Today, FHI announced that it is closing its FEM-PrEP HIV prevention clinical trial early because an independent monitoring committee concluded that based on current data, the study would be unable to demonstrate the effectiveness of the study drug in preventing HIV infection in the women enrolled in the trial. The Phase III clinical trial was examining whether once daily oral Truvada, an antiretroviral drug currently approved to treat HIV infection, could prevent male-to-female HIV infection among women at high risk for infection through sexual intercourse. The study was being conducted in Kenya, South Africa and Tanzania.
Currently, the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, is evaluating Truvada, along with two other strategies, in a study known as VOICE (Vaginal and Oral Interventions to Control the Epidemic). The VOICE study is comparing daily use of Truvada, oral tenofovir—another antiretroviral drug approved to treat HIV infection—and a tenofovir-based vaginal gel for safety and effectiveness in preventing male-to-female HIV transmission. The study, which launched in September 2009, is expected to enroll 5,000 women in South Africa, Uganda and Zimbabwe.
Earlier studies have demonstrated promising results using antiretrovirals as pre-exposure prophylaxis, or PrEP. For example, in the iPrEx study, sponsored by NIAID, Truvada was evaluated as an HIV prevention strategy among men who have sex with men and was found to reduce the risk of HIV acquisition in this population by 43.8 percent.
Although it is disappointing that the FEM-PrEP trial will be unable to continue and to provide information about Truvada’s potential as HIV prevention among women, the need for continued research in this area is imperative. In 2009, approximately half of the estimated 2.6 million new HIV infections globally occurred among females, the vast majority among women having unprotected sex with HIV-infected men.
Although male condoms effectively prevent HIV infection, women need methods to protect themselves that are not dependent on their sexual partners.
NIAID will continue with the VOICE study while informing all current participants about the FHI findings as soon as possible; potential new volunteers will be informed as part of the screening and enrollment process. The VOICE study includes numerous measures to protect the safety and well-being of the women participating in the study including routine counseling on safe sex practices and provision of free condoms, as well as regular testing for HIV infection and other sexually transmitted infections. Participant safety also is closely monitored throughout the trial by a data and safety monitoring board (DSMB), an independent committee composed of clinical research experts, statisticians and community representatives.
Results from the VOICE study are expected in 2013.
For more information about NIAID’s HIV/AIDS research, please see the NIAID HIV/AIDS Web portal. For more specific information about the VOICE study, please see the Microbicide Trials Network Web site.