An HIV treatment trial, stopped early today, has added another significant piece of evidence in support of the idea of using “treatment as prevention” to stop the spread of the virus.
The trial, HPTN052, was sponsored by the U.S. National Institute of Allergy and Infectious Diseases (NIAID). It tested whether treating a person infected with HIV with antiretroviral drugs could prevent the person from passing the virus on to his or her sexual partner. In the trial, the partners with HIV were randomly assigned either to start treatment right away, or to wait to start treatment until their immune systems began to weaken. Almost all of the couples in the trial were heterosexual. The trial had been scheduled to run until 2015.
Today, however, NIAID director Anthony Fauci and the leader of the trial, Myron Cohen of the University of North Carolina Chapel Hill, said that they are stopping the trial early because a data review panel found that the benefit of early treatment was clear.
Beginning treatment with antiretroviral drugs right away led to a 96 percent reduction in HIV transmission between partners.
Among 866 couples assigned to the early treatment group, only one new infection occurred, in contrast to 27 new infections among the 877 couples in which the HIV-infected partner waited to start treatment.
“The findings of this study strongly indicate that treating an HIV-infected individual with antiretroviral drugs sooner rather than later can have a major impact on reducing the risk of HIV transmission to his or her sexual partner,” Fauci said.
Previous studies had suggested that treatment could prevent transmission between sexual partners, but they were not specifically designed to address this question, so they could not prove that the treatment itself was causing declines in transmission. The trial results announced today are definitive proof that treatment cuts transmission between partners, Fauci said.
“This is a randomized study which nails that concept down very nicely,” Fauci said.
AIDS advocacy groups hailed the study as another piece of evidence in favor of “treatment as prevention” – the idea that using drugs to treat all patients with HIV as early as possible, rather than waiting for their immune systems to falter, is the best way to prevent the spread of the virus. This concept has gained popularity as the effort to design an effective HIV vaccine has stalled in recent years.
“These data must serve as a clarion call to funders, policy makers, civil society and implementers,” AVAC executive director Mitchell Warren said in a statement. “If deployed effectively, efficiently and ethically, early initiation of treatment will be fundamental to turning the tide of the epidemic.”
Margaret Chan, director-general of the U.N. World Health Organization, called the study a “crucial development,” and Michel Sidibe, executive director of the Joint United Nations Programme on HIV/AIDS, called the study a “serious game changer” that “makes HIV treatment a new priority prevention option.”
Warren also noted a spate of recent studies showing that using antiretroviral drugs in uninfected people can prevent them from acquiring HIV.
Robert Grant of the University of California San Francisco led one of those studies, which reported last year that treatment can prevent men who have sex with men from acquiring the virus. He pointed out a long list of prevention methods that have now been shown to prevent people from becoming infected with HIV, including use of male condoms, male circumcision, use of microbicide gels in women, providing clean needles to injecting drug users, and treating pregnant women with HIV to prevent them from transmitting the virus to their babies.
However, it has been difficult to use the prevention techniques already available, such as condoms, to make further gains against the spread of HIV.
And the newer methods, which use drugs to slow the spread, will be costly, and will require governments to invest much more money in efforts to diagnose people soon after they are infected with the virus, so that they can be treated.
UNAIDS estimates that only about half of the 33 million people living with HIV know their HIV status, and UNAIDS estimates that 10 million people who need treatment aren’t getting it.
“The challenge before funders and policy makers now is to increase investments to make new HIV treatment and prevention tools available to everyone who needs them, along with standard prevention methods such as male and female condoms, HIV testing and counseling, STD treatment and support for behavioral prevention approaches,” Grant said in a statement.
“HIV can be slowed and one day stopped if we use this new information.” Grant said.