Fact Sheet About the Microbicide Trials Network
Fast Facts
· 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) Division of AIDS (DAIDS), with co-funding from the National Institute of Mental Health and the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), all components of the U.S. National Institutes of Health.
· The MTN brings together international investigators and community and industry partners who are devoted to reducing the sexual transmission of HIV through the development and evaluation of topical and oral prevention products. The MTN works within a unique infrastructure specifically designed to facilitate the research required to support licensure of these products for widespread use.
· Based at the University of Pittsburgh and Magee-Womens Research Institute in Pittsburgh, MTN’s core operations are supported by a network laboratory at the University of Pittsburgh, a statistical and data management center housed within the Statistical Center for HIV/AIDS Research & Prevention at the Fred Hutchinson Cancer Research Center, and FHI 360, a U.S.-based global organization with expertise conducting clinical protocols.
· More than 25 clinical research sites in seven countries are affiliated with the MTN. Clinical research sites are located in Malawi, South Africa, Uganda, Zambia, Zimbabwe, India and the United States. MTN-affiliated sites are being added in Peru and Thailand.
· MTN’s research portfolio is designed to face the global urgency of the HIV/AIDS epidemic head-on by evaluating the safety and effectiveness of promising products for prevention of HIV. During the current funding period, 2006-2013, the MTN will have implemented a broad spectrum of clinical trials, including studies considered among the most critically important for advancing the field. To date, MTN researchers have competed nine studies, and 12 trials are ongoing or planned.
· VOICE – Vaginal and Oral Interventions to Control the Epidemic, is a major HIV prevention trial designed to evaluate the safety and effectiveness of two different antiretroviral (ARV)-based approaches for preventing sexual transmission of HIV in women: daily use of an ARV tablet (tenofovir or Truvada) or daily use of an ARV-based vaginal gel (tenofovir gel). The study began in September 2009 and enrolled 5,029 women in Uganda, South Africa and Zimbabwe. Researchers stopped testing tenofovir tablets following an independent review of study data that took place in September 2011 determined that although the tablets were safe they were no more effective than placebo in preventing HIV. A November 2011 routine review drew the same conclusions about tenofovir gel, finding it safe but not effective among the women in the study. VOICE continues to evaluate Truvada. Final results, due in early 2013, will determine whether its daily use is safe and effective in preventing HIV in the women who remain in the study as well as help to understand why the tenofovir tablets and tenofovir gel were not.
· MTN researchers have been conducting the only studies involving the use of HIV prevention products during pregnancy and breastfeeding to understand their safety in both women and their babies. 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.
· In addition to microbicides in the form of a gel, the MTN is exploring other formulations, including vaginal rings. Unlike a vaginal gel that is used every day or at the time of sex, rings under study are inserted monthly and release the active ingredient slowly over time so that feasibly a woman would have long-lasting protection against HIV. MTN will be conducting the first-ever Phase III trial of a vaginal ring. Expected to begin mid-2012, ASPIRE – A Study to Prevent Infection with a Ring for Extended Use – will evaluate the safety and effectiveness of a ring containing the ARV dapivirine.
· Although the majority of microbicide research has focused on products to prevent HIV through vaginal sex, anal sex is common among men who have sex with men, and practiced by women around the world. According to some estimates, the risk of becoming infected with HIV through unprotected anal sex is 20 times greater than through vaginal sex. The MTN is leading pioneering studies evaluating the rectal safety of vaginal microbicide gels, an important step toward eventually developing a product specifically for rectal use. In MTN-017, researchers plan to evaluate the safety and acceptability of a rectal formulation of tenofovir gel at sites in Peru, South Africa, Thailand and the U.S. The study, which will involve men who have sex with men and transgendered women, will be the first Phase II trial of a rectal microbicide.
About Microbicides
· Microbicides are substances designed to prevent or reduce the sexual transmission of HIV when used in the vagina or rectum. A microbicide can be formulated in many ways, such as a gel or cream, or as a ring that would release the active ingredient over time. Some microbicides are also being developed for rectal use. Different microbicide products are being tested in clinical trials, including trials conducted by the MTN, although none is currently approved or available for widespread use.
· If proven effective, microbicides could have particular impact among women in developing countries, where HIV most often is spread through unprotected heterosexual intercourse despite educational efforts that promote abstinence, monogamy and condoms. Microbicides also could help prevent HIV in both men and women who practice anal sex. Unlike condoms, the use of microbicides is not controlled by one’s sexual partner.
· Of the handful of microbicides tested in clinical trials, tenofovir gel has undergone the most study. In a trial called CAPRISA 004, tenofovir gel was found safe and to reduce the risk of HIV by 39 percent among women who used tenofovir gel before and after sex compared to a placebo gel. VOICE, however, has stopped testing tenofovir gel after an interim review of data determined that tenofovir gel, while safe, was not effective in the women enrolled in the study, who were asked to use the gel every day. Meanwhile, a Phase III trial of tenofovir gel called FACTS 001 is currently enrolling women at sites in South Africa. FACTS 001 is testing the same regimen used in CAPRISA 004.
Why Microbicides Are Needed
· Worldwide, an estimated 34 million people are living with HIV, more than two-thirds of whom live in sub-Saharan Africa. Since the epidemic began in the early 1980s, more than 60 million people have been infected with HIV and nearly 30 million people have died of HIV-related causes, according to UNAIDS statistics.
· Approximately 2.7 million people were newly infected with HIV in 2010 – more than 7,000 every day. The number of new infections continues to outstrip advances in treatment: For every person starting HIV treatment, there are two new infections.
· Although the rate of new HIV infections is stabilizing or decreasing in many countries around the world, the global epidemic continues to have its greatest toll on sub-Saharan Africa, a region that accounts for 67 percent of all new HIV infections and 80 percent of the world’s HIV-positive women.
· Women account for 59 percent of adults with HIV in sub-Saharan Africa, where unprotected heterosexual intercourse is the primary driver of the epidemic. Young women are especially vulnerable. In southern Africa, young women are up to five times more likely to become infected with HIV than young men. Among both men and women aged 15-24 in sub-Saharan Africa, 71 percent are women.
· Throughout the globe, racial and ethnic minorities and men who have sex with men are disproportionately affected. Men who have sex with men account for more than half of all new HIV infections in the U.S. each year, as well as nearly half of people living with HIV. This population bears the burden of the epidemic in many other parts of the world, such as Europe, Latin America, Australia and New Zealand.
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More information about HIV can be found in the UNAIDS Report on the Global AIDS Epidemic 2010, the current U.S. Centers for Disease Control and Prevention HIV Surveillance Report ,and Kaiser Family Foundation fact sheets on HIV/AIDS: http://www.kff.org/hivaids/factsheets.cfm. To learn more about the Microbicide Trials Network go to www.mtnstopshiv.org.
1-February-2012
