TitleContinuous Use of Vaginal Ring Shows Promise as Method for Preventing Both HIV and Pregnancy
A vaginal ring containing dapivirine and levonorgestrel delivered sustained levels of each drug when used continuously for 90 days -- levels likely sufficient to serve its dual purpose for protecting against both HIV and unwanted pregnancy, according to a study presented at the Virtual 4th HIV Research for Prevention Conference.
“It is so exciting to see the dapivirine ring nearing the finish line, and we can only hope that other HIV prevention products for women will follow,” said Sharon L. Achilles, MD, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania. “If there’s one thing we’ve learned from our experience with contraception uptake and delivery, it’s important that women have options, because they have different needs and preferences at different times in their lives. That’s why a product that could protect against both HIV and unwanted pregnancy might be especially attractive to many women.”
The dual-purpose ring contains 200 mg of dapivirine to allow for its extended release over 3 months, as well as 320 mg of levonorgestrel. A total of 25 women from Pittsburgh were randomised to use the combination dapivirine-levonorgestrel ring continuously for 90 days or cyclically for 90 days (3 cycles during which the ring was used for 28 days and removed for 2 days).
Bleeding patterns experienced by participants were nearly identical in both groups, and generally reassuring. Of the more than 2,100 total days of ring use across both groups, 58% were without bleeding and 31% only spotting. Likewise, moderate bleeding was reported to occur only 10% of the days and heavy bleeding only accounted for 1% to 2% of the days in each group. There were no significant product-related safety concerns.
While dapivirine levels decreased when the ring was removed, they remained within the range needed to be effective. Likewise, levonorgestrel levels in plasma remained consistent with those required for effective contraception. With respect to dapivirine levels in vaginal fluid, there was a rapid and steep decline after the ring’s removal.
“Because cyclic use is a common practice with many hormonal contraceptives, and, as a user-controlled product, periodic removal of the ring can be expected, we wanted to understand the impact this behavior would have on both bleeding patterns and HIV protection,” said Dr. Achilles. “So far, it does not appear likely that cyclic use will make a difference in bleeding patterns, but it remains to be seen whether or not periodic removals will allow for sustained protection against HIV infection. This is something that we will need to study further.”
While adherence to ring use was high -- about 91% -- more than 25% of the participants said they removed the ring at least once during the study. At the same time, 19 of the 25 participants reported that their ring partially come out on its own on 1 or more occasion. For 10 women, the ring fell out completely at least once.
Unlike the monthly and 90-day tenofovir rings, the combination dapivirine-levonorgestrel ring evaluated in the study was made to be more pliable and had a softer feel, which the researchers believe is the likely reason for the many expulsions. The manufacturer has since reformulated the ring, which it now plans to evaluate in a trial to be conducted in partnership with the Contraceptive Clinical Trials Network, part of the National Institutes of Health, Bethesda, Maryland.
The 90-day dual-purpose ring was developed by the nonprofit International Partnership for Microbicides (IPM). IPM is seeking the ring’s approval in several African countries, as well as from the US Food and Drug Administration. If approved, the monthly dapivirine ring would be the first biomedical HIV prevention method designed specifically for cisgender women and the first long-acting method.
SOURCE: Microbicide Trials Network