Microbicide vaginal rings (VR) provide sustained release of the NNRTI dapivirine (DPV). In a Phase 2a trial, we evaluated the adherence and acceptability of DPV VRs among postmenopausal U.S. women, a population with high biological, behavioral and social risks, in which 12% of new HIV infections occur.
We enrolled 96 HIV-uninfected postmenopausal women in MTN-024/IPM 03, a 2-arm, double-blinded, multi-site, randomized trial (3:1) of a monthly silicone VR containing 25 mg DPV or placebo, used continuously for 12 weeks. Adherence was assessed by case reports and computer-assisted self-interviewing (CASI) at monthly follow ups; and acceptability by CASI at the final visit, and by in-depth-interviews (IDIs) in a random subset (n=24). Analysis was blinded and behavioral data were combined across study groups.
Mean age was 56.8 years (range 46-65); 61% had a main partner, and 66% were currently sexually active. Study retention was 97%; 73% reportedly had the ring in place during the entire 12 weeks of use; 91% never had the ring out for more than 12 hours. Ever reporting the VR out decreased from 17% (week 4) to 5% (week 12). Six women reported full expulsions and 26 partial slippage, primarily due to bowel movements; 18 reported removals due to physical discomfort, worries, or to clean the VR. Most (99%) said the VR was very easy/easy to use; 96% indicated it never interfered with daily activities, 91% very much liked/liked the VR, 83% were never worried about it, and 65% preferred VR to condoms while 24% liked both equally. Thirty six percent reported vaginal changes with the VR, including wetness (21%) or dryness (10%). Of those sexually active, 49% did not feel the VR during sex, 82% said it did not change her sexual pleasure and 10% said her pleasure increased. Only 2 disliked wearing the VR during sex because their partners had sexual dysfunctions. During IDIs, women typically said the ring was empowering, “super-easy” to use, and preferred over condoms, as VR do not break, impact male performance, or interrupt sex. Side effects like vaginal wetness were perceived as beneficial and none had complaints about the VR interfering with other postmenopausal bodily changes. A few women had challenges with VR insertions and removals and needed staff assistance, for example due to obesity.
Participants reported high adherence, found VRs acceptable and preferred it to condoms. VR are a promising microbicide approach for HIV prevention in postmenopausal women.