Study results announced this morning unequivocally link early antiretroviral therapy (ART) for HIV-infected persons with a 96.3% less chance of transmitting the virus to an uninfected partner, as well as a decreased risk of contracting tuberculosis (TB), the number one killer of people living with HIV/AIDS.
The National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health (NIH), the study sponsors, convened a conference call Thursday morning with reporters conveying the preliminary results of the HPTN 052 study, led by Myron Cohen, MD, of the University of North Carolina, Chapel Hill. A review board halted the randomized, controlled study, a $73 million endeavor set to run until 2015, due to evidence of the unequivocal protective effect of starting HIV therapy early. “We think these results will be important to help improve both HIV treatment and prevention,” Cohen said in a press release.
HPTN 052 involved more than 1,700 HIV-discordant couples, where one partner is HIV-infected and the other is not, at 13 trial sites in eight countries including Botswana, Brazil, India, Kenya, Malawi, South Africa, Thailand, the United States and Zimbabwe. In order to participate, the HIV-infected partner had to have a CD4 cell count of between 350 and 550 cells/mm3 and not have had any AIDS related events – such as Pneumocystis pneumonia – within 60 days of entering the study. The uninfected partner had to test HIV-negative 14 days prior to starting the study. The couples were randomly split into two arms – in the first, the HIV-infected partner received immediate antiretroviral therapy; and in the second, treatment was delayed for the HIV-infected partner until their CD4 count had dropped to less than 250 cells/mm3. Ninety-seven percent of those who participated in the trial were heterosexual.
Only one case of HIV infection occurred among the couples assigned to receive immediate treatment compared to 27 cases among those in the delayed treatment arm. Seventeen cases of previously undiagnosed extrapulmonary tuberculosis also occurred among the HIV-infected partner in the deferred treatment arm, with only three cases occurring in the immediate arm. Cohen emphasized on the call that the results are only applicable to heterosexual couples.
“This rigorously conducted clinical trial demonstrates that ART dramatically reduces HIV transmission from an infected partner to an uninfected spouse or partner,” said HPTN Principal Investigator Sten Vermund, MD, PhD, member of the Center for Global Health Policy’s Scientific Advisory Committee, in a press release. “Earlier therapy is a superior option that benefits both an infected individual and his or her uninfected partner and we support global efforts to offer ART to everyone who needs it.”
NIAID Director Anthony Fauci, MD, echoed this sentiment when asked on the call with reporters whether these findings would inform policy decisions and if so, how to avoid setting up competition between people with urgent treatment needs and treatment for prevention. “My answer is utopian—universal access to treatment for whoever wants or needs it,” Fauci said.
The World Health Organization (WHO) eligibility requirements for treatment list a CD4 count of less than 350 cells/mm3, a standard lower than the level utilized in the immediate treatment arm – and still only 35 percent of people in developing countries are receiving treatment.
“Confirmation of the protective effect of treatment on HIV transmission to sexual partners is a giant step forward in confronting the HIV epidemic,” said Center Scientific Advisory Committee Member Wafaa El-Sadr, MD, MPH. “The finding of a protective effect of HIV treatment on the development of extrapulmonary tuberculosis may play an important role in avoiding this deadly complication in HIV-infected individuals.”
According to the NIH, antiretroviral therapy will be offered to the HIV-infected persons in the delayed treatment arm and study participants will be followed for at least one year. Investigators hope to make lots of statements regarding the one case of HIV transmission among the immediate treatment arm in the near future.