A three-month PrEP vaginal ring is better than the one-month ring

What is the research about? 

The trial compared how well the monthly dapivirine pre-exposure prophylaxis (PrEP) ring, which is replaced every 28 days, worked compared to the three-month ring, which lasts for 90 days. The phase I study, "IPM-054", took place at the FARMVOS Clinical Research Centre in South Africa, with 124 women participating and 104 completing the trial. The study involved two treatment phases.  

Half of the participants started with the one-month ring, which contained 25 mg of dapivirine, and then switched to the three-month ring containing 100 mg of dapivirine. The other half of the participants followed the reverse sequence; they began with the three-month ring and later switched to the one-month ring.  

The three-month ring was similar to the one-month ring: same silicone, same dimensions, and looked and felt the same. The average age of the participants was 28, with the majority (80%) being single.  

Why is this research important? 

According to UNAIDS, in 2023, women and girls accounted for 62% of all new HIV infections in sub-Saharan Africa. Among adolescent girls and young women, the situation is particularly dire – there were 160,000 new HIV infections among adolescent girls and young women aged 15-24 in sub-Saharan Africa in 2023. 

Many young women struggle to negotiate condom use during sex, making HIV prevention methods like PrEP essential. While oral PrEP is effective, it is usually offered in pill form, which must be taken daily. The need for daily dosing, coupled with the stigma associated with PrEP pills, has limited their use. 

The dapivirine vaginal ring offers an alternative. This ring is inserted into the vagina, where it slowly releases the antiretroviral drug dapivirine over time. The one-month ring has received positive reviews from regulatory authorities, including the European Medicines Agency, and is currently approved in 11 sub-Saharan African countries. 

What did the study find? 

The study demonstrated that the three-month dapivirine ring is superior to the one-month version. Based on dapivirine concentrations in plasma, the research team concluded that the extended-duration ring offers greater drug exposure and could provide enhanced protection against HIV. 

What does this mean for HIV Services? 

By reducing the frequency of ring changes (from 12 rings a year with the one-month ring to just four), the three-month ring may increase acceptability and adherence, potentially boosting its overall effectiveness. Additionally, the estimated cost of the three-month ring is $16, which could make it a more affordable option. Reduced waste and environmental impact are other potential benefits, along with the possibility that higher drug exposure may enhance efficacy. 

What did the women who participated in the study say? 

After their findings, the research team conducted a follow-up study to find out which ring women preferred: the three-month dapivirine ring or the one-month version. 

They interviewed a smaller group of women (31). Half (16) didn't feel the rings at all, while the other half (15) felt them during activities like using the bathroom, menstruation, or sex. 

Most participants (17) preferred the three-month ring because it was more convenient, needing to be changed only once every three months. Thirteen women liked the one-month ring better, with some saying the three-month ring caused more vaginal wetness or discomfort during sex. Two women didn't have a preference. 

“I don’t think the ring hinders anything. It was inside of me, and I didn’t feel it. Sometimes I would even forget that I have it. It wasn’t a hindrance, even hygiene-wise. Even if I was menstruating, it wouldn’t have made a difference,” said participant AB, 36 years old. 

“I like the one-month treatment because the medication is not too strong for me because they change it regularly, unlike the 3-month treatment”, said Participant B, 22 years old. 

Most of the participants believed women would be willing to switch to the three-month ring if the one-month ring was no longer available, as long as it was safe and didn't cause side effects. However, they also thought some women might prefer the one-month ring. Only one woman said she wouldn't use either ring in the future because her partner didn't like it. 

The researchers conclude that there is a market for both the one-month and three-month rings, but if only the three-month ring were available, most women would be willing to switch. 

Jeremy Nuttall from the Population Council's Center for Biomedical Research, who presented the findings, noted that the three-month ring will expand options for women, making HIV prevention more convenient and accessible. He also anticipated that the three-month ring could be introduced to the market by 2026.