Preference of Oral Tenofovir Disoproxil Fumarate/Emtricitabine Versus Rectal Tenofovir Reduced-Glycerin 1% Gel Regimens for HIV Prevention Among Cisgender Men and Transgender Women Who Engage in Receptive Anal Intercourse with Men

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.

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 topical rectal douche product containing Q-Griffithsin does not disrupt the epithelial border or alter CD4+ cell distribution in the human rectal mucosa

To reduce HIV transmission, locally applied pre-exposure prophylaxis (PrEP) products for anorectal use will be important complements to oral and injectable PrEP products already available. It is critical to preserve an intact rectal epithelium and avoid an influx of mucosal HIV target cells with such product use. In this phase 1 clinical trial, we evaluated application of a topical rectal douche product containing Q-Griffithsin (Q-GRFT). Colorectal tissue samples were obtained via sigmoidoscopy at baseline, 1 and 24 h after single-dose exposure in 15 healthy volunteers. In situ staining for epithelial junction markers and CD4⁺ cells were assessed as an exploratory endpoint. A high-throughput, digitalized in situ imaging analysis workflow was developed to visualize and quantify these HIV susceptibility markers. We observed no significant differences in epithelial distribution of E-cadherin, desmocollin-2, occludin, claudin-1, or zonula occludens-1 when comparing the three timepoints or Q-GRFT versus placebo. There were also no differences in %CD4⁺ cells within the epithelium or lamina propria in any of these comparisons. In conclusion, the rectal epithelium and CD4⁺ cell distribution remained unchanged following topical application of Q-GRFT. In situ visualization of HIV susceptibility markers at mucosal sites could be useful to complement standard product safety assessments.

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)

Efforts to develop a range of HIV prevention products that can serve as behaviorally congruent viable alternatives to consistent condom use and oral pre-exposure prophylaxis (PrEP) remain crucial. MTN-035 was a randomized crossover trial seeking to evaluate the safety, acceptability, and adherence to three placebo modalities (insert, suppository, enema) prior to receptive anal intercourse (RAI). If participants had no RAI in a week, they were asked to use their assigned product without sex. We hypothesized that the modalities would be acceptable and safe for use prior to RAI, and that participants would report high adherence given their behavioral congruence with cleansing practices (e.g., douches and/or enemas) and their existing use to deliver medications (e.g., suppositories; fast-dissolving inserts) via the rectum. Participants (N = 217) were sexual and gender minorities enrolled in five different countries (Malawi, Peru, South Africa, Thailand, and the United States of America). Mean age was 24.9 years (range 18-35 years). 204 adverse events were reported by 98 participants (45.2%); 37 (18.1%) were deemed related to the study products. The proportion of participants reporting "high acceptability" was 72% (95%CI: 65% - 78%) for inserts, 66% (95%CI: 59% - 73%) for suppositories, and 73% (95%CI: 66% - 79%) for enemas. The proportion of participants reporting fully adherent per protocol (i.e., at least one use per week) was 75% (95%CI: 69% - 81%) for inserts, 74% (95%CI: 68% - 80%) for suppositories, and 83% (95%CI: 77% - 88%) for enemas. Participants fully adherent per RAI-act was similar among the three products: insert (n = 99; 58.9%), suppository (n = 101; 58.0%) and enema (n = 107; 58.8%). The efficacy and effectiveness of emerging HIV prevention drug depends on safe and acceptable delivery modalities that are easy to use consistently. Our findings demonstrate the safety and acceptability of, and adherence to, enemas, inserts, and suppositories as potential modalities through which to deliver a rectal microbicide.

Evidence and implication of interventions across various socioecological levels to address pre-exposure prophylaxis uptake and adherence among men who have sex with men in the United States: a systematic review

BACKGROUND

Pre-exposure prophylaxis (PrEP) represents a proven biomedical strategy to prevent HIV transmissions among men who have sex with men (MSM) in the United States (US). Despite the design and implementation of various PrEP-focus interventions in the US, aggregated evidence for enhancing PrEP uptake and adherence is lacking. The objective of this systematic review is to synthesize and evaluate interventions aimed to improve PrEP uptake and adherence among MSM in the US, and identify gaps with opportunities to inform the design and implementation of future PrEP interventions for these priority populations.

METHODS

We followed the PRISMA guidelines and conducted a systematic review of articles (published by November 28, 2021) with a focus on PrEP-related interventions by searching multiple databases (PubMed, MEDLINE, Web of Science and PsycINFO). Details of PrEP interventions were characterized based on their socioecological level(s), implementation modalities, and stage(s) of PrEP cascade continuum.

RESULTS

Among the 1363 articles retrieved from multiple databases, 42 interventions identified from 47 publications met the inclusion criteria for this review. Most individual-level interventions were delivered via text messages and/or apps and incorporated personalized elements to tailor the intervention content on participants' demographic characteristics or HIV risk behaviors. Interpersonal-level interventions often employed peer mentors or social network strategies to enhance PrEP adoption among MSM of minority race. However, few interventions were implemented at the community-, healthcare/institution- or multiple levels.

CONCLUSIONS

Interventions that incorporate multiple socioecological levels hold promise to facilitate PrEP adoption and adherence among MSM in the US given their acceptability, feasibility, efficacy and effectiveness. Future PrEP interventions that simultaneously address PrEP-related barriers/facilitators across multiple socioecological levels should be enhanced with a focus to tackle contextual and structural barriers (e.g., social determinants of health, stigma or medical mistrust) at the community- and healthcare/institution-level to effectively promote PrEP use for MSM of color.

An Open-Label Pharmacokinetic and Pharmacodynamic Assessment of Tenofovir Gel and Oral Emtricitabine/Tenofovir Disoproxil Fumarate

The Microbicide Trials Network-017 study was undertaken to characterize the safety, acceptability, pharmacokinetic (PK), and pharmacodynamic profile of the reduced-glycerin (RG) 1% tenofovir (RG-TFV) gel compared to oral emtricitabine/tenofovir disoproxil fumarate (FTC/TDF). The study was a Phase 2, three-period, randomized sequence, open-label, expanded safety and acceptability crossover study. In each 8-week study period, HIV-1-uninfected participants were randomized to RG-TFV rectal gel daily or RG-TFV rectal gel before and after receptive anal intercourse (RAI) (or at least twice weekly in the event of no RAI), or daily oral FTC/TDF. A mucosal substudy was conducted at sites in the United States and Thailand. Samples were collected to evaluate PK and ex vivo biopsy challenge with HIV-1. A total of 195 men who have sex with men and transgender women were enrolled in the parent study and 37 in the mucosal substudy. As previously reported, both products were found to be safe and acceptable. Systemic TFV concentrations were significantly higher following oral exposure and daily rectal administration compared to RAI-associated product use (p < .001). All three routes of pre-exposure prophylaxis (PrEP) administration resulted in the inhibition of explant infection (p < .05), and there was a significant inverse correlation between explant HIV-1 p24 and tissue concentrations of TFV and FTC (p < .0001). Despite significant differences in systemic and mucosal drug concentrations, all three PrEP regimens were able to protect rectal explants from ex vivo HIV infection. These data suggest that there is a rationale for co-development of oral and topical antiretroviral PrEP for HIV prevention. Clinical Trial Registration number: NCT01687218.

Preference for using a variety of future HIV pre-exposure prophylaxis products among men who have sex with men in three US cities

BACKGROUND

Daily oral pre-exposure prophylaxis (PrEP) is available and recommended for men who have sex with men (MSM) at risk for HIV infection. Other HIV prevention products are being developed, including long-acting injectable (LAI) and event-based oral and topical formulations. Understanding preferences for potential products by MSM can help direct further development of prevention messaging.

METHODS

We present baseline data from HIV-negative participants enrolled in the US Mobile Messaging for Men (M-cubed) Study. Participants were asked their likelihood of and rank order preference for using daily oral PrEP and various potential prevention products (one- to -three-month injections, 2-1-1 sexual event oral dosing, anal or penile gel, or anal suppository), and their sociodemographic characteristics. Bivariate and multivariable logistics regression assessed demographic associations with likelihood of use and rank order preference.

RESULTS

Overall, most MSM reported a likelihood of using LAI (74%), sexual event-based pills (67%) and penile gel (64%). Men who reported recent unprotected (condomless and PrEPless) anal sex most preferred a penile gel formulation (74%), followed closely by LAI and event-based pills (73% each). Current PrEP users (vs. non-users) had greater odds of reporting likelihood to use LAI (AOR = 3.29, 95% CI = 2.12 to 5.11), whereas men reporting recent unprotected anal sex had a greater odds of likelihood to use a penile gel (AOR = 1.79, 95% CI = 1.27 to 2.52) and an anal suppository (AOR = 1.48, 95% CI = 1.08 to 2.02). Hispanic/Latino (vs. White) MSM (AOR = 2.29, 95% CI = 1.40 to 3.73) and, marginally, Black MSM (AOR = 1.54, 95% CI = 1.00 to 2.38) had greater odds of reporting likelihood to use penile gel. Similar patterns were found for rank ordering preference of products, including condoms.

CONCLUSIONS

Most MSM were interested in using various potential future HIV prevention products, especially LAI. However, two typologies of potential users emerged: men who prefer sexual event-based methods (condoms, event-based pill, sexual gels and suppositories) and men who prefer non-sexual event-based methods (daily pill, LAI). Men who reported recent unprotected anal sex preferred a penile gel product most, followed closely by sexual event-based pills and LAI. Racial/ethnic differences were noted as well. These findings on product preferences can help in formulation development and messaging.

Brief Report: Routine Use of Oral PrEP in a Phase 2 Rectal Microbicide Study of Tenofovir Reduced-Glycerin 1% Gel (MTN-017)

BACKGROUND

As daily oral preexposure prophylaxis (PrEP) becomes standard for HIV prevention, routine use of PrEP is likely to increase within clinical trials of novel preventive agents. We describe the prevalence and characteristics of participants reporting nonstudy oral PrEP use within Microbicide Trials Network-017 (MTN-017), a phase 2 trial of a rectal microbicide.

SETTING AND METHODS

One hundred ninety-five HIV-uninfected men who have sex with men and transgender women were enrolled and followed in MTN-017 across 8 sites in the United States, Thailand, South Africa, and Peru from 2013 to 2015. Nonstudy oral PrEP use was recorded on case report forms and progress notes. Characteristics of PrEP users and non-PrEP users were compared using tests of statistical significance.

RESULTS

Overall, 11% of participants reported nonstudy oral PrEP use, all from the San Francisco (SF) site, accounting for 58% (22/38) of participants enrolled in SF. There was a higher median number of sex partners reported in the past 8 weeks before enrollment among oral PrEP users vs. nonusers (7 vs. 2, P = 0.02). Most PrEP users (18/22, 82%) began PrEP treatment during screening/after enrollment, and most (19/22, 86%) decided to continue oral PrEP after study completion.

CONCLUSION

Nonstudy oral PrEP use in the first phase 2 study of tenofovir reduced-glycerin 1% gel was high at a single site in SF where community PrEP availability and use was expanding. Investigators should consider the evolving context of nonstudy oral PrEP use across trial sites when designing and interpreting trials of novel biomedical prevention modalities.

Topical Microbicides in HIV Prevention: State of the Promise

HIV topical microbicides are products with anti-HIV activity, generally incorporating a direct-acting antiretroviral agent, that when applied to the vagina or rectum have the potential to prevent the sexual acquisition of HIV in women and men. Topical microbicides may meet the prevention needs of individuals and groups for whom oral daily forms of pre-exposure prophylaxis (PrEP) have not been acceptable. Microbicides can provide personal control over HIV prevention and offer the possibility of discreet use, qualities that may be particularly important for receptive partners in sexual relationships such as women and transgender women and men, who together account for the clear majority of new HIV infections worldwide. Although the promise of such a product emerged nearly three decades ago, proof of concept has been demonstrated only within the last decade. A robust pipeline of microbicidal gels, films, inserts, and rings has been evaluated in multiple studies among at-risk women and men, and refinement of products for ease of use, reversibility, and high safety is the priority for the field.

Meeting the Sexual Health Needs of Bisexual Men in the Age of Biomedical HIV Prevention: Gaps and Priorities

The field of HIV/STI prevention has primarily focused on gay men (or "men who have sex with men" [MSM] as a broad category) with limited attention to bisexual men in particular. Although bisexual men are also at increased risk for HIV and other STI, they are less likely to utilize HIV/STI prevention services than gay men, and very few interventions have been developed to address their unique needs. Further, while biomedical advances are changing the field of HIV prevention, bisexual men are also less likely to use biomedical HIV prevention strategies (e.g., pre-exposure prophylaxis [PrEP]) than gay men. In an effort to advance research on bisexual men and their sexual health needs, the goals of this commentary are: (1) to review the empirical literature on the prevalence of HIV/STI among bisexual men, the few existing HIV/STI prevention interventions developed for bisexual men, and the use of biomedical HIV prevention among bisexual men; (2) to describe the ways in which the field of HIV/STI prevention has largely overlooked bisexual men as a population in need of targeted services; and (3) to discuss how researchers can better address the sexual health needs of bisexual men in the age of biomedical HIV prevention.

Meeting the Sexual Health Needs of Bisexual Men in the Age of Biomedical HIV Prevention: Gaps and Priorities

The field of HIV/STI prevention has primarily focused on gay men (or "men who have sex with men" [MSM] as a broad category) with limited attention to bisexual men in particular. Although bisexual men are also at increased risk for HIV and other STI, they are less likely to utilize HIV/STI prevention services than gay men, and very few interventions have been developed to address their unique needs. Further, while biomedical advances are changing the field of HIV prevention, bisexual men are also less likely to use biomedical HIV prevention strategies (e.g., pre-exposure prophylaxis [PrEP]) than gay men. In an effort to advance research on bisexual men and their sexual health needs, the goals of this commentary are: (1) to review the empirical literature on the prevalence of HIV/STI among bisexual men, the few existing HIV/STI prevention interventions developed for bisexual men, and the use of biomedical HIV prevention among bisexual men; (2) to describe the ways in which the field of HIV/STI prevention has largely overlooked bisexual men as a population in need of targeted services; and (3) to discuss how researchers can better address the sexual health needs of bisexual men in the age of biomedical HIV prevention.

Rectal Douching Practices Associated with Anal Intercourse: Implications for the Development of a Behaviorally Congruent HIV-Prevention Rectal Microbicide Douche

Tenofovir administration via rectal douching results in higher rectal-mucosa drug concentration than oral administration. Many who engage in receptive anal intercourse (RAI) use cleansing rectal douches. To inform development of a behaviorally-congruent tenofovir douche, 4751 individuals ≥ 18 years-old, born male, from all US states/territories, who engaged in anal intercourse responded to an online survey. Of those who reported RAI in the prior 3 months, 80% douched beforehand, 82% within 1 h, mean 2.9 consecutive applications; 27% douched afterwards, 83% within 1 h, mean 1.7 consecutive applications. Among multidose users, 78% applied doses within 2 min, and 76% retained liquid < 1 min. Most used tap water (89%) in an enema bottle (50%) or rubber bulb (43%), and douched for cleanliness (97%), to avoid smelling bad (65%), and to enhance pleasure (24%). 98% reported high likelihood of using an HIV-prevention douche. An ideal product will protect within a user's typical number of applications, within 1 h, and be dissolvable in tap water.

Pre-exposure prophylaxis for HIV prevention preferences among young adult African American men who have sex with men

Pre-exposure prophylaxis (PrEP) is effective in preventing HIV infections among men who have sex with men (MSM). PrEP uptake and adherence remain low and product preferences are unknown, especially among young African American MSM who are most at-risk. We conducted 26 qualitative interviews from 2014-2016 among young adult HIV-negative African American MSM regarding PrEP product preferences in Missouri. While the pill and injectable were most liked of all modalities, about a quarter preferred rectal products or patches. Most participants preferred a long-acting injectable (LAI) to daily oral pills due to better medication adherence and a dislike for taking pills. Many participants preferred daily oral pills to on-demand oral PrEP due to the inability to predict sex and the perception that insufficient time or medication would not achieve HIV protection with on-demand. A fear of needles and the perception that there would not be therapeutic levels for a long duration were concerns with injectable PrEP. Study findings highlight the need for a range of prevention options for African American MSM and can inform PrEP product development as well as dissemination and implementation efforts.

HIV Antiretroviral Pre-Exposure Prophylaxis: Development Challenges and Pipeline Promise

The US Food and Drug Administration (FDA) approved oral daily tenofovir/emtricitabine (Truvada) for pre-exposure prophylaxis of human immunodeficiency virus (HIV) infection in 2012 on the basis of two randomized controlled trials (RCTs), one in men who have sex with men (MSM) and another in HIV serodiscordant heterosexual couples. Subsequently, even greater efficacy has been demonstrated in MSM with rapid population-level incidence reductions in some locations. In contrast, studies of antiretroviral pre-exposure prophylaxis (PrEP) in heterosexual women showed only modest or no efficacy, largely attributed to low adherence. The mixed results of antiretroviral-based PrEP bear witness to unique drug development challenges at this complicated intersection of sexual behavior, public health, and drug development. Multiple innovative methods and formulation strategies followed to address unmet medical needs of persons struggling with daily oral PrEP adherence or preference for nonsystemic PrEP options. Clinical pharmacology plays essential roles throughout this PrEP development process, especially in early product development and through pharmacologically informed enhancement and interpretation of clinical trials.

Trajectory of use over time of an oral tablet and a rectal gel for HIV prevention among transgender women and men who have sex with men

We examined product adherence among 187 men who have sex with men and transgender women enrolled in a phase II, crossover trial comparing safety and acceptability of an oral tablet and a rectal gel used daily for HIV prevention. Participants reported adherence via daily text messages during 8-week periods. Trajectory analysis identified weekly patterns. Polytomous logistic regression identified characteristics associated with higher probability of trajectory group membership. We identified 3 groups per product: high-adherers (72% daily oral, 70% daily gel); decreasing-adherers (20% daily oral, 22% daily gel); and low-adherers (8% daily oral, 9% daily gel). Daily oral high-adherers (compared with low-adherers) were more likely to self-identify as male (OR = 4.76, 95% CI:1.35-16.67), to have more sexual partners (OR = 1.67, 95% CI:1.04-2.63), and to find the tablet easy to swallow (OR = 2.22, 95% CI:1.08-4.76). Daily gel high-adherers (compared with low-adherers) were more likely to be older (OR = 1.16, 95% CI:1.05-1.28), to find gel application easier at the last few applications (OR = 2.27, 95% CI:1.01-5.00), and to report a change in routine if gel was not used (OR = 5.26, 95% CI:1.23-100.00). Characteristics of participants likely to be high-adherers to product use vary according to product. Evaluation of acceptability prior to phase II/III trials could identify participants likely to maintain high adherence.

Factors Supporting and Hindering Adherence to Rectal Microbicide Gel Use with Receptive Anal Intercourse in a Phase 2 Trial

Adherence to product use in biomedical HIV prevention trials is essential to success. In MTN-017, a Phase 2 rectal microbicide gel trial, participants discussed applicator-inserted gel use in the context of receptive anal intercourse (RAI) with adherence counselors. We analyzed counseling session data to identify barriers to and facilitators of gel use for 26 participants in the United States who used gel with RAI as their first of three study regimens. The most common barriers were finding the gel application process cumbersome, physical discomfort after applying gel, difficulty with BAT-24 dosage regimen, and negative effects of gel on sex. The most common facilitators were incorporating gel use into routines, using gel in anticipation of sex, carrying gel when going out, reminders received via short message service, and ease of gel use. These findings can inform product development and future adherence counseling interventions for rectal gel trials to improve adherence outcomes.