HIV-Preventive Vaginal Ring Found Safe, Acceptable Among Adolescents

An experimental vaginal ring containing pre-exposure prophylaxis (PrEP) and the oral tablet Truvada was found to be safe and acceptable in adolescents.

PrEP is a daily medication designed to lower the chances of high-risk individuals contracting HIV. According to the CDC, PrEP reduces the risk of HIV infection from sex by more than 90%.

The findings from the 2 studies were presented at the annual IAS Conference on HIV Science in Paris, according to a press release.

Furthermore, they mark the first time the vaginal ring was tested in adolescent girls under 18 years of age, and the first time a PrEP clinical trial for adolescents specifically included girls.

“Adolescents and young people represent a growing share of people living with HIV worldwide,” Anthony S. Fauci, MD, director of the National Institute of Allergy and Infectious Diseases (NIAID), said in the release. “Science has demonstrated that the HIV prevention needs of adolescents may be different than those of adults, which is why these new study findings are so important.”

Daily Pill Adherence in Adolescents

In the phase 2 CHAMPS PlusPills study, investigators sought to evaluate the safety, acceptability, and use of daily oral Truvada. According to the release, it is only the second clinical trial to report the results of PrEP use solely in adolescents.

Included in study were 148 healthy, sexually active, HIV-negative South African individuals aged 15 to 19 years from Cape Town and Johannesburg. The participants consisted of 99 girls and 49 boys, who were asked to take Truvada daily for at least 3 months and up to 1 year if they chose to do so.

Although most of the participants opted to take Truvada, the number who were adherent was lower and decreased over time; however, by the end of the study, nearly 40% of the participants were adherent.

During the first 3 months of the study, participants had monthly study visits followed by subsequent visits on a quarterly basis. At each visit, the investigators collected blood samples from the participants and monitored their health. At each quarterly visit, the participants could choose to opt out of, continue or resume taking Truvada.

At 3 months, the results of the study showed that tenofovir was detectable in 57% of the blood samples. At this point, 82% opted to continue taking Truvada for PrEP.

Tenofovir was detected in the blood samples of 38% of participants at 6 months. Sixty-four percent opted to continue or resume taking Truvada. Additionally, 64% of participants also opted to continue or resume Truvada at 9 months.

At the end of the study, 38% of participants tested positive for tenofovir. Low-grade adverse events, such as nausea or headache, were frequently reported as the reasons for discontinuation.

HIV prevention packages given to all the study participants included HIV testing, management of sexually transmitted infections, guidance on how to reduce the risk of HIV, access to condoms, post-exposure prophylaxis, and counseling. Boys also received counseling and referral for male circumcision.

Three HIV prevention components designed specifically for adolescents were also offered: daily or weekly text message reminders to take Truvada and queries for any issues, eligibility to join adherence clubs, and receive real-time reports of the level of tenofovir in the blood during the study visits.

“The trend toward lower adherence to Truvada for PrEP as study visits became less frequent parallels what was observed in a study of PrEP in adolescent gay and bisexual boys, suggesting that monthly study visits may support greater adherence to oral PrEP among adolescents over time,” said Linda-Gail Bekker, MBCHB, PhD, protocol chair and president of the International AIDS Society and deputy director of the Desmond Tutu HIV Centre at the University of Cape Town.

HIV Prevention Via Vaginal Ring

Adolescent girls and young women aged 15 to 24 years account for 20% of new HIV infections among adults worldwide.

In the 2016 ASPIRE study, investigators sought to examine an experimental vaginal ring containing PrEP in women 18 to 45 years. Over 1 month, the ring continuously released dapivirine in the vagina of the participants. The results of the study showed a 27% protection overall, but no protection in women aged 18 to 21 years.

The results of a subsequent exploratory analysis found that using the ring most or all of the time reduced the risk of HIV by at least 56%.

Most recently, a phase 2a clinical trial conducted in the United States examined the safety and acceptability of the dapivirine ring among sexually active girls aged 15 to 17 years. A total of 96 girls enrolled at 6 sites across the US were randomized in a 3-to-1 ratio to receive either the dapivirine ring or a placebo ring.

The participants were instructed to insert a new ring each month for a 6-month period. During which, the investigators measured the amount of dapivirine in blood samples and used rings to monitor the patient’s health and gauge adherence.

The results of the study showed that the dapivirine ring was safe and acceptable among the participants, and adherence to the ring was high. Drug levels in 87% of blood samples and 95% of used rings met the prespecified adherence criteria, according to the release.

At 93% of study visits, participants reported that they liked the ring. Their primary concerns in using the ring were keeping it clean and that their primary sexual partner would feel the ring during intercourse.

“We are encouraged by these results of the dapivirine ring in 15- to 17-year-old girls,” Sharon Hillier, PhD, principal investigator of the Microbicide Trials Network. “The study has demonstrated that the ring is safe in US teens, and now we need data on the safety and acceptability of the ring in African adolescent girls. The REACH study, scheduled to launch later this year, will generate this data.”

The upcoming REACH study will evaluate the safety of the dapivirine ring and Truvada as oral PrEP among African adolescent girls and young women aged 16 to 21 years. Additionally, investigators will assess how participants use both preventive measures and their preferences for either or both approaches.