The Microbicide Trials Network (MTN) is an HIV/AIDS clinical trials network established in 2006 by the National Institute of Allergy and Infectious Diseases (NIAID), with co-funding from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and the National Institute of Mental Health, all of the U.S. National Institutes of Health (NIH). The MTN brings together international investigators and community and industry partners whose work is focused on the development and rigorous evaluation of promising microbicides – products applied inside the vagina or rectum that are intended to prevent the sexual transmission of HIV. Whether a small Phase I study testing a product’s safety and acceptability or a large-scale Phase III trial evaluating its effectiveness, every MTN trial is designed to collect the kind of data regulatory agencies require for determining whether to approve a product for widespread use. Because the effectiveness of a product is also dependent on its use, behavioral and social science is embedded within each study to gain understanding of the needs and desires of different high-risk groups. MTN’s research agenda includes populations considered among those at highest risk, including women in Sub-Saharan Africa, adolescents, pregnant and breastfeeding women, transgender women and men who have sex with men (MSM). More than 25 clinical research sites on four continents partner with the MTN in the conduct of its clinical trials.

By the end of 2013, when its first funding period had come to a close, the MTN had completed 13 trials, including VOICE, a major effectiveness study involving more than 5,000 women; and 11 more trials were planned or in progress, including MTN’s current flagship studies, ASPIRE and MTN-017. With its funding renewed for another seven years, the MTN will see these studies to their completion as well as look to evaluate different formulations of rectal microbicides, new classes of antiretroviral (ARV) drugs formulated as either vaginal or rectal products – or that can be used as both, and vaginal rings with the dual purpose of preventing both HIV and unwanted pregnancy.