The final results of HOPE, a phase 3 open-label extension trial, show high uptake and lower-than-anticipated HIV-1 incidence.
In 2016, ASPIRE (A Study to Prevent Infection with a Ring for Extended Use [MTN-020]) demonstrated that a monthly vaginal ring containing 25 mg of dapivirine used regularly could safely and effectively reduce a woman’s risk of acquiring HIV-1 infection by up to 56%.
Now, final results of HOPE (HIV Open-label Prevention Extension [MTN-025]), a phase 3 open-label extension trial, show high uptake and lower-than-anticipated HIV-1 incidence among women in southern and eastern Africa who used the ring continuously for 4 weeks and then swapped it out for a new one. The findings were presented at the 10th IAS Conference on HIV Science (IAS 2019).
Launched in July 2016 and concluded in August 2018, HOPE offered 1456 HIV-1-uninfected women who had participated in ASPIRE 12 months of access to the dapivirine vaginal ring at 14 sites in Malawi, South Africa, Uganda, and Zimbabwe. Median age of participants was 31 years.
Participants returned used rings at study visits (once a month for 3 months, and then quarterly) so investigators could test residual levels of dapivirine. The research team also performed HIV-1 serologic testing at each visit, and collected archived, frozen plasma samples quarterly to test for HIV-1 RNA with greater precision.
A total of 1342 (92%) women accepted the dapivirine ring at baseline, with 90%, 89%, 87%, 83%, and 79% acceptance at months 1, 2, 3, 6, and 9, respectively, while 86% of returned rings displayed residual dapivirine levels consistent with some use in the prior month (>0.9 mg released).
Thirty-five HIV infections were observed (incidence 2.7 per 100 person-years, 95% Confidence Interval [CI] 1.9-3.8), a statistic that fell below the expected incidence rate of 4.4 per 100 person-years (95% CI 3.2-5.8) in the absence of access to a dapivirine vaginal ring. According to investigators, incidence of ≤2.7 would be expected to occur in fewer than 33 in 10,000 samplings (0.33%).
HIV prevention modalities that don’t involve a daily pill burden are needed in places where individuals may not have easy access to health care. The HOPE results support the dapivirine vaginal ring as a potential option.
The study, “High adherence and sustained impact on HIV-1 incidence: Final results of an open-label extension trial of the dapivirine vaginal ring,” was presented Tuesday, July 23 2019, at IAS 2019 in Mexico City, Mexico.