Vaginal ring adherence in sub-Saharan Africa: expulsion, removal, and perfect use

Engineering vaginal film platform for mucoadhesion and sustained drug release for HIV-1 prevention

User adherence contributes to the effectiveness of topical pre-exposure prophylactic products designed to protect against human immunodeficiency virus type 1 (HIV-1) infection. Long-acting approaches that do not require daily or coitally-dependent use could potentially improve user adherence. This study aims to develop a long-acting vaginal film to deliver an integrase inhibitor, MK-2048, for prevention of HIV-1 infection. To this end, a film platform fabricated with thiolated chitosan and poly(lactide-co-Ɛ-caprolactone) (PLACL) was designed to achieve long residence time and sustained drug release profile, respectively. A series of PLACLs were synthesized with different lactic acid (LA) to caprolactone (CL) ratios and were chemically and thermally characterized. Films containing thiolated chitosan and PLACL copolymers were manufactured using solvent-casting and characterized for their physicochemical properties. The in vitro release of MK-2048 formulated in thiomer PLACL films was tested. The lead film composed of thiomers and PLACL 80 showed comparable elasticity with the marketed VCF® film (vaginal contraceptive film) and slower drug release rate compared to other compositions. The tissue mucoadhesion and permeability of MK-2048 were significantly improved by incorporation of thiolated chitosan in the film matrix. Importantly, the film showed no evidence of toxicity in excised human ectocervical tissue and demonstrated comparable anti-HIV activity as free MK-2048. The lead film evaluated in pigtail macaques showed drug concentrations above the IC95 (41 nM) in vaginal fluids and tissues for a period of at least 2 weeks, with no evidence of toxicity. Overall, these in vitro and in vivo studies demonstrate that this strategy can be applied to rationally develop polymeric film platforms that can sustain drug release in vivo, potentially improving user adherence.

Feasibility, safety and tolerability of estrogen and/or probiotics for improving vaginal health in Canadian African, Caribbean, and Black women: A pilot phase 1 clinical trial

BACKGROUND

A dysbiotic vaginal microbiome (VMB) is associated with clinical conditions such as bacterial vaginosis (BV) and an increased risk of human immunodeficiency virus (HIV-1) infection. Considering the high prevalence of BV among African, Caribbean and Black (ACB) women, we conducted a prospective, randomized, open-label phase 1 clinical trial to determine the feasibility, safety and tolerability of administering low-dose estrogen, probiotics or both in combination to improve vaginal health and decrease HIV-1 susceptibility.

METHODS

ACB women aged 18-49 from the Greater Toronto Area (GTA) were randomized to one of four study arms: intravaginal estradiol (Estring©; 7.5mg/day); a vaginal probiotic (RepHresh™ Pro-B™) administered twice daily; a combination of Estring© and vaginal RepHresh™ Pro-B™ (twice daily); or the Estring© and oral RepHresh™ Pro-B™ (twice daily), for a duration of 30 days. Feasibility was evaluated through enrolment, retention, and adherence rates, while safety and tolerability were determined by a pre- and post-treatment blood panel and reported adverse events (AEs).

RESULTS

Overall, 63 ACB women were screened, 50 were enrolled and received the intervention while 41 completed the study, resulting in 80% enrollment and 82% retention rates. Overall adherence to the study protocol was high at 93%, with an adherence of 92% for RepHresh™ Pro-B™ and 97% for Estring©. A total of 88 AEs were reported by 29 participants which were mild (66/88; 75%) and largely resolved (82/88;93%) by the end of the study, with no serious AEs (SAEs) noted. In addition, a panel of safety blood markers measured pre- and post-intervention confirmed no clinically significant changes in blood chemistry or blood cell count.

CONCLUSION

Overall, the administration of intravaginal estrogen and/or probiotics in pre-menopausal ACB women is feasible, safe, and well tolerated.

TRIAL REGISTRATION

The trial was registered with Clinicaltrials.gov (NCT03837015) and CIHR HIV Clinical Trials (CTN308).

Efficacy of the Dapivirine Vaginal Ring Accounting for Imperfect Adherence

Product adherence is critical to obtaining objective estimates of efficacy of pre-exposure prophylactic interventions against HIV-1 infection. With imperfect adherence, intention-to-treat analyses assess the collective effects of complete, sub-optimal and non-adherence, providing a biased and attenuated estimate of the average causal effect of an intervention. Using data from the MTN-020/ASPIRE phase III trial evaluating HIV-1 efficacy of the dapivirine vaginal ring, we conducted per-protocol, and adherence-adjusted causal inference analyses using principal stratification and marginal structural models. We constructed two adherence cut offs of ≥ 0.9 mg (low cutoff) and > 4.0 mg (high cutoff) that represent drug released from the ring over a 28-day period. The HIV-1 efficacy estimate (95% CI) was 30.8% (3.6%, 50.3%) (P = 0.03) from the per-protocol analysis, and 53.6% (16.5%, 74.3%) (P = 0.01) among the highest predicted adherers from principal stratification analyses using the low cutoff. Marginal structural models produced efficacy estimates (95% CIs) ranging from 48.8 (21.8, 66.4) (P = 0.0019) to 56.5% (32.8%, 71.9%) (P = 0.0002). Application of adherence-adjusted causal inference methods are useful in interpreting HIV-1 efficacy in secondary analyses of PrEP clinical trials.

High adherence to intermittent and continuous use of a contraceptive vaginal ring among women in a randomized controlled trial in Kigali, Rwanda

Background

The introduction of female-initiated drug-delivery methods, including vaginal rings, have proven to be a promising avenue to address sexually transmitted infections and unintended pregnancies, which disproportionally affects women and girls in sub-Saharan Africa. Efficient uptake of existing and new technologies such as vaginal rings requires in depth understanding of product adherence. This remains a major challenge as data on adherence to vaginal rings from African countries is limited. In this study, we explored adherence of contraceptive vaginal ring (NuvaRing®) use in Kigali, Rwanda using a mixed methods approach.

Methods

We collected quantitative and qualitative data at multiple time points from women participating in a clinical trial exploring the safety and acceptability of either intermittent or continuous use of the NuvaRing®. Various adherence categories were used including monthly and cumulative adherence measurement. The quantitative data were analysed using R and the qualitative data were analysed using a deductive, content-analytical approach based on categories related to the quantitative adherence measures. All data were compared and triangulated.

Results

Data from 120 enrolled participants showed that self-reported adherence was high at every study visit in both study groups. At first study visit 80% of the intermittent ring users and 79.7% of the continuous ring users reported perfect adherence (assessed as "the ring was never out"). Reporting of ring expulsions and removals were highest (28.3%) at the beginning of the trial. Self-reported perfect ring adherence increased during the study and reports of ring expulsions and removals declined as familiarity with this contraceptive method increased. The percentage of women with perfect cumulative adherence was non-significantly higher in the intermittent (61.7%) than in the continuous use group (54.3%). The low rate of discrepant adherence data after triangulation (6%) is in line with the perception of the participants as adherent throughout the study.

Conclusions

Self-reported adherence in both study groups was high with removals and expulsions being within the expected product range. Comprehensive adherence data triangulation allowed for a deeper understanding of context-driven behaviour that shaped adherence patterns and challenges. Our data categorisation and triangulation approach has shown potential for implementation in future vaginal ring studies aiming to better understand and measure adherence.

Advances in long-acting slow effective release antiretroviral therapies for treatment and prevention of HIV infection

Adherence to daily oral antiretroviral therapy (ART) is a barrier to both treatment and prevention of human immunodeficiency virus (HIV) infection. To overcome limitations of life-long daily regimen adherence, long-acting (LA) injectable antiretroviral (ARV) drugs, nanoformulations, implants, vaginal rings, microarray patches, and ultra-long-acting (ULA) prodrugs are now available or in development. These medicines enable persons who are or at risk for HIV infection to be treated with simplified ART regimens. First-generation LA cabotegravir, rilpivirine, and lenacapavir injectables and a dapivirine vaginal ring are now in use. However, each remains limited by existing dosing intervals, ease of administration, or difficulties in finding drug partners. ULA ART regimens provide an answer, but to date, such next-generation formulations remain in development. Establishing the niche will require affirmation of extended dosing, improved access, reduced injection volumes, improved pharmacokinetic profiles, selections of combination treatments, and synchronization of healthcare support. Based on such needs, this review highlights recent pharmacological advances and a future treatment perspective. While first-generation LA ARTs are available for HIV care, they remain far from ideal in meeting patient needs. ULA medicines, now in advanced preclinical development, may close gaps toward broader usage and treatment options.

Randomized, placebo controlled phase I trial of the safety, pharmacokinetics, pharmacodynamics and acceptability of a 90 day tenofovir plus levonorgestrel vaginal ring used continuously or cyclically in women: The CONRAD 138 study

Multipurpose prevention technologies (MPTs), which prevent sexually transmitted infection(s) and unintended pregnancy, are highly desirable to women. In this randomized, placebo-controlled, phase I study, women used a placebo or tenofovir (TFV) and levonorgestrel (LNG) intravaginal ring (IVR), either continuously or cyclically (three, 28-day cycles with a 3 day interruption in between each cycle), for 90 days. Sixty-eight women were screened; 47 were randomized to 4 arms: TFV/LNG or placebo IVRs used continuously or cyclically (4:4:1:1). Safety was assessed by adverse events and changes from baseline in mucosal histology and immune mediators. TFV concentrations were evaluated in multiple compartments. LNG concentration was determined in serum. Modeled TFV pharmacodynamic antiviral activity was evaluated in vaginal and rectal fluids and cervicovaginal tissue ex vivo. LNG pharmacodynamics was assessed with cervical mucus quality and anovulation. All IVRs were safe with no serious adverse events nor significant changes in genital tract histology, immune cell density or secreted soluble proteins from baseline. Median vaginal fluid TFV concentrations were >500 ng/mg throughout 90d. TFV-diphosphate tissue concentrations exceeded 1,000 fmol/mg within 72hrs of IVR insertion. Mean serum LNG concentrations exceeded 200 pg/mL within 2h of TFV/LNG use, decreasing quickly after IVR removal. Vaginal fluid of women using TFV-containing IVRs had significantly greater inhibitory activity (87-98% versus 10% at baseline; p<0.01) against HIV replication in vitro. There was a >10-fold reduction in HIV p24 antigen production from ectocervical tissues after TFV/LNG exposure. TFV/LNG IVR users had significantly higher rates of anovulation, lower Insler scores and poorer/abnormal cervical mucus sperm penetration. Most TFV/LNG IVR users reported no change in menstrual cycles or fewer days of and/or lighter bleeding. All IVRs were safe. Active rings delivered high TFV concentrations locally. LNG caused changes in cervical mucus, sperm penetration, and ovulation compatible with contraceptive efficacy. Trial registration: ClinicalTrials.gov #NCT03279120.

Patterns of Adherence to a Dapivirine Vaginal Ring for HIV-1 Prevention Among South African Women in a Phase III Randomized Controlled Trial

BACKGROUND

Persistent use of HIV prevention methods can be a challenge, particularly for some younger women. The long-acting, discreet, woman-centric dapivirine vaginal ring offers promise as a prevention method with less user burden, which could support continued use. We assessed dapivirine vaginal ring use to understand adherence patterns and identify characteristics influencing patterns.

SETTING

Participants enrolled in South Africa in the MTN-020/ASPIRE randomized placebo-controlled trial.

METHODS

We used group-based trajectory modeling to identify clusters of participants with similar longitudinal patterns of adherence in the last year of participation and potential predictors of group membership. Women with at least 1 year of follow-up were included (n = 626).

RESULTS

Five adherence patterns were identified: (1) consistently high, 34%, (2) consistently moderate, 34%, (3) consistently low, 16%, (4) decreasing, 9%, and (5) increasing, 7%. Women younger than 22 years [adjusted odds ratio (AOR) 1.8, 95% confidence interval (CI): 1.0 to 3.0], using an intrauterine device (AOR 3.3, 95% CI: 1.4 to 7.8) or oral contraceptives (AOR 3.9, 95% CI: 1.7 to 8.9), experiencing menses (AOR 1.8, 95% CI: 1.1 to 3.0), and who reported inconsistent condom use (AOR 1.8, 95% CI: 1.0 to 3.3) were more likely to be classified as consistently low compared to consistently high (referent).

CONCLUSIONS

Most South African women successfully persisted with a moderate or high level of use. Encouraging ring replacement with completion of menses may help to decrease concerns about hygiene and improve persistence. Associations between contraception and persistent low adherence suggest efforts may be needed to ensure contraceptive method choice does not interfere with ring use.

Acceptability and Preference for 3-Month Versus 1-Month Vaginal Rings for HIV-1 Risk Reduction Among Participants in a Phase 1 Trial

Background: The monthly dapivirine vaginal ring provides partial protection against HIV, and a longer duration ring may reduce user burden and improve adherence. We examined acceptability and preference for 3-month versus 1-month rings for HIV-1 risk reduction in a phase 1 clinical trial. Materials and Methods: In Microbicide Trials Network-036/International Partnership for Microbicides 047, 49 HIV-negative participants aged 18-45 were randomized to one of two 3-month rings or the 1-month ring. Acceptability ratings were collected at enrollment, week 4, and study exit (week 13). At exit, ring preference was assessed quantitatively among all participants and a randomly selected subset of 24 participants completed in-depth interviews. Quantitative and qualitative findings were integrated to explore factors influencing acceptability and preference. Results: Acceptability of each ring was initially moderate and increased during the trial. Ratings were lower in the 3-month ring arms than the 1-month arm at each time point, including baseline. Most participants (34/47; 72%) preferred a 3-month ring at exit; however, this proportion was significantly lower within some subgroups characterized by site, education, race/ethnicity, and experiences with ring use. Qualitative interviews revealed reservations about hygiene and safety of the 3-month ring, including discomfort with use during menses, but these were usually outweighed by its increased convenience. Conclusions: Both ring durations were highly acceptable at study exit. Although most participants preferred a 3-month ring, preference was more divided in certain subgroups, highlighting the benefit of offering different duration options. Providing additional support to address concerns about hygiene and safety may improve acceptability of a 3-month vaginal ring.

Vaginal ring acceptability: A systematic review and meta-analysis of vaginal ring experiences from around the world

OBJECTIVE

The vaginal ring (ring) is a female-initiated, long-acting drug delivery system for different indications, including HIV prevention. Our aim was to provide evidence for acceptability of the vaginal ring across indications to support dapivirine and multipurpose prevention technology ring introduction and roll out.

STUDY DESIGN

This systematic review and meta-analysis followed PRISMA guidelines. We searched PubMed, Web of Science, Embase, and grey literature for publications reporting favorable ring acceptability and secondary outcomes involving actual ring use (comfort, ease of ring use, ring comfort during sex, expulsions, and vaginal symptoms) or hypothetical acceptability for any indication published January 1, 1970-June 15, 2021. We estimated random-effects pooled prevalence, assessing between-study variation using meta-regression.

RESULTS

Of 2,234 records, we included 123 studies with 40,434 actual and hypothetical ring users. The primary outcome assessment included 50 studies with 60 ring subgroups totaling 19,271 ring users. The favorable acceptability pooled prevalence was 85.6% (95%CI 81.3, 89.0), while hypothetical acceptability among non-ring users was 27.6% (95%CI 17.5, 40.5). In meta-regression, acceptability was higher in menopause (95.4%; 95%CI 88.4, 98.2) compared to contraceptive rings (83.7%; 95%CI 75.6, 89.5). Acceptability was lower in pharmacokinetic studies (50%; 95%CI 22.1, 77.9) compared to RCTs (89.5%; 95%CI 85.8.92.4) and in studies assessing acceptability at ≥12 months (78.5%; 95%CI 66.5, 87.1) versus studies assessing acceptability at <3 months (91.9%; 95%CI 83.7, 96.1). European (90.6%; 95%CI 83.9, 94.7), Asian (97.1%; 95%CI 92.0, 99.0), and multi-region studies (93.5%; 95%CI 84.6, 97.4) reported more favorable acceptability compared to African studies (59.4%; 95%CI 38.3, 77.5). Secondary outcomes were similarly favorable, including ring comfort (92.9%; 95%CI 89.2, 95.4), ease of use (90.9%; 95%CI 86.5, 94.0), and comfort during sex (82.7%; 95%CI 76.4, 87.6). Limitations include inconsistent outcome definitions and unmeasured factors affecting acceptability.

CONCLUSIONS

Women who used vaginal rings reported they were acceptable across indications geographic regions and indications. Policy makers should consider the ring as an important option for pregnancy and HIV prevention drug development.

IMPLICATIONS

This review found favorable acceptability among vaginal ring users across indications and geographic areas, in contrast to low hypothetical acceptability among non-users. Vaginal rings are an important drug delivery system for pregnancy and HIV preventions, and scale-up should plan to address initial hesitancy among new users.

Genital Mucosal Drug Concentrations and anti-HIV Activity in Tenofovir-Based PrEP Products: Intravaginal Ring vs. Oral Administration

OBJECTIVE

To describe and compare systemic and local pharmacokinetics (PK) and cervicovaginal (CV) pharmacodynamics (PD) of oral tenofovir disoproxil fumarate (TDF) in combination with emtricitabine (FTC) with tenofovir (TFV) intravaginal ring (IVR).

DESIGN

Phase I, randomized, parallel-group study. Women (n = 22) used TDF/FTC oral tablets daily or TFV IVR continuously and were assessed at baseline and 14 days.

METHODS

TFV and FTC concentrations were measured in plasma, CV fluid (CVF), and CV tissue. TFV-diphosphate and FTC-triphosphate were assessed in CV tissue. In vitro PD antiviral activities of TFV and FTC (using in vivo concentration ranges) were modeled in the CVF and by infecting CV tissue explants ex vivo with HIV-1BaL.

RESULTS

Adverse events (AEs) were more common with oral TDF/FTC use (P < 0.01). The median CVF TFV concentrations were 106 ng/mL after use of TFV IVR vs. 102 ng/mL for TDF/FTC. The median TFV and TFV-diphosphate concentrations in CV tissue were >100-fold higher among IVR users. The median CVF FTC concentrations were 103 ng/mL. FTC and FTC-triphosphate were detected in all CV tissues from TDF/FTC users. HIV inhibitory activity of CVF increased significantly with treatment in both cohorts (P < 0.01) but was higher in TFV IVR users (P < 0.01). In vitro inhibition of tissue infection with ex vivo administration of TFV and FTC was dose dependent, with maximal efficacy achieved with 10 µg/mL TFV, 1 µg/mL FTC, and 0.1 µg/mL of TFV and FTC combined.

CONCLUSIONS

Both products were safe and increased mucosal HIV inhibitory activity. In addition to systemic protection, oral TDF/FTC displays a PK/PD profile compatible with CV mucosal antiviral activity. TFV IVR resulted in fewer AEs, lower TFV plasma concentrations, higher CVF and tissue TFV and TFV-DP concentrations, and greater anti-HIV activity in CVF.

Correlates of Adherence to the Dapivirine Vaginal Ring for HIV-1 Prevention

Understanding characteristics associated with adherence to pre-exposure prophylaxis (PrEP) methods for HIV-1 prevention may assist with optimizing implementation efforts. The dapivirine vaginal ring is a novel topical PrEP delivery method. Using data from a randomized, double-blind, placebo-controlled, phase III trial of the dapivirine vaginal ring conducted in four African countries, generalized estimating equation models were used to evaluate correlates of ring adherence. Two levels of quarterly dapivirine blood plasma, and dapivirine released from returned rings defined measures of adherence for recent and cumulative use, respectively. Time on study, calendar time, primary partner knowledge that the participant was taking part in the study, and use of long-acting contraceptive methods were associated with ring adherence whereas younger age, ring worries, condom use, episodes of menstrual bleeding and vaginal washing were associated with non-adherence. These findings may be useful for recruitment into future clinical studies and dapivirine ring implementation efforts.

How Has HIV Pre-Exposure Prophylaxis (PrEP) Changed Sex? A Review of Research in a New Era of Bio-behavioral HIV Prevention

In 2012, the U.S. FDA approved the first drug for use as HIV Pre-Exposure Prophylaxis (PrEP), which is nearly 99% effective when taken as prescribed. Although the manifest function of PrEP is to prevent HIV infection in the event of exposure, the drug has also had a significant impact on various facets of sexuality. In this review, we focus on research that emerged in the near decade since PrEP's approval, with a specific focus on the ways in which different elements of sex and sexuality have been impacted by gay, bisexual, and other men who have sex with men (GBMSM), cisgender women, and transgender individuals. We highlight evidence showing how PrEP has enhanced sexual self-esteem, improved sexual pleasure, reduced sexual anxiety, and has increased sexual agency for those taking it. For many, PrEP also serves as a gateway to improve routine health and increase sexual health-care utilization. Additionally, we review the question of whether PrEP is associated with increased sexual risk taking (i.e. risk compensation), and note that, although some data are mixed, PrEP is not intended as an intervention to reduce condomless anal sex or STIs: it aims to prevent HIV. Finally, our review highlights that, although the volume of research on PrEP among GBMSM is robust, it is underdeveloped for cisgender women and transgender populations and insufficient for inclusion in such a review for cisgender heterosexual men was. PrEP research with these populations is an important direction for future research. Finally, from 2012 to 2019, a single PrEP formulation and delivery method was FDA approved (oral emtricitabine/tenofovir disoproxil fumarate). As additional drug formulations (ie.g., emtricitabine/tenofovir alafenamide) and delivery methods (e.g., microbiocides, vaginal ring, injectable) come to market, it will be important to examine how these, too, impact the spectrum of sexuality.

Acceptability of the Dapivirine Vaginal Ring for HIV-1 Prevention and Association with Adherence in a Phase III Trial

We evaluated the acceptability of the 25 mg dapivirine vaginal ring (DVR) as an HIV prevention intervention and its influence on DVR adherence in the MTN-020/ASPIRE phase III trial. Acceptability measures were captured using ACASI at month 3 and end of product use (median 24 months, IQR 15-30). Monthly returned rings were classified as nonadherent if dapivirine release rate was ≤ 0.9 mg/month. Associations between acceptability measures and nonadherence were estimated using Poisson regression models with robust standard errors. At month 3 (N = 2334), 88% reported DVR was comfortable, 80% were unaware of it during daily activities, and 74% never felt it during sex. At exit, 66% were 'very likely' to use DVR in the future. Acceptability was found to differ significantly by country across several measures including wearing the ring during sex, during menses, partner acceptability, impact on sexual pleasure and willingness to use the ring in the future. Risk of nonadherence at month 12 was elevated if DVR was felt during sex at month 3 (aRR 1.67, 95% CI 1.26, 2.23). Risk of nonadherence in the last year of study participation was elevated if, at exit, participants minded wearing during sex (aRR 2.08, 95% CI 1.52, 2.85), during menses (aRR 1.57, 95% CI 1.06, 2.32), reported a problematic change to the vaginal environment (aRR 1.57, 95% CI 1.12, 2.21), and were not "very likely" to use DVR in the future (aRR 1.31, 95% CI 1.02, 1.68). DVR acceptability was overall high yet varied by country. Addressing perceived ring interference with sex, menses, or problematic changes to the vaginal environment in future interventions could help improve adherence, as could embracing sex-positive messaging related to ring use and increased pleasure.Trial Registration ClinicalTrials.gov Identifier: NCT01617096.

Men's Sexual Experiences with the Dapivirine Vaginal Ring in Malawi, South Africa, Uganda and Zimbabwe

The dapivirine vaginal ring has been well-tolerated and shown to prevent HIV in clinical trials. The ring is female initiated, yet endorsement for use is sought from male partners in many relationships. In clinical studies, participants have expressed worries about men detecting rings during vaginal sex, which introduces concerns about product use disclosure, sexual pleasure, penile harm, inter-partner dynamics, and ring removals. This study reports African men's firsthand sexual experiences with the ring. Qualitative data were captured through 11 focus group discussions and one in-depth interview with 54 male partners of ring-users at six research sites in Malawi, South Africa, Uganda and Zimbabwe. Following a semi-structured guide, and using demonstration rings, vulva and penis models, men were asked to discuss the ring's impact on sex and views on male engagement and ring use. Interviews were facilitated by local male social scientists, audio-recorded, translated into English, and analyzed thematically. 22 (41%) of the male partners reported feeling the ring during sex, often attributed to perceived incorrect insertion. Many men described the ring as "scratching" the tip of their penises, and sensations of "prodding" something that "blocked" the vagina and prohibited "full entry". In most cases, feelings dissipated with time or when sexual fluids increased. Less common descriptions included perceiving the vaginal texture, wetness and size as different, which increased pleasure for some, and decreased for others. Over half (59%) never noticed the ring; some attempting and failing to feel it during intercourse. A majority of men reported that the ring did not lead to changes in sexual positions, feelings, frequency or experience of sex, although some were initially afraid that the ring was a "magic snake" or "potion". Male partners expressed strong opinions that ring use was a shared prevention responsibility that men should be engaged in, especially for maintaining trust and open communication in relationships. The ring was noticed by many male partners, particularly during women's initial stages of ring use, although this led to few sexual problems or changes. Nevertheless, results suggest that risk of ring discovery should be discussed with women to mitigate any potential negative reactions or social harm. Strategies to increase male partner engagement will enhance support of this prevention method for women.

Use of simulated vaginal and menstrual fluids to model in vivo discolouration of silicone elastomer vaginal rings

Vaginal rings releasing antiretrovirals – either alone or in combination with contraceptive progestins – are being developed for prevention of human immunodeficiency virus (HIV) transmission via vaginal sex. Following Phase I trials, significant discolouration was observed on the surface of investigational silicone elastomer antiretroviral-contraceptive matrix-type vaginal rings containing either 25 mg dapivirine or 200 mg dapivirine plus levonorgestrel. In this study, potential causes of the discolouration have been assessed in vitro using simulated vaginal and menstrual fluids (SVF and SMF, respectively) to model in vivo exposure. The fluid compositions also included hydrogen peroxide (H₂O₂), hydrogen peroxide plus a copper intrauterine device (IUD), or synthetic dyes (representing personal care and household cleaning products). No discolouration was observed for rings exposed to SVF + hydrogen peroxide (with or without an IUD). However, the SVF + dye compositions showed significant ring discolouration, with staining patterns similar to those observed with rings that had been exposed to highly-coloured personal care and household cleaning products during clinical trial use. Exposure of rings to SMF compositions invariably caused yellow surface discolouration, dark spotting and markings, similar to the staining patterns observed following clinical use. The darker marks on the ring surface were identified as blood debris derived from the SMF. The study indicates that surface discolouration of rings in vivo can be attributed to exposure to menstrual fluid or highly coloured personal care or household cleaning products. Discolouration of the rings was not associated with any specific safety risks for the user, though severe discolouration could potentially impact acceptability and adherence.

Disclosure of PrEP use by young women in South Africa and Tanzania: qualitative findings from a demonstration project

Investigating how young women disclose oral pre-exposure prophylaxis (PrEP) use is important given evidence that disclosure is associated with higher adherence. We report qualitative results on PrEP disclosure among young women in South Africa and Tanzania who participated in a PrEP demonstration project (EMPOWER). In total, 81 in-depth interviews were conducted with 39 young women aged 16-24 years-25 from Johannesburg and 14 from Mwanza-at approximately 3, 6 and/or 9 months post-enrolment. Analysis of data was thematic and inductive. Most Johannesburg participants were students in the inner-city; in Mwanza, all worked in recreational venues, occasionally engaging in sexual transactions with customers. A continuum of approaches was evident. Partner disclosure was common in Johannesburg but less so in Mwanza, where many partners were feared as judgemental and potentially violent. In both sites, participants commonly disclosed to family to secure support, and to friends and work colleagues to advocate about PrEP and encourage uptake among at-risk peers. Adherence clubs appeared helpful in building participants' skills and confidence to disclose, particularly in gender-inequitable sexual relationships. PrEP counselling for young women should focus on strengthening communication skills and helping develop strategies for safe disclosure.

Progesterone vaginal ring as a new contraceptive option for lactating mothers: Evidence from a multicenter non-randomized comparative clinical trial in India

OBJECTIVES

Evaluate and compare contraceptive efficacy, safety, continuation rates and duration of lactational amenorrhea (LA) in married lactating women (20-35 years) using the progesterone vaginal ring (PVR) or Copper-T380A intrauterine device (IUD) during the first postpartum year.

STUDY DESIGN

We conducted a one-year multicenter, non-randomized, non-inferiority, open-label, comparative trial at 20 centers in India and compared efficacy, safety, continuation and LA plus feeding patterns and growth/well-being of participants' infants. Women used four 3-month PVRs consecutively (lost PVRs were not replaced) and were to breastfeed at least four times/day. We used Pearl Index (PI) and Kaplan Meier (K-M) rates to analyze pregnancy and K-M for continuation.

RESULTS

We enrolled 789 women (459 PVR, 330 IUD). Neither PI nor K-M one-year pregnancy rates differed significantly between groups (PI: PVR-0.62; IUD-0.35); (K-M: PVR-0.7; IUD-0.4, p = 0.58). Continuation rates at 12 months were 78.5% (IUD) vs. 56.9% (PVR) (p < 0.001). Ring expulsions and menorrhagia were the most common discontinuation among PVR/IUD users respectively. The median duration of LA among PVR vs. IUD users was 405 vs. 120 days (p < 0.001). Both groups reported similar adverse events (PVR: 24.2%; IUD: 23.0%); there were no serious adverse events among PVR users. Infants from both groups fed 12-7 times/day and grew at expected rates.

CONCLUSIONS

Efficacy and safety outcomes were comparable among women in both groups. Continuation rates for PVR, a woman-controlled method, were shorter than IUD rates while PVR users maintained LA significantly longer than IUD users. Infant breastfeeding and growth patterns/well-being were favorable in both groups.

IMPLICATIONS

PVR, a user-controlled device, offers an additional contraceptive choice for lactating women for one-year postpartum use and can help to address the unmet need for contraception among postpartum women while encouraging breastfeeding to enhance infant growth and well-being.

Relationship Type and Use of the Vaginal Ring for HIV-1 Prevention in the MTN 020/ASPIRE Trial

Gender roles and imbalances in sexual power contribute to the heightened HIV-1 risk faced by women in Sub-Saharan Africa. This has led prevention research to focus on the development of female controlled methods. Despite the design of products such as vaginal rings to be used autonomously by women, male partners and women's perceptions of relationships influence HIV prevention choices. To understand the influences that male partners and dyadic dynamics had on the use of the Dapivirine Vaginal Ring in the ASPIRE trial, this analysis of qualitative data explored the types of intimate partner relationships that women engaged in. This paper describes how partners facilitated or challenged women's ring use and how women dealt with these challenges within six different types of relationships characterized by power dynamics and commitment levels. We offer insights into how future use of female-initiated HIV prevention products can be promoted through recognition of different relationship types.

First Impressions Matter: How Initial Worries Influence Adherence to the Dapivirine Vaginal Ring

BACKGROUND

In MTN-020/ASPIRE, a dapivirine vaginal ring effectiveness trial in sub-Saharan Africa, we assessed whether worries about ring use changed over time and were associated with adherence.

METHODS

Participants (N = 2585) were surveyed at baseline and follow-up about worries regarding daily ring use. First, they answered a question about general worries and then responded to 15 items covering specific worries. From a nested qualitative component (N = 214), we extracted themes related to ring worries and adherence. Seven months into the trial, aggregate adherence data were shared with study sites as part of an intervention that included counseling and social support. Nonadherence was defined as dapivirine plasma levels of ≤95 pg/mL. Mixed-effect logistic regression models were used to assess changes in ring worries and nonadherence from baseline to month 3 and later.

RESULTS

Worry about wearing the ring decreased from 29% at baseline to 4% at month 3 (P < 0.001), while having a specific worry decreased from 47% to 16% (P < 0.001). Among those enrolled before intervention, 29% with baseline worries were nonadherent at month 3 (95% confidence interval: 19% to 39%) compared to 14% without worries (95% confidence interval: 9% to 19%; P = 0.005); the difference persisted through month 6. There was no difference in nonadherence by baseline worry for those enrolled after intervention (P = 0.40). In the qualitative subset, initial ring anxieties reportedly subsided with self-experimentation and practice and the beneficial influence of the intervention.

CONCLUSIONS

Although worries may be an initial deterrent to correct ring use, intervening early by leveraging social influences from peers and clinicians should facilitate successful adoption and correct ring use.

A Mixed-Methods Study Examining Adherence to and Acceptability of Intravaginal Rings for HIV Prevention: Behavioral Results of MTN-027

Intravaginal rings (IVR) containing antiretroviral drugs are a promising method for HIV prevention. We triangulated quantitative and qualitative assessments to evaluate the acceptability of four IVRs used continuously for 28 days as part of a Phase I trial (N = 48 HIV-negative women; ages 18-45). Adherence was high throughout the trial, yet 30% of participants reported involuntary IVR expulsions followed by re-insertion. Most participants (93.6%) felt comfortable with the IVR being inside their body. Participants reported liking the IVR more (36.2%) or the same amount (55.3%) since starting the study. When given the option of choosing between the IVR and/or a male condom for HIV-prevention, most reported preferring the IVR (n = 29, 63.0%), and over a quarter of the sample reported liking them equally (n = 12, 26.1%). We observed no differences in IVR acceptability across the study arms. High adherence and acceptability underscores the promise of an IVR as a female-controlled, sustained mechanism for HIV prevention.

Hygiene, Blood Flow, and Vaginal Overload: Why Women Removed an HIV Prevention Vaginal Ring During Menstruation in Malawi, South Africa, Uganda and Zimbabwe

We assessed the interference between vaginal ring use and menses among women who participated in the qualitative component of the MTN-020/ASPIRE vaginal ring trial in Malawi, South Africa, Uganda and Zimbabwe (N = 214). A common reason for imperfect ring adherence and premature removal of the vaginal ring cited by participants related to vaginal bleeding or menses. Whereas self-reporting via survey questions suggested that the majority (60%) of women did not mind wearing the ring while menstruating, and did not remove it (91%) during menses, in the qualitative interviews women frequently described removing the ring during menses. Their reasons included hygiene, beliefs that the ring blocked the flow of menstrual blood, fears that the ring would come out with blood or during tampon removal, and concerns around an 'overburdened' vagina. Examining women's narratives and subjective experiences related to menstruation helps build a better understanding of factors affecting ring use and adherence.

Vaginal ring acceptability and related preferences among women in low- and middle-income countries: A systematic review and narrative synthesis

The vaginal ring (VR) is a female-initiated drug-delivery platform used for different indications, including HIV pre-exposure prophylaxis (PrEP). We conducted a systematic review of VR acceptability, values and preferences among women in low- and middle-income countries (LMIC) to inform further investment and/or guidance on VR use for HIV prevention. Following PRISMA guidelines, we used structured methods to search, screen, and extract data from randomized controlled trials (RCTs) and observational studies reporting quantitative outcomes of acceptability of the VR for any indication published 1/1970-2/2019 (PROSPERO: CRD42019122220). Of 1,110 records identified, 68 met inclusion criteria. Studies included women 15-50+ years from 25 LMIC for indications including HIV prevention, contraception, abnormal bleeding, and menopause. Overall VR acceptability was high (71-98% across RCTs; 62-100% across observational studies), with 80-100% continuation rates in RCTs and favorable ease of insertion (greater than 85%) and removal 89-99%). Users reported concerns about the VR getting lost in the body (8-43%), although actual expulsions and adverse events were generally infrequent. Most women disclosed use to partners, with some worrying about partner anger/violence. The VR was not felt during intercourse by 70-92% of users and 48-97% of partners. Acceptability improved over time both within studies (as women gained VR experience and worries diminished), and over chronological time (as the device was popularized). Women expressed preferences for accessible, long-acting, partner-approved methods that prevent both HIV and pregnancy, can be used without partner knowledge, and have no impact on sex and few side effects. This review was limited by a lack of standardization of acceptability measures and study heterogeneity. This systematic review suggests that most LMIC women users have a positive view of the VR that increases with familiarity of use; and, that many would consider the VR an acceptable future delivery device for HIV prevention or other indications.

A Qualitative Systematic Review of Women's Experiences Using Contraceptive Vaginal Rings: Implications for New Technologies

CONTEXT

Vaginal rings are available for contraception and hormone replacement, and are being developed as HIV/STD or multipurpose prevention technologies. A comprehensive understanding of women's expectations of and experiences with rings is urgently needed to inform product development and to optimize ring use.

METHODS

Three databases (PubMed, Global Health and CINAHL) were searched for English-language, peer-reviewed articles published between January 1996 and November 2017 that reported qualitative data on barriers to and facilitators of use of female-controlled contraceptive methods. Data on study methods, findings and conclusions pertaining to contraceptive rings were extracted, organized and analyzed.

RESULTS

Twenty-six articles, all published since 2008, met the inclusion criteria. Seven studies focused largely or entirely on rings (and involved current, former or potential users), while the others focused on other contraceptive methods but included ring-specific data. Familiarity with the ring was low, and women commonly had initial concerns about the method-often related to insertion and removal, cleanliness and discomfort with touching their vagina-that were typically overcome over time. Other major themes were issues related to ring use and discontinuation, the importance of ring-related properties and characteristics, and considerations related to sexual partners and health care providers.

CONCLUSIONS

Qualitative data have the potential to inform ring design and promotion. Future research should further explore women's expectations and experiences with the ring, the value of involving male partners in ring evaluation, and evaluation of interventions to improve patient-provider communication concerning ring choice and use.

A Qualitative Systematic Review of Women's Experiences Using Contraceptive Vaginal Rings: Implications for New Technologies

CONTEXT

Vaginal rings are available for contraception and hormone replacement, and are being developed as HIV/STD or multipurpose prevention technologies. A comprehensive understanding of women's expectations of and experiences with rings is urgently needed to inform product development and to optimize ring use.

METHODS

Three databases (PubMed, Global Health and CINAHL) were searched for English-language, peer-reviewed articles published between January 1996 and November 2017 that reported qualitative data on barriers to and facilitators of use of female-controlled contraceptive methods. Data on study methods, findings and conclusions pertaining to contraceptive rings were extracted, organized and analyzed.

RESULTS

Twenty-six articles, all published since 2008, met the inclusion criteria. Seven studies focused largely or entirely on rings (and involved current, former or potential users), while the others focused on other contraceptive methods but included ring-specific data. Familiarity with the ring was low, and women commonly had initial concerns about the method-often related to insertion and removal, cleanliness and discomfort with touching their vagina-that were typically overcome over time. Other major themes were issues related to ring use and discontinuation, the importance of ring-related properties and characteristics, and considerations related to sexual partners and health care providers.

CONCLUSIONS

Qualitative data have the potential to inform ring design and promotion. Future research should further explore women's expectations and experiences with the ring, the value of involving male partners in ring evaluation, and evaluation of interventions to improve patient-provider communication concerning ring choice and use.

End-user preference for and choice of four vaginally delivered HIV prevention methods among young women in South Africa and Zimbabwe: the Quatro Clinical Crossover Study

INTRODUCTION

Adherence to HIV prevention methods is a challenge, particularly for young women in Sub-Saharan Africa. End-user research during product development can inform modifiable factors to increase future uptake and adherence.

METHODS

Preferences for four vaginally inserted placebo HIV prevention methods were assessed among Zimbabwean and South African young women using a crossover clinical design. For each of months 1 to 4, participants were asked to use a pre-coitally inserted film, insert (vaginal tablet) and gel once/week for a month, and a monthly ring in a randomly assigned sequence. Participants subsequently chose one preferred product to use as directed for the final study month. Women ranked the four products from most preferred to least preferred at enrolment and after trying all products.

RESULTS

A total of 200 women aged 18 to 30 (mean 23) were enrolled; 178 (89%) completed follow-up. At baseline, 41% of participants selected the gel as their most preferred product and 61% selected the ring as least preferred. During the crossover period, most (82% to 85%) self-reported using each product at least once a week, although only half the time with sex. Objective biomarker data confirmed adequate use of all products. After trying each product, rankings changed with the film, ring, insert and gel being selected by 29%, 28%, 26% and 16% respectively. Choice varied significantly by country (p < 0.001): More Zimbabweans chose the film (45%), and more South Africans chose the insert (34%). Among women choosing the ring, 88% reported using it every time with sex. By contrast, self-reported adherence was lower for "on-demand" (coitally associated) products, with 40% to 55% using them every time during sex (p < 0.001).

CONCLUSIONS

Preferences for these four dosage forms varied before and after use, and both within and across countries - there was no clear favourite - indicating the need for a range of options for end-users The ring's popularity increased the most with use, was the second most preferred delivery system, and per self-report, provided more coverage during sex. These end-user perspectives provide important information to product developers and funding agencies.

"We are not the same": African women's view of multipurpose prevention products in the TRIO clinical study

Purpose

Unintended pregnancy and HIV infection present dual risks for young women in sub-Saharan Africa. New multipurpose prevention technologies (MPTs) are in development to simultaneously prevent unintended pregnancy and HIV, but there is a need for end-user research to ensure these products suit women’s needs. The Tablet, Rings and Injectables as Options (TRIO) for women study took place in Kisumu, Kenya, and Soshanguve, South Africa, with the goal of eliciting young women’s feedback on three potential MPTs.

Methods

Women in TRIO used three placebo products that represented potential MPTs: daily oral tablets, monthly vaginal rings, and monthly dual injections in a randomized crossover design followed by a period in which they chose a product to use. Eighty-eight TRIO participants completed in-depth interviews and focus group discussions to understand their experiences using each product. Qualitative analyses were conducted after stratifying by product preference at the end of the crossover period.

Results

The majority (65%) of participants preferred injections, with the remainder evenly split between tablets and rings. Discussions of preference for one product were closely linked with expressed dislike of another product’s attributes. Participants recognized heterogeneity in preferences and choices across users and stressed the need for multiple MPT options that confer a low burden on women’s daily lives.

Conclusion

Rather than choosing a product to use based on the product’s perceived advantages, women’s choices were based on the unfavorable attributes of other TRIO products. Moreover, the importance that women placed on a given disadvantage varied. Disadvantages that women deemed as most important emerged as a greater driver of product preference than selecting products based on their advantages and favorable characteristics.

Phase I trial of pod-intravaginal rings delivering antiretroviral agents for HIV-1 prevention: Rectal drug exposure from vaginal dosing with tenofovir disoproxil fumarate, emtricitabine, and maraviroc

BACKGROUND

Intravaginal rings (IVRs) can deliver antiretroviral (ARV) agents for HIV pre-exposure prophylaxis (PrEP), theoretically overcoming adherence concerns associated with frequent dosing. However, topical vaginal ARV drug delivery has not simultaneously led to sufficient rectal drug exposure to likely protect from HIV infection as a result of receptive anal intercourse (RAI). Unprotected RAI has a higher risk of infection per sex act and, for women, also can be associated with vaginal exposure during a single sexual encounter, especially in higher-risk subsets of women. The physiologically inflamed, activated, immune-cell dense colorectal mucosa is increasingly appreciated as the sexual compartment with highly significant risk; this risk is increased in the setting of co-infections. Ex vivo studies have shown that colorectal tissue and rectal fluid concentrations correlated with HIV protection. Given these important results, efforts to document colorectal compartment ARV drug concentration from pod-IVR delivery was assessed to determine if vaginal application could provide protective ARV levels in both compartments.

METHODOLOGY/PRINCIPAL FINDINGS

A crossover clinical trial (N = 6) evaluated 7 d of continuous TDF pod-IVR use, a wash-out phase, followed by 7 d with a TDF-FTC pod-IVR. A subsequent clinical trial (N = 6) consisted of 7 d of continuous TDF-FTC-MVC pod-IVR use. Rectal fluids were collected on Day 7 at IVR removal in all three ARV-exposures (two Phase 1 trials) and drug concentrations quantified by LC-MS/MS. Median rectal fluid concentrations of TFV, the hydrolysis product of the prodrug TDF, were between 0.66 ng mg-1 (TDF pod-IVR group) and 1.11 ng mg-1 (TDF-FTC pod-IVR group), but below the analytical lower limit of quantitation in 5/6 samples in the TDF-FTC-MVC pod-IVR group. Unexpectedly, median FTC (TDF-FTC pod-IVR, 20.3 ng mg-1; TDF-FTC-MVC pod-IVR, 0.18 ng mg-1), and MVC rectal fluid concentrations (0.84 ng mg-1) were quantifiable and higher than their respective in vitro EC50 values in most samples. Due to participant burden in these exploratory trials, rectal fluid was used as a surrogate for rectal tissue, where drug concentrations are expected to be higher.

CONCLUSIONS/SIGNIFICANCE

The concentrations of FTC and MVC in rectal fluids obtained in two exploratory clinical trials of IVRs delivering ARV combinations exceeded levels associated with in vitro efficacy in HIV inhibition. Unexpectedly, MVC appeared to depress the distribution of TFV and FTC into the rectal lumen. Here we show that vaginal delivery of ARV combinations may provide adherence and coitally independent dual-compartment protection from HIV infection during both vaginal and receptive anal intercourse.

Perspectives of South African youth in the development of an implant for HIV prevention

INTRODUCTION

Implants are a new dosage form in development for HIV pre-exposure prophylaxis (PrEP) with potential for high adherence given that they are provider-administered and are intended for long-acting protection. Integrating end-user preference into early stage product development may further overcome challenges with future product uptake and adherence. Hence, we sought to optimize the design of a PrEP implant in early-stage development by gathering opinions about implant attributes from potential end-users in South Africa.

METHODS

We conducted 14 focus group discussions (FGDs) with young women and men aged 18 to 24 in Cape Town and Soshanguve, South Africa, inviting participants into discussion as co-designers. FGDs were homogenous by gender and previous implant experience. During FGDs, we showed prototype devices and followed a semi-structured guide with questions on history of contraceptive implant use, preferences for physical characteristics of an implant, implant biodegradability, insertion process, participant-driven ideas for implant design, and social adoption considerations. FGDs were facilitated in English, isiXhosa, Tswana, isiZulu, or Tsonga, audio-recorded, transcribed into English, and qualitatively coded and analysed.

RESULTS

In this qualitative sample of 105 youth (68 women and 37 men), 58 participants were from Soshanguve and 47 from Cape Town, and 23% had previously used contraceptive implants. Participants expressed preferences for several implant design features; specifically, longer duration (≥6 months) was more important to most participants than the size or number of devices implanted. A majority preferred a flexible versus stiff implant to minimize palpability, thereby increasing discreetness and comfort. Nearly all participants favoured a biodegradable implant to avoid removal and thus reduce clinic visits. Concerns about the implant centred on its possible side effects and the "plastic" look of the prototype displayed for demonstration.

CONCLUSIONS

This study offers preliminary insights into an implant for HIV prevention that provides long-lasting protection may be well received among young South Africans. Additionally, flexibility, discreetness, and biodegradability may increase acceptability of the implant. Such end-user feedback is being incorporated into current implant designs in the hope of creating an effective long-acting PrEP product that is likely to achieve high uptake and adherence in target populations.

Reasons for nonadherence to the dapivirine vaginal ring: narrative explanations of objective drug-level results

OBJECTIVE(S)

MTN-020/ASPIRE trial and IPM-027/Ring Study recently proved the dapivirine vaginal ring was safe and effective with consistent use. To optimize the ring's impact, the barriers and facilitators to ring adherence must be understood and addressed.

METHODS

Former ASPIRE participants were stratified by age group (18-21; 22-45) and randomly selected at seven sites in Malawi, South Africa, Uganda and Zimbabwe, 12-17 months after trial exit. Using in-depth interviews or focus group discussions, ring use barriers were explored using structured guides and visual tools including individual-level depictions of dapivirine levels detected in plasma and returned rings.

RESULTS

A total of 187 were enrolled; 37% were 18-21 years when they began ASPIRE. Most (75%) had drug-level results, suggesting inconsistent ring use throughout ASPIRE. Participants viewed themselves as adherent, while simultaneously describing regular instances and reasons for ring removal (e.g. for sex or menses). Less adherent women reported fears that partners would oppose the ring or feel it during sex. High adherers expressed altruistic motivations for ring use. Women of all ages attributed young women's nonadherence to their tendency to be less 'serious' about the future, HIV prevention and the study; motivated predominantly by benefits; more fearful of fertility-related consequences; and to having less relationship control.

CONCLUSION

When presented with objective adherence data, participants provided reasons for intermittent ring use, while simultaneously portraying themselves as consistent ring users. Further research is needed to understand how women could use the ring in a way that fits into the context of their relationships and their lives while still conferring adequate HIV prophylaxis.

Randomized, placebo controlled phase I trial of safety, pharmacokinetics, pharmacodynamics and acceptability of tenofovir and tenofovir plus levonorgestrel vaginal rings in women

To prevent the global health burdens of human immunodeficiency virus [HIV] and unintended/mistimed pregnancies, we developed an intravaginal ring [IVR] that delivers tenofovir [TFV] at ~10mg/day alone or with levonorgestrel [LNG] at ~20μg/day for 90 days. We present safety, pharmacokinetics, pharmacodynamics, acceptability and drug release data in healthy women. CONRAD A13-128 was a randomized, placebo controlled phase I study. We screened 86 women; 51 were randomized to TFV, TFV/LNG or placebo IVR [2:2:1] and 50 completed all visits, using the IVR for approximately 15 days. We assessed safety by adverse events, colposcopy, vaginal microbiota, epithelial integrity, mucosal histology and immune cell numbers and phenotype, cervicovaginal [CV] cytokines and antimicrobial proteins and changes in systemic laboratory measurements, and LNG and TFV pharmacokinetics in multiple compartments. TFV pharmacodynamic activity was measured by evaluating CV fluid [CVF] and tissue for antiviral activity using in vitro models. LNG pharmacodynamic assessments were timed based on peak urinary luteinizing hormone levels. All IVRs were safe with no significant colposcopic, mucosal, immune and microbiota changes and were acceptable. Among TFV containing IVR users, median and mean CV aspirate TFV concentrations remained above 100,000 ng/mL 4 hours post IVR insertion and mean TFV-diphosphate [DP] concentrations in vaginal tissue remained above 1,000 fmol/mg even 3 days post IVR removal. CVF of women using TFV-containing IVRs completely inhibited [94-100%] HIV infection in vitro. TFV/LNG IVR users had mean serum LNG concentrations exceeding 300 pg/mL within 1 hour, remaining high throughout IVR use. All LNG IVR users had a cervical mucus Insler score <10 and the majority [95%] were anovulatory or had abnormal cervical mucus sperm penetration. Estimated in vivo TFV and LNG release rates were within expected ranges. All IVRs were safe with the active ones delivering sustained high concentrations of TFV locally. LNG caused changes in cervical mucus, sperm penetration, and ovulation compatible with contraceptive efficacy. The TFV and TFV/LNG rings are ready for expanded 90 day clinical testing. Trial registration ClinicalTrials.gov #NCT02235662.

Safety of a silicone elastomer vaginal ring as potential microbicide delivery method in African women: A Phase 1 randomized trial

BACKGROUND

Women in sub-Saharan Africa are in urgent need of female-initiated human immunodeficiency virus (HIV) preventative methods. Vaginal rings are one dosage form in development for delivery of HIV microbicides. However, African women have limited experience with vaginal rings.

OBJECTIVES

This Phase I, randomized, crossover trial assessed and compared the safety, acceptability and adherence of a silicone elastomer placebo vaginal ring, intended as a microbicide delivery method, inserted for a 12-week period in healthy, HIV-negative, sexually active women in South Africa and Tanzania.

METHODS

170 women, aged 18 to 35 years were enrolled with 88 women randomized to Group A, using a placebo vaginal ring for 12 weeks followed by a 12-week safety observation period. 82 women were randomized to Group B and observed for safety first, followed by a placebo vaginal ring for 12 weeks. Safety was assessed by clinical laboratory assessments, pelvic/colposcopy examinations and adverse events. Possible carry-over effect was addressed by ensuring no signs or symptoms of genital irritation at crossover.

RESULTS

No safety concerns were identified for any safety variables assessed during the trial. No serious adverse events were reported considered related to the placebo vaginal ring. Vaginal candidiasis was the most common adverse event occurring in 11% of participants during each trial period. Vaginal discharge (2%), vaginal odour (2%), and bacterial vaginitis (2%) were assessed as possibly or probably related to the vaginal ring. Thirty-four percent of participants had sexually transmitted infections (STIs) at screening, compared to 12% of participants who tested positive for STIs at crossover and the final trial visit. Three participants (2%) tested HIV positive during the trial.

CONCLUSIONS

The silicone elastomer vaginal ring had no safety concerns, demonstrating a profile favorable for further development for topical release of antiretroviral-based microbicides.

Acceptability of a Tenofovir Disoproxil Fumarate Vaginal Ring for HIV Prevention Among Women in New York City

Vaginal rings for pre-exposure prophylaxis are a female-initiated HIV prevention method that does not require daily or coitally-dependent dosing. As part of a randomized placebo-controlled trial of a tenofovir disoproxil fumarate intravaginal ring, we assessed product acceptability through in-depth interviews with 18 women during and after 14 days of continuous use. Women reported that the ring was comfortable with few side effects, regardless of experimental arm. However, interest in future use by this cohort was modest for several reasons including: low self-perceived HIV risk; concern that use implied promiscuity; potential for interference with relationship formation and trust; concern for interference with menstruation and cleanliness; and worries about partners' acceptability and sexual pleasure. Potential issues were raised with duration of use prior to ring exchange. Future studies should continue to identify and address individual and relationship factors that influence acceptability, early in the product development process.

Nanotechnologies for early diagnosis, in situ disease monitoring, and prevention

Nanotechnology is an enabling technology with great potential for applications in stem cell research and regenerative medicine. Fluorescent nanodiamond (FND), an inherently biocompatible and nontoxic nanoparticle, is well suited for such applications. We had developed a prospective isolation method using CD157, CD45, and CD54 to obtain lung stem cells. Labeling of CD45⁻CD54⁺CD157⁺ cells with FNDs did not eliminate their abilities for self-renewal and differentiation. The FND labeling in combination with cell sorting, fluorescence lifetime imaging microscopy, and immunostaining identified transplanted stem cells allowed tracking of their engraftment and regenerative capabilities with single-cell resolution. Time-gated fluorescence (TGF) imaging in mouse tissue sections indicated that they reside preferentially at the bronchoalveolar junctions of lungs, especially in naphthalene-injured mice. Our results presented in Subchapter 1.1 demonstrate not only the remarkable homing capacity and regenerative potential of the isolated stem cells, but also the ability of finding rare lung stem cells in vivo using FNDs.

The topical use of antiretroviral-based microbicides, namely of a dapivirine ring, has been recently shown to partially prevent transmission of HIV through the vaginal route. Among different formulation approaches, nanotechnology tools and principles have been used for the development of tentative vaginal and rectal microbicide products. Subchapter 1.2 provides an overview of antiretroviral drug nanocarriers as novel microbicide candidates and discusses recent and relevant research on the topic. Furthermore, advances in developing vaginal delivery platforms for the administration of promising antiretroviral drug nanocarriers are reviewed. Although mostly dedicated to the discussion of nanosystems for vaginal use, the development of rectal nanomicrobicides is also addressed.

Infectious diseases are currently responsible for over 8 million deaths per year. Efficient treatments require accurate recognition of pathogens at low concentrations, which in the case of blood infection (septicemia) can go as low as 1 mL^–1. Detecting and quantifying bacteria at such low concentrations is challenging and typically demands cultures of large samples of blood (∼1 mL) extending over 24–72 h. This delay seriously compromises the health of patients and is largely responsible for the death toll of bacterial infections. Recent advances in nanoscience, spectroscopy, plasmonics, and microfluidics allow for the development of optical devices capable of monitoring minute amounts of analytes in liquid samples. In Subchapter 1.3 we critically discuss these recent developments that will, in the future, enable the multiplex identification and quantification of microorganisms directly on their biological matrix with unprecedented speed, low cost, and sensitivity.

Radiolabeled nanoparticles (NPs) are finding an increasing interest in a broad range of biomedical applications. They may be used to detect and characterize diseases, to deliver relevant therapeutics, and to study the pharmacokinetic/pharmacodynamic parameters of nanomaterials. The use of radiotracer techniques in the research of novel NPs offers many advantages, but there are still some limitations. The binding of radionuclides to NPs has to be irreversible to prevent their escape to other tissues or organs. Due to the short half-lives of radionuclides, the manufacturing process is time limited and difficult, and there is also a risk of contamination. Subchapter 1.4 presents the main selection criteria for radionuclides and applicable radiolabeling procedures used for the radiolabeling of various NPs. Also, an overview of different types of NPs that have so far been labeled with radionuclides is presented.

Thermoplastic polyurethane-based intravaginal rings for prophylaxis and treatment of (recurrent) bacterial vaginosis

The aim of the present study was to develop thermoplastic polyurethane (TPU)-based intravaginal rings (IVRs) for prophylaxis and treatment of bacterial vaginosis via hot melt extrusion/injection molding. Therefore, different TPU grades were processed in combination with lactic acid or metronidazole, targeting a sustained lactic acid release over a 28day-period and sustained metronidazole release over 4-7days. Hot melt extrusion of lactic acid/TPU combinations required a lower extrusion temperature due to the plasticizing properties of lactic acid, evidenced by the lower glass transition temperature (T_g) and cross-over point (T_tanδ=1) values. NIR-chemical imaging data showed a homogenous distribution of lactic acid in TPU matrices at drug loads up to 30% (w/w). The addition of metronidazole did not lower processing temperatures, as the active pharmaceutical ingredient remained crystalline in the TPU matrix. Hydrophobic TPUs with a low ratio between the soft and hard segments (SS/HS ratio) in the polymer structure were suitable carriers for the lactic acid-eluting device over a 28-day period, while hydrophilic TPUs were needed to achieve the required release rate of metronidazole-eluting IVRs. IVRs manufactured with a TPU grade having a higher SS/HS ratio and lactic acid/TPU ratio exhibited a more elastic behavior. The addition of 25% (w/w) metronidazole did not affect the mechanical properties of the IVRs. Hydrophilic TPUs were most prone to biofilm formation by Candida albicans and Staphylococcus aureus, but the incorporation of metronidazole in the device prevented biofilm formation. Based on the drug eluting performance and mechanical tests, a mixture of lactic acid and Tecoflex™ EG-93A (20/80, w/w) and a combination of metronidazole and Tecophilic™ SP-93A-100 (25/75, w/w) were selected to design IVRs for the prophylaxis and treatment of bacterial vaginosis, respectively. Slug mucosal irritation tests predicted low irritation potency for both devices.

Historical development of vaginal microbicides to prevent sexual transmission of HIV in women: from past failures to future hopes

Infection with human immunodeficiency virus (HIV) remains a global public health concern and is particularly serious in low- and middle-income countries. Widespread sexual violence and poverty, among other factors, increase the risk of infection in women, while currently available prevention methods are outside the control of most. This has driven the study of vaginal microbicides to prevent sexual transmission of HIV from men to women in recent decades. The first microbicides evaluated were formulated as gels for daily use and contained different substances such as surfactants, acidifiers and monoclonal antibodies, which failed to demonstrate efficacy in clinical trials. A gel containing the reverse transcriptase inhibitor tenofovir showed protective efficacy in women. However, the lack of adherence by patients led to the search for dosage forms capable of releasing the active principle for longer periods, and hence to the emergence of the vaginal ring loaded with dapivirine, which requires a monthly application and is able to reduce the sexual transmission of HIV. The future of vaginal microbicides will feature the use of alternative dosage forms, nanosystems for drug release and probiotics, which have emerged as potential microbicides but are still in the early stages of development. Protecting women with vaginal microbicide formulations would, therefore, be a valuable tool for avoiding sexual transmission of HIV.

Acceptability and use of a dapivirine vaginal ring in a phase III trial

BACKGROUND

The MTN-020/ASPIRE trial evaluated the safety and effectiveness of the dapivirine vaginal ring for prevention of HIV-1 infection among African women. A nested qualitative component was conducted at six of 15 study sites in Uganda, Malawi, Zimbabwe and South Africa to evaluate acceptability of and adherence to the ring.

METHOD

Qualitative study participants (n = 214) were interviewed with one of three modalities: single in-depth interview, up to three serial interviews or an exit Focus Group Discussion. Using semistructured guides administered in local languages, 280 interviews were audio-recorded, transcribed, translated, coded and analyzed.

RESULTS

We identified three key findings: first, despite initial fears about the ring's appearance and potential side effects, participants grew to like it and developed a sense of ownership of the ring once they had used it. Second, uptake and sustained adherence challenges were generally overcome with staff and peer support. Participants developed gradual familiarity with ring use through trial progression, and most reported that it was easy to use and integrate into their lives. Using the ring in ASPIRE was akin to joining a team and contributing to a broader, communal good. Third, the actual or perceived dynamics of participants' male partner relationship(s) were the most consistently described influence (which ranged from positive to negative) on participants' acceptability and use of the ring.

CONCLUSION

It is critical that demonstration projects address challenges during the early adoption stages of ring diffusion to help achieve its potential public health impact as an effective, long-acting, female-initiated HIV prevention option addressing women's disproportionate HIV burden.

An intravaginal ring for real-time evaluation of adherence to therapy

Two recent Phase III clinical trials to investigate an intravaginal ring for preventing HIV infection demonstrated that adherence to prescribed device use was a primary driver of efficacy. Surrogate methods for determining adherence in the studies were limited in their inability to monitor temporal patterns of use and allow deconvolution of the effects of adherence and device efficacy on HIV infection rates. To address this issue, we have developed functionality in an intravaginal ring to continuously monitor when the device is being used and maintain a log of adherence that can be accessed by clinicians after it is removed. An electronic module fabricated with common, inexpensive electronic components was encapsulated in a silicone intravaginal ring. The device uses temperature as a surrogate measure of periods of device insertion and removal, and stores a record of the data for subsequent retrieval. The adherence-monitoring intravaginal ring accurately recorded the device status over 33 simulated IN-OUT cycles and more than 1000 measurement cycles in vitro. Following initial in vitro testing in a temperature-controlled chamber, the device was evaluated in vivo in sheep using a predetermined insertion/removal pattern to simulate intravaginal ring use. After insertion into the vaginal cavity of a sheep, the logged data correctly indicated the device status over 29 hours of continuous measurement including three cycles of insertion and removal. The device described here is a promising, low-cost method for real-time adherence assessment in clinical trials involving medicated intravaginal rings or other intravaginal devices.

Evaluation of poly(lactic-co-glycolic acid) and poly(dl-lactide-co-ε-caprolactone) electrospun fibers for the treatment of HSV-2 infection

More diverse multipurpose prevention technologies are urgently needed to provide localized, topical pre-exposure prophylaxis against sexually transmitted infections (STIs). In this work, we established the foundation for a multipurpose platform, in the form of polymeric electrospun fibers (EFs), to physicochemically treat herpes simplex virus 2 (HSV-2) infection. To initiate this study, we fabricated different formulations of poly(lactic-co-glycolic acid) (PLGA) and poly(dl-lactide-co-ε-caprolactone) (PLCL) EFs that encapsulate Acyclovir (ACV), to treat HSV-2 infection in vitro. Our goals were to assess the release and efficacy differences provided by these two different biodegradable polymers, and to determine how differing concentrations of ACV affected fiber efficacy against HSV-2 infection and the safety of each platform in vitro. Each formulation of PLGA and PLCL EFs exhibited high encapsulation efficiency of ACV, sustained-delivery of ACV through one month, and in vitro biocompatibility at the highest doses of EFs tested. Additionally, all EF formulations provided complete and efficacious protection against HSV-2 infection in vitro, regardless of the timeframe of collected fiber eluates tested. This work demonstrates the potential for PLGA and PLCL EFs as delivery platforms against HSV-2, and indicates that these delivery vehicles may be expanded upon to provide protection against other sexually transmitted infections.

Adherence and Acceptability of a Multidrug Vaginal Ring for HIV Prevention in a Phase I Study in the United States

We evaluated the adherence and acceptability of a vaginal ring containing dapivirine, maraviroc, or both drugs for 28 days during a Phase I placebo-controlled trial in 48 HIV-negative sexually abstinent U.S. women aged 18-40. Adherence was assessed weekly by clinical interview and computer-assisted self-interviewing; acceptability assessment occurred at the last product-use visit. Study retention was 98 % (47/48); 94 % (45/48) reported being fully adherent with ring use during the 28-day period. Two participants experienced the ring partially coming out. Analysis was blinded and behavioral data were combined across study groups. Most women reported being very comfortable having the ring in their vagina; 44 % preferred continuous use, whereas 51 % had no preference compared to episodic use. Although a range of minor ring concerns were expressed, few were actually experienced. High adherence to and acceptability of this vaginal ring in this Phase I trial contributes to its promise as a sustained mechanism for multidrug vaginal microbicide delivery.

Will dapivirine redeem the promises of anti-HIV microbicides? Overview of product design and clinical testing

Microbicides are being developed in order to prevent sexual transmission of HIV. Dapivirine, a non-nucleoside reverse transcriptase inhibitor, is one of the leading drug candidates in the field, currently being tested in various dosage forms, namely vaginal rings, gels, and films. In particular, a ring allowing sustained drug release for 1month is in an advanced stage of clinical testing. Two parallel phase III clinical trials are underway in sub-Saharan Africa and results are expected to be released in early 2016. This article overviews the development of dapivirine and its multiple products as potential microbicides, with particular emphasis being placed on clinical evaluation. Also, critical aspects regarding regulatory approval, manufacturing, distribution, and access are discussed.

Microbicide vaginal rings: Technological challenges and clinical development

Vaginal rings (VRs) are flexible, torus-shaped, polymeric devices designed to sustain delivery of pharmaceutical drugs to the vagina for clinical benefit. Following first report in a 1970 patent application, several steroid-releasing VR products have since been marketed for use in hormone replacement therapy and contraception. Since 2002, there has been growing interest in the use of VR technology for delivery of drugs that can reduce the risk of sexual acquisition of human immunodeficiency virus type 1 (HIV-1), the causative agent of acquired immunodeficiency syndrome (AIDS). Although no vaginally-administered product has yet been approved for HIV reduction/prevention, extensive research efforts are continuing and a number of VR devices offering sustained release of so-called 'HIV microbicide' compounds are currently being evaluated in late-stage clinical studies. This review article provides an overview of the published scientific literature within this important field of research, focusing primarily on articles published within peer-reviewed journal publications. Many important aspects of microbicide-releasing VR technology are discussed, with a particular emphasis on the technological, manufacturing and clinical challenges that have emerged in recent years.

Characteristics of women screened for a contraceptive intravaginal ring study in Kisumu, Kenya, 2014

BACKGROUND

HIV antiretroviral-based intravaginal rings with and without co-formulated contraception hold promise for increasing HIV prevention options for women. Acceptance of and ability to correctly and consistently use this technology may create challenges for future ring-based microbicide trials in settings where this technology has not been introduced. We examined baseline factors associated with enrolling in a contraceptive intravaginal ring study in Kisumu, Kenya and describe notional acceptability (willingness to switch to a contraceptive ring based solely on information received about it).

METHODS

Demographic, psychosocial, and behavioral eligibility screening of women 18-34 years was undertaken. Testing for pregnancy, HIV, and other sexually transmitted infections (STIs) was also conducted. We compared enrollment status across groups of categorical predictors using prevalence ratios (PR) and 95% confidence interval (CI) estimates obtained from a log-binomial regression model.

RESULTS

Out of 692 women pre-screened April to November 2014, 463 completed screening, and 302 women were enrolled. Approximately 97% of pre-screened women were willing to switch from their current contraceptive method to use the intravaginal ring exclusively for the 6-month intervention period. Pregnancy, HIV, and STI prevalence were 1.7%, 14.5%, and 70.4% respectively for the 463 women screened. Women 18-24 (PR=1.47, CI 1.15-1.88) were more likely to be enrolled than those 30-34 years of age, as were married/cohabitating women (PR=1.62, CI 1.22-2.16) compared to those separated, divorced, or widowed. In adjusted analyses, sexual debut at less than 17 years of age, one lifetime sexual partner, abnormal vaginal bleeding in the past 12 months, condomless vaginal or anal sex in the past 3 months, and not having a sexual partner of unknown HIV status in the past 3 months were predictive of enrollment.

CONCLUSION

High notional acceptability suggests feasibility for contraceptive intravaginal ring use. Factors associated with ring use initiation and 6-month use will need to be assessed.

Combination Pod-Intravaginal Ring Delivers Antiretroviral Agents for HIV Prophylaxis: Pharmacokinetic Evaluation in an Ovine Model

Preexposure prophylaxis (PrEP) against HIV using oral regimens based on the nucleoside reverse transcriptase inhibitor tenofovir disoproxil fumarate (TDF) has been effective to various degrees in multiple clinical trials, and the CCR5 receptor antagonist maraviroc (MVC) holds potential for complementary efficacy. The effectiveness of HIV PrEP is highly dependent on adherence. Incorporation of the TDF-MVC combination into intravaginal rings (IVRs) for sustained mucosal delivery could increase product adherence and efficacy compared with oral and vaginal gel formulations. A novel pod-IVR technology capable of delivering multiple drugs is described. The pharmacokinetics and preliminary local safety characteristics of a novel pod-IVR delivering a combination of TDF and MVC were evaluated in the ovine model. The device exhibited sustained release at controlled rates over the 28-day study and maintained steady-state drug levels in cervicovaginal fluids (CVFs). Dilution of CVFs during lavage sample collection was measured by ion chromatography using an inert tracer, allowing corrected drug concentrations to be measured for the first time. Median, steady-state drug levels in vaginal tissue homogenate were as follows: for tenofovir (TFV; in vivo hydrolysis product of TDF), 7.3 × 10(2) ng g(-1) (interquartile range [IQR], 3.0 × 10(2), 4.0 × 10(3)); for TFV diphosphate (TFV-DP; active metabolite of TFV), 1.8 × 10(4) fmol g(-1) (IQR, 1.5 × 10(4), 4.8 × 10(4)); and for MVC, 8.2 × 10(2) ng g(-1) (IQR, 4.7 × 10(2), 2.0 × 10(3)). No adverse events were observed. These findings, together with previous pod-IVR studies, have allowed several lead candidates to advance into clinical evaluation.

A phase 1 randomized placebo-controlled safety and pharmacokinetic trial of a tenofovir disoproxil fumarate vaginal ring

BACKGROUND

Tenofovir disoproxil fumarate (TDF), a prodrug of tenofovir (TFV), may be ideal for topical HIV preexposure prophylaxis because it has higher tissue and cell permeability than TFV; is not adversely impacted by seminal proteins; and its active metabolite, TFV-diphosphate (TFV-DP), has a long intracellular half-life. We engineered a TDF eluting polyurethane reservoir intravaginal ring (IVR) to provide near constant mucosal antiretroviral concentrations.

METHODS

A first-in-human randomized placebo-controlled trial was conducted to assess the safety and pharmacokinetics of the TDF IVR in healthy, sexually abstinent women (15 TDF and 15 placebo). Drug concentrations were measured in cervicovaginal fluid (CVF) obtained by swab, cervical tissue, plasma, and dried blood spots (DBS) over 14 days of continuous ring use.

RESULTS

There were 43 total, 23 reproductive tract, and eight product-related grade 1 adverse events. Steady-state CVF TFV concentrations were achieved proximal (vagina, ectocervix) and distal (introitus) to the TDF IVR 1 day after ring insertion. Median tissue TFV-DP concentrations 14 days after TDF IVR placement were 120 fmol/mg (interquartile range 90, 550). CVF collected from the cervix 1 week and 2 weeks after TDF IVR insertion provided significant protection against ex-vivo HIV challenge. Eleven of 14 (78%) participants had detectable TFV-DP DBS concentrations 14 days after TDF IVR placement, suggesting that DBS may provide a surrogate marker of adherence in future clinical trials.

CONCLUSION

A TDF IVR is safe, well tolerated, and results in mucosal TFV concentrations that exceed those associated with HIV protection. The findings support further clinical evaluation of this TDF IVR.

Safety, Acceptability and Adherence of Dapivirine Vaginal Ring in a Microbicide Clinical Trial Conducted in Multiple Countries in Sub-Saharan Africa

Background

This was the first microbicide trial conducted in Africa to evaluate an antiretroviral-containing vaginal ring as an HIV prevention technology for women.

Objectives

The trial assessed and compared the safety, acceptability and adherence to product use of a 4-weekly administered vaginal ring containing the antiretroviral microbicide, dapivirine, with a matching placebo ring among women from four countries in sub-Saharan Africa.

Methods

280 Healthy, sexually active, HIV-negative women, aged 18 to 40 years were enrolled with 140 women randomised to a dapivirine vaginal ring (25 mg) and 140 women to a matching placebo ring, inserted 4-weekly and used over a 12-week period. Safety was evaluated by pelvic examination, colposcopy, clinical laboratory assessments, and adverse events. Blood samples for determination of plasma concentrations of dapivirine were collected at Weeks 0, 4 and 12. Residual dapivirine levels in returned rings from dapivirine ring users were determined post-trial. Participant acceptability and adherence to ring use were assessed by self-reports.

Results

No safety concerns or clinically relevant differences were observed between the dapivirine and placebo ring groups. Plasma dapivirine concentrations immediately prior to ring removal were similar after removal of the first and third ring, suggesting consistent ring use over the 12-week period. No clear relationship was observed between the residual amount of dapivirine in used rings and corresponding plasma concentrations. Self-reported adherence to daily use of the vaginal rings over the 12-week trial period was very high. At the end of the trial, 96% of participants reported that the ring was usually comfortable to wear, and 97% reported that they would be willing to use it in the future if proven effective.

Conclusions

The dapivirine vaginal ring has a favourable safety and acceptability profile. If proven safe and effective in large-scale trials, it will be an important component of combination HIV prevention approaches for women.

Trial Registration

ClinicalTrials.gov NCT01071174

The Promise of Intravaginal Rings for Prevention: User Perceptions of Biomechanical Properties and Implications for Prevention Product Development

Intravaginal rings (IVRs) are currently under investigation as devices for the delivery of agents to protect against the sexual transmission of HIV and STIs, as well as pregnancy. To assist product developers in creating highly acceptable rings, we sought to identify characteristics that intravaginal ring users consider when making decisions about ring use or non-use. We conducted four semi-structured focus groups with 21 women (aged 18-45) who reported using an IVR in the past 12 months. Participants manipulated four prototype rings in their hands, discussed ring materials, dimensionality, and "behavior," and shared perceptions and appraisals. Five salient ring characteristics were identified: 1) appearance of the rings' surfaces, 2) tactile sensations of the cylinder material, 3) materials properties, 4) diameter of the cylinder, and 5) ring circumference. Pliability (or flexibility) was generally considered the most important mechanical property. Several ring properties (e.g., porousness, dimensionality) were associated with perceptions of efficacy. Women also revealed user behaviors that may impact the effectiveness of certain drugs, such as removing, rinsing and re-inserting the ring while bathing, and removing the ring during sexual encounters. As product developers explore IVRs as prevention delivery systems, it is critical to balance product materials and dimensions with use parameters to optimize drug delivery and the user experience. It is also critical to consider how user behaviors (e.g., removing the ring) might impact drug delivery.

An intravaginal ring for the sustained delivery of tenofovir disoproxil fumarate

Recent clinical trials have demonstrated that pre-exposure prophylaxis (PrEP) may prevent HIV infection in a significant number of HIV-1 negative individuals in venerable populations; however, trial efficacy has been highly variable, with notable successes and failures. Poor adherence to PrEP regimens has been implicated as a primary factor in determining efficacy of these trials. With the exception of CAPRISA 004 where use of a pericoital tenofovir gel led to a 39% reduction in HIV infection, all successful PrEP regimens to date have used the fumarate salt of the tenofovir disoproxil ester prodrug of tenofovir (TDF) alone or in combination with emtricitabine (FTC). A sustained-release, intravaginal ring (IVR) formulation of TDF holds promise for improving adherence and, thus, increasing the effectiveness of PrEP. Here, a novel IVR delivering TDF with sustained zero-order release characteristics that may be controlled over nearly two orders of magnitude is described. Pod-IVRs containing 1-10 pods delivering TDF at 0.01-10 mg d(-1) were fabricated and their release characteristics evaluated in vitro. The pod-IVRs stabilized TDF against hydrolytic degradation both in storage and during in vitro release experiments. Successful translation of the TDF pod-IVR from laboratory evaluation to large-scale clinical trials requires the ability to manufacture the devices at low cost and in high quantity. Methods for manufacturing and scale-up were developed and applied to pilot-scale production of TDF pod-IVRs that maintained the IVR's release characteristics while significantly decreasing the variability in release rate observed between pod-IVRs. This pod-IVR enables for the first time the dose-ranging clinical studies that are required to optimize topical TDF PrEP in terms of efficacy and safety.