Posted: 4 September 2023
An existing blood cancer drug has shown promise in killing ‘silent’ HIV cells and delaying reinfections – a significant pre-clinical discovery that could lead to a future cure for the disease.
Hidden HIV cells, known as latent infection, are responsible for the virus permanently remaining in the body and cannot be treated by current therapy options. These hibernating, infected cells are the reason why people living with HIV require life-long treatment to suppress the virus.
Led by WEHI and The Peter Doherty Institute for Infection and Immunity (Doherty Institute), the landmark study is being translated into a new clinical trial to assess whether the blood cancer treatment can be repurposed to offer a pathway towards an HIV cure.
An estimated 39 million people worldwide are living with HIV, including more than 29,400 Australians.
Antiretroviral therapy (ART) is the standard of care treatment given to people living with HIV and is highly effective. But the medication cannot target hibernating HIV-infected cells, meaning it can only suppress the virus – not cure it.
ART for people living with HIV is life-long: if a person stops taking this medication, hibernating HIV-infected cells will reactivate within a very short timeframe, leading to a resurgence of the virus.
An estimated 98% of Australians living with HIV currently have undetectable levels of the virus, as it is completely suppressed by their ongoing ART treatment.
In the new study, WEHI researchers used the cancer drug venetoclax on enhanced pre-clinical models of HIV and found it delayed the virus from rebounding by two weeks, even without ART.
Co-first author, Dr Philip Arandjelovic from WEHI, said the discovery is an exciting step towards developing treatment options for the tens of millions of people currently living with HIV globally.
“In attacking dormant HIV cells and delaying viral rebound, venetoclax has shown promise beyond that of currently approved treatments,” he said.
“Every achievement in delaying this virus from returning brings us closer to preventing the disease from re-emerging in people living with HIV. Our findings are hopefully a step towards this goal.”
The study marks the first time venetoclax has been used on its own to assess HIV persistence in pre-clinical models.
However, researchers also found the cancer treatment can be combined with another drug that acts on the same pathway and is currently in clinical trials, to achieve a longer delay in viral rebound, with a shorter duration of venetoclax treatment.
“It has long been understood that one drug may not be enough to completely eliminate HIV. This finding has supported that theory, while uncovering venetoclax’s powerful potential as a weapon against HIV,” Dr Arandjelovic said.
