Inspired by the promising results in mice, the researchers have now started testing the effects of the drug on humans.
“This is an exciting result. We have now started a clinical trial in Oxford to see if we can show the same results in cancer patients,” said study lead author Gillies McKenna from Cancer Research UK Radiation Research Centre in Oxford.
“We hope that this existing low cost drug will mean that resistant tumours can be re-sensitised to radiotherapy,” McKenna said.
The study looked at the effect of the drug, called atovaquone, on tumours with low oxygen levels in mice to see if it could be repurposed to treat cancer.
This medicine is no longer patented and is readily and cheaply available from generic medicines manufacturers.
This research showed that the anti-malaria drug slows down the rate at which cancer cells use oxygen by targeting the mitochondria, the powerhouses of the cell that make energy, a process that uses oxygen.
By slowing down the use of oxygen, this drug reverses the low-oxygen levels in nearly all of the tumours. The fully-oxygenated tumours are more easily destroyed by radiotherapy.
In a study published in the journal Nature Communications, the drug was shown to be effective in a wide range of cancers, including lung, bowel, brain, and head and neck cancer.
“The types of cancer that tend to have oxygen deprived regions are often more difficult to treat – such as lung, bowel, brain and head and neck cancer,” Emma Smith, Cancer Research UKâ€™s Science Information Manager said in a statement.
“Clinical trials will tell us whether this drug could help improve treatment options for patients with these types of tumour,” Smith noted.