Acceptability of potential rectal microbicide delivery systems for HIV prevention: a randomized crossover trial

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 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).

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.

Acceptability of PC-1005 Gel Administered Rectally to HIV-1 Seronegative Adults at Three Different Volume Levels (MTN-037)

Multipurpose prevention technologies (MPT) have been increasingly researched for their dual-purpose preventative properties against HIV and other STIs. The acceptability of PC-1005, a topical MPT candidate, was explored among men and women participating in the MTN-037 Phase I trial at two U.S. sites (Pittsburgh, PA, and Birmingham, AL). We triangulated quantitative and qualitative assessments of the acceptability of three volumes (4 mL, 16 mL, 32 mL) of PC-1005 administered rectally (N = 12; 6 males, 6 females). Participants rated overall gel acceptability on a scale of 1-10, with a median of 7.17 (SD = 2.04) and had positive feelings about all three dose volumes, citing them to be very comfortable or comfortable (dose 1 = 91.7%; dose 2 = 91.7%; dose 3 = 83.3%). High acceptability of and comfort with all three dose volumes shows promise for PC-1005 as an MPT to prevent HIV and STIs, warranting future clinical development.

Overcoming COVID-19 disruptions: Innovations in product provision in a multi-national clinical trial among cisgender men, transgender men and transgender women in five countries

Clinical trials often depend on participants receiving study product to meet objectives of the protocol. Vitally important are considerations for how sites receive and dispense study product during a study while ensuring appropriate handling, accountability and compliance. The process for provision of study product is detailed in Standard Operating Procedures (SOPs) which are adhered to by the research site throughout the trial. The COVID-19 pandemic unexpectedly affected the ability of study participants to receive study product. We report on the various methods implemented by trial sites to ensure timely provision of study product to participants during this unprecedented pandemic. In MTN-035, participants received 3 potential rectal microbicide formulations in randomized sequences to understand user preferences. Trial sites were permitted to revise dispensing methods to enable participants to continue to receive study product during COVID-19 restrictions. These actions mitigated disruption of study product administration and preserved the integrity of the trial. Out of the 78 participants expecting to receive study products on or after the onset of restrictions due to COVID-19, only four participants (5%) did not receive all three products. Adopting alternative methods to provide product to study participants in extraordinary circumstances was key to successful study completion and maintaining study integrity.

Preferences for Long-Acting and Alternative Modalities for PrEP among Military Men Who Have Sex with Men: Segmentation Results of an Adaptive Choice-Based Conjoint Analysis Study

The use of pre-exposure prophylaxis (PrEP) for HIV prevention within the U.S. military is low. Implementing preference-based alternative modalities of PrEP delivery, however, can be an innovative strategy to address the specific barriers to PrEP uptake among military MSM. We sought to identify population-based, segment-specific preferences for longer-acting and alternative PrEP delivery modalities to guide patient-centered strategies to optimize uptake within military-serving healthcare systems. HIV-negative military men who have sex with men (MSM) completed an anonymous, adaptive choice-based conjoint (ACBC) analysis survey consisting of five key attributes of interest (dosing method, provider type, visit location, lab work evaluation location, and dispensing venue). Relative importance and part-worth utility scores were generated using Hierarchical Bayes (HB) estimation, and cluster ensemble analysis grouped participants into "phenotype" segments by preference similarity. The randomized first-choice model was then used to examine changes in program interest rates among segments through market simulation. The 429 participants were segmented into five preference groups. The dosing method attribute was found to be the most important to nearly all segments. Simulations revealed that PrEP program interest among two segments with low interest levels increased when smartphone, civilian-based, and long-acting injectable PrEP options were involved. Findings also suggested a need for clinics to be responsive and sensitive to sexual practices, risk perception, and functional PrEP knowledge. Responsiveness to segment-specific preferences in the design of military PrEP programs and acting on the importance of clinical relationships within the context of PrEP engagement within a military setting may contribute to increasing PrEP uptake.

Designing Dual Compartment HIV Prevention Products: Women's Sensory Perceptions and Experiences of Suppositories for Rectal and Vaginal Use

Dual compartment suppositories are being developed to prevent HIV and other sexually transmitted infections. Such products, for use in the rectum, the vagina, or both, could have a significant public health impact by decreasing global incidence of these diseases. In this study, 16 women each used two rheologically distinct suppositories in their vagina and rectum. User Sensory Perception and Experience (USPE) scales assessed sensory experiences during sexual activity to understand whether, and how, women perceive formulation properties in the vagina and rectum. Qualitative data from individual in-depth interviews captured women's descriptions and comparisons of the experiences. Significant differences and large Cohen's d effect sizes between vaginal and rectal experiences of suppository-A were found for three scales: Application (APP): Product Awareness, SEX: Initial Penetration; and SEX: Effortful. Qualitative data provided user experience details that credibly align with these score differences. Near significant differences and large effect sizes were found for two additional scales: SEX: Perceived Wetness with suppository-A and SEX: Messiness with suppository-B. In addition, other scale scores showed medium-to-large effect sizes that correspond to hypothesized sensations associated with biophysical properties of the suppositories. Statistical significance combined with large effect sizes and qualitative data accurately represent the hypothesized perceptibility of suppository properties and identifies performance characteristics relevant to acceptability and adherence; together these data provide discernment of factors that can guide the development of dual compartment products. The Clinical Trial Registration number: NCT02744261.

Preferences for pre-exposure prophylaxis among U.S. military men who have sex with men: results of an adaptive choice based conjoint analysis study

BACKGROUND

Pre-exposure prophylaxis (PrEP) prevents human immunodeficiency virus (HIV) infection, but its use remains low among U.S. military men who have sex with men (MSM), likely due to mis-matching with personal preferences. We conducted a study to characterize preferences to PrEP measures within this population.

METHODS

HIV-negative military MSM were recruited through a closed, Lesbian, Gay, Bisexual, and Transgendered (LGBT) military social media group. The survey was anonymous, and consisted of five experimentally varied attributes in service delivery: dosing method, provider type, visit location, lab work evaluation location, and dispensing venue. Relative importance and part-worth utility scores were generated using hierarchical bayes (HB) estimation, and the randomized first choice model was used to examine participation interest across eight possible PrEP program scenarios.

RESULTS

A total of 429 participants completed the survey. Among the eight scenarios with varying attributes, the most preferred scenario featured a daily tablet, PrEP injection or implant, along with a military provider, smartphone/telehealth visit, and on-base locations for lab evaluation and medication pick-up. The results also emphasized the importance for providers to be familiar with PrEP prescription knowledge, and to provide interactions sensitive to sexual identity and mental health.

CONCLUSION

A PrEP program consisting of daily tablet is preferred in military healthcare settings is preferred. Long-acting implants and injections are also desired.

The Impact of Advertisement Messaging on Enrollment of Young Men Who Have Sex With Men for Web-Based Research: Observational Study

Background

Recruiting young men who have sex with men (YMSM) in community settings is difficult. The use of Web-based social networks and dating apps for recruitment can be successful approaches, although little work has been done on the impact of study advertisement content on recruitment.

Objective

The aim of this study was to evaluate the effects of advertisement message content on the recruitment of YMSM (aged 18-26 years) for a Web-based focus group study, examining perspectives and preferences for a mobile app that was designed to support sexual health among YMSM.

Methods

Between March and April 2017, a recruitment campaign to promote human papillomavirus vaccination was launched on a popular social networking and dating app for YMSM, with 3 different text-based advertisement themes (technology, cancer prevention, and sexual innuendo). The campaign recruited YMSM across 3 states (Massachusetts, New York, and Pennsylvania). We examined the click-through rates, conversion rates, and enrollment rates of each of the advertisements and examined differences in views and clicks by age, state, and time of day.

Results

The sexual innuendo advertisement had the highest click rates when compared with both the technology (click rate ratio [CRR] 2.06, 95% CI 1.74-2.45) and cancer prevention (CRR 1.62, 95% CI 1.38-1.90) advertisements. The sexual innuendo advertisement also had higher study enrollment rates compared with the technology (CRR 1.90, 95% CI 1.23-2.83) and cancer prevention (CRR 2.06, 95% CI 1.37-3.13) advertisements. No differences were observed in clicks or enrollment by age, state, or time of day.

Conclusions

Our marketing campaign, targeting YMSM, was effective in recruiting participants for a qualitative study, using Web-based focus groups. The sexual innuendo advertisement was the most effective and cost-efficient advertisement of the 3 approaches trialed. Different populations need different targeted strategies for study recruitment. Researchers should work with key representatives to develop and test culturally relevant messaging and approaches that utilize current and popular technologies.

Transcutaneously refillable nanofluidic implant achieves sustained level of tenofovir diphosphate for HIV pre-exposure prophylaxis

Pre-exposure prophylaxis (PrEP) with antiretroviral (ARV) drugs are effective at preventing human immunodeficiency virus (HIV) transmission. However, implementation of PrEP presents significant challenges due to poor user adherence, low accessibility to ARVs and multiple routes of HIV exposure. To address these challenges, we developed the nanochannel delivery implant (NDI), a subcutaneously implantable device for sustained and constant delivery of tenofovir alafenamide (TAF) and emtricitabine (FTC) for HIV PrEP. Unlike existing drug delivery platforms with finite depots, the NDI incorporates ports allowing for transcutaneous refilling upon drug exhaustion. NDI-mediated drug delivery in rhesus macaques resulted in sustained release of both TAF and FTC for 83 days, as indicated by concentrations of TAF, FTC and their respectively metabolites in plasma, PBMCs, rectal mononuclear cells and tissues associated with HIV transmission. Notably, clinically relevant preventative levels of tenofovir diphosphate were achieved as early as 3 days after NDI implantation. We also demonstrated the feasibility of transcutaneous drug refilling to extend the duration of PrEP drug delivery in NHPs. Overall, the NDI represents an innovative strategy for long-term HIV PrEP administration in both developed and developing countries.

On-demand microbicide products: design matters

Sexual intercourse (vaginal and anal) is the predominant mode of human immunodeficiency virus (HIV) transmission. Topical microbicides used in an on-demand format (i.e., immediately before or after sex) can be part of an effective tool kit utilized to prevent sexual transmission of HIV. The effectiveness of prevention products is positively correlated with adherence, which is likely to depend on user acceptability of the product. The development of an efficacious and acceptable product is therefore paramount for the success of an on-demand product. Acceptability of on-demand products (e.g., gels, films, and tablets) and their attributes is influenced by a multitude of user-specific factors that span behavioral, lifestyle, socio-economic, and cultural aspects. In addition, physicochemical properties of the drug, anatomical and physiological aspects of anorectal and vaginal compartments, issues relating to large-scale production, and cost can impact product development. These factors together with user preferences determine the design space of an effective, acceptable, and feasible on-demand product. In this review, we summarize the interacting factors that together determine product choice and its target product profile.

Designing and developing suppository formulations for anti-HIV drug delivery

Despite a long history of use for rectal and vaginal drug delivery, the current worldwide market for suppositories is limited primarily due to a lack of user acceptability. Therefore, virtually no rational pharmaceutical development of antiviral suppositories has been performed. However, suppositories offer several advantages over other antiviral dosage forms. Current suppository designs have integrated active pharmaceutical ingredients into existing formulation designs without optimization. As such, emerging suppository development has been focused on improving upon the existing classical design to enhance drug delivery and is poised to open suppository drug delivery to a broader range of drugs, including antiretroviral products. Thus, with continuing research into rational suppository design and development, there is significant potential for antiretroviral suppository drug delivery.

Patterns of a Rectal Microbicide Placebo Gel Use in a Preparatory Stage for a Phase I Trial Among Young Men Who Have Sex with Men

We examined young gay, bisexual, and other men who have sex with men's (YGBMSM) usage patterns of a pre-coital, applicator-administered rectal placebo gel. An ethnically diverse sample of 94 YGBMSM (aged 18-30 years) were asked to insert hydroxyethylcellulose placebo gel rectally before receptive anal intercourse (RAI) and report their gel use through an interactive voice response system (IVRS) across 12 weeks. We used trajectory analyses to characterize participants' use of the rectal gel over the 12 weeks, and examine whether these trajectories varied based on participants' sociodemographic characteristics, sexual behaviors, application and insertion behaviors, and experiences using the placebo gel. A cubic model was the best fit for these longitudinal data, with two distinct trajectories of gel use observed. The first trajectory ('High with Varying Gel Use per Week') represented YGBMSM (N = 38; 40.3%) who reported using the rectal gel on several occasions per week. The second trajectory ('Low and Consistent Gel Use per Week') represented participants (N = 56; 59.7%) who reported a consistent average use of one gel per week. Participants in the High with Varying Gel Use Trajectory reported trying out a greater number of positions when inserting the gel across the 12-weeks than peers in the Low and Consistent Gel Use Trajectory. YGBMSM reporting more RAI occasions during the trial were more likely be present in the High with Varying Gel Use Trajectory than peers in the Low and Consistent Gel Use Trajectory. Future research examining how to facilitate gel application and adherence among YGBMSM is merited.

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

Oral pre-exposure prophylaxis (PrEP) can prevent HIV transmission. Yet, some may prefer not to take systemic daily medication. MTN-017 was a 3-period, phase 2 safety and acceptability study of microbicide gel applied rectally either daily or before and after receptive anal intercourse (RAI), compared to daily oral tablet. At baseline, cisgender men and transgender women who reported RAI (N = 187) rated the daily oral regimen higher in overall liking, ease of use, and likelihood of future use than the gel regimens. After trying all three, 28% liked daily oral the least. Gel did not affect sexual enjoyment (88%) or improved it (7-8%). Most partners had no reaction to gel use. Ease of gel use improved significantly between the first and the last few times of daily use. A rectal gel used before and after RAI may constitute an attractive alternative to daily tablet. Experience with product use may increase acceptability.

"Like Holding an Umbrella Before It Rains": Acceptability of Future Rectal Microbicides Among Men Who Have Sex With Men in India-A Modified Technology Acceptance Model

Topical rectal microbicides (RMs) are a new prevention technology in development that aims to reduce the risk of HIV acquisition from anal sex. We examined RM acceptability among men who have sex with men (MSM) in India. We conducted a qualitative exploratory study guided by a modified Technology Acceptance Model, with 10 focus groups ( n = 61) of MSM and 10 key informant interviews. Data were explored using framework analysis. RM acceptability was influenced by technological contexts: perceived usefulness of RMs, perceived ease of use of RM and applicator, and habits around condom and lubricant use; individual and interpersonal contexts: perceived relevance and preferences for product formulation and dosing frequency; and MSM community/social contexts: perceived social approval, RM-related stigma, social support. Implementation of RMs for MSM in India may be supported by multi-level interventions that engage community-based organizations in destigmatizing and distributing RMs, ideally gel-based products that enable on-demand use before sex.

Lessons for Rectal Microbicide Development From an Acceptability Trial of a Placebo Gel Applied Prior to Receptive Anal Intercourse

Rectal microbicides, formulated as a gel to be applied before and/or after intercourse, are promising HIV prevention agents and are now in Phase II trials. However, both an optimal formulation and a practical delivery system are needed to ensure that the target population will use the product once efficacy is demonstrated. The precise dynamics of lubricant application by gay and bisexual men who practice anal sex and the qualities they seek in these products are underexplored. As part of a Phase I microbicide acceptability and adherence study conducted in one Puerto Rican and two continental U.S. cities, we recruited 124 young men who have sex with men (YMSM) with a history of unprotected receptive anal intercourse (RAI) and provided them with 40 rectal applicators containing a placebo gel to use prior to RAI during a 12-week period as a proxy for an eventual rectal microbicide. Ninety-five YMSM completed the trial. Their varied preferences as to product viscosity, durability, residue, and mode of application provide important lessons for the design of a product that will be satisfactory to users. Despite many reservations, the participants used the product frequently and found ways to overcome a range of obstacles. A successful rectal microbicide product may need to be presented in a range of viscosities to attract a broad client base.

Patients' appropriateness, acceptability, usability and preferences for pharmaceutical preparations: Results from a literature review on clinical evidence

Patients play an important role in achieving the desired therapeutic outcomes, as they are frequently responsible for their own medication management. To facilitate drug administration and overcome medication issues, the patients' needs and preferences should be considered in the pharmaceutical drug product design. With the aim to evaluate the current state of evidence for patient appropriateness, acceptability, usability and preference for aspects of this design, a literature search was performed. Comparative clinical studies that assessed such endpoints for different patient populations were included and summarized descriptively. The search identified 45 publications that met the inclusion criteria. A detailed analysis of the studies identified two main areas investigating either packaging design (n=10) or dosage form design (n=35). Studies on packaging design showed preferences for wing top and screw cap openings, push-through blisters and suppositories with slide system. Additionally, child-resistant containers should be avoided concerning specific patient populations. Regarding dosage form design, sprinkles and minitablets were the most preferred in studies involving young patients, while preferences varied considerably depending on route of administration and geographical region in studies with adult patients. Review of the methodology used in the studies revealed that ten studies had used well-defined protocols and observational endpoints to investigate patient appropriateness. Studies focusing on methodology for testing the appropriateness and usability of drug products by patients were not found. In conclusion, more interdisciplinary scientific efforts are required to develop and increase research in understanding patient needs and preferences.

Rectal Douching Prevalence and Practices Among Peruvian Men Who have Sex with Men and Transwomen: Implications for Rectal Microbicides

Peruvian men who have sex with men (MSM) and transwomen (TW) could benefit from a rectal microbicide (RM) formulated as a rectal douche to prevent HIV infection. However, little is known about rectal douching practices among Peruvian MSM and TW, information necessary to inform RM douche development and future uptake. Using a self-administered interview, we examined the prevalence of and factors associated with rectal douching among a convenience sample of 415 Peruvian MSM and 68 TW. In the previous 6 months, 18 % of participants reported rectal douching using pre-filled commercial kits or plastic bottles or enema bags filled with water, water/soap or saltwater. Multivariate logistic analysis found that "equally insertive and receptive" or "exclusively/mainly receptive" sex roles were associated with douche use. Rectal douching among Peruvian MSM and TW is similar to reports from other studies and supports the potential uptake of a douche-formulated RM in these populations.

Acceptability and Preferences for Hypothetical Rectal Microbicides among a Community Sample of Young Men Who Have Sex with Men and Transgender Women in Thailand: A Discrete Choice Experiment

Rectal microbicides (RMs) may offer substantial benefits in expanding HIV prevention options for key populations. From April to August 2013, we conducted Tablet-Assisted Survey Interviewing, including a discrete choice experiment, with participants recruited from gay entertainment venues and community-based organizations in Chiang Mai and Pattaya, Thailand. Among 408 participants, 74.5 % were young men who have sex with men, 25.5 % transgender women, with mean age = 24.3 years. One-third (35.5 %) had ≤9th grade education; 63.4 % engaged in sex work. Overall, 83.4 % reported they would definitely use a RM, with more than 2-fold higher odds of choice of a RM with 99 versus 50 % efficacy, and significantly higher odds of choosing gel versus suppository, intermittent versus daily dosing, and prescription versus over-the-counter. Sex workers were significantly more likely to use a RM immediately upon availability, with greater tolerance for moderate efficacy and daily dosing. Engaging key populations in assessing RM preferences may support biomedical research and evidence-informed interventions to optimize the effectiveness of RMs in HIV prevention.

Using conjoint analysis to determine the impact of product and user characteristics on acceptability of rectal microbicides for HIV prevention among Peruvian men who have sex with men

OBJECTIVES

Men who have sex with men (MSM) are in need of novel and acceptable HIV prevention interventions. In Peru, a Phase II clinical trial was recently completed evaluating rectally applied tenofovir gel among Peruvian MSM and transgender women. If deemed safe and acceptable, the product could move into efficacy testing, but acceptability data for similar products are needed now in order to prepare for future implementation. Peru is in need of expanded, national acceptability data among likely users.

METHODS

Using conjoint analysis of an online cross-sectional survey taken by 1008 Peruvian MSM and transgender women, we tested the acceptability of eight hypothetical rectal microbicide (RM) products comprising six, dual-value attributes. We also assessed the relationship of select product attributes with sample characteristics.

RESULTS

Highest acceptability was found for a RM that was 90% effective, used before and after sex, without side effects, costing approximately $0.30, had no prescription requirement and had a single-use applicator. Product effectiveness and presence of side effects were the factors most likely to drive RM acceptance and use. Education, sexual orientation, sexual role and concern for HIV infection were also related to aspects of RM acceptability.

CONCLUSION

RM acceptability was high, confirming the results of earlier, smaller studies and placing confidence in the acceptability of RMs. Analysis of the relationships with product attributes and sample characteristics underscore the need to consider the impact of factors such as sexual orientation, sexual role, level of education and concern for HIV acquisition on RM acceptability.

Formulation and delivery of anti-HIV rectal microbicides: advances and challenges

Men and women engaged in unprotected receptive anal intercourse (RAI) are at higher risk of acquiring HIV from infected partners. The implementation of preventive strategies is urgent and rectal microbicides may be a useful tool in reducing the sexual transmission of HIV. However, pre-clinical and first clinical trials have been able to identify limitations of candidate products, mostly related with safety issues, which can in turn enhance viral infection. Indeed, the development of suitable formulations for the rectal delivery of promising antiretroviral drugs is not an easy task, and has been mostly based on products specifically intended for vaginal delivery, but these have been shown to provide sub-optimal outcomes when administered rectally. Research and development in the rectal microbicide field are now charting their own path and important information is now available. In particular, specific formulation requirements of rectal microbicide products that need to be met have just recently been acknowledged despite additional work being still required. Desirable rectal microbicide product features regarding characteristics such as pH, osmolality, excipients, dosage forms, volume to be administered and the need for applicator use have been studied and defined in recent years, and specific guidance is now possible. This review provides a synopsis of the field of rectal microbicides, namely past and ongoing clinical studies, and details on formulation and drug delivery issues regarding the specific development of rectal microbicide products. Also, future work, as required for the advancement of the field, is discussed.

Rectal-specific microbicide applicator: evaluation and comparison with a vaginal applicator used rectally

An applicator designed for rectal delivery of microbicides was tested for acceptability by 95 young men who have sex with men, who self-administered 4 mL of placebo gel prior to receptive anal intercourse over 90 days. Subsequently, 24 of the participants self-administered rectally 4 mL of tenofovir or placebo gel over 7 days using a vaginal applicator, and compared both applicators on a Likert scale of 1-10, with 10 the highest rating. Participants reported high likelihood to use either applicator in the future (mean scores 9.3 and 8.8 respectively, p = ns). Those who tested both liked the vaginal applicator significantly more than the rectal applicator (7.8 vs. 5.2, p = 0.003). Improvements in portability, conspicuousness, aesthetics, tip comfort, product assembly and packaging were suggested for both. This rectal-specific applicator was not superior to a vaginal applicator. While likelihood of future use is reportedly high, factors that decrease acceptability may erode product use over time in clinical trials. Further attention is needed to develop user-friendly, quick-acting rectal microbicide delivery systems.

Commercial lubricant use among HIV-negative men who have sex with men in Los Angeles: implications for the development of rectal microbicides for HIV prevention

To inform the development and assess potential use of rectal microbicide gels for HIV prevention among men who have sex with men (MSM), we examined the dynamics and contexts of commercial lubricant use during receptive anal intercourse (RAI) within this population. From 2007 to 2010, 168 HIV-negative MSM living in Los Angeles who practice RAI completed computer-assisted self-interviews, which collected information on their last sexual event with ≤3 recent partners, at baseline, three months, and one-year study visits. Logistic generalized linear mixed models were used to identify individual- and sexual event-level characteristics associated with commercial lubricant use during RAI at the last sexual event within 421 partnerships reported by participants over the course of follow-up. During RAI at their last sexual event, 57% of partnerships used a condom and 69% used commercial lubricant. Among partnerships that used commercial lubricant, 56% reported lubricant application by both members of the partnership, 66% first applied lubricant during sex, but before penetration, and 98% applied lubricant at multiple locations. The relationship between substance use and commercial lubricant use varied by condom use (interaction p-value = 0.01). Substance use was positively associated with commercial lubricant use within partnerships that did not use condoms during RAI at their last sexual event (AOR = 4.47, 95% [corrected] [CI]: 1.63-12.28), but no association was observed within partnerships that did use condoms (AOR = 0.66, 95% CI: 0.23-1.85). Commercial lubricant use during RAI was also positively associated with reporting more sexual partners (AOR = 1.18, 95% CI: 1.05-1.31), while older age (units = 5 years; AOR = 0.75, 95% CI: 0.61-0.94), homelessness (past year; AOR = 0.32, 95% CI: 0.13-0.76), and having sex with an older (>10 years) partner (AOR = 0.37, 95% CI: 0.14-0.95) were negatively associated with commercial lubricant use. These factors should be considered in the development of rectal microbicide gels to enhance their acceptability and use among MSM.

Preparing for rectal microbicides: sociocultural factors affecting product uptake among potential South American users

OBJECTIVES

We examined views on rectal microbicides (RMs), a potential HIV prevention option, among men who have sex with men and transgender women in 3 South American cities.

METHODS

During September 2009 to September 2010, we conducted 10 focus groups and 36 in-depth interviews (n = 140) in Lima and Iquitos, Peru, and Guayaquil, Ecuador, to examine 5 RM domains: knowledge, thoughts and opinions about RM as an HIV prevention tool, use, condoms, and social concerns. We coded emergent themes in recorded and transcribed data sets and extracted representative quotes. We collected sociodemographic information with a self-administered questionnaire.

RESULTS

RM issues identified included limited knowledge; concerns regarding plausibility, side effects, and efficacy; impact on condom use; target users (insertive vs receptive partners); and access concerns.

CONCLUSIONS

Understanding the sociocultural issues affecting RMs is critical to their uptake and should be addressed prior to product launch.

The development of rectal microbicides for HIV prevention

INTRODUCTION

Individuals practicing unprotected receptive anal intercourse are at particularly high risk of HIV infection. Men who have sex with men in the developed and developing world continue to have disproportionate and increasing levels of HIV infection. The last few years have seen important progress in demonstrating the efficacy of oral antiretroviral pre-exposure prophylaxis, vaginal microbicides, and treatment as prevention, but there has also been significant progress in the development of rectal microbicides for HIV prevention.

AREAS COVERED

The purpose of this review is to summarize the status of rectal microbicide research and to identify opportunities, challenges, and future directions in this important field of HIV prevention research. The design of completed and ongoing Phase I rectal microbicide studies that include the generation of comprehensive pharmacokinetic/pharmacodynamic data may allow for more rational decisions about which rectal microbicides should be advanced to later stage development.

EXPERT OPINION

There is a strong rationale for the development of rectal microbicides for HIV prevention. Preclinical data provide supportive evidence for the feasibility of this approach, and there is significant interest in rectal microbicide development from communities at risk of HIV acquisition through unprotected receptive anal intercourse in both the developed and developing world. Demonstration of sustained safety, acceptability, and product adherence in the MTN-017 Phase II study of tenofovir 1% gel will be an important step in rectal microbicide development and will hopefully lead to Phase III effectiveness testing of this novel HIV prevention strategy.

Rectal pre-exposure prophylaxis (PrEP)

Rectal pre-exposure prophylaxis (PrEP) will be a critical component of HIV prevention products due to the prevalence of unprotected receptive anal intercourse among men who have sex with men and heterosexual couples. Given the biological considerations of this compartment and the complexity of HIV infection, design of a successful rectal microbicide product faces a number of challenges. Important information is being compiled to begin to address deficits in knowledge toward design of rectal PrEP products for men and women. Aspects of formulation development and preclinical and clinical evaluation of rectal products studied to date are summarized in this review. This article is based on a presentation at the "Product Development Workshop 2013: HIV and Multipurpose Prevention Technologies," held in Arlington, Virginia on February 21-22, 2013. It forms part of a special supplement to Antiviral Research.

Rectal douching and implications for rectal microbicides among populations vulnerable to HIV in South America: a qualitative study

OBJECTIVE

While gel-formulated rectal microbicides (RM) are the first to enter clinical trials, rectal douching in preparation for anal intercourse is a common practice; thus RMs formulated as douches may be a convenient alternative to gels. Nonetheless, little is known about potential users' thoughts regarding douche-formulated RMs or rectal douching practices, data that is needed to inform the advancement of douche-based RMs. This qualitative study examined thoughts regarding douches, their use as an RM and current douching practices among men who have sex with men and transgender women.

METHODS

12 focus groups and 36 in-depth interviews were conducted (N=140) to examine the overall acceptability of RM, of which one component focused on rectal douching. Focus groups and interviews were recorded, transcribed verbatim and coded; text relating to rectal douching was extracted and analysed. Sociodemographic information was collected using a self-administered questionnaire.

RESULTS

Support for a douche-formulated RM centred on the possibility of combined precoital hygiene and HIV protection, and it was believed that a deeply penetrating liquid douche would confer greater HIV protection than a gel. Drawbacks included rectal dryness, impracticality and portability issues, and potential side effects. Non-commercial douching apparatus use was common and liquids used included detergents, vinegar, bleach, lemon juice and alcohol.

CONCLUSIONS

A douche-formulated RM, while desirable and perceived as more effective than a gel-formulated RM, also generated questions regarding practicality and side effects. Of immediate concern were the non-commercial liquids already being used that likely damage rectal epithelia, potentially increasing HIV infection risk. Precoital rectal douching is common and an RM formulated as such is desirable, but education on rectal douching practices is needed now.