A recent experiment performed by the US National Institutes of Health and pharmaceutical company Sanofi could have just given the human race its best weapon yet in the fight against HIV. By combining three natural HIV-fighting antibodies, the researchers created a new treatment that tackles 99% of the virus’ different strains. This kind of broad attack is essential for combating the virus, since it takes many forms and is known to mutate very quickly. In tests on monkeys, the new treatment prevented infection in all of 24 subjects that were injected with HIV. The researchers published their results in Science on the 20 September.
The Science paper reports that HIV-attacking antibodies have been isolated before, having been extracted from patients whose bodies are fighting the virus. These broadly neutralising antibodies, referred to as bnAbs, have shown an impressive ability to combat HIV in multiple different forms and different levels of strength, and since 2010 many of them have been taken to the clinical trial stage.
However, they are not ideal. Every HIV patient has a different combination of strains, and the antibodies extracted will only be equipped to deal with a certain number of them. Even with the best natural antibodies, which combat up to 90% of current strains, most patients will have some form of the virus which resists treatment.
What makes the situation worse is that HIV is one of the fastest evolving entities in the world, due to its high rate of mutation. New varieties of the virus are constantly arising, and treating a patient with antibodies that only tackle some strains can speed up the evolutionary process by promoting those strains which are resistant. This means that a patient who is given natural antibodies could end up developing an even worse case of HIV than they had before.
In this new study, the researchers experimented by combining the abilities of two, then three different natural antibodies into one. The resulting “trispecific antibodies” were able to block the process of infection at three different places, covering an incredible 99% of strains, according to Dr Gary Nabel, the chief scientific officer at Sanofi. This means that the treatment is much more likely to prevent infection in a given patient than any currently known natural antibody, and this fact is reflected in the researchers’ successful tests on primates. The first human trials are scheduled for next year.
Responses from health organisations have ranged from intrigue to wild excitement, especially over the prospect of seeing clinical trials so soon. The president of the International Aids Society, Professor Linda-Gail Bekker, told the BBC that the research is “an exciting breakthrough”, and that there is an “urgency to confirm these findings in humans as soon as possible”, since the virus currently takes so many lives around the world.
HIV is one of the most persistent health problems across the world, since it has proved very difficult to treat and it attacks the body’s immune system, making sufferers very vulnerable to other diseases including cancers. According to the CDC, 36.7 million people were found to be living with HIV last year, and 1 million people died from illnesses related to AIDS, the most advanced stage of HIV.
This means that advances like the NIH’s and Sanofi’s new antibody, if they prove successful in next year’s trials, could save hundreds of thousands of lives.