Scientists Working to Stop HIV See Fresh Hope in Vaginal Ring Trials
In 2012, when researchers first announced plans to develop a vaginal ring that could prevent HIV infections, hopes ran high that the global HIV epidemic might have finally met its match. But the technology has encountered a number of bumps in the road on its way to reaching the women who need it most.
In early 2016, the first round of clinical trials in Africa returned success rates that were lower than expected. Even more troubling: Efficacy rates for the rings in women ages 18 to 21, one of the most at-risk groups for new HIV infections, were so low they showed “little to no protection” against HIV. But according to researchers, these results are incredibly promising when it comes to the big picture.
Globally, women make up more than half of all people living with HIV, and for women ages 15 to 44, HIV/AIDS is still the leading cause of death worldwide. Since 1981, HIV/AIDS have caused 25 million deaths, and an estimated 2 million people still become infected with HIV every year. Although treatment options have come a long way, many of the newly infected live in places with inadequate access to treatment. Sub-Saharan Africa has the most serious HIV/AIDS epidemic in the world, accounting for 71 percent of the global total of 36.9 million people living with HIV.
“Nothing has been more transformative for women than the availability of effective contraception, and for many women in high HIV-incidence areas, they’ve never been able to take charge of protecting themselves against STDs and, in particular, HIV in quite the same way,” Sharon Hillier, a microbiologist and head of the University of Pittsburgh–based Microbicide Trials Network, told TakePart.
Hillier’s group coordinated the largest clinical trial to date of vaginal rings containing the antiretroviral drug dapivirine with more than 2,000 women in Uganda, South Africa, Malawi, and Zimbabwe. The study found that participants under 25 saw a negligible 10 percent reduction in HIV infection risk, but women over 25 experienced a 61 percent reduction in risk. Hillier suggested this could be because older women used the ring more consistently, noting that similar age-based trends have been seen in almost every other study of HIV-prevention drugs for women.
The National Institutes of Health agrees and has provided a fresh round of funding, so Hillier’s group is now coordinating a follow-up study (fittingly dubbed HOPE) that will drop the double-blind aspect of the trial, which it believes will result in more consistent use of the ring across all demographics. Precedent suggests that’s likely: Initial trials of another drug taken to prevent HIV infection, Pre-exposure prophylaxis, known as PrEP, which comes in the form of a daily pill, showed a similarly low overall effectiveness rate of just 44 percent in 2011—but that rate jumped to greater than 90 percent once the people taking the drug knew for certain they were receiving medication and not a placebo. Five years later, PrEP is beginning to see widespread public-health use.
“I’m really optimistic about HOPE,” Jared Baeten, who led the vaginal ring study and has also been involved in PrEP research for a decade, told TakePart. “The appeal is that now people will know [the vaginal ring] is proven, it’s safe, and it’s newly available. That can really bring in tremendous enthusiasm for people for whom this product is the best choice...which can drastically change the outcome of the trials.”
Both Baeten and Hillier emphasized the importance of choice when it comes to effective methods for HIV prevention. One of the biggest advantages of the vaginal ring over PrEP, aside from having to take a daily pill, is that it delivers a much lower dosage of antiretroviral drugs locally instead of systemically, meaning there’s virtually no risk of the potential side effects that can be caused by PrEP, which can occasionally include serious liver or kidney problems.
“The pill isn’t for everyone,” Hillier said, “and the ring won’t be for everyone, but just like in the field of family planning, the more options women have for prevention, the more likely they’ll be to find and use one that will actually work for them.”
Hillier explained that her group is also coordinating a separate study to look at how to increase young women’s engagement in protecting themselves from HIV with more than one option. For that study, women 16 to 21 years old in Africa will be given both the dapivirine ring and PrEP for a number of months and will be asked to choose which one they’d prefer to use long-term.
That study will also look for any biological differences causing the discrepancy in the effectiveness of the vaginal ring between age groups—Hillier noted that young people tend to have more sex (and with more sexual partners) and may have a different biological environment in their reproductive tract as a result. They may also still be undergoing some of the physical changes that occur in the reproductive tract as people age, which could require a shift in dosage.
The International Partnership for Microbicides, the nonprofit product-development partnership creating the ring, has indicated that it plans to begin the regulatory approval process at the end of 2016 or the beginning of 2017, meaning that if all goes according to plan, the rings, which it estimates will initially cost around $5 each, could be made widely available as early as 2018 or 2019. The International Partnership for Microbicides and a number of other drug companies are also in the process of making products that would combine both contraception and HIV prevention in a single vaginal ring.
“My vision has always been that I want to see a time when a young woman—whether she’s in Pittsburgh, Pennsylvania, or Durban, South Africa—can walk into a clinic and get not only products that can protect her from pregnancy if she needs that, but can also reduce her risk of HIV and other sexually transmitted infections,” Hillier said, adding that after 29 years of researching microbicides, knowing that the ring could begin helping women within two or three years feels nothing short of miraculous.
“In the HIV-prevention world,” Baeten told TakePart, “our biggest hope is that in 20 years, we’ll all be out of business.”