A Phase 1 pharmacokinetic study of a single-dose bioadhesive clindamycin 2% gel for bacterial vaginosis.

OBJECTIVES: To evaluate pharmacokinetics (PK) of a single dose of an investigational 2% clindamycin phosphate vaginal gel in healthy women by assessment of plasma and vaginal clindamycin concentrations over 7 days, and assess safety. METHODS: Single-centre, Phase 1, single-dose PK study. Blood and vaginal samples were collected daily and safety was evaluated through to Day 7. RESULTS: Twenty-one subjects were enrolled; 20 completed the study. Plasma clindamycin concentrations demonstrated quantifiable values in all subjects through to 24 h post-dose, remaining above the limits of quantification (LOQ) through to 48 h for the majority of subjects. Systemic exposure (AUC0-t) was 1179 (range 62-3822) h·ng/mL. Arithmetic mean AUC0-24 was 818 (range 51-3287) h·ng/mL. Vaginal clindamycin phosphate levels were relatively high 24 h following administration in 15/21 subjects (6 subjects had values >400 µg/g and 9 had values of 100-400 µg/g). The levels dropped in most participants to below the LOQ 2 days following dosing. In a few participants, levels remained elevated for several days. Maximal amounts of vaginal clindamycin occurred on Day 2 with a mean value of 30.3 µg. One treatment-emergent adverse event (TEAE) of moderate-severity headache not related to study drug was reported and resolved on Day 1. No TEAEs were related to physical examinations, pelvic examinations, laboratory values or vital signs. CONCLUSIONS: The vaginal concentrations of clindamycin phosphate plus the clindamycin plasma profile over time are consistent with release of drug from the investigational gel over 24 to 72 h. A single dose was well tolerated.

The postcoital test in the development of new vaginal contraceptives†.

Postcoital tests (PCTs) have been used for over a century in the clinical evaluation of infertile couples, and for nearly 70 years in the evaluation of new vaginal contraceptive products. PCTs have been largely replaced by more modern methods in the study of infertility, but they remain the most useful way to obtain preliminary data on the effectiveness of vaginal contraceptive products. The World Health Organization has described important aspects of the procedure. It involves collection of cervical mucus at a certain time point after intercourse and the counting and characterization of sperm found in the mucus. A wide range of progressively motile sperm (PMS) has been associated with pregnancy rates in infertility studies. Eligibility for contraceptive trials includes the requirement that couples achieve a certain threshold number of PMS per high power field at midcycle in a baseline cycle without the test product. The primary endpoint, or definition of a satisfactory result in test cycles, is predefined. A literature review identified 10 PCT studies of vaginal contraceptives involving nine test products. Phase II trials of vaginal contraceptives have not been deemed feasible in the development of any vaginal contraceptive to date. A PCT study of a test product can be predictive of contraceptive efficacy, although ultimate contraceptive effectiveness is influenced by the ease of use of the product, along with patient compliance. PCT results similar to results seen with products that later showed satisfactory performance in efficacy trials is the best indicator of likely success of a test product.

Clinical safety and pharmacology trial.

Guidelines for establishing clinical safety of microbicides in early clinical studies have evolved significantly since the first trials. In addition, because of the difficulty of establishing efficacy of a microbicide prior to Phase III testing, there has been an increasing emphasis on establishing pharmacokinetic (PK)/pharmacodynamic (PD) relationships using genital samples collected in vivo in Phase I studies. A healthy pipeline is critical to success; however, it is unlikely that the majority of microbicide candidates will progress to clinical testing. Those that do enter clinical testing may have different mechanisms of action than early candidates. Given this, drug-specific modifications for early clinical assessment will need to be considered. These emerging issues associated with early clinical trials of microbicides will be reviewed, along with recommendations for future clinical safety and PK/PD evaluation.

Comparison of visual and ultraviolet light inspection versus DNA/protein biomarkers to assess product adherence with vaginal microbicide applicators.

BACKGROUND: Objective biomarkers of product use and protocol compliance are urgently needed. We compared the sensitivity and specificity of DNA and protein-based biomarkers, obtained from used vaginal gel applicators, to visual inspection of those applicators under ambient light (visual inspection of returned applicator [VIRA]) and ultraviolet light (UVL). METHODS: Forty women inserted hydroxyethylcellulose placebo gel vaginal applicators under direct observation. Applicators were evaluated by VIRA, UVL, and DNA/protein-based methods at 2 time points: within 7 days of the visit and after storing applicators for approximately 30 days. Semen biomarkers were assayed from vaginal swabs and returned applicators. RESULTS: The overall sensitivity and specificity of DNA and protein-based biomarkers in determining vaginal insertion versus sham handling of returned applicators were 98.3% and 100%, respectively, at both 7- and 30-day evaluations. The overall sensitivity and specificity of VIRA at 7 and 30 days after collection were significantly lower than those of DNA and protein-based biomarkers. Ultraviolet light inspection also had significantly lower overall sensitivity and overall specificity compared with DNA and protein biomarkers. The sensitivity of DNA and protein-based biomarkers for detecting insertion of wiped applicators was 95%, whereas the sensitivity of VIRA (range of 24%-28%) and UVL inspection (range, 38%-84%) was low for this subset. It was feasible to obtain semen biomarkers from vaginal swabs and returned used applicators. CONCLUSIONS: DNA and protein-based biomarkers offer significantly higher sensitivity and specificity compared with VIRA and UVL assessment. The accuracy of these objective biomarkers is maintained despite storage of returned products for approximately 30 days and under conditions potentially modeling field use.

Safety testing of Ovaprene: An investigational nonhormonal monthly vaginal contraceptive.

OBJECTIVES: Evaluate the safety of Ovaprene, an investigational nonhormonal vaginal contraceptive designed for monthly use. STUDY DESIGN: Open-label, multicenter study enrolling heterosexually-active women with previous permanent contraception who underwent assessments during five menstrual cycles: baseline postcoital test cycle, diaphragm postcoital test cycle, Ovaprene safety cycle, and two Ovaprene postcoital test cycles. Safety outcomes included treatment-emergent adverse events, systemic laboratory findings, pelvic examinations, colposcopies, Nugent scores, determination of community state types of vaginal microbiota, and anti-Escherichia coli activity and inflammatory markers in cervicovaginal fluids. RESULTS: We enrolled 38 participants. Of these, 33 used Ovaprene and completed 77 Ovaprene cycles. The most common product-related urogenital treatment-emergent adverse events were bacterial vaginosis and vaginal odor. The frequency of transitioning from Lactobacillus-dominated community state type to community state type IV (not Lactobacillus-dominated) was similar before Ovaprene use and afterwards. Mean Nugent scores were <4 at each visit without a discernible upward trend. Inflammatory markers showed wide variation but no upward trend, and E. coli inhibitory activity of cervical secretions did not change. We found no Staphylococcus aureus, the causative agent in toxic shock syndrome, on used Ovaprenes or in vaginal samples. No clinically important changes in systemic laboratory findings, pelvic examinations, or colposcopies occurred during Ovaprene use. CONCLUSIONS: Ovaprene use did not result in cervicovaginal irritation or adverse effects on resident vaginal microbiota and did not impact transitions from a Lactobacillus-dominated community state type to community state type IV. IMPLICATIONS: The finding that the use of Ovaprene, an investigational monthly user-controlled nonhormonal vaginal contraceptive, does not appear to result in adverse changes in vaginal health during short-term use supports further evaluation of the contraceptive potential of the device.

Successful postcoital testing of Ovaprene: An investigational non-hormonal monthly vaginal contraceptive.

OBJECTIVE: Evaluate reduction in progressively motile sperm per high power field (HPF) in midcycle cervical mucus after intercourse with Ovaprene: an investigational monthly non-hormonal vaginal contraceptive consisting of a vaginal ring and mechanical barrier, releasing spermiostatic ferrous gluconate. STUDY DESIGN: Open-label, multicenter study enrolling heterosexually-active women with previous permanent contraception. Participants underwent a baseline postcoital test cycle with no device to confirm the presence of sperm, followed by one diaphragm postcoital test cycle, one Ovaprene safety cycle, and two Ovaprene postcoital test cycles. In each postcoital test cycle, participants underwent a midcycle cervical mucus evaluation to confirm an Insler score ≥10 and absence of sperm, and then returned two to four hours after vaginal intercourse for repeat cervical mucus evaluation. We considered <5 progressively motile sperm/HPF indicative of preliminary contraceptive effectiveness. RESULTS: We enrolled 38 participants; 23 completed the study. All participants had ≥5 progressively motile sperm/HPF in the baseline cycle and <5 progressively motile sperm/HPF in all 49 Ovaprene cycles and all 35 diaphragm cycles, meeting the definition of a successful postcoital test. This was true regardless of examiner blinding, prior vaginal delivery or vaginal ring use, body mass index, or dislodgements noted by the participant or investigator. The mean of 27.2 (±17.9) progressively motile sperm/HPF in baseline postcoital test cycles was reduced to 0.5 (±1.1) and 0.5 (±1.3) progressively motile sperm/HPF in the first and second Ovaprene cycles, respectively. Ovaprene fit all participants and all could insert, position, and remove it. CONCLUSION: Use of Ovaprene resulted in meeting the prespecified criterion for contraceptive effect by all participants during all postcoital test cycles. IMPLICATIONS: The finding that use of Ovaprene, an investigational monthly non-hormonal vaginal contraceptive, resulted in postcoital testing of cervical mucus that met the pre-specified definition of success (<5 progressively motile sperm/HPF) supports further evaluation of contraceptive efficacy of the device in users at risk for pregnancy.

A phase 1/2, open-label, parallel group study to evaluate the preliminary efficacy and usability DARE-HRT1 (80 µg estradiol/4 mg progesterone and 160 µg estradiol/8 mg progesterone intravaginal RinGSM) over 12 weeks in healthy postmenopausal women.

OBJECTIVES: The exploratory objectives of this study were to evaluate the usability and acceptability and to conduct a preliminary evaluation of the efficacy of DARE-HRT1. DARE-HRT1 is an intravaginal ring (IVR) that releases 17ß2-estradiol (E2) with progesterone (P4) over 28 days. It is the first combination E2 and P4 IVR being developed for the treatment of vasomotor symptoms (VMS) in healthy postmenopausal women with an intact uterus. METHODS: This was a randomized, open-label, 2-arm, parallel group study in 21 healthy postmenopausal women. Women were randomized (1:1) to either DARE-HRT1 IVR1 (E2 80 µg/d with P4 4 mg/d) or DARE-HRT1 IVR2 (E2 160 µg/d with P4 8 mg/d). They used the assigned IVR for three 28-day cycles, inserting a new IVR monthly. Preliminary genitourinary syndrome of menopause (GSM) treatment efficacy was estimated by measuring changes from baseline in vaginal pH, vaginal maturation index (VMI), and changes in the severity of GSM symptoms. Preliminary systemic VMS efficacy was measured by changes in responses to the Menopause-Specific Quality of Life (MENQOL) questionnaire. Acceptability was assessed by product experience surveys. RESULTS: Preliminary local GSM treatment efficacy was supported by significant decreases in vaginal pH and % parabasal cells, and significant increases in the overall VMI and % superficial cells for both IVR groups (all P values <0.01). Preliminary VMS efficacy was supported by significant decreases in all domains of the MENQOL questionnaire from baseline for both dosing groups (all P values <0.01). CONCLUSIONS: Data from this study support further development of DARE-HRT1 for the treatment of menopausal symptoms.

A phase 1/2, open-label, parallel group study to evaluate the safety and pharmacokinetics of DARE-HRT1 (80 µg estradiol/4 mg progesterone and 160 µg estradiol/8 mg progesterone intravaginal rings) over 12 weeks in healthy postmenopausal women.

OBJECTIVES: Primary objectives were to evaluate the safety and systemic pharmacokinetics (PK) of DARE-HRT1, an intravaginal ring (IVR), which releases 17ß2-Estradiol (E2) with progesterone (P4) for 28 days in healthy postmenopausal women. METHODS: This was a randomized, open-label, 2-arm, parallel group study in 21 healthy postmenopausal women with an intact uterus. Women were randomized (1:1) to either DARE-HRT1 IVR1 (E2 80 µg/d with P4 4 mg/d) or DARE-HRT1 IVR2 (E2 160 µg/d with P4 8 mg/d). They used the IVR for three 28-day cycles, inserting a new IVR monthly. Safety was measured by treatment emergent adverse events and changes in systemic laboratories and the endometrial bilayer width. Baseline adjusted plasma PK of E2, P4, and estrone (E1) was described. RESULTS: Both DARE-HRT1 IVR were safe. All treatment emergent adverse events were mild or moderate and were distributed similarly among IVR1 versus IVR2 users. Month 3 median maximum plasma ( Cmax ) P4 concentrations were 2.81 and 3.51 ng/mL and Cmax E2 was 42.95 and 77.27 pg/mL for IVR1 and IVR2 groups, respectively. Month 3 median steady state ( Css ) plasma P4 concentrations were 1.19 and 1.89 ng/mL, and Css E2 was 20.73 and 38.16 pg/mL for IVR1 and IVR2 users, respectively. CONCLUSIONS: Both DARE-HRT1 IVRs were safe and released E2 in systemic concentrations, which were in the low, normal premenopausal range. Systemic P4 concentrations predict endometrial protection. Data from this study support further development of DARE-HRT1 for the treatment of menopausal symptoms.

Acceptability of Single-dose Clindamycin Gel for Bacterial Vaginosis: A Randomized Controlled Trial.

PURPOSE: The goal of this study was to assess the acceptability of a single-dose bioadhesive 2% clindamycin vaginal gel for bacterial vaginosis (BV). METHODS: This double-blind, placebo-controlled, randomized study compared a new clindamycin gel with placebo gel (2:1 ratio). The primary objective was efficacy; secondary objectives were safety and acceptability. Subjects were evaluated at screening, days 7 to 14 (Day 7-14), and days 21 to 30 (test-of-cure [TOC]). An acceptability questionnaire with 9 questions was administered at the Day 7-14 visit, and a subset of questions (#7-#9) was asked again at the TOC visit. At Visit 1, subjects were provided with a daily electronic diary (e-Diary) to collect information regarding study drug administration, vaginal discharge, odor, itching, and any other treatments used. Study site staff reviewed e-Diaries at the Day 7-14 and TOC visits. FINDINGS: A total of 307 women with BV were randomized to treatment (204 to the clindamycin gel group and 103 to the placebo gel group). Most (88.3%) reported at least one previously diagnosed BV episode, and more than one half (55.4%) had experience with other vaginal treatments for BV. At the TOC visit, almost all (91.1%) of the clindamycin gel subjects described their overall experience with the study drug as "satisfied" or "very satisfied," 95.8% indicated that they would be "likely" or "very likely" to use the product again if it became available after the study and they had BV again, and 93.7% would be "likely" or "very likely" to recommend their treatment to a friend who had BV. Almost all (90.2%) clindamycin-treated subjects responded that application was "clean" or "fairly clean," as opposed to "neither clean nor messy," "fairly messy," or "messy." Although 55.4% experienced leakage in the days after application, only 26.9% of those indicated that it was bothersome. Subjects receiving clindamycin gel also reported improvement in both odor and discharge, commencing shortly after dosing and continuing through the assessment period, regardless of whether they met the critical cure criteria. IMPLICATIONS: A single dose of a new bioadhesive 2% clindamycin vaginal gel showed rapid resolution of symptoms and was highly acceptable as a treatment for bacterial vaginosis. CLINICALTRIALS: gov identifier: NCT04370548.

A quantitative glycogen assay to verify use of self-administered vaginal swabs.

BACKGROUND: Self-administered swabs are used to sample vaginal contents for a variety of clinical purposes including detection of sexually transmitted infections, condom breakage, and vaginal product use. The goal of this study was to determine whether a quantitative glycogen assay can be used to assess whether a swab has been exposed to the vagina to assure study compliance. STUDY DESIGN: Buccal, skin, or vaginal samples were tested to determine whether a commercial quantitative glycogen assay can differentiate vaginal specimens. In addition, archived remnant de-identified vaginal swabs from clinical trials were tested. Periodic acid-Schiff stain was used to identify glycogen-positive cells as a confirmation test. RESULTS: Glycogen concentrations in eluates of vaginal swabs from reproductive-aged women were significantly higher than those from unused swabs (mean ± SE, 964 ± 135 µg/mL vs. 14.7 ± 2.5 µg/mL, P < 0.001) and swabs exposed to buccal and finger/hand epithelia (40.3 ± 4.8 and 18.5 ± 5.4 µg/mL, P < 0.001). Glycogen concentrations were lower and more variable in vaginal swabs from older perimenopausal/menopausal women (mean ± SE, 235 ± 123, P < 0.01). Semen and sample storage longer than 1 year did not affect glycogen detection. Using a cutoff of 100 µg/mL of glycogen, 30 of 30 vaginal swabs from reproductive-aged women versus 0 of 28 control swabs were positive, for an assay sensitivity of 1 (95% confidence interval, 0.86-1) and specificity of 1 (95% confidence interval, 0.85-1). Periodic acid-Schiff stain correlated with soluble glycogen results but was less specific. CONCLUSIONS: The quantitative glycogen assay provides a simple and inexpensive method to validate the use of self-administered swabs for sampling vaginal contents in clinical studies.

Colposcopy: still useful in microbicide safety trials?

BACKGROUND: Colposcopy is used to evaluate vaginal microbicides, but its link to risk of HIV is unknown. This reanalysis of 9 safety studies determined the impact of omitting colposcopy on the number of findings detected and assessed whether colposcopy was useful in identifying nonoxynol-9 (N-9) as an unsafe product in one study. METHODS: Product-related findings seen with naked eye and colposcopy or by colposcopy alone were evaluated. Using data from one study, the ratio of findings in N-9 users to those in hydroxyethylcellulose (HEC) users was compared for findings seen by naked eye and colposcopy versus findings detected only by colposcopy. RESULTS: Of the 403 finding observations in the 9 studies, 173 (43%) would have been missed without colposcopy. Data from the N-9/HEC study showed that without colposcopy, there would have been 7 times as many observations in the N-9 group as in the HEC group (63 vs. 9). With colposcopy, the N-9/HEC ratio was 13:9 or 1.4. Considering epithelial integrity, finding type, and size showed similar patterns, except that among the smallest findings (<5 mm), the N-9/HEC ratio was 1.2 by naked eye and nearly the same at 1.4 by colposcopy. CONCLUSION: Colposcopy was not helpful in identifying an unsafe product: the conclusions reached using naked eye examination alone were more alarming regarding the safety of N-9 than reached by including colposcopy. Recommendations include: (1) naked eye examinations should be continued in microbicide studies; (2) colposcopy may be considered for early studies, such as first-in-human studies, but has no place in large studies; and (3) colposcopy should be replaced as soon as possible with a more objective validated biomarker of HIV risk.

Single-Dose, Bioadhesive Clindamycin 2% Gel for Bacterial Vaginosis: A Randomized Controlled Trial.

OBJECTIVE: To assess efficacy and safety of a single-dose vaginal clindamycin gel for bacterial vaginosis treatment. METHODS: We conducted a double-blind, placebo-controlled, randomized study comparing clindamycin gel with placebo (2:1 ratio). Entry required clinical diagnosis of bacterial vaginosis, that is, all four Amsel's criteria, without other genital infections. Nugent scores of 7-10 were required for efficacy assessment, per updated 2019 U.S. Food and Drug Administration guidance. Patients were evaluated at screening, day 7-14, and day 21-30 (test of cure). Clinical cure was defined as resolution of three of four Amsel's criteria. Bacteriologic cure was defined as Nugent score lower than 4. Therapeutic cure was both clinical and bacteriologic cure. Primary outcome was clinical cure at the test-of-cure visit. Secondary endpoints were clinical cure at day 7-14, and bacteriologic and therapeutic cures at day 7-14 and test of cure. A sample size of 188 patients in the clindamycin group compared with 94 patients in the placebo group had 90% power to detect statistically significant difference (P=.05, 2-tailed). RESULTS: Participants were seen between July 9, 2020, and November 12, 2020. Of 307 randomized women, 56.0% were Black and 88.3% reported one or more previous bacterial vaginosis episodes. In the modified intention-to-treat population, 70.5% of patients in the clindamycin group and 35.6% in the placebo group achieved clinical cure at test of cure (primary outcome) (difference of 34.9, 95% CI 19.0-50.8), as did 77.5% of patients in the clindamycin group and 42.6% of patients in the placebo group in the per-protocol population (difference of 34.9, 95% CI 17.0-52.7). Statistically significant differences between groups were seen for all secondary endpoints. Clinical cure rate in patients in the clindamycin group with more than three bacterial vaginosis episodes in the prior year was 70.0%. Approximately 15% (15.3%) of patients in the clindamycin group experienced one or more treatment-emergent adverse events related to study treatment, as did 9.7% of patients in the placebo group. The most frequent treatment-related, treatment-emergent adverse event was vulvovaginal candidiasis. CONCLUSION: A new, single-dose clindamycin vaginal gel was highly effective, with excellent safety, in women disproportionately affected by bacterial vaginosis, with Nugent scores of 7-10 at study entry. FUNDING SOURCE: The study was funded by Daré Bioscience, Inc. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov, NCT04370548.

As the world grows: contraception in the 21st century.

Contraceptives that are readily available and acceptable are required in many poorer countries to reduce population growth and in all countries to prevent maternal morbidity and mortality arising from unintended pregnancies. Most available methods use hormonal steroids or are variations of barrier methods. Reports from several fora over the last 12 years have emphasized the number of unwanted pregnancies and resultant abortions, which indicate an unmet need for safe, acceptable, and inexpensive contraceptive methods. This unmet need can be assuaged, in part, by development of new nonhormonal contraceptive methods. This Review addresses the contribution that the "omic" revolution can make to the identification of novel contraceptive targets, as well as the progress that has been made for different target molecules under development.

Baseline variation and associations between subject characteristics and five cytokine biomarkers of vaginal safety among healthy non-pregnant women in microbicide trials.

Interleukins (IL)-8, IL-1α, IL-1ß, and IL-1 receptor antagonist (IL-1RA) have emerged as indicators of vaginal inflammation and HIV-1 transmission risk. We provide values and factors of normal variation of these immune mediators in premenopausal women to allow their wider clinical application as biomarkers of vaginal health. Cross-sectional analyzes (Kruskal-Wallis and Wilcoxon exact tests) of cytokine concentrations in relation to sociodemographic variables and Nugent score were performed on baseline (prior to product) cervicovaginal lavage from two Phase I randomized microbicide trials. All women in the analysis had regular menstrual cycles, 72 h abstinence, normal blood and Pap tests, and absence of genitourinary infections, study-relevant allergies, antibiotics use and history of substance abuse. Cytokine norms were defined as the values among those with Nugent score <4. Among women with normal Nugent score (n=92), IL-8 and IL-1ß were lowest in those using abstinence as compared to hormonal contraceptives or male/female sterilization as their primary method for birth control. No difference was found by age, prior pregnancy, or education, and also by race after controlling for contraceptive method. Women with abnormal (>7) and borderline (4-6) Nugent scores had elevated IL-1α and/or IL-1ß although their IL-1RA-to-IL(α+ß) ratio remained within the normal range due to higher IL-1RA. Women with borderline Nugent scores had IL-8 levels above the normal range. IL-8 and the IL-1RA-to-IL-1 ratio can be used as independent biomarkers of vaginal immune balance. More studies must determine the role of sexual activity, contraceptive method, and borderline Nugent scores, which normally are not exclusion criteria for enrollment in microbicide trials but may affect product tolerability and HIV-1 risk due to the aberrant cytokine levels.

Biomarkers of semen exposure.

Biomarkers of semen exposure have historically played their most important role in forensics, i.e., determining whether ejaculation took place in the course of a crime. However, it is becoming increasingly recognized that biomarkers of semen exposure can be useful in the development of new vaginal methods of HIV/sexually transmitted infections (STI) prevention and contraception. This review is based on the presentations of Drs. Michael Coppola (ContraVac, Inc.), Maurizio Macaluso (Centers for Disease Control and Prevention), Andrezej Kulczycki (University of Alabama at Birmingham), Christine Mauck (CONRAD), Robin Maguire (Population Council), and the subsequent discussion led by Drs. Susan Ballagh (CONRAD) and Johan Melendez (Johns Hopkins University) during a session entitled "Biomarkers of semen exposure" held during the conference entitled "Biomarkers for evaluation of vaginal microbicides and contraceptives: Discovery and early validation," organized by CONRAD and the Alliance for Microbicide Development in November of 2006.

Biomarkers for evaluating vaginal microbicides and contraceptives: discovery and early validation.

A biomarker has been defined as "a characteristic that is objectively measured and evaluated as an indicator of normal biological processes, pathogenic processes, pharmacological responses to a therapeutic intervention." Biomarkers can reduce the costs and time required to get a drug from discovery to market. Topical microbicides are new drugs designed to prevent HIV and other sexually transmitted infections (STIs). Biomarkers that may be important in microbicide development include biomarkers of semen exposure, biomarkers of cervicovaginal inflammation, and biomarkers of HIV and STIs. The development of biomarkers for use in microbicide development is a high priority. This supplement reports on a meeting entitled "Biomarkers for Evaluating Vaginal Microbicides and Contraceptives: Discovery and Early Validation," held in Reston, VA on November 16 to 17, 2006. It was sponsored by CONRAD and the Alliance for Microbicide Development with funding from the Bill and Melinda Gates Foundation and the United States Agency for International Development (USAID). The meeting was convened to look at the ways in which biomarkers could be used to attenuate the challenges alluded to above. Availability of key biomarkers could expedite the development of microbicides, for which there is a pressing need, especially in developing countries where combinations of cultural and socioeconomic pressures on women constrain their ability to protect themselves from STIs. Although the meeting was held 2 years ago, the material reviewed and conclusions drawn are still relevant.

Biomarker discovery: validation and decision-making in product development.

The conference on which this supplement reports was organized to bring together microbicide researchers with researchers in the areas of drug prophylaxis and therapeutics development. The goal of session 1 was to share methods used to validate markers of disease, elucidate the logic used to substantiate the performance of those markers, and identify ways to translate this experience into practical steps for developing microbicides. The experiences discussed ranged from de novo discovery of new therapeutics to qualification of biomarkers across all stages of development, and covered the complexity of biomarker identification, use, and assessment in the clinical areas of cancer and infectious disease. This review is based on the presentations of Drs. Harsukh Parmar (AstraZeneca), Sudhir Srivastava (National Cancer Institute [NCI]), and Juan Leal (Exelixis Inc.), and the subsequent discussion led by Drs. Sam Niedbala (Lehigh University) and Thomas Moench (ReProtect) during a background session held at the conference entitled "Biomarkers for evaluation of vaginal microbicides and contraceptives: Discovery and early validation," organized by CONRAD and the Alliance for Microbicide Development in November 2006.

Effect of Hormonal Contraception on Pharmacokinetics of Vaginal Tenofovir in Healthy Women: Increased Tenofovir Diphosphate in Injectable Depot Medroxyprogesterone Acetate Users.

OBJECTIVE: Endogenous and exogenous contraceptive hormones may affect mucosal pharmacokinetics (PKs) of topical antiretrovirals such as tenofovir. We present PK data from healthy women using tenofovir vaginal gel, at baseline (follicular and luteal phases) and after oral contraceptive pill (OCP) or depot medroxyprogesterone acetate (DMPA) use. METHODS: CONRAD A10-114 was a prospective, interventional, open-label, parallel study. We enrolled 74 women and 60 completed the study (32 and 28 who selected OCPs or DMPA, respectively). Participants used 2 doses of tenofovir gel separated by 2 hours, without intercourse, and were examined 3 or 11 hours after the last dose. We assessed pharmacokinetics in plasma, cervicovaginal (CV) aspirate, and vaginal tissue. RESULTS: In general, there were no significant differences in mucosal tenofovir and tenofovir diphosphate concentrations (P > 0.23) in the follicular and luteal phases, except for lower mean tenofovir tissue concentrations (P < 0.01) in the follicular phase. Tenofovir concentrations significantly decreased in CV aspirate (P < 0.01) after contraceptive use, but overall remained very high (>10 ng/mL). Mean tissue tenofovir diphosphate increased to 6229 fmol/mg after DMPA use compared with 3693 and 1460 fmol/mg in the follicular and luteal phases, respectively (P < 0.01). The molecular conversion of tenofovir into tenofovir diphosphate was more effective in DMPA users (molecular ratio of 2.02 versus 0.65 luteal phase, P < 0.01). CONCLUSIONS: Both menstrual cycle phase and exogenous hormones affect topical tenofovir mucosal and systemic PKs. However, high levels of tenofovir and tenofovir diphosphate were observed in the CV mucosa in the presence or absence of OCPs and DMPA, with tissue levels exceeding benchmarks of predicted mucosal anti-HIV efficacy (tenofovir >1.00 ng/mL in CV aspirate and tenofovir diphosphate >1000 fmol/mg).

The Effect of Hormonal Contraception on Cervicovaginal Mucosal End Points Associated with HIV Acquisition.

Reproductive age women may choose to concurrently use topical antiretrovirals and hormonal contraceptives (HCs) to simultaneously prevent HIV-1 infection and unintended/mistimed pregnancy. There are conflicting data on the effect of HCs on mucosal susceptibility to HIV-1. The objective of this study was to evaluate cervicovaginal (CV) mucosal data from healthy women before and after initiation of either oral contraceptive pills (OCPs) or depot medroxyprogesterone acetate (DMPA) injection. CONRAD A10-114 was a prospective, open-label, parallel cohort study. We enrolled 74 women and 62 completed the visits (32 and 30 who selected OCPs and DMPA, respectively). Participants provided CV lavage, vaginal biopsies, and CV swabs at baseline in the luteal phase and then ∼6 weeks after initiating HCs. After contraceptive initiation, there were significant increases in vaginal immune cell density among both DMPA and OCP users. Changes for OCP users were concentrated in the subepithelial lamina propria, whereas for DMPA users, they were distributed throughout the vaginal tissue, including the epithelium (CD45+, CD3+, CD4+, and CD1a+). Contraceptive use altered concentrations of soluble CV inflammatory and immune mediators, with significant reductions in some proinflammatory cytokines and secretory leukoprotease inhibitor. Compared with baseline, p24 antigen production after ex vivo HIV-1 infection of vaginal biopsies doubled after DMPA use, but all p-values were >.05. HIV-1 replication was significantly higher in DMPA-exposed tissues compared with those from the OCP group at the end of the tissue culture (p = .01). Although not statistically significant, median in vitro inhibition of HIV-1 by CV fluid (innate antiviral activity), was reduced by ∼50% with HCs (p > .21). Exposure to exogenous contraceptive hormones significantly increased vaginal immune cells and reduced CV proinflammatory cytokines and antimicrobial peptides. DMPA users showed higher susceptibility to HIV-1 ex vivo infection.