Cancer drug could one day help cure HIV by waking up dormant viruses

An existing cancer drug has been found to also wake up dormant HIV, and it could eventually work with an HIV medicine in a “kick and kill” strategy

By Clare Wilson

Today, HIV can be kept under control, but for most people, there is no cure because the virus can become dormant so HIV medicines have no effect. That could change in future, now progress has been made in waking up dormant viruses.

People with HIV can take antiviral medicines that stop the virus from reproducing, giving them nearly normal lifespans. But HIV inserts copies of its genetic material into human immune cells, which then become dormant. As a result, people have to take the antivirals for the rest of their lives because, if they stop, viruses inside the cells wake up and start infecting more and more immune cells.

Now, a drug already used to treat cancer has been found to make HIV reactivate. To be turned into a cure, it would have to be combined with a second kind of medicine that kills the immune cells churning out viruses. No such medicine is yet proven to work, although some experimental versions are in development.

The idea that dormant viruses could be reactivated before being destroyed is sometimes known as a “kick and kill” strategy. In the latest work, Sharon Lewin at the University of Melbourne, Australia, and her colleagues studied people with HIV who also had cancer and were being treated with a relatively new medicine called pembrolizumab.

This is an antibody that blocks a protein on immune cells called PD-1, which normally acts as a brake on immune cell activity. Taking away the brake helps the immune system attack tumour cells.

It now seems that removing the brake also makes HIV inside dormant immune cells wake up. In 32 people who received pembrolizumab, the amount of HIV in their blood rose 1.6-fold.

But the approach needs further work, as strategies to kill immune cells with actively replicating HIV, such as vaccines and antibodies, are still in development. “It’s an additional tool that we can use to perturb the HIV reservoir, and we would need that in combination with other interventions,” says Lewin.

Other researchers have found that combining another cancer medicine with an experimental HIV vaccine let some people – although only a minority – stop taking their antiviral drugs for several months without HIV levels rebounding.

Journal reference: Science Translational Medicine , DOI: 10.1126/scitranslmed.abl3836