Multiple sclerosis drug trial reveals unexpected sensitivity

A clinical trial led by Professor Anne La Flamme from Te Herenga Waka—Victoria University of Wellington’s School of Biological Sciences has revealed unexpected results for a new drug to help people with multiple sclerosis.

MRI brain scan

The trial was funded by the Ministry of Business, Innovation and Employment and completed in partnership with the Capital and Coast District Health Board.

“The trial was a small therapeutic trial evaluating the suitability of two re-purposed medications for progressive multiple sclerosis,” Professor La Flamme says. “The results were very surprising, but potentially quite valuable—they suggest that people with multiple sclerosis are more sensitive to the medications we tested, even at very low doses.”

The trial tested two medications—clozapine and risperidone—which are normally used to treat several neurological diseases including schizophrenia and Parkinson’s disease. They have recently been proven to reduce inflammation in the brain, prompting Professor La Flamme and her team to find out if they could help slow down or stop progressive disability in multiple sclerosis patients.

“Based on our pre-clinical findings, we knew that these drugs targeted the pathways in the brain involved in mulitple sclerosis. The next step, which was tested in this trial, was to make sure that these medications were well tolerated by people with progressive multiple sclerosis,” Professor La Flamme says. “After that, the next stage of testing would investigate whether the medications could slow down or stop the progression of multiple sclerosis by affecting these pathways.”

Professor La Flamme’s trial showed that people with multiple sclerosis are very sensitive to clozapine, even at a dose that is 10 times lower than is typically given to patients to treat psychosis. This finding is useful for future treatments as it suggests that during progressive multiple sclerosis there are changes to the pathways in the brain targeted by clozapine and merits future investigation, Professor La Flamme says.

“Together our research suggests that clozapine or risperidone may be able to regulate inflammation in the brain, but more work is required to understand how the pathways targeted by these medicines are altered during multiple sclerosis,” Professor La Flamme says. “The sensitivity revealed by this trial also reinforces that caution must be used when repurposing medications.”

Work is now underway to identify how the pathways in the brain affected by clozapine have changed in people with multiple sclerosis, Professor La Flamme says. This research will help us ot understand how best to use these medications to benefit people with multiple sclerosis.