A University of Calgary study has found promising results for the generic drug hydroxychloroquine when used to treat the evolution of disability of primary progressive multiple sclerosis (MS), the least treatable form of the autoimmune disease.

MS has been known to affect about 90,000 Canadians with about 15 per cent of those diagnosed with primary progressive MS, one of the highest rates in the world. Cumming School of Medicine research teams led by Dr Marcus Koch, MD, PhD, and Dr Wee Yong, PhD, found that hydroxychloroquine helped to slow the worsening of the disability during the 18-month study involving participants at the MS clinic in Calgary. The research was published in 'Annals of Neurology'.

"With primary progressive MS, there is no good treatment to stop or reverse the progression of disease. The disability progressively worsens through time," said Koch, a clinician-investigator in the Department of Clinical Neurosciences and member of the Hotchkiss Brian Institute (HBI).

"Dr Yong's research team, with whom we closely collaborate, has been screening a large number of generic drugs over several years and the results with hydroxychloroquine show some promise. Our trial is a preliminary success that needs further research. We hope sharing these results will help inspire that work, specifically larger scale clinical trials into the future," he added.

The experimental study, known as a single-arm phase II futility trial, followed 35 people between November 2016 and June 2021. Researchers expected to see at least 40 per cent, or 14 participants, experience a significant worsening of their walking function, but at the end of the trial, only eight participants had worsened. Hydroxychloroquine was generally well-tolerated.

Hydroxychloroquine is an anti-malaria medication, more commonly used to manage the symptoms of rheumatoid arthritis and autoimmune conditions such as lupus. It was chosen because it was widely used in rheumatological diseases and generally well-tolerated.

"Based on research in our lab on models of MS, we predicted that hydroxychloroquine would reduce disability in people living with MS. Calgary has a vibrant bench-to-bedside MS program and the work from Dr Koch's trial offers further evidence which we were pleased to see," said Yong, a professor in the Department of Clinical Neurosciences and HBI member.

The cause of MS still remains unknown. It is said to cause the body's immune system to attack its own tissues and has generally been long-lasting. It has also been known to often affect the brain, spinal cord and the optic nerves in one's eyes. It causes problems with vision, balance and muscle control, although the effects vary from person to person.