sexual enjoyment, iso-osmolar and hypo-osmolar placebo douches were provided for at-home use before receptive anal sex (RAS).

METHODS

Eighteen HIV-uninfected men who have RAS were administered three tenofovir douches at the research clinic: Product A, an iso-osmolar dose; Product B, an iso-osmolar escalation dose; and Product C, a hypo-osmolar escalation dose. Following Products A and C, participants were given a saline douche of matching osmolarity to use at home before RAS. Participants reported acceptability via a computer-assisted self-interview and in-depth interview in this mixed-methods study.

RESULTS

All three products were rated acceptable by 17 (95%) of the participants. A majority (94%) would be likely or very likely to use any of the three products before RAS. Of those who used the saline douches before RAS and then rated their sexual enjoyment, most reported that their sexual enjoyment was not affected. Interview data revealed that participants found the product easy to incorporate into their regular routine, but would prefer to use more liquid for cleansing.

CONCLUSIONS

These findings indicate that the hypo-osmolar Product C, which also provides the most rapid delivery of tenofovir for HIV prevention, is acceptable for future safety trials and that our sample reports high likelihood of using a rectal microbicide douche for HIV prevention. Our findings support continued pursuit of a tenofovir rectal microbicide douche.

TRIAL REGISTRATION NUMBER

NCT02750540.

History of Rectal Product Use and Country of Residence Influence Preference for Rectal Microbicide Dosage Forms Among Young Sexual and Gender Minorities: A Multi-country Trial Comparing Placebo Douche, Suppository, and Insert Products

The DESIRE Study (MTN-035) explored product preference among three placebo rectal microbicide (RM) formulations, a rectal douche (RD), a suppository, and an insert, among 210 sexually active transgender people and men who have sex with men in five counties: the United States, Peru, Thailand, South Africa, and Malawi. Participants used each product prior to receptive anal sex (RAS) for 1 month, following a randomly assigned sequence, then selected their preferred product via computer assisted self-interview. In-depth interviews examined reasons for preference. We compared product preference and prior product use by country to explore whether geographic location and experience with the similar products impacted preference. A majority in the United States (56%) and Peru (58%) and nearly half in South Africa (48%) preferred the douche. Most in Malawi (59%) preferred the suppository, while half in Thailand (50%) and nearly half in South Africa (47%) preferred the insert. Participants who preferred the douche described it as quick and easy, already routinized, and serving a dual purpose of cleansing and protecting. Those who preferred the insert found it small, portable, discreet, with quick dissolution. Those who preferred the suppository found the size and shape acceptable and liked the added lubrication it provided. Experience with product use varied by country. Participants with RD experience were significantly more likely to prefer the douche (p = 0.03). Diversifying availability of multiple RM dosage forms can increase uptake and improve HIV prevention efforts globally.

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.

A conjoint experiment of three placebo rectal products used with receptive anal sex: results from MTN-035

INTRODUCTION

End-user perspectives are vital to the design of new biomedical HIV prevention products. Conjoint analysis can support the integration of end-user perspectives by examining their preferences of potential pre-exposure prophylaxis (PrEP) products. The Microbicides Trial Network (MTN) 035 protocol examined three placebo rectal dosage forms (insert, enema and suppository) that could deliver PrEP prior to receptive anal sex (RAS).

METHODS

Between April 2019 and July 2020, we enrolled 217 HIV-negative, cisgender men who have sex with men (MSM; n = 172; 79.3%) and transgender people (n = 47; 20.7%) ages 18-35 into a randomized cross-over trial across Malawi, Peru, South Africa, Thailand and the United States. Participants used each product prior to RAS over 4-week periods. Participants completed a conjoint experiment where they selected between random profiles using seven features (dosage form, timing of use before sex, side effects, duration of protection, effectiveness, frequency of use and need for a prescription).

RESULTS

Effectiveness was the strongest determinant of choice (30.4%), followed by modality (18.0%), potential side effects (17.2%), frequency of use (10.8%), duration of protection (10.4%), timing of use before sex (7.4%) and need for a prescription (5.9%). Relative utility scores indicated that the most desirable combination of attributes was a product with 95% efficacy, used 30 minutes before sex, offering a 3- to 5-day protection window, used weekly, having no side effects, in the form of an enema and available over-the-counter.

CONCLUSIONS

Choice in next-generation PrEP products is highly desired by MSM and transgender people, as no one-size-fits-all approach satisfies all the preferences. MTN-035 participants weighed product features differently, recognizing the need for diverse, behaviourally congruent biomedical options that fit the needs of intended end-users.

A latent trajectory analysis of young sexual and gender minorities' adherence to three rectal microbicide placebo formulations (MTN-035; a randomized crossover trial)

BACKGROUND

Rectal microbicides (RM) are biomedical HIV prevention products that aim to prevent or reduce the transmission of HIV and other sexually transmitted infections (STIs). RM modalities may be beneficial for populations who have complex lifestyles, difficulties adhering to pre-exposure prophylaxis (PrEP) regimens, and/or have limited access to care. MTN-035 (DESIRE; Developing and Evaluating Short-Acting Innovations for Rectal Use), a randomized crossover trial, aimed to evaluate the safety and acceptability of, and adherence to, three placebo RM modalities (douche, insert, and suppository) prior to receptive anal intercourse.

METHODS

We conducted latent trajectory analysis to identify clusters of individuals who shared similar trajectories in acceptability and adherence for each product (douche, insert, and suppository) over time. We analyzed weekly short messaging service (SMS) use reports for each modality as reported by enrolled sexual and gender minority (SGM) participants.

RESULTS

Two trajectories for each product were identified: a "protocol compliant" trajectory (i.e., at least one product use occasion per week) and "high use" trajectory (i.e., more than three product use occasions per week). Participants with high use were more likely to lack access to PrEP and have higher intentions to utilize RM modalities compared to those who were protocol compliant.

CONCLUSIONS

This study highlighted high adherence to RM modalities among SGM. As research into viable HIV prevention modalities continues to evolve, tailored intervention strategies are needed to support the uptake of and adherence to alternative prevention modalities that are behaviorally congruent with targeted users.

TRIAL REGISTRATION

NCT03671239 (14/09/2018).