Caprisa’s findings will be presented at the 21 International Aids Conference now taking place in Durban. Now, a ring that dodges drugs has been found to significantly reduce women’s risk of being infected with HIV in early tests. The level of HIV protection for those who used the ring most consistently, ranged from 75 per cent in one analysis to 92 per cent in another. “Adherence is key to HIV prevention”.
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The ring tested in the new study contained 25 mg of dapivirine, about 4 mg of which gets released over 28 days. “The HOPE trial will provide additional data that either reinforce or refute this hypothesis”.
MTN researchers also announced the launch of an extension study to ASPIRE, known as HOPE, at the AIDS 2016 conference Monday. Brown is a research professor at the Fred Hutchinson Cancer Research Center and the University of Washington in Seattle.
While Dr. Brown and her colleagues hail the new results as encouraging, they admit there are inherent limitations in such kinds of exploratory analyses, and that further analysis is required to validate the current outcome.
One year into the ASPIRE study, investigators began to measure the amount of dapivirine left in the rings women returned to study staff. After the trial ended, researchers used these measurements along with data on which women became HIV-infected during the study to examine the relationship between adherence to the ring and the risk of HIV infection.
A study called Aspire was carried out on 2,600 Zimbabwean women.
Adherence was associated with a reduction in risk of HIV infection of at least 56 percent, and high adherence was associated with a risk reduction of potentially 75 percent or more. Low adherence was not associated with statistically significant protection from HIV infection.
The research team found that women’s risk of catching the human immunodeficiency virus (HIV) on average was cut by 56 percent.
Researchers are unsure about whether the ring was less effective for young women because young women are less likely than older women to use it consistently, or for physiological reasons. When we were conducting ASPIRE, we did not know whether the ring would be effective for HIV prevention.
Unlike a Phase III clinical trial, there is no placebo group in an open-label study.
For the studies, researchers enlisted 1,959 women from South Africa and Uganda for The Ring Study, and 2,629 in South Africa, Uganda, and Zimbabwe. In some cases, women may join a trial for other benefits, such as the health care and social support that comes with it, with little incentive to actually use the product.
Truvada, a daily antiretroviral pill, is an approved and effective method of prevention for women and men, Brown said, but the dapivirine ring may be an appealing alternative for some women – they won’t have to keep in mind to take a pill every day and it can be used discretely. Thereafter, they will attend quarterly visits where they may obtain three rings at a time, a schedule that more closely resembles how the ring would be distributed in a real-world setting.
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Participants may remain in the HOPE study regardless of whether they accept or use new rings. The researchers were thus able to stratify levels of adherence from those who didn’t use the ring at all to those who used it almost perfectly. The ring, developed by the nonprofit International Partnership for Microbicides (IPM), is placed high inside the vagina where it steadily releases the medication over the course of the month.
