Antibody clinical trial sends HIV into hiding for months
HIV is a life sentence, but while the disease can't be completely cured (at least not yet) it can be managed through antiretroviral therapy (ART) medication. The problem is that if a patient doesn't stick to this strict routine of drugs the virus will resurge, leading to health problems and an increased chance of spreading to others. New clinical trials in humans have shown that drugs based on two antibodies naturally found in some people can put HIV into hiding for months at a time.
These antibodies were first identified by studying how certain people seem to be naturally "good" at defending themselves against HIV. In these people, researchers from Rockefeller University identified two antibodies – known as 3BNC117 and 10-1074 – which rally the body's immune system to fight off the infection by targeting certain proteins on the virus' surface.
To mimic the effects of these antibodies, drugs called broadly neutralizing antibodies (bNAbs) have been developed in the past, but their effectiveness was relatively fleeting before the virus evolves resistance to them.
However, these drugs have previously only been built around one antibody. So the Rockefeller researchers set out to design bNAb drugs that combine 3BNC117 and 10-1074, which work in different ways in the body.
After an earlier test that showed promise in animals, the researchers began human clinical trials of these new drugs. The first test involved nine participants who had versions of the virus that were vulnerable to both antibodies. These patients stopped their usual ART treatments – which had already reduced the virus to very low levels in their bloodstream – and instead received three infusions of the bNAbs drugs three weeks apart.
The new treatment was found to suppress HIV for 21 weeks on average, and in the most effective cases two patients remained in the clear for more than six months, ending the trial period with no resurgence. The team reports that the virus didn't develop resistance to the treatment in any of the patients, and the worst side effect experienced was some mild fatigue.
In the second trial, the team conducted a similar test of seven patients with viremic HIV, meaning that unlike the first group the virus was still actively circulating in their bloodstream. The bNAb treatment was found to work here too, keeping the virus under control for around three months. Again, no resistance to the drugs emerged.
As promising as the development is, the researchers point out that these particular antibodies won't work on all strains of HIV. That said, the technique could be adapted to use different bNAbs to target different versions of the virus. Doing so might also boost how long they remain effective for.
If this treatment gets off the ground, the researchers say it could help keep the virus under better control in general by freeing patients from having to remember to take a pill every day. Other techniques currently in the works include gene therapy and vaccines that could even lead to an eventual HIV cure.
Source: Rockefeller University