A drug commonly used to treat Parkinson’s disease could be repurposed as cancer medication after trials demonstrated that it has significant anti-cancer effects.
Carbidopa, a drug prescribed to patients alongside levodopa or L-DOPA (in order to reduce the med’s negative nauseating side effects) inhibits the growth of cells and tumours in mice, according to the study published in the Biochemical Journal.
Lead author on the study, Dr Yangzom Bhutia, said: “Carbidopa as an anti-cancer agent to treat [pancreatic] cancer would be something truly amazing.”
It is estimated that around 1 in every 500 people in the UK are affected by Parkinson’s disease, meaning there is approximately 127,000 people living with the condition.
The degenerative neurological disorder influences movement and motor skills, with symptoms including shaking, rigidity and difficulty in walking. But there is currently no cure, only things that can slow the progression.
One of these treatments is a combination of dopamine-producing drug L-DOPA and carbidopa, which is taken to counteract the effects of excess dopamine travelling around the body, as only 5-10% of L-DOPA is actually absorbed and crosses the blood-brain barrier.
Patients who take this magical cocktail of drugs have been shown to have lower cancer rates than most of the population (except in the case of melanoma).
L-DOPA has already been investigated in the past and was found not to be the cause of the reduced cancer stats, so Bhutia’s team decided to look at carbidopa instead: “Interestingly, no one has previously suspected carbidopa as a potential player in this phenomenon,” he said.
They then tested the effects of carbidopa on a human pancreatic cancer cell line and also in mouse models of pancreatic cancer and found it did “significantly” inhibit the growth of cancerous cells.
The recommended dose of carbidopa for Parkinson’s disease patients is 200 mg/day, but when given at a dose even as high as 450 mg/day, they found there are no side effects, so it could be prescribed in high quantities to fight cancer.
The team are hoping that moving this research into clinical trials will not be too difficult, or expensive, as the drug is already FDA-approved for Parkinson’s and therefore wouldn’t require rigorous testing that new drugs to the market normally have to undergo.
“We would like to partner with oncologists to design and conduct clinical trials in cancer patients to establish whether or not carbidopa would be useful as an anticancer drug in humans,” said Bhutia.
Parkinson’s expert, Professor Aideen Sullivan, University College, Cork, added: “Since carbidopa has already been proven to be safe and well-tolerated by people with Parkinson’s, its application in cancer treatment, where most current therapies are associated with severe and long-lasting side-effects, will be welcomed by patients.”