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Study: Antibody Therapy Shows Promise for HIV Treatment

A small human study has found that infusing a person's blood with HIV antibodies can cut the amount of virus in their body even if they are not taking antiretroviral drugs.

A small human study has found that infusing a person's blood with HIV antibodies can cut the amount of virus in their body even if they are not taking antiretroviral drugs. Shutterstock

Researchers in the United States and Germany have found that infusing a person’s blood with HIV antibodies can cut the amount of virus in their body even if they are not taking antiretroviral drugs.

The findings were published in a recent issue of the journal Nature.

Certain antibodies can prevent HIV from binding to CD4 cells, which serve as host cells for the virus. Between 10 and 30 percent of individuals living with HIV are able to produce these antibodies naturally, but it often takes a few years after infection. That gives HIV time to mutate in ways that allow it to evade the antibodies once they form.

Researchers hope that by introducing synthetic antibodies sooner, they can prevent the virus both from invading CD4 cells and from mutating. This approach, which has been called passive immunization, has been successful in trials on monkeys and mice but, until this study, had not been found effective in humans.

For this study, researchers worked with 29 people, 17 of whom were HIV-positive. Among those, 15 were not on antiretroviral drugs during the study. Participants received an antibody called 3BNC117, which has been shown to be active against 195 of the 237 known strains of HIV.

Researchers tested four doses of the antibody. They found that one infusion of the highest dose of the antibody (given to eight participants) cut the amount of virus in their blood by between eight and 250 times for 28 days. But the antibodies became 80 percent less effective at neutralizing the virus after the 28-day mark.

The researchers theorized that the virus was able to change shape during that time to evade the antibodies.

Despite the short-lived success, researchers believe their findings are important and that antibody therapy may be the future of HIV treatment and prevention.

Michel Nussenzweig, the study’s lead other, explained to Nature.com, “The goal is a once-a-year shot for prevention and a combination approach for cure”

“In contrast to conventional antiretroviral therapy, antibody-mediated therapy can also engage the patient’s immune cells, which can help to better neutralize the virus,” said Florien Klein, one of the study’s co-authors.

Others in the field, however, are questioning this method, and wondering if can ever be affordable and accessible to the majority of people living with HIV, many of whom live in developing countries.

“The practicality, utility and efficacy of this approach are hugely open questions,” Mitchell Warren, executive director of AVAC, an HIV-prevention agency, told Nature.com.

Warren, however, was optimistic that the cost of the treatment would eventually come down if it is widely accepted. “Some people would have said 10-to-15 years ago that ARVs [antiretroviral drugs] were not going to be affordable, either.”