A combination of two powerful antibodies could suppress HIV
for several months at a time, freeing patients from a daily drug regimen, a small clinical trial has found.
Researchers at Rockefeller University in the United States found that broadly neutralising antibodies, or bNAbs, kept the deadly virus at bay for an average of 21 weeks among participants with relatively low levels of HIV in their bloodstream.
But while the trial was small, with 11 participants and nine responding to the treatment, the results represent the first step in the process to develop HIV drugs which do not need to be administered on a daily basis. Currently, people with HIV have to take antiretroviral (ARV) drugs on a daily basis for the rest of their lives.
“This is the first study that combines these antibodies and shows that suppression can be maintained for long periods of time,” Dr Marina Caskey, associate professor of clinical investigation at Rockefeller University, told The Telegraph.
“The results are very exciting, and open up lots of possibilities to explore in this field of research.”
While ARVs work almost perfectly in the clinical trials, in the real world success is less clear cut, with patients often forgetting to take their medication or being unable to afford it.
Not only does this endanger the individual, but it also increases the chance of HIV spreading.
The US Agency for International Development would like to see 90 per cent of people with HIV on biological suppression medication, said Dr Caskey. “But that varies hugely – in the US the average is just 50 per cent.
“If people could go from taking drugs every day to every three, four, even six months – that would make a real impact in increasing treatment rates,” she said.
Previous studies have shown that treatment with a single bNAb can reduce levels of HIV in the blood. However, efforts to control the virus for extended periods were unsuccessful as HIV mutated and became resistant to the antibodies.
But the new study, published in Nature Medicine, suggests that by using two antibodies resistance is avoided. If larger trials confirm the finding, the therapy could have the potential to transform HIV treatment.
“If everything happens as planned, we would hope for our antibody therapy to be approved as a treatment in the next five years,” said Dr Caskey.
At the moment, however, using antibodies is incredibly expensive. But analysis by the Bill and Melinda Gates Foundation has suggested that the treatment could be cost effective if researchers can demonstrate that one gram of antibodies can suppress HIV for a year and can be manufactured for under US$100.
If successful, researchers hope that the antibodies could be used to prevent HIV developing, as well as treating existing cases.
“The goal would be to take such treatment to Sub-Saharan Africa”, said Dr Caskey. “We’re optimistic, but this would be years down the line. This is just the first step.”