NEWS POST: New Antibody Attacks 99% Of HIV Strains

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Scientists have engineered an antibody that attacks 99% of HIV strains and can prevent infection in primates. It is built to attack three critical parts of the virus - making it harder for HIV to resist its effects.

The work is a collaboration between the US National Institutes of Health and the pharmaceutical company Sanofi.

The International Aids Society said it was an "exciting breakthrough". Human trials will start in 2018 to see if it can prevent or treat infection.

Our bodies struggle to fight HIV because of the virus' incredible ability to mutate and change its appearance. These varieties of HIV - or strains - in a single patient are comparable to those of influenza during a worldwide flu season. So the immune system finds itself in a fight against an insurmountable number of strains of HIV.

Super-antibodies

But after years of infection, a small number of patients develop powerful weapons called "broadly neutralizing antibodies" that attack something fundamental to HIV and can kill large swathes of HIV strains. Researchers have been trying to use broadly neutralizing antibodies as a way to treat HIV, or prevent infection in the first place.

The study, published in the journal Science, combines three such antibodies into an even more powerful "tri-specific antibody".

Dr Gary Nabel, the chief scientific officer at Sanofi and one of the report authors, told the BBC News website: "They are more potent and have greater breadth than any single naturally occurring antibody that's been discovered."

The best naturally occurring antibodies will target 90% of HIV strains.

"We're getting 99% coverage, and getting coverage at very low concentrations of the antibody. It was quite an impressive degree of protection," said Dr Nabel.

Experiments on 24 monkeys showed none of those given the tri-specific antibody developed an infection when they were later injected with the virus.

The work included scientists at Harvard Medical School, The Scripps Research Institute, and the Massachusetts Institute of Technology.

'Exciting'

Clinical trials to test the antibody in people will start next year.

Prof Linda-Gail Bekker, the president of the International Aids Society, stated: "This paper reports an exciting breakthrough. These super-engineered antibodies seem to go beyond the natural and could have more applications than we have imagined to date. It's early days yet, and as a scientist I look forward to seeing the first trials get off the ground in 2018. As a doctor in Africa, I feel the urgency to confirm these findings in humans as soon as possible."

Dr Anthony Fauci, the director of the US National Institute of Allergy and Infectious Diseases, said it was an intriguing approach.

Scientists Create 'Three-In-One' Antibody That Attacks 99% Of HIV Strains

While this is a promising result, the treatment has only be tested on monkeys and the primate form of HIV

During trials, the anitbody protected monkeys from two forms of SHIV, the primate form of HIV, in 24 primates. It works by binding to three critical sites on the virus, making it harder for HIV to resist its attack.  It is known as a ‘broadly neutralizing antibody’ because it can attack many forms of HIV, even when the virus changes shape.

"They are more potent and have greater breadth than any single naturally occurring antibody that's been discovered,” Dr Gary Nabel, the chief scientific officer at Sanofi and one of the report authors, told the BBC.

As a comparison, and to put this research into perspective, the best natural antibodies previously developed attack 90 per cent of strains, while this new ‘trispecific’ antibody attacks 99 per cent.

While this is a promising result, the treatment has not been tested in humans yet. The companies are now planning to start clinical trials, using the antibody on people with and without HIV.

 "Combinations of antibodies that each bind to a distinct site on HIV may best overcome the defenses of the virus in the effort to achieve effective antibody-based treatment and prevention," said Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases, part of NIH.

"The concept of having a single antibody that binds to three unique sites on HIV is certainly an intriguing approach for investigators to pursue."

"This paper reports an exciting breakthrough,” Prof Linda-Gail Bekker, the president of the International Aids Society. "These super-engineered antibodies seem to go beyond the natural and could have more applications than we have imagined to date.”

The results of the study, by the US National Institutes of Health and the pharmaceutical company Sanofi, are published in Science.

Thankfully, HIV is not the life sentence it once was. This latest breakthrough joins a line of research into curing and treating the virus. 

In October, the NHS working with immunologists at UK universities reported that the first patient being treated in an HIV study had shown "remarkable" results, with no sign of the virus after initial treatment.

Then, at the start of May, researchers at the Lewis Katz School of Medicine at Temple University (LKSOM) and the University of Pittsburgh found they could remove HIV DNA from genomes of living animals – in this case, mice – using gene-editing tool CRISPR.

Originally published on BBC HEALTH and ALPHR