An experimental cancer drug has been found to be effective at treating Ebola, drug-resistant HIV and a host of other viral infections. The drug, known as AR-12, is currently being trialled for the treatment of some types of tumour. Scientists are now arguing new clinical trials should be launched to better understand its anti-viral capabilities.
The international team of researchers found that in animal models, AR-12 doubled the survival of haemorrhagic fever virus while also suppressing liver damage. It protected cells from Ebola and was far more effective at suppressing drug-resistant strains of HIV than any treatments currently approved for use. Findings are published in the Journal of Cell Physiology.
AR-12 – also known as OSU-03012 – works by targeting GRP78. This is a protein chaperone, which keeps enzymes and virus coat proteins in their correct shape. If the shape is incorrect, the enzyme cannot work, so the virus cannot form.
Previous research has shown how GRP78 is essential for the replication of almost every known pathogenic virus. To replicate and take over a cell, a virus must be able to create a protective coating to make new viruses. It must also hijack the cell's signalling so it does not know it is being taken over – if the cell becomes stressed it can trigger a process to kill itself, in which case the virus cannot take over.
The latest study built on this research. Lead researcher Paul Dent, from Virginia Commonwealth University, said: "Basically, we have fully worked out how the drug works and why it stops so many different kinds of virus." They found that when combined with other drugs, AR-12 can inhibit many chaperone proteins – not just GRP78. This triggers cell self-destruction and the virus cannot take hold.
The team said the most significant finding was the suppression of multiple drug-resistant strains of HIV. Dent said AR-12 could be more effective at controlling other inhibitor drugs, while it also could produce fewer side effects than treatments currently available.
"As AR-12 has already undergone phase I evaluation in heavily pre-treated cancer patients, our present data argue for patient based anti-viral clinical studies," they concluded.