In vitro and in vivo characterization of a potential universal placebo designed for use in vaginal microbicide clinical trials

Selection, activity, and nuclease stabilization of cross-neutralizing DNA aptamers targeting HSV-1 and HSV-2

Cross-neutralizing aptamers targeting both HSV-1 and HSV-2 were developed by selecting against the ectodomains of glycoprotein D (gD) from both viruses in parallel as well as sequentially using the SELEX method. Since gD facilitates viral invasion, sterically blocking the host-receptor interaction prevents infection. Candidate aptamers were screened, and lead aptamers were identified that exhibited exceptional neutralizing activity against both viruses in vitro. The specificity of the aptamers was confirmed by comparing their activity to scrambled versions of themselves. Modifications of the lead compounds were tested to define critical motifs to guide development. Stability of the aptamers was increased using phosphorothioate backbone linkages, and 2' methoxy substitutions of terminal and key internal bases. Aptamers were applied in a guinea pig vaginal HSV-2 infection model and found to reduce both the viral load of infected animals and the severity of the resulting disease. These results suggest that cross-neutralizing aptamers can be developed into on-demand antiviral interventions effective against both HSV-1 and HSV-2.

Topical reinforcement of the cervical mucus barrier to sperm

Close to half of the world's pregnancies are still unplanned, reflecting a clear unmet need in contraception. Ideally, a contraceptive would provide the high efficacy of hormonal treatments, without systemic side effects. Here, we studied topical reinforcement of the cervical mucus by chitosan mucoadhesive polymers as a form of female contraceptive. Chitosans larger than 7 kDa effectively cross-linked human ovulatory cervical mucus to prevent sperm penetration in vitro. We then demonstrated in vivo using the ewe as a model that vaginal gels containing chitosan could stop ram sperm at the entrance of the cervical canal and prevent them from reaching the uterus, whereas the same gels without chitosan did not substantially limit sperm migration. Chitosan did not affect sperm motility in vitro or in vivo, suggesting reinforcement of the mucus physical barrier as the primary mechanism of action. The chitosan formulations did not damage or irritate the ewe vaginal epithelium, in contrast to nonoxynol-9 spermicide. The demonstration that cervical mucus can be reinforced topically to create an effective barrier to sperm may therefore form the technological basis for muco-cervical barrier contraceptives with the potential to become an alternative to hormonal contraceptives.

Synthetic Mucin Gels with Self-Healing Properties Augment Lubricity and Inhibit HIV-1 and HSV-2 Transmission

Mucus is a self-healing gel that lubricates the moist epithelium and provides protection against viruses by binding to viruses smaller than the gel's mesh size and removing them from the mucosal surface by active mucus turnover. As the primary nonaqueous components of mucus (≈0.2%-5%, wt/v), mucins are critical to this function because the dense arrangement of mucin glycans allows multivalence of binding. Following nature's example, bovine submaxillary mucins (BSMs) are assembled into "mucus-like" gels (5%, wt/v) by dynamic covalent crosslinking reactions. The gels exhibit transient liquefaction under high shear strain and immediate self-healing behavior. This study shows that these material properties are essential to provide lubricity. The gels efficiently reduce human immunodeficiency virus type 1 (HIV-1) and genital herpes virus type 2 (HSV-2) infectivity for various types of cells. In contrast, simple mucin solutions, which lack the structural makeup, inhibit HIV-1 significantly less and do not inhibit HSV-2. Mechanistically, the prophylaxis of HIV-1 infection by BSM gels is found to be that the gels trap HIV-1 by binding to the envelope glycoprotein gp120 and suppress cytokine production during viral exposure. Therefore, the authors believe the gels are promising for further development as personal lubricants that can limit viral transmission.

Chitosan-poly(ethylene oxide) nanofibrous mat as a vaginal platform for tenofovir disoproxyl fumarate - The effect of vaginal pH on drug carrier performance

In the present work, a solution blow spun nanofibrous mat comprised of chitosan (CS) and poly(ethylene oxide) (PEO) was obtained as vaginal platform for tenofovir disoproxil fumarate (TDF) to prevent sexually transmitted infections. Apart from physicochemical and mechanical analysis, the specific steps involved studies on nanofibrous mat mucoadhesive and swelling characteristics upon pH fluctuations over the physiological range. Physicochemical analysis showed uniform drug distribution within the CS/PEO mat volume and pointed toward physical interactions between the drug and polymers. TDF-loaded CS/PEO nanofibrous mat was shown potentially safe when evaluated by the MTT metabolic activity and JC-1 assays in human vaginal epithelial cells VK2-E6/E7. In vitro antiviral studies indicated inhibition efficacy of TDF-CS/PEO nanofibrous mat toward HSV-2 virus and proved the SBS process does not change the microbicidal activity of drug molecule. Fluctuations in the physiological vaginal pH range of 3.8 to 5.0 substantially affected mucoadhesive and swelling behavior of chitosan which in turn impacted drug dissolution rate from polymer carrier. The rate of permeation and accumulation of TDF in vaginal tissue differed in response to vaginal pH. Faster drug permeation assessed at pH 5.0 suggests that an increase in vaginal pH could improve TDF bioavailability at earlier time points.

The Impact of Over-The-Counter Lactic Acid Containing Vaginal Gels on the Integrity and Inflammatory State of the Vaginal Epithelium in vitro

The vaginal microbiome influences a wide range of health outcomes in women, where a microbiome dominated by Lactobacillus spp. is considered optimal and associated with reduced risk of pre-term birth and acquisition of sexually transmitted infections including HIV. Conversely, replacement of lactobacilli by non-optimal bacteria leads to the development of bacterial vaginosis, which is associated with increased risk of these outcomes. Lactobacilli produce the metabolite lactic acid (LA) which is a potent antibacterial and antiviral agent. The potential therapeutic benefits of LA have prompted the development of numerous over-the-counter LA-containing gels for use in the vagina, although a comprehensive analysis of the impact of these formulations on the cervicovaginal epithelium and pro-inflammatory cytokine/chemokine responses, has not been assessed. Here, we evaluated the properties of 11 over-the-counter gels, including 9 containing LA, marketed for use in the vagina. Ten of the 11 gels had an osmolality greater than vaginal fluid from women with Lactobacillus-dominated microbiota (370 ± 40 mOsmol/kg in women with Nugent score 0–3), with six gels that were hyperosmolal >2,000 mOsmol/kg. Using a reconstructed primary cell model of the vaginal epithelium, we found hyperosmolal gels had a detrimental impact on epithelial barrier integrity, resulting in substantial cellular toxicity (<10% viability as compared to untreated cells) and reduced epithelial barrier integrity [≈30% of untreated cells, assessed by transepithelial electrical resistance (TEER)]. Treatment of vaginal tissues with most of the gels elicited the production of pro-inflammatory factors including IL-1α (8 of 11) and IL-1β (10 of 11) which are associated with heightened risk of HIV acquisition in vivo. The majority of the OTC gels elicited moderate tissue damage as determined by histology. The detrimental effects of these gels on the human vaginal epithelium in vitro may predict compromised epithelial barrier integrity and genital inflammation in vivo, which has implications for sexual and reproductive health. This study highlights the importance of evaluating the impact of intravaginal products on the integrity and inflammatory status of the mucosal epithelium to avoid unfavorable off target effects.

Development and Preclinical Investigation of Physically Cross-Linked and pH-Sensitive Polymeric Gels as Potential Vaginal Contraceptives

This study explored the development of cross-linked gels to potentially provide a physical barrier to vaginal sperm transport for contraception. Two types of gels were formulated, a physically cross-linked iota-carrageenan (Ci) phenylboronic acid functionalized hydroxylpropylmethyacrylate copolymer (PBA)-based (Ci-PBA) gel, designed to block vaginal sperm transport. The second gel was pH-shifting cross-linked Ci-polyvinyl alcohol-boric acid (Ci-PVA-BA) gel, designed to modulate its properties in forming a viscoelastic, weakly cross-linked transient network (due to Ci gelling properties) on vaginal application (at acidic pH of ~3.5-4.5) to a more elastic, densely cross-linked (due to borate-diol cross-linking) gel network at basic pH of 7-8 of seminal fluid, thereby acting as a physical barrier to motile sperm. The gels were characterized for dynamic rheology, physicochemical properties, and impact on sperm functionality (motility, viability, penetration). The rheology data confirmed that the Ci-PBA gel was formed by ionic interactions whereas Ci-PVA-BA gel was chemically cross-linked and became more elastic at basic pH. Based on the screening data, lead gels were selected for in vitro sperm functionality testing. The in vitro results confirmed that the Ci-PBA and Ci-PVA-BA gels created a barrier at the sperm-gel interface, providing sperm blocking properties. For preclinical proof-of-concept, the Ci-PBA gels were applied vaginally and tested for contraceptive efficacy in rabbits, demonstrating only partial efficacy (40-60%). Overall, the in vitro and in vivo results support the development and further optimization of cross-linked gels using commercially available materials as vaginal contraceptives.

Recent Advances in the Excipients Used in Modified Release Vaginal Formulations

The formulation of an ideal vaginal drug delivery system (DDS), with the requisite properties, with respect to safety, efficacy, patient compliance, aesthetics, harmonization with the regulatory requirements, and cost, requires a meticulous selection of the active ingredients and the excipients used. Novel excipients defined by diversity and multifunctionality are used in order to ameliorate drug delivery attributes. Synthetic and natural polymers are broadly used in pharmaceutical vaginal formulations (solid, semi-solid dosage forms, implantable devices, and nanomedicines) with a promising perspective in improving stability and compatibility issues when administered topically or systemically. Moreover, the use of biopolymers is aiming towards formulating novel bioactive, biocompatible, and biodegradable DDSs with a controllable drug release rate. Overviewing vaginal microenvironment, which is described by variable and perplexed features, a perceptive choice of excipients is essential. This review summarizes the recent advances on the excipients used in modified vaginal drug delivery formulations, in an attempt to aid the formulation scientist in selecting the optimal excipients for the preparation of vaginal products.

Characterization of the Ovine Vaginal Microbiome and Inflammation Patterns as an Improved Testing Model of Human Vaginal Irritation

The development of therapies targeted to improve the health of women has utilized direct vaginal delivery as a more effective and less toxic method of protection from HIV and other pathogens. Vaginal applicants and delivery devices that provide sustained effects have been met with increasing acceptability, but the efficacy and toxicity outcomes have not been successfully predicted by preclinical in vitro studies and animal modeling. We have explored the utilization of sheep as a model for testing the safety of vaginal applicants and devices based on spatial and structural similarities to the human vagina. As recently noted by the FDA, an additional safety measure is an impact on the vaginal microbiome (VMB) that is known to contribute to vaginal health and influence pathogen susceptibility and drug metabolism. To advance the utility of the sheep vaginal model, we completed a thorough molecular characterization of the ovine VMB utilizing both next-generation sequencing (NGS) and PCR methods. The process also created a custom PCR array to quantify ovine VMB community profiles in an affordable, higher throughput fashion. The results from vaginal swabs (>475 samples) collected from non-pregnant crossbred Dorset and Merino ewes treated with selected vaginal applicants or collected as sham samples established 16 VMB community types (VMB CTs). To associate VMB CTs with eubiosis or dysbiosis, we also completed custom ELISAs for six cytokines identifying IL1B, IL8, TNFa, and CXCL10 as useful markers to support the characterization of ovine vaginal inflammation. The results indicated that Pasteurella, Actinobacillus, Pseudomonas, Bacteroides, Leptotrichia, and E. coli were common markers of eubiosis (low inflammatory marker expression), and that Haemophilus, Ureaplasma, and Corynebacterium were associated with dysbiosis (high cytokine levels). Utilizing the optimized workflow, we also confirmed the utility of three commonly used vaginal applicants for impact on the VMB and inflammatory state, producing a dataset that supports the recommendation for the use of sheep for testing of vaginal applicants and devices as part of preclinical pipelines.

HIV Incidence Among Pregnant and Nonpregnant Women in the FACTS-001 Trial: Implications for HIV Prevention, Especially PrEP Use

BACKGROUND

During pregnancy and postpartum period, the sexual behaviors of women and their partners change in ways that may either increase or reduce HIV risks. Pregnant women are a priority population for reducing both horizontal and vertical HIV transmission.

SETTING

Nine sites in 4 South African provinces.

METHODS

Women aged 18-30 years were randomized to receive pericoital tenofovir 1% gel or placebo gel and required to use reliable modern contraception. We compared HIV incidence in women before, during, and after pregnancy and used multivariate Cox Proportional hazards models to compare HIV incidence by pregnancy status.

RESULTS

Rates of pregnancy were 7.1 per 100 woman-years (95% confidence interval [CI]: 6.3 to 8.1) and highest in those who reported oral contraceptive use (25.1 per 100 woman-years; adjusted hazard ratio 22.97 higher than other women; 95% CI: 5.0 to 105.4) or had 2 children. Birth outcomes were similar between trial arms, with 59.8% having full-term live births. No difference was detected in incident HIV during pregnancy compared with nonpregnant women (2.1 versus 4.3%; hazard ratio = 0.56, 95% CI: 0.14 to 2.26). Sexual activity was low in pregnancy and the early postpartum period, as was consistent condom use.

CONCLUSIONS

Pregnancy incidence was high despite trial participation being contingent on contraceptive use. We found no evidence that rates of HIV acquisition were elevated in pregnancy when compared with those in nonpregnant women. Risks from reductions in condom use may be offset by reduced sexual activity. Nevertheless, high HIV incidence in both pregnant and nonpregnant women supports consideration of introducing antiretroviral-containing pre-exposure prophylaxis for pregnant and nonpregnant women in high HIV prevalence settings.

The Vaginal Microbiome of Nonhuman Primates Can Be Only Transiently Altered to Become Lactobacillus Dominant without Reducing Inflammation

The vaginal microbiome composition in humans is categorized based upon the degree to which one of four species of Lactobacillus is dominant (Lactobacilluscrispatus, community state type I [CST I], Lactobacillusgasseri, CST II, Lactobacillus iners, CST III, and Lactobacillus jensenii, CST V). Women with a vaginal microbiome not dominated by one of the four Lactobacillus species tend to have a more diverse microbiome, CST IV. CSTs I, II, III, and V are common in North America and Europe and are associated with lower incidences of some pathogens, such as human immunodeficiency virus (HIV), human papillomavirus (HPV), and Gardnerella vaginalis. As a result, therapeutic interventions to change the composition of the vaginal microbiomes are under development. However, Homo sapiens is the only mammalian species which has high frequencies of Lactobacillus-dominated vaginal microbiomes. Here, we treated female nonhuman primates (NHPs) with regimens of metronidazole and high levels of L.crispatus to determine how well these animals could be colonized with L.crispatus, how this influenced the immunological milieu, and how Lactobacillus treatment influenced or was influenced by the endogenous vaginal microbiome. We find that NHPs can transiently be colonized with L. crispatus, that beta diversity and not the number of doses of L. crispatus or pretreatment with metronidazole predicts subsequent L. crispatus colonization, that L. crispatus does not alter the local immunological milieu, and that the vaginal microbiome composition was resilient, normalizing by 4 weeks after our manipulations. Overall, this study suggests these animals are not amenable to long-term L. crispatus colonization.

IMPORTANCE NHPs have proven to be invaluable animal models for the study of many human infectious diseases. The use of NHPs to study the effect of the microbiome on disease transmission and susceptibility is limited due to differences between the native microbiomes of humans and NHPs. In particular, Lactobacillus dominance of the vaginal microbiome is unique to humans and remains an important risk factor in reproductive health. By assessing the extent to which NHPs can be colonized with exogenously applied L. crispatus to resemble a human vaginal microbiome and examining the effects on the vaginal microenvironment, we highlight the utility of NHPs in analysis of vaginal microbiome manipulations in the context of human disease.

Potential of mucoadhesive chitosan glutamate microparticles as microbicide carriers - antiherpes activity and penetration behavior across the human vaginal epithelium

Chitosan glutamate (gCS) spray-dried microparticles appear promising carriers to overcome challenges associated with vaginal microbicide delivery. This study aimed at elucidating the penetration and mucoadhesive behavior of developed gCS multiunit carriers with zidovudine (ZVD) as a model antiretroviral agent in contact with excised human vaginal epithelium followed with an examination of in vitro antiherpes activity in immortal human keratinocytes HaCaT and human vaginal epithelial cells VK2-E6/E7. Both ZVD dispersion and placebo microparticles served as controls. Microparticles displayed feasible (comparable to commercial vaginal product) mucoadhesive and mucoretention characteristics to isolated human vaginal tissue. Ex vivo penetration studies revealed that gCS increased the accumulation of active agent in the vaginal epithelium but surprisingly did not facilitate its penetration across human tissue. Finally, the obtained antiviral results demonstrated the potential of gCS as an antiherpes adjunctive, whose mode of action was related to blocking viral attachment.

Safety Assessment of Microbicide 2P23 on the Rectal and Vaginal Microbiota and Its Antiviral Activity on HIV Infection

Containment of the AIDS pandemic requires reducing HIV transmission. HIV infection is initiated by the fusion of the membrane between the virus and the cell membrane of the host. 2P23 is an effective HIV membrane fusion inhibitor that may be a good entry inhibitor microbicide candidate. This study evaluated the potential of using gel-formulated 2P23 as a topical microbicide to prevent sexual transmission of HIV in the rectum and vagina. Our data revealed that 2P23 formulated in gel is effective against HIV. There was no change in antiviral activity at 25°C for 4 months or 60°C for 1 week. In addition, we demonstrated that the 2P23 gel was stable and fully functional at pH 4.0-8.0 and under different concentrations of H2O2. Finally, the 2P23 gel exhibited no cytotoxicity or antimicrobial activity and did not induce inflammatory changes in the rectal or vaginal mucosal epithelium in New Zealand rabbits after 20 mg/day daily rectovaginal application for 14 consecutive days. Despite repeated tissue sampling and 2P23 gel treatment, the inflammatory cytokines and microbiota of the rectum and vagina remained stable. These results add to general knowledge on the in vivo evaluation of anti-HIV microbicide application concerning inflammatory cytokines and microbiota changes in the rectum and vagina. These findings suggest that the 2P23 gel is an excellent candidate for further development as a safe and effective pre-exposure prophylactic microbicide for the prevention of HIV transmission.

Peptide Inhibitor of Complement C1, RLS-0071, Reduces Zosteriform Spread of Herpes Simplex Virus Type 1 Skin Infection and Promotes Survival in Infected Mice

Herpes simplex virus type 1 (HSV-1) is a prevalent human pathogen primarily transmitted through skin-to-skin contact, especially on and around mucosal surfaces where there is contact with contaminated saliva during periods of viral shedding. It is estimated that 90% of adults worldwide have HSV-1 antibodies. Cutaneous HSV-1 infections are characterized by a sensation of tingling or numbness at the initial infection site followed by an eruption of vesicles and then painful ulcers with crusting. These symptoms can take ten days to several weeks to heal, leading to significant morbidity. Histologically, infections cause ballooning degeneration of keratinocytes and formation of multinucleated giant cells, ultimately resulting in a localized immune response. Commonly prescribed treatments against HSV-1 infections are nucleoside analogs, such as acyclovir (ACV). However, the emergence of ACV-resistant HSV (ACV^R-HSV) clinical isolates has created an urgent need for the development of compounds to control symptoms of cutaneous infections. RLS-0071, also known as peptide inhibitor of complement C1 (PIC1), is a 15-amino-acid anti-inflammatory peptide that inhibits classical complement pathway activation and modulates neutrophil activation. It has been previously shown to aid in the healing of chronic diabetic wounds by inhibiting the excessive activation of complement component C1 and infiltration of leukocytes. Here, we report that treatment of cutaneous infections of HSV-1 and ACV^R-HSV-1 in BALB/cJ mice with RLS-0071 significantly reduced the rate of mortality, decreased zosteriform spread, and enhanced the healing of the infection-associated lesions compared to control-treated animals. Therefore, RLS-0071 may work synergistically with other antiviral drugs to aid in wound healing of HSV-1 cutaneous infection and may potentially aid in rapid wound healing of other pathology not limited to HSV-1.

Nanoaggregate-forming lipid-conjugated AS1411 aptamer as a promising tumor-targeted delivery system of anticancer agents in vitro

Nanoparticles offer targeted delivery of drugs with minimal toxicity to surrounding healthy tissue and have great potential in the management of human papillomavirus (HPV)-related diseases. We synthesized lipid-modified AS1411 aptamers capable of forming nanoaggregates in solution containing Mg²⁺. The nanoaggregates presented suitable properties for pharmaceutical applications such as small size (100 nm), negative charge, and drug release. The nanoaggregates were loaded with acridine orange derivative C₈ for its specific delivery into cervical cancer cell lines and HPV-positive tissue biopsies. This improved inhibition of HeLa proliferation and cell uptake without significantly affecting healthy cells. Finally, the nanoaggregates were incorporated in a gel formulation with promising tissue retention properties aiming at developing a local delivery strategy of the nanoaggregates in the female genital tract. Collectively, these findings suggest that the nanoformulation protocol has great potential for the delivery of both anticancer and antiviral agents, becoming a novel modality for cervical cancer management.

A trifunctional contraceptive gel enhances the safety and quality of sexual intercourse

Current contraceptive methods come with a number of drawbacks, including low efficacy, in the case of commercial contraceptive gels, and a reduction in the quality of sexual intercourse, in the case of condoms. Adding pharmacologically-active agents to contraceptive gels holds the potential to improve sexual experience, and hardbor safety and hygiene. In this study, we fabricated a Carbomer-based contraceptive gel consisting of three agents: tenofovir, gossypol acetate, and nitroglycerin (TGN), with pH adjusted to 4.5 (to be compatible with the vagina). In vitro, the gossypol component of the contraceptive gel proved to be a significantly effective spermicide. When the concentration of gossypol acetate was 10 mg/ml, the spermicidal ability reached 100% after 30s. In addition, tenofovir in the gel significantly inhibited lentiviral transfection efficiency in cell-containing media. In 6 pairs of rats, the gel successfully prevented all females from conceiving after successful mating. Moreover, increased sexual frequency and enhanced erection, which were promoted by the nitroglycerin in the components, were observed in male rats that had the gel applied to their penises. This novel TGN contraceptive gel yielded a higher contraceptive success rate than that of the commercial contraceptive gel (Contragel®). In addition, it has the added benefits to prevent sexually transmitted diseases and improve male libido and erection function during sexual intercourse. Combining three FDA-approved and marketed agents together, our trifunctional TGN gel has a great potential for further translation and commercialization.

Ginkgolic Acid Inhibits Herpes Simplex Virus Type 1 Skin Infection and Prevents Zosteriform Spread in Mice

Herpes simplex virus type 1 (HSV-1) causes a lifelong latent infection with an estimated global prevalence of 66%. Primary and recurrent HSV infections are characterized by a tingling sensation, followed by an eruption of vesicles, which can cause painful erosions. Commonly used antiviral drugs against HSV infection are nucleoside analogues including acyclovir (ACV), famciclovir, and valacyclovir. Although these nucleoside analogues reduce morbidity and mortality in immunocompetent individuals, ACV-resistant HSV strains (ACV^R-HSV) have been isolated from immunocompromised patients. Thus, ACV^R-HSV infection poses a critical emerging public health concern. Recently, we reported that ginkgolic acid (GA) inhibits HSV-1 by disrupting viral structure, blocking fusion, and inhibiting viral protein synthesis. Additionally, we showed GA affords a broad spectrum of fusion inhibition of all three classes of fusion proteins, including those of HIV, Ebola, influenza A and Epstein Barr viruses. Here we report GA’s antiviral activity against HSV-1 skin infection in BALB/cJ mice. GA-treated mice demonstrated a significantly reduced mortality rate and decreased infection scores compared to controls treated with dimethylsulfoxide (DMSO)-vehicle. Furthermore, GA efficiently inhibited ACV^R-HSV-1 strain 17+ in vitro and in vivo. Since GA’s mechanism of action includes virucidal activity and fusion inhibition, it is expected to work alone or synergistically with other anti-viral drugs, and we anticipate it to be effective against additional cutaneous and potentially systemic viral infections.

The Role of Volume in the Perceptibility of Topical Vaginal Formulations: User Sensory Perceptions and Experiences of Heterosexual Couples During Vaginal Sex

Users' sensory perceptions and experiences (USPEs; perceptibility) of drug formulations can critically impact product adoption and adherence, especially when products rely on appropriate user behaviors (timing of administration, dosing measurement) for effectiveness. The use of topical gel formulations for effective antihuman immunodeficiency virus/sexually transmitted infection (HIV/STI) vaginal microbicides has been associated with messiness and other use-associated challenges, resulting in low adherence. Nonetheless, such formulations remain attractive due to good pharmacokinetics and resulting pharmacodynamics through their volume and surface contact for drug delivery into luminal fluids and mucosa. Consequently, advocates and scientists continue to pursue topical forms [semisolid (e.g., gel, suppository); solid (e.g., film)] to deliver select drugs and offer user choice in HIV/STI prevention. The current data build on previously validated USPE scales evaluating perceptibility of gels with various biophysical/rheological properties. Specifically, increased formulation parameter space adds a new set of properties inherent in quick-dissolving film. We compared film, a product adding no discernable volume to the vaginal environment, to 2 and 3.5 mL hydroxyethyl cellulose gel to consider the impact of volume on user experience. We also examined the USPE scales for evaluation of male sexual partners' experiences. The original USPE scales functioned as expected. Additionally, six new USPE scales were identified in this enhanced parameter space. Significant differences were noted between USPEs in pairwise comparisons, with largest differences between film and high-volume gel. Product developers and behavioral scientists can use these scales to design products, optimizing user experience and maximizing adherence and delivery of efficacious anti-HIV/STI pharmaceuticals. They can be extended to evaluation of additional formulations, devices, and compartments, as well as single- and multipurpose pharmaceuticals. In broader contexts, USPEs could be of value in evaluating formulations and devices to prevent/treat other diseases (e.g., ophthalmologic, dermatologic). Steadfast attention should be given to patient experience, and, where applicable, experiences of partners and/or caregivers.

Sexual frequency and pain in a randomized clinical trial of vaginal estradiol tablets, moisturizer, and placebo in postmenopausal women

OBJECTIVE

To evaluate the efficacy of two common interventions for bothersome postmenopausal vaginal symptoms on improving sexual frequency and pain.

METHODS

This is a post-hoc analysis of data from a 12-week double-blind placebo-controlled trial that randomized postmenopausal women (ages 45-70 years) with moderate-severe genitourinary discomfort to vaginal 10 μg estradiol tablet plus placebo gel (n = 102), placebo tablet plus vaginal moisturizer (n = 100), or dual placebo (n = 100). Outcomes were proportion of sexually active women at 12 weeks, frequency of sexual activity, and pain severity with sexual activity (0-3 scale). Consistent with the original study design, comparisons were made between each active arm and the dual placebo arm.

RESULTS

Most women enrolled in the trial, 294/302 (97%), had sufficient data to be included in this analysis. Mean age of participants was 61 years, most were white (88%), college educated (66%), and most reported sexual activity in the month before enrollment (81%). After 12 weeks of treatment, a similar proportion of women in the vaginal estrogen and dual placebo groups reported sexual activity in the past week (50% and 40%; P = 0.10) and the past month (78% and 84%, P = 0.52). Mean (standard deviation) pain with sexual activity scores at 12 weeks were similar between vaginal estrogen (1.0 [1.0]) and placebo (0.9 [0.9], P = 0.52] groups. The proportion sexually active at 12 weeks (35%) and mean (standard deviation) pain severity in the vaginal moisturizer group (1.1 [0.9]) did not differ from placebo (P = 0.36).

CONCLUSIONS

Compared to placebo, neither low-dose vaginal estradiol nor vaginal moisturizer treatment over 12 weeks resulted in significantly greater increases in the proportions of women reporting sexual activity or improvement in pain scores with sexual activity.

TRIAL REGISTRATION

Clinical trials.gov: NCT02516202.

A phase 2, double-blind, multicenter, randomized, placebo-controlled, dose‑ranging study of the efficacy and safety of Astodrimer Gel for the treatment of bacterial vaginosis

Background

Astodrimer Gel contains a novel dendrimer intended to treat and prevent bacterial vaginosis. We assessed the efficacy and safety of Astodrimer Gel for treatment of bacterial vaginosis.

Methods

132 women with bacterial vaginosis were randomized 1:1:1:1 to Astodrimer 0.5% (N = 34), 1% (N = 33), or 3% (N = 32) Gel or hydroxyethyl cellulose placebo gel (N = 33) at a dose of 5 g vaginally once daily for 7 days at 6 centers in the United States. The primary endpoint was clinical cure (no bacterial vaginosis vaginal discharge and no more than one of 1) vaginal pH ≥4.5; 2) ≥20% clue cells; or 3) positive whiff test) at study days 21–30. Secondary analyses included clinical cure at study days 9–12, patient-reported symptoms, acceptability and adverse events.

Results

The Astodrimer 1% Gel dose was superior to placebo for the primary and selected secondary efficacy measures in the modified intent-to-treat population. Clinical cure rates at day 9–12 were superior to placebo for the Astodrimer 3%, 1% and 0.5% Gel groups (62.5% [15/24; P = .002], 74.1% [20/27; P < .001], and 55.2% [16/29; P = .001], respectively, vs. 22.2% [6/27]). At day 21–30, clinical cure rates were 46.2% (12/26) for the 1% dose vs. 11.5% for placebo (3/26; P = .006). A greater proportion of patients reported absence of vaginal discharge and vaginal odor at day 9–12 and day 21–30 for Astodrimer Gel groups compared with placebo. Adverse events considered potentially treatment-related occurred in only 25% of Astodrimer Gel-treated patients vs. 22% of placebo patients.

Conclusion

Astodrimer Gel once daily for 7 days was superior to placebo for treatment of bacterial vaginosis and was well-tolerated. The 1% dose consistently showed the strongest efficacy across endpoints. These results support a role for Astodrimer Gel, 1%, as an effective treatment for bacterial vaginosis.

Serine protease inhibitor disrupts sperm motility leading to reduced fertility in female mice†

Inhibition of the sperm transport process in the female reproductive tract could lead to infertility. We previously showed that a pan-serine protease inhibitor, 4-(2-aminoethyl)benzenesulfonyl fluoride (AEBSF), blocked semen liquefaction in vivo and resulted in a drastic decrease in the number of sperm in the oviduct of female mice. In this study, we used a mouse model to test the efficacy of AEBSF as a reversible contraceptive, a sperm motility inhibitor, and a spermicide. Additionally, this study evaluated the toxicity of AEBSF on mouse vaginal tissues in vivo and human endocervical cells in vitro. We found that female mice treated with AEBSF had significantly less pups born per litter as well as fertilization rates in vivo compared to the vehicle control. We then showed that AEBSF reduced sperm motility and fertilization capability in vitro in a dose-dependent manner. Furthermore, AEBSF also exhibited spermicidal effects. Lastly, AEBSF treatment in female mice for 10 min or 3 consecutive days did not alter vaginal cell viability in vivo, similar to that of the vehicle and non-treated controls. However, AEBSF decreased cell viability of human ectocervical (ECT) cell line in vitro, suggesting that cells in the lower reproductive tract in mice and humans responded differently to AEBSF. In summary, our study showed that AEBSF can be used as a prototype compound for the further development of novel non-hormonal contraceptives for women by targeting sperm transport in the female reproductive tract.

Trichomonas vaginalis Motility Is Blocked by Drug-Free Thermosensitive Hydrogel

Trichomonas vaginalis motility in biological fluids plays a prominent, but understudied, role in parasite infectivity. In this study, the ability of a thermosensitive hydrogel (pluronic F127) to physically immobilize T. vaginalis was investigated. Blocking parasite motility could prevent its attachment to the mucosa, thus reducing the acquisition of the infection. The trajectory of individual parasites was monitored by multiple particle tracking. Mean square displacement, diffusivity, and velocity were calculated from x, y coordinates during time. Major results are that T. vaginalis exhibited different types of trajectories in a diluted solution composed of lactate buffer similar to "run-and-tumble" motion reported for flagellated bacteria. The fastest T. vaginalis specimen moves with a velocity of 19 μm/s. Observation of T. vaginalis movements showed that the cell body remains rigid during swimming and that the propulsive forces necessary to generate the movement are the result of flagellar beating. Parasite motility was partially slowed down using hydroxyethylcellulose hydrogel, used as a reference for the development of vaginal microbicides, while 100% of T. vaginalis were immobile in F127 hydrogel. Once completed by biological investigations on mice, this report suggests using drug-free formulation composed of F127 as a new strategy to prevent T. vaginalis attachment to the mucosa. The concept will be extended to other flagellated organisms where the motility is driven by cilia and flagella.

Modified cyclodextrins as broad-spectrum antivirals

Viral infections kill millions of people and new antivirals are needed. Nontoxic drugs that irreversibly inhibit viruses (virucidal) are postulated to be ideal. Unfortunately, all virucidal molecules described to date are cytotoxic. We recently developed nontoxic, broad-spectrum virucidal gold nanoparticles. Here, we develop further the concept and describe cyclodextrins, modified with mercaptoundecane sulfonic acids, to mimic heparan sulfates and to provide the key nontoxic virucidal action. We show that the resulting macromolecules are broad-spectrum, biocompatible, and virucidal at micromolar concentrations in vitro against many viruses [including herpes simplex virus (HSV), respiratory syncytial virus (RSV), dengue virus, and Zika virus]. They are effective ex vivo against both laboratory and clinical strains of RSV and HSV-2 in respiratory and vaginal tissue culture models, respectively. Additionally, they are effective when administrated in mice before intravaginal HSV-2 inoculation. Lastly, they pass a mutation resistance test that the currently available anti-HSV drug (acyclovir) fails.

Two phase 3, double-blind, placebo-controlled studies of the efficacy and safety of Astodrimer 1% Gel for the treatment of bacterial vaginosis

OBJECTIVE

Astodrimer is a dendrimer formulated in a vaginal gel to treat bacterial vaginosis (BV) and prevent recurrence. The objective of these studies was to confirm the efficacy and safety of Astodrimer 1 % Gel for treatment of BV.

STUDY DESIGN

Women with bacterial vaginosis were randomized 1:1 to Astodrimer 1 % Gel (Study 1 conducted in the United States, N = 127; Study 2 conducted in the United States, Germany and Belgium, N = 128) or placebo gel (Study 1, N = 123; Study 2, N = 123) at a dose of 5 g vaginally once daily for 7 days. The primary endpoint was clinical cure, defined as i) absence of bacterial vaginosis vaginal discharge; ii) <20 % clue cells; and iii) negative whiff test at day 9-12. Secondary efficacy analyses included clinical cure at day 21-30. Other endpoints at days 9-12 and 21-30 included Nugent cure (Nugent score ≤3), absence of symptoms, and adverse events. The primary analysis in the modified intent-to-treat population used the Cochran Mantel Haenszel test stratified by analysis center with a two-sided significance level of α = .05.

RESULTS

Astodrimer 1 % Gel was superior to placebo for the primary and selected secondary efficacy measures. Clinical cure rates at day 9-12 were 50.4 % (59/117) vs 16.5 % (19/115, P < .001) (Study 1) and 56.7 % (68/120) vs 21.4 % (25/117, P < .001) (Study 2) for astodrimer vs placebo. At day 21-30, clinical cure results showed a similar trend but the difference to placebo was not statistically significant. Nugent cure rates at day 9-12 were 12.8 % (15/117) vs 2.6 % (3/115, P = .004) (Study 1) and 13.3 % (16/120) vs 5.1 % (6/117, P = .030) (Study 2) for astodrimer vs placebo. A greater proportion of women receiving astodrimer reported absence of vaginal discharge and absence of vaginal odor at day 9-12 and day 21-30 compared with placebo. Adverse events were generally mild and self-limiting. For the combined studies, adverse events potentially related to treatment occurred in 14.7 % (37/252) of astodrimer patients vs 9.4 % (23/244) for placebo, including vulvovaginal candidiasis reported for 2.4 % (6/252) of astodrimer patients.

CONCLUSION

These results support a role for Astodrimer 1 % Gel as an effective, safe and well-tolerated treatment for women with bacterial vaginosis.

A phase I randomized safety study of a single-size silicone rubber diaphragm used with or without a lactic-acid-containing diaphragm gel

OBJECTIVES

To evaluate a lactic-acid-containing diaphragm gel (Contragel®) approved outside the United States for use with a silicone rubber diaphragm (Caya®). The study gel is being evaluated as a safer alternative to nonoxynol-9 (N-9) gel, which has been associated with risk of increasing susceptibility to human immunodeficiency virus (HIV).

STUDY DESIGN

This was a Phase I randomized, parallel study evaluating the safety of the novel diaphragm gel versus hydroxyethylcellulose (HEC) universal placebo gel delivered by the study diaphragm for two 7-day test cycles of daily use, without and with intercourse. The primary clinical safety endpoint was treatment emergent adverse events. Mucosal safety endpoints included colposcopic findings, anti-Escherichia coli activity of endocervical and vaginal fluid, immune mediators, Nugent score and ectocervical immune cell density. Endpoints were assessed prior to each test cycle and at day 7 of each test cycle. We compared the two independent groups and also evaluated paired changes from baseline in each gel cohort.

RESULTS

Twenty-three participants used the study diaphragm with the novel gel (n=11) or with HEC (n=12). Use of either gel resulted in few genital AEs and no colposcopic findings. There were no differences in ectocervical histology and lymphocyte density or phenotype between the two cohorts at baseline or after each test cycle. We found no clinically important differences in the anti-microbial (anti Escherichia coli) activity of endocervical or vaginal fluid or concentrations of genital immune mediators (e.g. anti-inflammatory secretory leukocyte protease inhibitor (SLPI) or pro-inflammatory mediator RANTES) between the two gel cohorts at any visit. There were no important paired changes from baseline among participants using either gel in Nugent score, ectocervical histology or anti-microbial activity of genital secretions.

CONCLUSIONS

We found no clinically significant differences in clinical and mucosal safety endpoints between the two cohorts. The mucosal safety profiles of the study gel and HEC placebo gel were similar.

IMPLICATIONS

Our data demonstrate no clinically important differences between the safety profiles of the lactic-acid-containing diaphragm gel versus HEC placebo gel when used with the study diaphragm. N-9 can no longer be used with contraceptive diaphragms in high HIV prevalence regions. Although larger studies are needed, the novel gel appears safe for use with the study diaphragm, which is the first over-the-counter, non-hormonal, diaphragm.

Development and clinical assessment of new objective adherence markers for four microbicide delivery systems used in HIV prevention studies

Background

Adherence is critical for successful topical, vaginally delivered anti-retroviral (ARV)-based HIV pre-exposure prophylaxis (PrEP). Quantitating systemic or tissue ARV levels through LC–MS/MS is currently viewed as the most reliable measure of adherence. However, for placebo-controlled trials, this is a high cost analysis that measures adherence only in the drug treatment group. A desirable marker of adherence is one that is measured in both placebo and drug treatment groups using a simple on-site clinical laboratory test, which allows necessary interventions for supporting participant adherence. Our objective was to develop adherence markers for four vaginal placebo products currently used as microbicide delivery systems: gel, film, insert, and intravaginal ring. Excipient and spectroscopy-based approaches were used for preclinical development of the placebo markers and subsequently validated by the CONRAD 135 study. The study collected vaginal swabs collected each day for 1 week post vaginal application of gel, film, or insert in the clinic with or without sex. Intravaginal rings were collected after 1 day, 7, and 30 days of use.

Results

Placebo gel, film, and insert in vaginal swabs were successfully detected by specific excipient colorimetric or probe-based assays for hydroxyethylcellulose, glycerin, and sorbitol respectively, as well as spectroscopy-based prediction models. The range of detection for gel, film, and insert in swabs collected up to 16 h post vaginal application was 70-100% of the total swabs per time point, with some markers showing potential for longer duration. Decreasing residual glycerin levels and increasing bioanalyte penetration of vaginally used intravaginal rings showed significant changes between 1 and 30 days of use.

Conclusions

We demonstrated clinical proof-of-concept that adherence markers for placebo product can be measured using simple, lower cost approaches. Measuring adherence in both placebo and drug arms of a HIV PrEP study would better inform future trial designs.

Electronic supplementary material

The online version of this article (10.1186/s40169-018-0213-6) contains supplementary material, which is available to authorized users.

Tenofovir 1% vaginal gel for prevention of HIV-1 infection in women in South Africa (FACTS-001): a phase 3, randomised, double-blind, placebo-controlled trial

BACKGROUND

Young women in southern Africa have substantial risk of HIV acquisition. Female-controlled biomedical interventions are needed to mitigate this risk. We aimed to assess the safety and efficacy of a pericoitally applied tenofovir 1% gel.

METHODS

We did a phase 3, double-blind, randomised, placebo-controlled trial at nine community-based clinical trial sites in South Africa to evaluate the safety and efficacy of tenofovir 1% gel. Sexually active women who were HIV negative and aged 18-30 years were enrolled. Participants were randomly assigned (1:1) using sequential participant numbers to either tenofovir 1% gel or a placebo gel (one dose within 12 h before sex and one dose within 12 h after sex [BAT-24 regimen]), using dynamic permuted block sizes of 8 and 16 within each site. Women received monthly HIV-1 testing, risk reduction support, physical examinations, and product dispensing for up to 27 months. The primary efficacy outcome was incident HIV infection and the primary safety outcome was occurrence of grade 2-4 adverse events, both analysed in the modified intention-to-treat population. To assess the efficacy of tenofovir gel, the cumulative probability of HIV infection was calculated for each treatment using the Kaplan-Meier method. This trial is registered with ClinicalTrials.gov, number NCT01386294.

FINDINGS

From Oct 11, 2011, to Aug 29, 2014, 3844 women were screened, 2059 enrolled, and 2029 included in the primary analysis (1032 in the tenofovir group and 1027 in the placebo group); 39 (4%) in the tenofovir group and 36 (4%) in the placebo group were lost to follow-up. 123 HIV-1 infections occurred over 3036 woman-years of observation; 61 in the tenofovir group (HIV incidence 4·0 per 100 woman-years, 95% CI 3·1-5·2) and 62 in the placebo group (4·0 per 100 woman-years, 3·1-5·2; incidence rate ratio [IRR] 0·98, 95% CI 0·7-1·4). A higher incidence of grade 2 adverse events was observed in the tenofovir group than in the placebo group (IRR 1·09, 95% CI 1·0-1·2; p=0·02). The most common grade 2 or higher product-related adverse events were hypophosphataemia (n=22 for tenofovir vs n=22 for placebo), genital symptoms (n=6 for tenofovir vs n=2 for placebo), or elevated transaminases (n=2 for tenofovir vs n=2 for placebo). No product-related serious adverse events were reported, and no differences in product-related adverse events (p=0·78), grade 3 events (p=0·64), or grade 4 events (p=0·74) were observed between treatment groups.

INTERPRETATION

Overall, pericoital tenofovir gel did not prevent HIV-1 acquisition in this population of young women at risk of HIV infection in South Africa. Alternate safe and effective products that are less user dependent than this product or do not require high adherence are needed.

FUNDING

The US Agency for International Development (USAID), the Bill & Melinda Gates Foundation, and the South African Department of Science and Technology and Department of Health.

Development of a Vaginal Fast-Dissolving Insert Combining Griffithsin and Carrageenan for Potential Use Against Sexually Transmitted Infections

Precoital, on-demand topical microbicides to reduce a woman's risk of sexually transmitted infections have been in development for nearly 3 decades, but no product has been approved due to acceptability issues and poor adherence in clinical trials. We set out to develop a self-administered vaginal fast-dissolving insert (FDI) produced by freeze-drying that would deliver safe and effective amounts of the antiviral agents griffithsin (GRFT) and carrageenan (CG) and would have properties women and their partners find acceptable. We evaluated FDI physical criteria, attributes of the gel produced upon dissolving, and GRFT stability. The lead formulation, FDI-024, was selected from 13 candidates and contains 4 mg of GRFT, 15 mg of CG, and excipients (the cryoprotectant sucrose and bulking agents dextran 40 and mannitol). The FDI exhibits good friability and hardness and is stable for at least 6 months at up to 40°C/75% relative humidity. It disintegrates in less than 60 s in a physiologically relevant volume (∼1 mL) of simulated vaginal fluid, forming a viscous semi-solid gel with favorable mucoadhesive and spreading properties. The formulation retains the antiviral activity of GRFT and CG against HIV type 1 and human papillomavirus, respectively, in cell-based assays.

Rapid measures of user's adherence to vaginal drug products using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and multivariate discriminant techniques

Background

The topical HIV prevention (microbicides) field is in acute need of a method to rapidly and objectively measure adherence to product use in clinical trials. Infrared (IR) spectroscopy has been used in many pharmaceutical and forensic applications but has yet to be applied to adherence monitoring. In this study, we report on efforts to test the feasibility of using IR spectroscopy as a means to measure residual active or placebo vaginal product, semen exposure and vaginal insertion from a single swab.

Methods

A portable IR spectrometer equipped with diamond attenuated total reflectance (ATR) was used to capture spectra of unused vs. vaginally-used swabs, vaginal swabs containing semen, and vaginal swabs to which either tenofovir-containing or matching placebo products (vaginal gel or insert) were added. Spectral data obtained from swabs placed directly on the spectrometer were divided into calibration and testing sets for developing and validating discriminant models set up to provide yes/no predictions of: vaginal vs. non-vaginal use, presence vs. no presence of each test product, and presence vs. no presence of semen. Further validation of models was performed using vaginal swabs collected from a clinical study evaluating vaginally administered placebo insert formulations.

Results

For each discriminant model developed to predict vaginal vs. non-vaginal use, presence vs. no presence of each test product, and presence vs. no presence of semen, classified validation samples not included in the model development were correctly identified into their respective classes with minimal prediction error. Clinically obtained vaginal swabs collected 15–60 minutes after placebo insert use were also correctly identified, further validating the models.

Conclusion

Our findings demonstrate the proof of concept that IR spectroscopy can be a method for rapid detection and characterization of microbicide products and biological fluids present in vaginal swabs. This novel method has potential to support real-time, on-site adherence monitoring in clinical or field settings.

Impact of the griffithsin anti-HIV microbicide and placebo gels on the rectal mucosal proteome and microbiome in non-human primates

Topical microbicides are being explored as an HIV prevention method for individuals who practice receptive anal intercourse. In vivo studies of these microbicides are critical to confirm safety. Here, we evaluated the impact of a rectal microbicide containing the antiviral lectin, Griffithsin (GRFT), on the rectal mucosal proteome and microbiome. Using a randomized, crossover placebo-controlled design, six rhesus macaques received applications of hydroxyethylcellulose (HEC)- or carbopol-formulated 0.1% GRFT gels. Rectal mucosal samples were then evaluated by label-free tandem MS/MS and 16 S rRNA gene amplicon sequencing, for proteomics and microbiome analyses, respectively. Compared to placebo, GRFT gels were not associated with any significant changes to protein levels at any time point (FDR < 5%), but increased abundances of two common and beneficial microbial taxa after 24 hours were observed in HEC-GRFT gel (p < 2E-09). Compared to baseline, both placebo formulations were associated with alterations to proteins involved in proteolysis, activation of the immune response and inflammation after 2 hours (p < 0.0001), and increases in beneficial Faecalibacterium spp. after 24 hours in HEC placebo gel (p = 4.21E-15). This study supports the safety profile of 0.1% GRFT gel as an anti-HIV microbicide and demonstrates that current placebo formulations may associate with changes to rectal proteome and microbiota.

Efficacy of Vaginal Estradiol or Vaginal Moisturizer vs Placebo for Treating Postmenopausal Vulvovaginal Symptoms: A Randomized Clinical Trial

IMPORTANCE

Nearly half of postmenopausal women report bothersome vulvovaginal symptoms, but few data support the efficacy of 2 commonly recommended treatments.

OBJECTIVE

To compare the efficacy of a low-dose vaginal estradiol tablet and a vaginal moisturizer, each vs placebo, for treatment of moderate-to-severe postmenopausal vulvovaginal symptoms.

DESIGN, SETTING, AND PARTICIPANTS

This 12-week multicenter randomized clinical trial enrolled postmenopausal women with moderate to severe symptoms of vulvovaginal itching, pain, dryness, irritation, or pain with penetration.

INTERVENTIONS

Vaginal 10-μg estradiol tablet (daily for 2 weeks, then twice weekly) plus placebo gel (3 times a week) (n = 102) vs placebo tablet plus vaginal moisturizer (n = 100) vs dual placebo (n = 100).

MAIN OUTCOMES AND MEASURES

The main outcome was decrease in severity (0-3) of most bothersome symptom (MBS) between enrollment and 12 weeks. Additional measures included a composite vaginal symptom score, Female Sexual Function Index (FSFI) score (2-36), modified Female Sexual Distress Score-Revised item 1, treatment satisfaction and meaningful benefit, Vaginal Maturation Index, and vaginal pH.

RESULTS

The 302 women had a mean (SD) age of 61 (4) years and were primarily white (267 [88%]), college educated (200 [66%]), and sexually active (245 [81%]). Most women (294 [97%]) provided data for the primary analysis. The most commonly reported MBS was pain with vaginal penetration (182 [60%]), followed by vulvovaginal dryness (63 [21%]). Mean baseline MBS severity was similar between treatment groups: estradiol, 2.4 (95% CI, 2.3 to 2.6); moisturizer, 2.5 (95% CI, 2.3 to 2.6); placebo, 2.5 (95% CI, 2.4 to 2.6). All treatment groups had similar mean reductions in MBS severity over 12 weeks: estradiol, -1.4 (95% CI, -1.6 to -1.2); moisturizer, -1.2 (95% CI, -1.4 to -1.0); and placebo, -1.3 (95% CI, -1.5 to -1.1). No significant differences were seen between estradiol (P = .25) or moisturizer (P = .31) compared with placebo. Mean total FSFI improvement was similar between estradiol (5.4; 95% CI, 4.0 to 6.9) and placebo (4.5; 95% CI, 2.8 to 6.1) (P = .64), and between moisturizer (3.1; 95% CI, 1.7 to 4.5) and placebo (P = .17).

CONCLUSIONS AND RELEVANCE

Our results suggest that neither prescribed vaginal estradiol tablet nor over-the-counter vaginal moisturizer provides additional benefit over placebo vaginal tablet and gel in reducing postmenopausal vulvovaginal symptoms.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02516202.

Evaluation of the fusion inhibitor P3 peptide as a potential microbicide to prevent HIV transmission in women

Microbicides are an important strategy for preventing the sexual transmission of HIV but, so far, the most advanced tenofovir-based microbicides have had modest efficacy. This has been related to adherence problems and high prevalence of tenofovir-resistant HIV-1 strains. P3 is a new peptide with potent activity against HIV that may be a good microbicide candidate. In this work P3 was formulated in a gel of hydroxyethyl cellulose and its activity, stability and safety profile in Balb/c mice were evaluated. HIV infection was fully blocked by a 1.5% gel containing P3 at the IC90 (366.4 nM) concentration. The antiviral activity did not change at 4°C during 4 months and at 25, 37 and 65°C for 1 week. P3 was stable and fully functional at acidic pH up to 24h, under different concentrations of hydrogen peroxide and in the presence of genital fluids up to 48h. P3 had no antibacterial activity and did not affect sperm motility and vitality. Finally, P3 didn't cause significant alterations in the vaginal epithelium of Balb/c mice at 0.06 (456.8 μM) and 0.2 mg/day (1522.7 μM) doses. These findings indicate that P3 is an excellent candidate for further development as a microbicide gel for the prevention of HIV transmission in women.

The Effect of Commonly Used Excipients on the Epithelial Integrity of Human Cervicovaginal Tissue

Pharmaceutical excipients are widely used in vaginal drug products. The epithelial integrity of the cervicovaginal tissue is important for HIV-1 prevention. However, the effects of excipients on cervicovaginal epithelium remain unknown. This study aims at assessing the effects of vaginal product excipients on the integrity of human cervicovaginal epithelium and on a lead HIV prevention antiretroviral drug, tenofovir (TFV). In the current study, nine excipients commonly used in vaginal formulations were incubated for 6 h with excised human ectocervical tissue. The effects of the excipients were examined by measuring the transepithelial electrical resistance (TEER), epithelial morphology, paracellular/transcellular permeability, and cell viability. The efficacy of TFV for preventing HIV-1 infection in the ex vivo cultured ectocervix was also tested. We found that disodium ethyl-enediaminetetraacetate (EDTA), sorbic acid, and benzoic acid had no effect on the tissue TEER. Butylated hydroxyanisole, glycerin, propylene glycol, methylparaben, and propylparaben slightly to moderately decreased tissue TEER, whereas citric acid significantly decreased the TEER in a time-dependent manner. Tissue morphology observed post-exposure strongly correlated with TEER data; however, a less strong correlation was observed between paracellular permeability and TEER data after exposure to different excipients. In addition, treatment with EDTA, methylparaben, and propylene glycol at tested levels had no effect on the efficacy of TFV in preventing tissue HIV-1 infection. In conclusion, the combined measurements of TEER, morphology, permeability, and viability using human cervicovaginal tissue represent a clinically relevant platform for safety evaluation of excipients and formulated products for HIV-1 prevention.

Pharmacokinetics of the Protein Microbicide 5P12-RANTES in Sheep following Single-Dose Vaginal Gel Administration

5P12-RANTES, a chemokine analogue that potently blocks the HIV CCR5 coreceptor, is being developed as both a vaginal and rectal microbicide for prevention of sexual transmission of HIV. Here, we report the first pharmacokinetic data for 5P12-RANTES following single-dose vaginal gel administration in sheep. Aqueous gel formulations containing low (1.24-mg/ml), intermediate (6.18-mg/ml), and high (32.0-mg/ml; suspension-type gel) concentrations of 5P12-RANTES were assessed via rheology, syringeability, and in vitro release testing. Following vaginal gel administration to sheep, 5P12-RANTES concentrations were measured in vaginal fluid, vaginal tissue, and serum over a 96-h period. All gels showed non-Newtonian pseudoplastic behavior, with the high-concentration gels exhibiting a greater viscosity and cohesive structure than the intermediate- and low-concentration gels. In in vitro release testing, >90% 5P12-RANTES was released from the low- and intermediate-concentration gels after 72 h. For the high-concentration gel, ∼50% 5P12-RANTES was detected, attributed to protein denaturation during lyophilization and/or subsequent solvation of the protein within the gel matrix. In sheep, 5P12-RANTES concentrations in vaginal fluid, vaginal tissue, and serum increased in a dose-dependent manner. The highest concentrations were measured in vaginal fluid (10⁵ to 10⁷ ng/ml), followed by vaginal tissue (10⁴ to 10⁶ ng/ml). Both of these concentration ranges are several orders of magnitude above the reported half-maximal inhibitory concentrations. The lowest concentration was measured in serum (<10² ng/ml). The 5P12-RANTES pharmacokinetic data are similar to those reported previously for other candidate microbicides. These data, coupled with 5P12-RANTES's potency at picomolar concentrations, its strong barrier to resistance, and the full protection that it was observed to provide in a rhesus macaque vaginal challenge model, support the continued development of 5P12-RANTES as a microbicide.

Vaginal semisolid products: Technological performance considering physiologic parameters

Vaginal semisolid products are frequently used to treat vaginal infections and atrophy-related symptoms of menopause. Formulations composition and the methods for their characterization, especially those developed concerning the target epithelia, are key tools to predict in vivo results at early stages of product development. However, recent studies on this subject have been almost exclusively focused on anti-HIV preparations. The aim of this work consists on improving traditional characterization methods by using physiological parameters in order to construct predictive tools to characterize a new ideal vaginal semisolid formulation whatever target it may have. Ten vaginal antimicrobial and hormonal products already available in the market were studied (Gino-Canesten®, Sertopic®, Dermofix®, Gyno-pevaryl®, Lomexin®, Gino Travogen®, Dalacin V®, Ovestin®, Blissel®, Colpotrophine®). Furthermore, Universal Placebo gel and Replens® were used for comparison. Products were characterized in terms of: pH and buffering capacity in a vaginal fluid simulant (VFS); osmolality - directly and upon dilution in VFS; textural parameters (firmness, adhesiveness and bioadhesion) using vaginal ex vivo porcine epithelium; and viscosity (including VFS dilution at 37°C and after administration on an ex vivo model). Interestingly, the majority of the tested commercial vaginal formulations did not present technological characteristics close to the ideal ones when tested under target biological conditions. The inclusion of such methodologic adaptations is expected to optimize cost-efficiency of new formulations development by predicting efficacy and safety profiles at early stages of product development.

First-in-Human Trial of MIV-150 and Zinc Acetate Coformulated in a Carrageenan Gel: Safety, Pharmacokinetics, Acceptability, Adherence, and Pharmacodynamics

OBJECTIVE

To evaluate the safety and pharmacokinetics of MIV-150 and zinc acetate in a carrageenan gel (PC-1005). Acceptability, adherence, and pharmacodynamics were also explored.

DESIGN

A 3-day open-label safety run-in (n = 5) preceded a placebo-controlled, double-blind trial in healthy, HIV-negative, abstinent women randomized (4:1) to vaginally apply 4 mL of PC-1005 or placebo once daily for 14 days.

METHODS

Assessments included physical examinations, safety labs, colposcopy, biopsies, cervicovaginal lavages (CVLs), and behavioral questionnaires. MIV-150 (plasma, CVL, tissue), zinc (plasma, CVL), and carrageenan (CVL) concentrations were determined with LC-MS/MS, ICP-MS, and ELISA, respectively. CVL antiviral activity was measured using cell-based assays. Safety, acceptability, and adherence were analyzed descriptively. Pharmacokinetic parameters were calculated using noncompartmental techniques and actual sampling times. CVL antiviral EC50 values were calculated using a dose-response inhibition analysis.

RESULTS

Participants (n = 20) ranged from 19-44 years old; 52% were black or African American. Among those completing the trial (13/17, PC-1005; 3/3, placebo), 11/17 reported liking the gel overall; 7 recommended reducing the volume. Adverse events, which were primarily mild and/or unrelated, were comparable between groups. Low systemic MIV-150 levels were observed, without accumulation. Plasma zinc levels were unchanged from baseline. Seven of seven CVLs collected 4-hour postdose demonstrated antiviral (HIV, human papillomavirus) activity. High baseline CVL anti-herpes-simplex virus type-2 (HSV-2) activity precluded assessment of postdose activity.

CONCLUSIONS

PC-1005 used vaginally for 14 days was well tolerated. Low systemic levels of MIV-150 were observed. Plasma zinc levels were unchanged. Postdose CVLs had anti-HIV and anti-human papillomavirus activity. These data warrant further development of PC-1005 for HIV and sexually transmitted infection prevention.

Evaluation of Vaginal Drug Levels and Safety of a Locally Administered Glycerol Monolaurate Cream in Rhesus Macaques

The human immunodeficiency virus epidemic affects millions of people worldwide. As women are more vulnerable to infection, female-controlled interventions can help control the spread of the disease significantly. Glycerol monolaurate (GML), an inexpensive and safe compound, has been shown to protect against simian immunodeficiency virus infection when applied vaginally. However, on account of its low aqueous solubility, fabrication of high-dose formulations of GML has proven difficult. We describe the development of a vaginal cream that could be loaded with up to 35% GML. Vaginal drug levels and safety of 3 formulations containing increasing concentrations of GML (5%w/w, 15%w/w, and 35%w/w) were tested in rhesus macaques after vaginal administration. GML concentration in the vaginal tissue increased as the drug concentration in the cream increased, with 35% GML cream resulting in tissue concentration of ∼0.5 mg/g, albeit with high interindividual variability. Compared with the vehicle control, none of the GML creams had any significant effect on the vaginal flora and cytokine (macrophage inflammatory protein 3α and interleukin 8) levels, suggesting that high-dose GML formulations do not induce local adverse effects. In summary, we describe the development of a highly loaded vaginal cream of GML, and vaginal drug levels and safety after local administration in macaques.

M48U1 and Tenofovir combination synergistically inhibits HIV infection in activated PBMCs and human cervicovaginal histocultures

Microbicides are considered a promising strategy for preventing human immunodeficiency virus (HIV-1) transmission and disease. In this report, we first analyzed the antiviral activity of the miniCD4 M48U1 peptide formulated in hydroxyethylcellulose (HEC) hydrogel in activated peripheral blood mononuclear cells (PBMCs) infected with R5- and X4–tropic HIV-1 strains. The results demonstrate that M48U1 prevented infection by several HIV-1 strains including laboratory strains, and HIV-1 subtype B and C strains isolated from the activated PBMCs of patients. M48U1 also inhibited infection by two HIV-1 transmitted/founder infectious molecular clones (pREJO.c/2864 and pTHRO.c/2626). In addition, M48U1 was administered in association with tenofovir, and these two antiretroviral drugs synergistically inhibited HIV-1 infection. In the next series of experiments, we tested M48U1 alone or in combination with tenofovir in HEC hydrogel with an organ-like structure mimicking human cervicovaginal tissue. We demonstrated a strong antiviral effect in absence of significant tissue toxicity. Together, these results indicate that co-treatment with M48U1 plus tenofovir is an effective antiviral strategy that may be used as a new topical microbicide to prevent HIV-1 transmission.

A Phase 1 Trial to Assess the Safety, Acceptability, Pharmacokinetics, and Pharmacodynamics of a Novel Dapivirine Vaginal Film

BACKGROUND

Films may deliver antiretroviral drugs efficiently to mucosal tissues. In this first in-human trial of a vaginal film for delivering the nonnucleoside reverse transcriptase inhibitor dapivirine, safety, pharmacokinetics, and pharmacodynamics of film and gel formulations were compared with placebo.

METHODS

Sixty-one healthy HIV-negative women were randomized to daily dapivirine (0.05%) or placebo gel, or dapivirine (1.25 mg) or placebo film for seven days. The proportion of participants experiencing grade 2 and higher adverse events related to study product were compared. Plasma dapivirine concentrations were quantified. Paired cervical and vaginal tissue biopsies obtained ∼2 hours after the last dose were measured for tissue drug concentration and exposed to HIV in an ex vivo challenge assay.

RESULTS

Two grade 2 related adverse events occurred in the placebo film group. Women randomized to gel and film products had 4 log10 higher of dapivirine in cervical and vaginal tissues than plasma. Although gel and film users had comparable plasma dapivirine concentrations, tissue concentrations of dapivirine were 3-5 times higher in the gel users when compared with film users. HIV replication in the ex vivo challenge assay was significantly reduced in vaginal tissues from women randomized to dapivirine film or gel; furthermore, tissue drug concentrations were highly correlated with HIV protection. Women rated the film more comfortable with less leakage but found it more difficult to insert than gel.

DISCUSSION

Both film and gel delivered dapivirine at concentrations sufficient to block HIV ex vivo. This proof-of-concept study suggests film formulations for microbicides merit further investigation.

A Small Molecule, Which Competes with MAdCAM-1, Activates Integrin α4β7 and Fails to Prevent Mucosal Transmission of SHIV-SF162P3

Mucosal HIV-1 transmission is inefficient. However, certain viral and host characteristics may play a role in facilitating HIV acquisition and systemic expansion. Cells expressing high levels of integrin α4β7 have been implicated in favoring the transmission process and the infusion of an anti-α4β7 mAb (RM-Act-1) prior to, and during a repeated low-dose vaginal challenge (RLDC) regimen with SIVmac251 reduced SIV acquisition and protected the gut-associated lymphoid tissues (GALT) in the macaques that acquired SIV. α4β7 expression is required for lymphocyte trafficking to the gut lamina propria and gut inductive sites. Several therapeutic strategies that target α4β7 have been shown to be effective in treating inflammatory conditions of the intestine, such as inflammatory bowel disease (IBD). To determine if blocking α4β7 with ELN, an orally available anti-α4 small molecule, would inhibit SHIV-SF162P3 acquisition, we tested its ability to block MAdCAM-1 (α4β7 natural ligand) and HIV-gp120 binding in vitro. We studied the pharmacokinetic profile of ELN after oral and vaginal delivery in macaques. Twenty-six macaques were divided into 3 groups: 9 animals were treated with ELN orally, 9 orally and vaginally and 8 were used as controls. All animals were challenged intra-vaginally with SHIV-SF162P3 using the RLDC regimen. We found that ELN did not protect macaques from SHIV acquisition although it reduced the SHIV-induced inflammatory status during the acute phase of infection. Notably, integrins can exist in different activation states and, comparing the effect of ELN and the anti-α4β7 mAb RM-Act-1 that reduced susceptibility to SIV infection, we determined that ELN induces the active conformation of α4β7, while RM-Act-1 inhibits its activation through an allosteric mechanism. These results suggest that inhibition of α4β7 activation may be necessary to reduce susceptibility to SIV/SHIV infection and highlight the complexity of anti-integrins therapeutic approach in HIV as well as in IBD and other autoimmune diseases.

Perceptibility and the "Choice Experience": User Sensory Perceptions and Experiences Inform Vaginal Prevention Product Design

The development of pericoital (on demand) vaginal HIV prevention technologies remains a global health priority. Clinical trials to date have been challenged by nonadherence, leading to an inability to demonstrate product efficacy. The work here provides new methodology and results to begin to address this limitation. We created validated scales that allow users to characterize sensory perceptions and experiences when using vaginal gel formulations. In this study, we sought to understand the user sensory perceptions and experiences (USPEs) that characterize the preferred product experience for each participant. Two hundred four women evaluated four semisolid vaginal formulations using the USPE scales at four randomly ordered formulation evaluation visits. Women were asked to select their preferred formulation experience for HIV prevention among the four formulations evaluated. The scale scores on the Sex-associated USPE scales (e.g., Initial Penetration and Leakage) for each participant's selected formulation were used in a latent class model analysis. Four classes of preferred formulation experiences were identified. Sociodemographic and sexual history variables did not predict class membership; however, four specific scales were significantly related to class: Initial Penetration, Perceived Wetness, Messiness, and Leakage. The range of preferred user experiences represented by the scale scores creates a potential target range for product development, such that products that elicit scale scores that fall within the preferred range may be more acceptable, or tolerable, to the population under study. It is recommended that similar analyses should be conducted with other semisolid vaginal formulations, and in other cultures, to determine product property and development targets.

A Pilot Study Measuring the Distribution and Permeability of a Vaginal HIV Microbicide Gel Vehicle Using Magnetic Resonance Imaging, Single Photon Emission Computed Tomography/Computed Tomography, and a Radiolabeled Small Molecule

Vaginal microbicide gels containing tenofovir have proven effective in HIV prevention, offering the advantage of reduced systemic toxicity. We studied the vaginal distribution and effect on mucosal permeability of a gel vehicle. Six premenopausal women were enrolled. In Phase 1, a spreading gel containing (99m)technetium-DTPA ((99m)Tc) radiolabel and gadolinium contrast for magnetic resonance imaging (MRI) was dosed intravaginally. MRI was obtained at 0.5, 4, and 24 h, and single photon emission computed tomography with conventional computed tomography (SPECT/CT) at 1.5, 5, and 25 h postdosing. Pads and tissues were measured for activity to determine gel loss. In Phase 2, nonoxynol-9 (N-9), containing (99m)Tc-DTPA, was dosed as a permeability control; permeability was measured in blood and urine for both phases. SPECT/CT showed the distribution of spreading gel throughout the vagina with the highest concentration of radiosignal in the fornices and ectocervix; signal intensity diminished over 25 h. MRI showed the greatest signal accumulation in the fornices, most notably 1-4 h postdosing. The median (interquartile range) isotope signal loss from the vagina through 6 h was 29.1% (15.8-39.9%). Mucosal permeability to (99m)Tc-DTPA following spreading gel was negligible, in contrast to N-9, with detectable radiosignal in plasma, peaking at 8 h (5-12). Following spreading gel dosing, 0.004% (0.001-2.04%) of the radiosignal accumulated in urine over 12 h compared to 8.31% (7.07-11.01%) with N-9, (p=0.043). Spreading gel distributed variably throughout the vagina, persisting for 24 h, with signal concentrating in the fornices and ectocervix. The spreading gel had no significant effect on vaginal mucosal permeability.

Recent advances on anti-HIV vaginal delivery systems development

A review of the recent outcomes regarding technologies to prevent vaginal transmission of HIV, mainly by using antiretroviral (ARV) drugs formulated as microbicides. An introduction about the HIV transmission mechanisms by the vaginal route is included, together with the recent challenges faced for development of successful microbicide products. The outcomes of clinical evaluations are mentioned, and the different formulation strategies studied to-date, with the requirements, advantages, disadvantages and limitations of each dosage-form type, are presented. Finally, the recent attempts to apply various types of nanotechnologies in order to develop advanced microbicide-products and overcome existing limitations, are discussed.

Griffithsin and Carrageenan Combination To Target Herpes Simplex Virus 2 and Human Papillomavirus

Extensive preclinical evaluation of griffithsin (GRFT) has identified this lectin to be a promising broad-spectrum microbicide. We set out to explore the antiviral properties of a GRFT and carrageenan (CG) combination product against herpes simplex virus 2 (HSV-2) and human papillomavirus (HPV) as well as determine the mechanism of action (MOA) of GRFT against both viruses. We performed the experiments in different cell lines, using time-of-addition and temperature dependence experiments to differentiate inhibition of viral attachment from entry and viral receptor internalization. Surface plasmon resonance (SPR) was used to assess GRFT binding to viral glycoproteins, and immunoprecipitation and immunohistochemistry were used to identify the specific glycoprotein involved. We determined the antiviral activity of GRFT against HSV-2 to be a 50% effective concentration (EC₅₀) of 230 nM and provide the first evidence that GRFT has moderate anti-HPV activity (EC₅₀ = 0.429 to 1.39 μM). GRFT blocks the entry of HSV-2 and HPV into target cells but not the adsorption of HSV-2 and HPV onto target cells. The results of the SPR, immunoprecipitation, and immunohistochemistry analyses of HSV-2 combined suggest that GRFT may block viral entry by binding to HSV-2 glycoprotein D. Cell-based assays suggest anti-HPV activity through α₆ integrin internalization. The GRFT-CG combination product but not GRFT or CG alone reduced HSV-2 vaginal infection in mice when given an hour before challenge (P = 0.0352). While GRFT significantly protected mice against vaginal HPV infection when dosed during and after HPV16 pseudovirus challenge (P < 0.026), greater CG-mediated protection was afforded by the GRFT-CG combination for up to 8 h (P < 0.0022). These findings support the development of the GRFT-CG combination as a broad-spectrum microbicide.

Tenofovir Gel for the Prevention of Herpes Simplex Virus Type 2 Infection

BACKGROUND

Globally, herpes simplex virus type 2 (HSV-2) infection is the most common cause of genital ulcer disease. Effective prevention strategies for HSV-2 infection are needed to achieve the goals of the World Health Organization global strategy for the prevention and control of sexually transmitted infections.

METHODS

We assessed the effectiveness of pericoital tenofovir gel, an antiviral microbicide, in preventing HSV-2 acquisition in a subgroup of 422 HSV-2-negative women enrolled in the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004 study, a double-blind, randomized, placebo-controlled trial. Incident HSV-2 cases were identified by evidence of seroconversion on an HSV-2 IgG enzyme-linked immunosorbent assay between study enrollment and exit. A confirmatory analysis was performed by Western blot testing.

RESULTS

The HSV-2 incidence rate was 10.2 cases per 100 person-years (95% confidence interval [CI], 6.8 to 14.7) among 202 women assigned to tenofovir gel, as compared with 21.0 cases per 100 person-years (95% CI, 16.0 to 27.2) among 222 women assigned to placebo gel (incidence rate ratio, 0.49; 95% CI, 0.30 to 0.77; P=0.003). The HSV-2 incidence rate among the 25 women with vaginal tenofovir concentrations of 10,000 ng per milliliter or more was 5.7 cases per 100 person-years, as compared with 15.5 cases per 100 person-years among the 103 women with no detectable vaginal tenofovir (incidence rate ratio, 0.37; 95% CI, 0.04 to 1.51; P=0.14). As confirmed by Western blot testing, there were 16 HSV-2 seroconversions among women assigned to tenofovir gel as compared with 36 among those assigned to the placebo gel (incidence rate ratio, 0.45; 95% CI, 0.23 to 0.82; P=0.005).

CONCLUSIONS

In this study in South Africa, pericoital application of tenofovir gel reduced HSV-2 acquisition in women. (Funded by the U.S. Agency for International Development and others; ClinicalTrials.gov number, NCT00441298.).

Unexpected Inflammatory Effects of Intravaginal Gels (Universal Placebo Gel and Nonoxynol-9) on the Upper Female Reproductive Tract: A Randomized Crossover Study

Intravaginal anti-HIV microbicides could provide women with a self-controlled means for HIV prevention, but results from clinical trials have been largely disappointing. We postulated that unrecognized effects of intravaginal gels on the upper female reproductive tract might contribute to the lower-than-expected efficacy of HIV microbicides. Our objective was to study the effects of intravaginal gels on the immune microenvironment of the cervix and uterus. In this randomized crossover study, 27 healthy female volunteers used a nightly application of intravaginal nonoxynol-9 (N9) gel as a "failed" microbicide or the universal placebo gel (UPG) as a "safe" gel (intervention cycles), or nothing (control cycle) from the end of menses to the mid-luteal phase. At a specific time-point following ovulation, all participants underwent sample collection for measurements of T-cell phenotypes, gene expression, and cytokine/chemokine protein concentrations from 3 anatomic sites above the vagina: the cervical transformation zone, the endocervix and the endometrium. We used hierarchical statistical models to estimate mean (95% CI) intervention effects, for N9 and UPG relative to control. Exposure to N9 gel and UPG generated a common "harm signal" that included transcriptional up-regulation of inflammatory genes chemokine (C-C motif) ligand 20 (macrophage inflammatory factor-3alpha) and interleukin 8 in the cervix, decreased protein concentrations of secretory leukocyte protease inhibitor, and transcriptional up-regulation of inflammatory mediators glycodelin-A and osteopontin in the endometrium. These results need to be replicated with a larger sample, but underscore the need to consider the effects of microbicide agents and gel excipients on the upper female reproductive tract in studies of vaginal microbicides.

Nucleocapsid Protein: A Desirable Target for Future Therapies Against HIV-1

The currently available anti-HIV-1 therapeutics is highly beneficial to infected patients. However, clinical failures occur as a result of the ability of HIV-1 to rapidly mutate. One approach to overcome drug resistance is to target HIV-1 proteins that are highly conserved among phylogenetically distant viral strains and currently not targeted by available therapies. In this respect, the nucleocapsid (NC) protein, a zinc finger protein, is particularly attractive, as it is highly conserved and plays a central role in virus replication, mainly by interacting with nucleic acids. The compelling rationale for considering NC as a viable drug target is illustrated by the fact that point mutants of this protein lead to noninfectious viruses and by the inability to select viruses resistant to a first generation of anti-NC drugs. In our review, we discuss the most relevant properties and functions of NC, as well as recent developments of small molecules targeting NC. Zinc ejectors show strong antiviral activity, but are endowed with a low therapeutic index due to their lack of specificity, which has resulted in toxicity. Currently, they are mainly being investigated for use as topical microbicides. Greater specificity may be achieved by using non-covalent NC inhibitors (NCIs) targeting the hydrophobic platform at the top of the zinc fingers or key nucleic acid partners of NC. Within the last few years, innovative methodologies have been developed to identify NCIs. Though the antiviral activity of the identified NCIs needs still to be improved, these compounds strongly support the druggability of NC and pave the way for future structure-based design and optimization of efficient NCIs.

The Vaginal Acquisition and Dissemination of HIV-1 Infection in a Novel Transgenic Mouse Model Is Facilitated by Coinfection with Herpes Simplex Virus 2 and Is Inhibited by Microbicide Treatment

Epidemiological studies have demonstrated that herpes simplex virus 2 (HSV-2) infection significantly increases the risk of HIV-1 acquisition, thereby contributing to the expanding HIV-1 epidemic. To investigate whether HSV-2 infection directly facilitates mucosal HIV-1 acquisition, we used our transgenic hCD4/R5/cT1 mouse model which circumvents major entry and transcription blocks preventing murine HIV-1 infection by targeting transgenic expression of human CD4, CCR5, and cyclin T1 genes to CD4(+) T cells and myeloid-committed cells. Productive infection of mucosal leukocytes, predominantly CD4(+) T cells, was detected in all hCD4/R5/cT1 mice intravaginally challenged with an HIV-1 infectious molecular clone, HIV-Du151.2env-NLuc, which expresses an env gene (C.Du151.2) cloned from an acute heterosexually infected woman and a NanoLuc luciferase reporter gene. Lower genital tract HIV-1 infection after HIV-Du151.2env-NLuc intravaginal challenge was increased ~4-fold in hCD4/R5/cT1 mice coinfected with HSV-2. Furthermore, HIV-1 dissemination to draining lymph nodes was detected only in HSV-2-coinfected mice. HSV-2 infection stimulated local infiltration and activation of CD4(+) T cells and dendritic cells, likely contributing to the enhanced HIV-1 infection and dissemination in HSV-2-coinfected mice. We then used this model to demonstrate that a novel gel containing tenofovir disoproxil fumarate (TDF), the more potent prodrug of tenofovir (TFV), but not the TFV microbicide gel utilized in the recent CAPRISA 004, VOICE (Vaginal and Oral Interventions to Control the Epidemic), and FACTS 001 clinical trials, was effective as preexposure prophylaxis (PrEP) to completely prevent vaginal HIV-1 infection in almost half of HSV-2-coinfected mice. These results also support utilization of hCD4/R5/cT1 mice as a highly reproducible immunocompetent preclinical model to evaluate HIV-1 acquisition across the female genital tract.

IMPORTANCE

Multiple epidemiological studies have reported that genital herpes simplex virus 2 (HSV-2) infection increases the risk of HIV-1 sexual acquisition by severalfold. Understanding the underlying mechanisms by which HSV-2 facilitates HIV-1 infection and optimizing the efficacy of therapies to inhibit HIV-1 infection during HSV-2 coinfection should contribute to reducing HIV-1 transmission. Using our novel transgenic hCD4/R5/cT1 mouse model infectible with HIV-1, we demonstrated that HSV-2 infection enhances vaginal transmission and dissemination of HIV-1 infection while stimulating recruitment and activation of CD4(+) T cells and dendritic cells in the lower genital tract. HIV acquisition by hCD4/R5/cT1 mice vaginally coinfected with HSV-2 could be completely prevented in almost half the mice by preexposure prophylaxis (PrEP) with a novel gel containing tenofovir disoproxil fumarate (TDF), the tenofovir prodrug, but not with the tenofovir microbicide gel utilized in CAPRISA-004, VOICE, and FACTS-001 clinical trials. The hCD4/R5/cT1 mice represent a new preclinical mouse model to evaluate vaginal HIV-1 acquisition.

The rational design and development of a dual chamber vaginal/rectal microbicide gel formulation for HIV prevention

The DuoGel™ was developed for safe and effective dual chamber administration of antiretroviral drugs to reduce the high incidence of HIV transmission during receptive vaginal and anal intercourse. The DuoGel™s containing IQP-0528, a non-nucleoside reverse transcriptase inhibitor (NNRTI), were formulated from GRAS excipients approved for vaginal and rectal administration. The DuoGel™s were evaluated based upon quantitative physicochemical and biological evaluations defined by a Target Product Profile (TPP) acceptable for vaginal and rectal application. From the two primary TPP characteristics defined to accommodate safe rectal administration three DuoGel™ formulations (IQB3000, IQB3001, and IQB3002) were developed at pH 6.00 and osmolality ⩽400mmol/kg. The DuoGel™s displayed no in vitro cellular or bacterial toxicity and no loss in viability in ectocervical and colorectal tissue. IQB3000 was removed from consideration due to reduced NNRTI delivery (∼65% reduction) and IQB3001 was removed due to increase spread resulting in leakage. IQB3002 containing IQP-0528 was defined as our lead DuoGel™ formulation, possessing potent activity against HIV-1 (EC50=10nM). Over 12month stability evaluations, IQB3002 maintained formulation stability. This study has identified a lead DuoGel™ formulation that will safely deliver IQP-0528 to prevent sexual HIV-1 transmission in the vagina and rectum.

Mucosal effects of tenofovir 1% gel

Tenofovir gel is being evaluated for vaginal and rectal pre-exposure prophylaxis against HIV transmission. Because this is a new prevention strategy, we broadly assessed its effects on the mucosa. In MTN-007, a phase-1, randomized, double-blinded rectal microbicide trial, we used systems genomics/proteomics to determine the effect of tenofovir 1% gel, nonoxynol-9 2% gel, placebo gel or no treatment on rectal biopsies (15 subjects/arm). We also treated primary vaginal epithelial cells from four healthy women with tenofovir in vitro. After seven days of administration, tenofovir 1% gel had broad-ranging effects on the rectal mucosa, which were more pronounced than, but different from, those of the detergent nonoxynol-9. Tenofovir suppressed anti-inflammatory mediators, increased T cell densities, caused mitochondrial dysfunction, altered regulatory pathways of cell differentiation and survival, and stimulated epithelial cell proliferation. The breadth of mucosal changes induced by tenofovir indicates that its safety over longer-term topical use should be carefully monitored.