In a “surprising” discovery, a drug used to treat cocaine addiction could be a safe and effective form of treatment for advanced colorectal cancer, according to a new Canadian study.
University of Ottawa researchers tested vanoxerine in mice and tumour samples taken from human patients and found that the drug was able to effectively block the activity of colorectal cancer stem cells.
The findings of this research — seven years in the making — were published in the Nature Cancer journal on Tuesday.
“It seems like the drug is rewiring the genome of the cancer cells in a way that it makes them more obvious or easier to detect by the immune system, which is quite an impactful finding in terms of future treatment of colon cancer,” said Dr. Yannick Benoit, lead study author and associate professor in the department of cellular and molecular medicine at the University of Ottawa.
Cancer stem cells are the “nastiest or most aggressive cells” found inside of tumours, Benoit said, and suppressing this cell population could increase the likelihood of successfully treating patients.
“We think that having vanoxerine combined in the future with the standard drugs of chemotherapy that are used, we could have, higher chances of success in treating patients,” he told Global News in an interview Wednesday.
Vanoxerine, which is given via an intramuscular injection, is currently not approved for use in Canada or the United States.
It has been tested in various clinical trials for Parkinson’s disease, depression and cocaine dependence.
Benoit said one of the adverse effects observed in U.S. clinical trials was that if the drug is taken at the same time as consuming cocaine, then that could raise some heart rate problems. But he added that cocaine consumption is not likely to be a problem in the case of a patient undergoing cancer treatment.
In their lab experiments, vanoxerine resulted in “very low toxicity,” Benoit said.
He is hopeful that their discovery will spark interest in this drug from clinicians and the private sector with the aim of starting clinical trials in the context of colorectal cancer to test vanoxerine’s efficacy in patients.
“We hope that it could be eventually a safe approach to treat (colorectal) cancer.”
Colorectal cancer is the fourth most common form of cancer in Canada and the second deadliest, according to data recently published by the World Health Organization (WHO).
In 2022, there were 23,725 new colorectum cancer cases and 11,521 new deaths reported in the country.
Cases of colorectal cancer have particularly been increasing among the country’s younger population.
Unhealthy diet, physical inactivity, smoking and alcohol consumption increase the risks for this type of cancer, but family history is also a contributing factor, experts say.
Colorectal cancer is commonly treated with surgery and chemotherapy.
In advanced cases, targeted therapy involving drugs to “target specific molecules on cancer cells or inside them” may also be sometimes used, according to the Canadian Cancer Society.
Colorectal cancer starts in the colon or rectum – which are part of the large intestine – and can spread to other parts of the body.
In the early stages, colorectal cancer may not cause any signs or symptoms because the cancer is “very small”, but symptoms often appear once a tumour grows into surrounding tissues and organs, according to the CCS.
Bevacizumab, Cetuximab, Panitumumab, Encorafenib and Regorafenib are some of the targeted therapy drugs that may be given for advanced or recurrent colorectal cancer, the CCS says on its website.