Drug used to treat cancer may also help fight HIV, Australian research finds

Date Added: January 27, 2022 07:37:12 AM
Author: Sutra Web Directory
Category: Health & Beauty: News & Media

New research co-led by the director of the Doherty Institute, Prof Sharon Lewin, has found a medicine used to treat cancer can also draw HIV out of hibernation, exposing the virus to the immune system and making it more susceptible to attack.

HIV’s ability to “hide” in cells, even in people on antiretroviral therapy and with undetectable amounts of the virus in their blood, is one of the significant barriers to finding a cure for the disease.

While HIV patients on antiretroviral drug treatments have no chance of passing it on and can live normal and healthy lives, the virus is never eliminated from their cells entirely.

This is because a HIV reservoir “hides” in a state of hibernation in immune system cells. To destroy the virus, these cells need assistance from killer T-cells. But because these T-cells cannot detect and find the hidden HIV, they are unable to kill it.

In cancer patients, killer T-cells become dysfunctional, leading them to express exhaustion proteins on their surface called PD1. Previous research by Lewin found PD1 are the same exhaustion markers which allow HIV to hide in cells.

Pembrolizumab, an immunotherapy drug administered intravenously, blocks these exhaustion markers in cancer patients, allowing the killer T-cells to regain function and fight the cancer. The anti-PD1 drug has revolutionised the treatments of several cancers, including melanoma.

A barrier in testing the treatment for HIV patients has been that pembrolizumab can lead to significant side-effects.

“Five to 10% of people will get an adverse event from pembrolizumab,” Lewin said. “In a cancer setting this isn’t a major concern as you have a life-threatening illness, but in HIV, the situation is very different. People can now live normal and healthy lives with HIV, so any intervention for a cure must have very low toxicity.”