New HIV Treatment Shows Promise in Early Research

But new antibody was only helpful for those who hadn't received HIV therapy yet

Wednesday, December 23, 2015

WEDNESDAY, Dec. 23, 2015 (HealthDay News) -- Preliminary new research raises the prospect that a recently discovered antibody -- an important component of the immune system -- could be enlisted to boost the body's response to HIV, the virus that causes AIDS.

A single injection of the antibody, currently dubbed VRC01, dramatically reduced the level of HIV in the blood of people who hadn't yet been given antiretroviral drug treatment (ART). ART is the current standard treatment for managing HIV infections, according to the study's authors from the Vaccine Research Center at the National Institute of Allergy and Infectious Diseases in Bethesda, Md.

But in people who'd already been treated with ART, the antibody injection had no effect on HIV levels, presumably because the ART therapy had already reduced the levels of HIV virus in their blood, the researchers said.

And the researchers were quick to note that the study was small and even patients who respond may not be completely rid of HIV.

Still, "this offers a potential alternative to antiretroviral therapy," said Julian Ma, director of the Institute for Infection and Immunity at St. George's Hospital Medical School in London. "We desperately need them given our dependence on a relatively small number of antiretroviral therapy drugs."

Eventually, this new approach could be combined with other treatments aimed at lowering levels of HIV in the body and preventing dangerous strains from emerging, Ma said. He wasn't part of the research but was familiar with the study findings.

But many questions still remain. The study was small, and at this stage, little is known about the side effects, benefits and potential cost of the treatment. Still, experts are hopeful about the early results that suggest patients can tolerate treatment with the antibody well.

The study appears in the Dec. 23 issue of Science Translational Medicine.

The new research included 14 people with HIV. Six were already receiving ART therapy.

Those six who were already being treated received two infusions of the new antibody treatment, but didn't have a significant response to the treatment, the study showed.

People who hadn't yet received HIV treatment -- eight patients -- were given a single infusion of the drug, the study said.

Levels of the virus in the blood dropped or even vanished in six out of the eight HIV patients who hadn't been taking ART. That doesn't mean they were cured of HIV. The virus still remains in the body, just at undetectable levels. Those who didn't respond to the treatment had strains of HIV that were resistant to the treatment, the study authors said.

The researchers didn't see signs of side effects. However, the research is in the early stages, representing only the first of three stages of research needed before drugs are typically approved in the United States. Future studies need to look in greater detail at how the drugs work in people who have varying levels of the virus, and what concentration of the antibody is most effective at suppressing the virus, the study authors noted.

The treatment's costs are unknown, although Ma said these kinds of drugs are generally expensive, which potentially limits their use in poor countries.

Dr. James Crowe, director of the Vanderbilt Vaccine Center in Nashville, Tenn., said the study is impressive and promising. But he cautioned that the effects of single doses of the antibody treatment are "relatively minor and temporary," and some patients quickly developed immunity to it. As a result, the antibody on its own isn't likely to work as a long-term treatment, he said.

Ma praised the study but also cautioned about the challenge of HIV strains that are immune to the treatment. "This points to the need to combine this antibody with other antibodies or drugs," he said.

Going forward, he said, the treatment could be used in conjunction with existing medications, or in cases when those drugs don't work. Or, Ma said, it could help HIV-infected pregnant women avoid transmitting the virus to their unborn children.

SOURCES: Julian Ma, Ph.D., director, Institute for Infection and Immunity, and chair of Molecular Immunology, St. George's Hospital Medical School, London; James Crowe, M.D., director, Vanderbilt Vaccine Center, Vanderbilt University School of Medicine, Nashville, Tenn.; Dec. 23, 2015, Science Translational Medicine

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