Two studies advance HIV prevention options for women

Two early clinical studies of novel HIV prevention products for women — the first combination antiretroviral (ARV) vaginal ring and a vaginal film — show the products to be safe and open the door to product improvements that could expand options for women-initiated prevention tools. The results of both studies were presented today at the 21st Conference on Retroviruses and Opportunistic Infections (CROI).

The combination ring study, known as MTN-013/IPM 026, was conducted by the National Institutes of Health (NIH)-funded Microbicide Trials Network (MTN), in collaboration with the International Partnership for Microbicides (IPM), which developed the product. The study evaluated the safety of IPM's vaginal ring designed to provide sustained release of the ARV drugs dapivirine and maraviroc for one month.

The vaginal film study, known as FAME-02 (Film Antiretroviral Microbicide Evaluation), evaluated a film releasing the ARV dapivirine for use around the time of sex. Researchers at the University of Pittsburgh and Magee-Womens Research Institute (MWRI) in Pittsburgh conducted the study, which was sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), a component of the NIH. IPM provided dapivirine to MWRI, which then developed the film. The study compared the film to dapivirine gel, which IPM developed and evaluated previously in Phase II trials.

"Women bear an unequal burden of the HIV/AIDS epidemic, and these two products bring new hope to the fight against HIV," said Dr. Zeda F. Rosenberg, ScD, chief executive officer of IPM. "IPM remains committed to working with partners to ensure that women around the world have an array of options to protect themselves, and these early results will lead the way to the next steps in development on two new approaches."

Combination Ring Study Results (MTN-013/IPM 026)

MTN-013/IPM 026 was the first clinical study of a vaginal ring to combine two ARVs and the first vaginal microbicide in development that contains maraviroc.

The two drugs in the slow-release combination ring work against HIV in different ways. Dapivirine belongs to a class of ARVs called non-nucleoside reverse transcriptase inhibitors (NNRTIs) that prevent HIV from making copies of itself. Maraviroc, an entry inhibitor, blocks HIV from getting inside target cells. Combining the two drugs, which act at different points in the HIV "life cycle," may provide greater protection against HIV than a single drug alone, particularly in the presence of drug-resistant HIV virus.

The monthly combination ring was found to be safe and well-tolerated, and acceptable by the 48 participants enrolled in the MTN-led study. The Phase I clinical study took place at the University of Pittsburgh, the Fenway Institute in Boston and the University of Alabama at Birmingham. Women were randomly assigned to use the combination dapivirine-maraviroc ring, a ring containing only maraviroc, a ring containing only dapivirine or one with no active drug. The study's protocol chair, Beatrice A. Chen, MD, assistant professor of obstetrics, gynecology and reproductive sciences at the University of Pittsburgh School of Medicine, reported the results.