Phase 2a Safety, Pharmacokinetics, and Acceptability of Dapivirine Vaginal Rings in US Postmenopausal Women.

BACKGROUND: Postmenopausal women have unique sociobiological human immunodeficiency virus (HIV) risks. We evaluated the safety, pharmacokinetics, and acceptability of a microbicide dapivirine (DPV) vaginal ring (VR) versus placebo in postmenopausal women. METHODS: We enrolled 96 HIV-negative postmenopausal US women in a phase 2a double-blind, randomized (3:1) trial of monthly VRs containing 25 mg DPV or placebo used continuously for 12 weeks. We assessed safety by adverse events (AEs). DPV concentrations were quantified in plasma and vaginal fluid. Steady-state concentrations were analyzed at 4, 8, and 12 weeks using repeated measures ANOVA. We assessed acceptability by self-report. RESULTS: We found no differences in the proportion of women with related grade 2 or higher reproductive system AEs (DPV: 6/72 (8%), placebo: 3/24 (13%), P = .68) or grade 3 or higher AEs (DPV: 4/72 (6%), placebo: 0/24 (0%), P = .57). In the DPV arm, 2/72 (3%) declined to resume product use due to AEs. Median DPV concentrations in plasma (262.0 pg/mL at week 12) and vaginal fluid (40.6 ng/mg at week 12) were constant over 12 weeks and exceeded the in vitro 50% effective concentration by 5000-fold in vaginal fluid by week 4. VR acceptability was high; 84/93 (90%) "very much liked or liked" the VR. CONCLUSIONS: DPV VRs were safe, well tolerated, and acceptable in postmenopausal women. Plasma concentrations were comparable to published data on DPV use in reproductive-age women (median plasma concentration: 264 pg/mL). Given the reassuring safety and pharmacokinetic data, the DPV VR is promising for preexposure prophylaxis in postmenopausal women. CLINICAL TRIALS REGISTRATION: NCT02010593.

Contraceptive Preference Among Women at Risk of HIV Acquisition in a Preparatory Screening Study for a Phase III Microbicide Trial in South Western Uganda.

Contraceptive preferences of women at risk for HIV acquisition are not well documented. We report on contraceptive choices among women residing in small townships in southwestern Uganda. This was part of preparatory efforts for recruitment into the Ring Study, a phase 3 microbicide trial, between July 2013 and October 2014. Clinicians provided contraceptives per a woman's choice. HIV testing and screening for other sexually transmitted infections were done at first contact and at screening for the trial. Contraceptive choice was summarized by demographics and regression analysis to show factors associated with use of the injectable method. Of 6725 women contacted, 489 were prescreened. Of these 489 women, most (306, 63%) were already using contraception. Injectables were most preferred (58.7%), followed by implants (23.9%). Women living with a regular sexual partner preferred the injectable method (61.0%, P = 0.06), compared with other methods. Women at risk for HIV infection are willing to initiate use of modern contraceptives, which may reduce study dropout during intervention trials due to unintended pregnancy. Registration no: NCT01539226.

A randomized male tolerance study of dapivirine gel following multiple topical penile exposures (MTN 012/IPM 010).

Dapivirine (DPV) is a nonnucleoside reverse transcriptase inhibitor with a favorable safety profile following vaginal application. A penile tolerance study was conducted prior to further development of DPV as a candidate vaginal microbicide. Twenty-four circumcised and 24 uncircumcised (N=48) healthy HIV-negative male participants aged 18 years or older were randomized 2:1:1 to apply DPV 0.05% gel, matched placebo gel, or universal placebo gel, respectively, to their penis once daily for 7 sequential days. The safety, acceptability, and pharmacokinetic profile of DPV 0.05% gel were assessed by the presence of Grade 2 or higher genitourinary adverse events (AEs) and systemic AEs, a behavioral questionnaire, and pharmacokinetic plasma blood draw, respectively, at the final clinic visit (FCV). There were no Grade 2 genitourinary AEs in 47 participants completing the FCV. One participant in the DPV arm failed to attend the FCV. There were 13 AEs reported; all were Grade 1 except one Grade 2 corneal laceration unrelated to study product. Participants liked the gel to a moderate extent, yet 72% reported they would be "very likely" to use a gel like the one they used in the study every time they have intercourse. DPV was detectable in plasma in all 23 DPV arm study participants at the FCV. On average, the circumcised participants' DPV concentrations were 54% of those in uncircumcised participants (p=0.07). Topical seven-day penile application of DPV 0.05% gel was locally and systemically safe, was acceptable to male participants, and resulted in systemic exposure to the drug.

Acceptability of vaginal film, soft-gel capsule, and tablet as potential microbicide delivery methods among African women.

BACKGROUND: Vaginal microbicides are in development for the prevention of HIV transmission to women via sexual intercourse. Acceptability of the microbicide delivery method in the targeted population is important to product adherence and, therefore, product effectiveness. It is anticipated that multiple delivery methods will be required to satisfy personal preferences among future microbicide users. METHODS: A total of 526 sexually active women aged 18-30 years participated in a consumer product preference study in Burkina Faso, Tanzania, and Zambia. Screened women who had given consent were instructed to use each of the three products (placebo formulations of a vaginal tablet, film, and soft-gel capsule) once daily for 7 consecutive days for a total of 21 days. Women were interviewed about their impressions of the product at the completion of each 7-day trial period. RESULTS: Over 80% of women reported they liked using each dosage form, and over 85% said they would definitely use it. The film and soft-gel capsule were chosen significantly more often than the tablet as the preferred dosage form (39% and 37% vs. 25%, respectively) mainly because of faster dissolving time and easier insertion. Women in Burkina Faso and Tanzania preferred the soft-gel capsule (42%-46%), whereas Zambian women preferred the film (51%). Age, socioeconomic status, and marital status did not significantly affect product preference. CONCLUSIONS: All three dosage forms were acceptable to the women surveyed. Preferred dosage forms varied by country. These data suggest that the availability of microbicides in multiple dosage forms may increase acceptability, adherence, and, therefore, effectiveness.

Pharmacokinetic assessment of dapivirine vaginal microbicide gel in healthy, HIV-negative women.

UNLABELLED: To assess the pharmacokinetics of dapivirine in plasma and dapivirine concentrations in cervicovaginal fluids (CVF) and cervicovaginal tissues following vaginal administration of dapivirine microbicide gel in healthy, HIV-negative women for 10 days. A randomized, double-blind, phase I study was conducted at a single research center in South Africa. A total of 18 women used dapivirine gel (0.001%, 0.005%, or 0.02%) once daily on Days 1 and 10 and twice daily on Days 2-9. Pharmacokinetics of dapivirine were assessed in plasma on Days 1 and 10. Dapivirine concentrations were measured in CVF on Days 1 and 10 and in cervicovaginal tissues on Day 10. Safety was evaluated through laboratory tests (hematology, clinical chemistry, and urinalysis), physical examinations, and assessment of adverse events. Plasma concentrations of dapivirine increased over time with gel dose and were greater on Day 10 (C(max) 31 to 471 pg/ml) than Day 1 (C(max) 23 to 80 pg/ml). T(max) was 10-12 h on Day 1, and 9 h on Day 10. Concentrations in CVF generally increased with dose but were highly variable among participants. Mean peak values ranged from 4.6-8.3 × 10(6) pg/ml on Day 1 and from 2.3-20.7 × 10(6) pg/ml on Day 10 across dose groups. Dapivirine was detectable in all tissue biopsies on Day 10 at concentrations of 1.0-356 × 10(3) pg/mg. CONCLUSIONS: Dapivirine was widely distributed throughout the lower genital tract with low systemic absorption when administered in a vaginal gel formulation for 10 consecutive days. The gel was safe and well tolerated.

Pharmacokinetics of 2 dapivirine vaginal microbicide gels and their safety vs. Hydroxyethyl cellulose-based universal placebo gel.

Dapivirine, a nonnucleoside reverse transcriptase inhibitor, is in development as a microbicide for the protection of women against HIV infection. A randomized, double-blind, phase 1 trial was conducted in 36 healthy HIV-negative women to compare the pharmacokinetics of 2 dapivirine vaginal gel formulations (0.05% each) and their safety with the hydroxyethyl cellulose-based universal placebo gel. Gel was self-administered once daily for a total of 11 days. Blood and vaginal fluid samples were collected sequentially over 24 days for pharmacokinetic analysis. Safety was evaluated by pelvic examination, colposcopy, adverse events, and clinical laboratory assessments. Adverse event profiles were similar for the 3 gels. Most events were mild and not related to study gel. Headache and vaginal hemorrhage (any vaginal bleeding) were most common. Plasma concentrations of dapivirine did not exceed 1.1 ng/mL. Steady-state conditions were reached within approximately 10 days. Dapivirine concentrations in vaginal fluids were slightly higher for Gel 4789, but Cmax values on days 1 and 14 were not significantly different. Terminal half-life was 72-73 hours in plasma and 15-17 hours in vaginal fluids. Both formulations of dapivirine gel were safe and well tolerated. Dapivirine was delivered to the lower genital tract at concentrations at least 5 logs greater than in vitro inhibitory concentrations.

Safety, tolerability, and systemic absorption of dapivirine vaginal microbicide gel in healthy, HIV-negative women.

OBJECTIVES: To assess the local and systemic safety of dapivirine vaginal gel vs. placebo gel as well as the systemic absorption of dapivirine in healthy, HIV-negative women. METHODS: Two prospective, randomized, double-blind, placebo-controlled phase I/II studies were conducted at five research centers, four in Africa and one in Belgium. A total of 119 women used dapivirine gel (concentrations of 0.001, 0.002, 0.005, or 0.02%), and 28 used placebo gel twice daily for 42 days. The primary endpoints were colposcopic findings, adverse events, Division of AIDS grade 3 or grade 4 laboratory values, and plasma levels of dapivirine. RESULTS: Safety data were similar for the dapivirine and placebo gels. None of the adverse events with incidence more than 5% occurred with greater frequency in the dapivirine than placebo groups. Similar percentages of placebo and dapivirine gel users had adverse events that were considered by the investigator to be related to study gel. A total of five serious adverse events occurred in the two studies, and none was assessed as related to study gel. Mean plasma concentrations of dapivirine were approximately dose proportional, and, within each dose group, mean concentrations were similar on days 7, 28, and 42. The maximum observed mean concentration was 474 pg/ml in the 0.02% gel group on day 28. Two weeks after the final application of study gel, mean concentrations decreased to 5 pg/ml or less. CONCLUSION: Twice daily administration of dapivirine vaginal gel for 42 days was safe and well tolerated with low systemic absorption in healthy, HIV-negative women suggesting that continued development is warranted.