NEW YORK, May 12, 2011—The International AIDS Vaccine Initiative (IAVI) welcomes the news that a large, multinational clinical study led by the HIV Prevention Trials Network (HPTN) has demonstrated that oral antiretroviral therapy (ART) administered earlier in the course of infection can reduce the sexual transmission of HIV among discordant couples, or couples in which one partner is HIV infected and the other is HIV negative.
The trial, known as HPTN 052, compared two groups. In the first group, the infected partner initiated ART upon enrollment in the trial, when CD4+ T-cell counts ranged between 350 and 550 (early-initiation group). In the second group, the administration of ART was delayed until CD4+ T-cell counts in the infected partner reached less than 250 (delayed-initiation group). The requirement that study participants have a CD4+ T-cell count of 350 – 500 at enrollment meant that, under World Health Organization guidelines, HIV treatment was not required.
Trial results showed that ART was 96% effective in preventing sexual transmission of HIV from the infected partner to the uninfected partner. Among the infections confirmed to have been transmitted from one partner to the other, one HIV infection was reported in the early-initiation group, compared to 27 HIV infections reported in the delayed-initiation group. The trial’s Data and Safety Monitoring Board recommended that the results be released as soon as possible and that the findings be shared with study participants and investigators.
HPTN 052 was conducted by the HIV Prevention Trials Network, and involved 1,763 discordant couples at 13 research centers across Africa, Asia and the Americas. The trial was funded by the U.S. National Institute of Allergy and Infectious Diseases (NIAID) of the U.S. National Institutes of Health. Additional support was provided by the NIAID-funded Adult Clinical Trials Group. The antiretroviral drugs used in the study were made available by Abbott Laboratories; Boehringer Ingelheim Pharmaceuticals, Inc.; Bristol-Myers Squibb; Gilead Sciences; GlaxoSmithKline; and Merck & Co., Inc.
The findings of this study represent an important step for the HIV-prevention field. IAVI supports a comprehensive response to the AIDS pandemic, and providing antiretroviral therapy to all those who need it is an essential component of the fight against AIDS. A combination of increased access to ART, the expansion of existing prevention options and the development and widespread use of new tools, including vaccines, to prevent HIV has the potential to end to the AIDS pandemic once and for all.
We congratulate HPTN 052 and its partners on these promising results and applaud their contribution to the global effort to defeat AIDS. We look forward to further exploration of these findings.