Promoting continuous use as a strategy for achieving adherence in a trial of the diaphragm with candidate microbicide

A novel approach to mixing qualitative and quantitative methods in HIV and STI prevention research

Mixed-method designs are increasingly used in sexually transmitted infection (STI) and HIV prevention research. The authors designed a mixedmethod approach and applied it to estimate and evaluate a predictor of continued female condom use (6+ uses, among those who used it at least once) in a 6-month prospective cohort study. The analysis included 402 women who received an intervention promoting use of female and male condoms for STI prevention and completed monthly quantitative surveys; 33 also completed a semistructured qualitative interview. The authors identified a qualitative theme (couples' female condom enjoyment [CFCE]), applied discriminant analysis techniques to estimate CFCE for all participants, and added CFCE to a multivariable logistic regression model of continued female condom use. CFCE related to comfort, naturalness, pleasure, feeling protected, playfulness, ease of use, intimacy, and feeling in control of protection. CFCE was associated with continued female condom use (adjusted odds ratio: 2.8, 95% confidence interval: 1.4-5.6) and significantly improved model fit (p < .001). CFCE predicted continued female condom use. Mixed-method approaches for "scaling up" qualitative findings from small samples to larger numbers of participants can benefit HIV and STI prevention research.

A modified SILCS contraceptive diaphragm for long-term controlled release of the HIV microbicide dapivirine

BACKGROUND

There is considerable interest in developing new multipurpose prevention technologies to address women's reproductive health needs. This study describes an innovative barrier contraceptive device--based on the SILCS diaphragm--that also provides long-term controlled release of the lead candidate anti-HIV microbicide dapivirine.

STUDY DESIGN

Diaphragm devices comprising various dapivirine-loaded polymer spring cores overmolded with a nonmedicated silicone elastomer sheath were fabricated by injection molding processes. In vitro release testing, thermal analysis and mechanical characterization were performed on the devices.

RESULTS

A diaphragm device containing a polyoxymethylene spring core loaded with 10% w/w dapivirine provided continuous and controlled release of dapivirine over a 6-month period, with a mean in vitro daily release rate of 174 mcg/day. The mechanical properties of the new diaphragm were closely matched to the SILCS diaphragm.

CONCLUSIONS

The study demonstrates proof of concept for a dapivirine-releasing diaphragm with daily release quantities potentially capable of preventing HIV transmission. In discontinuous clinical use, release of dapivirine may be readily extended over 1 or more years.

An intravaginal ring that releases the NNRTI MIV-150 reduces SHIV transmission in macaques

Microbicides may prevent HIV and sexually transmitted infections (STIs) in women; however, determining the optimal means of delivery of active pharmaceutical ingredients remains a major challenge. We previously demonstrated that a vaginal gel containing the non-nucleoside reverse transcriptase inhibitor MIV-150 partially protected macaques from SHIV-RT (simian/HIV reverse transcriptase) infection, and the addition of zinc acetate rendered the gel significantly protective. We test the activity of MIV-150 without the addition of zinc acetate when delivered from either ethylene vinyl acetate (EVA) or silicone intravaginal rings (IVRs). MIV-150 was successfully delivered, because it was detected in vaginal fluids and tissues by radioimmunoassay in pharmacokinetic studies. Moreover, EVA IVRs significantly protected macaques from SHIV-RT infection. Our results demonstrate that MIV-150-containing IVRs have the potential to prevent HIV infection and highlight the possible use of IVRs for delivering drugs that block HIV and other STIs.

Factors that affect acceptance of HIV microbicides among women

Globally, women make up more than half of those infected with HIV. For women in nearly every region around the world, the primary mode of HIV transmission is through heterosexual sex. However, over thirty years into the HIV/AIDS epidemic women still lack sufficient means of protecting themselves against HIV. Vaginal HIV microbicides (VHMs) are a promising new method to prevent HIV infection. VHMs are chemical substances that can destroy HIV, block its entry into or fusion with the target cell or inhibit HIV replication once the virus has entered a target cell. They can be applied through various delivery methods intravaginally. VHMs are designed to be used by women and to that end it is crucial to understand women's preferences for formulation, use and other characteristics in order to determine how to increase adherence and acceptability. Of particular consideration is how relationship dynamics will affect microbicide usage. The purpose of this review is to examine the most recent body of literature regarding male and female perceptions of VHMs to prevent male to female transmission of HIV in order to gain a greater understanding of the factors that affect adherence and acceptability of VHM usage among women. A greater understanding of the factors that affect adherence and acceptance of VHMs will have an impact on the uptake of VHMs, allow nurses and other health care providers to counsel clients more effectively about their use and point to new directions needed on the research and development of future microbicides.

Drug delivery in multiple indication (multipurpose) prevention technologies: systems to prevent HIV-1 transmission and unintended pregnancies or HSV-2 transmission

INTRODUCTION

The development of multiple indication (multipurpose) prevention technologies (MIPTs) is driven by overlapping relationships in the area of female reproductive health.

AREAS COVERED

In this review, the basis for MIPTs is detailed. The current state of the field for the use of drug delivery in novel MIPTs is covered. Of particular interest is the application of intravaginal rings (IVRs) for the delivery of two drugs simultaneously, to prevent one STI and pregnancy, or two STIs. IVRs are currently available commercially for contraception and have been developed for release of microbicides to prevent sexual transmission of HIV-1. Novel IVRs capable of releasing relatively large amounts of drugs such as tenofovir are discussed, along with those that contain independent delivery elements, such as pods, that can be used to release drugs at independent rates. The vaginal administration of macromolecules (antibodies and vaccines) is also reviewed in the context of MIPTs.

EXPERT OPINION

The field of MIPTs remains one of potential. There is yet to be a proven microbicide effective at preventing sexual transmission of HIV-1. Development of MIPTs in the near term will proceed under the assumption that one or more antiretroviral (ARV) drugs will eventually be proven successful. IVRs have already demonstrated success in the area of contraception. Prevention of sexual transmission of HIV-1 and herpes simplex virus-2 (HSV-2) (or suppression of recurrence) remains an attractive MIPT target. In the long term, development of MIPTs will require validation of surrogate end points, particularly for prevention of HIV-1 transmission.

An acceptability and safety study of the Duet cervical barrier and gel delivery system in Zimbabwe

Background

Adherence problems with coitally dependent, female-initiated HIV prevention methods have contributed to several trials' failure to establish efficacy. Continuous use of a cervical barrier with once-daily cleaning and immediate reinsertion may simplify use for women and improve adherence. We assessed the acceptability and safety of precoital and continuous use of the Duet^®, a cervical barrier and gel delivery system, in Zimbabwean women.

Methods

Using a two-arm crossover design with a parallel observation group, we randomized 103 women in a 2:2:1 ratio: (1) to use the Duet continuously for 14 days, followed by a minimum of seven days of washout and then 14 days of precoital use; (2) to use the same Duet regimens in reverse order; or (3) for observation only. Women were aged 18 to 40 years; half were recruited from a pool of previous diaphragm study participants and the other half from the general community. Acceptability and adherence were assessed through an interviewer-administered questionnaire at each of two follow-up visits. Safety was monitored through pelvic speculum exams and report of adverse events.

Results

The proportion of women who reported consistent Duet use during sex was virtually identical during continuous and precoital regimens (88.6% vs. 88.9%). Partner refusal was the most common reason cited for non-use during sex in both use regimens. Not having the device handy was the most common reason cited for non-daily use (in the continuous regimen). Most women were "very comfortable" using it continuously (86.3%) and inserting it precoitally (92.8%). The most favoured Duet attribute was that it did not interfere with "natural" sex (55%). The least favoured Duet attribute was the concern that it might come out during sex (71.3%). No serious adverse events were reported during the study; 57 participants reported 90 adverse events classified as mild or moderate. There were no statistically significant differences in: (1) the proportion of women reporting adverse events; (2) the severity of events among those using the Duet and observational controls; or (3) event severity reported during each regimen use period.

Conclusions

In this study, the Duet was found to be acceptable and safe when inserted precoitally or used continuously for 14 days. Assignment to use of the Duet continuously did not increase adherence to the Duet during sex. Future HIV prevention trials should evaluate use of the Duet (precoitally and continuously) with promising microbicide candidates.