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LONDON, July 25 (Reuters) - An off-patent malaria drug couldhelp to destroy cancer cells by making them more susceptible toradiotherapy, according to early work that has prompted Britishscientists to start a clinical trial.
Researchers reported on Monday that atovaquone boostedoxygen levels in tumour cells in mice, making radiotherapy moreeffective against a range of cancer types, including lung,bowel, brain and head and neck cancer.
Cancer cells with low oxygen levels are more difficult totreat with radiotherapy and are more likely to spread to otherparts of the body.
"We have now started a clinical trial ...to see if we canshow the same results in cancer patients," said lead researcherGillies McKenna of the Cancer Research UK Radiation ResearchCentre in Oxford.
"We hope that this existing low-cost drug will mean thatresistant tumours can be re-sensitised to radiotherapy. Andwe're using a drug that we already know is safe."
His team's findings were published in the journal NatureCommunications.
The idea of repurposing existing drugs to fight cancer isgaining traction as scientists realise that older medicines cansometimes complement other therapies.
The fact that such drugs are already off patent means theyare cheap, but the lack of patent protection is also a potentialproblem because drug companies investing in late-stage researchhave less certainty of a commercial payback.
Atovaquone is used to both treat and prevent malaria. It isusually prescribed to travellers as Malarone, a combination ofatovaquone and proguanil developed by GlaxoSmithKline. (Reporting by Ben Hirschler; editing by John Stonestreet)
