MTN was established in 2006 to bring together international HIV/AIDS investigators with community and industry partners to explore another avenue for prevention of HIV/AIDS transmission. Network investigators and partners work together to develop and evaluate microbicides—products taken orally or applied topically—to prevent HIV transmission.
The network is co-funded by the National Institute of Allergy and Infectious Diseases, the NICHD Maternal and Pediatric Infectious Disease Branch (MPIDB), and the National Institute of Mental Health. Funding from NICHD supports the MTN leadership group for the conduct of studies in adolescents and pregnant and breastfeeding women. Funding is provided through a Cooperative Agreement (UM1) mechanism.
Because the effectiveness of a product is also dependent on its use, behavioral and social science is embedded within each microbicide 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.
Nineteen clinical trial research sites in seven countries are affiliated with MTN: the United States, Thailand, Malawi, Kenya, Uganda, Zimbabwe, and South Africa. In addition, MTN collaborates with the NICHD Adolescent Medicine Trials Network for HIV/AIDS Interventions (ATN) for domestic clinical trials of microbicides to prevent HIV transmission in adolescents.
ASPIRE and The Ring Study are the first effectiveness trials of a vaginal ring for HIV prevention, as well as an HIV prevention product that contains an antiretroviral (ARV) drug other than tenofovir or a tenofovir combination. As sister studies, the two trials are designed to provide the evidence to support potential licensure of the dapivirine vaginal ring for preventing HIV in women. Approval of the dapivirine ring will also be contingent on data from a suite of studies, including a Phase I safety study, MTN-023/IPM 30, of the dapivirine vaginal ring in adolescent girls, which is being conducted by ATN and MTN.
MTN Organization and Structure
Each MTN study has its own protocol team consisting of investigators from clinical trial sites and representatives from different specialty areas and disciplines. MTN relies on three working groups to ensure scientific quality and consideration of community perspectives, including:
- The Biomedical Science Working Group. Provides input and innovative ideas to enhance understanding or monitoring of patient safety (e.g., biomarkers) and specimen collection.
- The Behavioral Research Working Group. Provides expertise and perspective in the design of studies to better understand and address the complex interplay between human behavior and HIV risk and prevention.
- The Community Working Group. Ensures the successful conduct of studies through community-researcher partnerships and engagement and participation of the community at the site level.
MTN-affiliated researchers and partners work within a unique infrastructure specifically designed to facilitate the research required to support licensure of the tested products for widespread use.
By the end of 2013, when its first funding period came to a close, 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. MTN will also evaluate different formulations of rectal microbicides, new classes of 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.
- Microbicide safety trials. MTN researchers are conducting the only studies involving the use of HIV prevention microbicides during pregnancy and breastfeeding to evaluate the safety of their use in women and infants. These studies are critical because women need a product that will be safe and effective to use in all stages of life, including during pregnancy, when the risk of acquiring HIV from an infected partner is particularly high. Because women often continue to use medications when they are pregnant or breastfeeding, knowing whether microbicides are safe for use in this population is also vitally important.
- Prevention trials of existing ARV therapies. Emphasis has been on the evaluation of ARV-based prevention strategies, examining whether some of the same ARVs commonly used to treat HIV can also be used for prevention. This preventive approach is called pre-exposure prophylaxis. Formulations currently being tested for prevention include vaginal gels and oral tablets.
- Efficacy studies of new formulations for women, including adolescent girls (in collaboration with the ATN). In addition to gel microbicides, MTN is exploring other types of formulations, including vaginal rings. Unlike a vaginal gel that must be used every day or at the time of sexual activity, the vaginal rings currently being studied are inserted monthly and release the active ingredient slowly so that a woman would have long-lasting protection against HIV.
- Efficacy studies of additional formulations. Although the majority of microbicide research focuses on products to prevent HIV during vaginal sex, anal sex is common among men who have sex with men, and among some women around the world. MTN is making significant contributions in the area of rectal microbicide research and is leading the way toward developing a microbicide to protect against HIV transmitted through anal sex.
For a complete list of MTN studies, visit http://www.mtnstopshiv.org/research/studies.