- Results of the open-label extension of the ASPIRE trial showed that most women had high interest and adherence in using the vaginal ring (23 mg dapivirine, 1 month).
Why this matters
- Trial was an opportunity to evaluate interest in the ring among high-risk women knowing that it reduces HIV transmission risk.
- A lower than expected HIV-1 incidence was observed.
- Former uninfected women participants in ASPIRE were offered 12 months of ring supplies; 14 sites (Malawi, South Africa, Uganda, Zimbabwe).
- Rings were returned monthly for 3 months, then quarterly, and tested for residual levels of dapivirine.
- HIV-1 serologic testing done at each visit, frozen plasma samples tested quarterly for HIV-1 RNA.
- Infections occurring after enrollment up to month-12 visit were considered.
- HIV-1 incidence compared with expected incidence by weighted bootstrap sampling of placebo arm of ASPIRE, matched on trial site, age, and presence of a curable sexually transmitted infection at trial entry.
- 1456 women, median age, 31 years.
- Baseline 92% acceptance; 90%, 89%, 87%, 83%, and 79% at months 1, 2, 3, 6, and 9, respectively.
- 86% returned rings had residual dapivirine levels consistent with some use during the prior month (>0.9 mg released).
- 35 HIV-1 infections observed (2.7/100 person-years; 95% CI, 1.9-3.8).
- Expected HIV-1 incidence: 4.4/100 person-years (95% CI, 3.2-5.8) without vaginal ring.
- Incidence of ≤2.7 would be expected to occur
- Study lacked a contemporaneous placebo group; results presented at a conference without peer review.
- In a statement, Jared Baeten, professor at the University of Washington, Seattle, said, “We wanted women to know the decision was theirs to make.” Baeten reported the final results, which showed that most participants wanted the ring and used it more consistently than in a previous study.