New clinical trials further assess vaginal microbicide ring for HIV prevention

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Dr. Zeda Rosenberg demonstrates the flexibility and size of the dapivirine vaginal ring being studied for potential HIV prevention at a press conference Tuesday at the International AIDS Conference in Washington.

First potential participants screened Tuesday for inclusion in ASPIRE trial

Scientists presented progress in assessing the potential of a vaginal ring containing the potent antiretroviral drug dapivirine in preventing HIV infection in women, as two studies to assess its safety and efficacy move into Phase III.

Often times women are unable to negotiate the use of condoms to protect themselves against HIV and other sexually transmitted infections. “Women everywhere like options… Different people like different things,” said Sharon Hillier, PhD, of the University of Pittsburgh School of Medicine. “We really think we need options that fit readily into women ‘s lives and that’s why we are so excited about this discreet, inserted once a month ring that will revolutionize prevention for women.”

Hillier joined experts from the National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health (NIH), the International Partnership for Microbicides (IPM) and the NIH-funded Microbicide Trials Network (MTN) Tuesday at the International AIDS Conference in Washington to outline new clinical trials testing microbicide delivery through vaginal rings.

The first of the studies discussed, the so-called “Ring Study” or IPM 027, began enrolling patients at four sites in South Africa in April. As of July 19 they had screened 831 women and enrolled 393 participants at these four sites, and a fourth site in Kigali, Rwanda, Rwanda, should begin enrolling in the coming weeks.

The MTN 020 phase III efficacy study, otherwise known as “A Study to Prevent Infection with a Ring for Extended Use (ASPIRE),” which screened its first three patients for enrolment Tuesday in Kampala, Uganda, will eventually enroll 3,500 women in Uganda, Zimbabwe, Zambia, Malawi and South Africa.

The complementary studies are both designed to measure a clinically important decrease in HIV among study participants using the ring of at least 60 percent as compared to women not using the ring – on the order of study design for prior studies of oral truvada for HIV protection and the truvada vaginal gel – but the experts said they are hopeful the ring will achieve that level of protection and higher. Results from both studies are expected in 2015.

“Adherence should improve with a ring that only needs to be changed once a month – offering better protection from HIV,” said panelist Carl Dieffenbach, PhD, director of NIAID’s Division of AIDS. Early testing phases showed very high acceptability of the ring, ease of use and ease of re-insertion of the ring among the eight percent of study participants who did remove the ring at some point during the month. Panelists also noted that study participants reporting the ring came out during sexual intercourse was “quite rare.”

Chief Executive Officer of IPM Dr. Zeda Rosenberg said they are working with their ring manufacturer now – Q Pharma in Sweden –  and are hopeful they will be able to transfer the technology to other companies in the world closer to where the rings will be delivered and accessed. Although cost estimates are premature at the Phase III manufacturing scale, she said, they hope the cost of the ring can be very low if it makes it to public availability, potentially quite low if the ring can be changed out every two to three months, as they are hoping.

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