Sep 21, 2017

New studies show 100% HIV protection in monkeys via antibody combos

NIAID scientists identify and isolate anti-HIV antibodies. Photo: NIAID

Two separate research teams showed a unique combinations of antibodies led to 100% protection from HIV-like viruses in test monkeys. They'll next enter human clinical trials, first testing their safety, in the hopes of eventually creating both a vaccine and therapies.

What they did: The two studies published Wednesday — one using a "first of a kind" antibody molecule that can bind to three different places on the HIV virus and the other using a cocktail of two single antibodies — state they believe the antibodies' ability to target different regions of the virus, which can mutate rapidly, prevented infection.

Why it is important: In the U.S., roughly 1.1 million people are living with HIV, and one in seven of them don't know it. The majority of new cases are reported in the South, showing a disparity of infection rates.

Study 1 details: NIH investigators working with the pharmaceutical company Sanofi created an antibody with three HIV-binding segments. "This has never been done before," NIH scientist and study author Richard Koup told Axios. By testing and finding the best performing combination of three antibodies and then combining them into one, they were able to effectively hit all the types of HIV virus they tested in monkeys.

Barton Haynes, an immunologist who was not part of the study, said the "new strategy in the case of the trispecific antibody for dealing with HIV diversity" was significant.

Added benefit: Another benefit to developing the trispecific antigen, Koup said, is that it could be applied to other resistant diseases, like cancer, Ebola, Zika, yellow fever and tuberculosis. Ebola, for example, has multiple strains that a single antibody may not cover but the trispecific antibody might be able to.

Study 2 details: A separate study (although some of the scientists overlapped between the two) developed a "cocktail" of two antibodies that together targeted different regions of the HIV virus and prevented 100% of the monkeys from becoming infected. These results were compared with using only one antibody, which resulted in little protection. "These data suggest that a combination antibody approach will likely be more effective than single antibodies for both prevention and treatment of HIV infection in humans, as a result of HIV diversity and resistance," study author Dan Barouch told Axios.

Yes, but: Koup warned that HIV vaccine and treatment protocol is still years away. "This is a major advance toward the development of a preventative strategy, but it's not a vaccine," Koup said. "We are still working toward the goal of creating a vaccine."

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