A common drug therapy used for people with the relapsing-remitting form of multiple sclerosis is not associated with a significant change in the progression of disability, according to researchers at the Faculty of Medicine and Vancouver Coastal Health.
The study, published in the Journal of the American Medical Association (JAMA), shows no strong evidence that beta interferons (β-IFNs) prescribed to treat MS had a measurable impact on the long-term disability progression of the disease. The team examined the linked health records of 2,656 B.C. patients between 1985 and 2008 in a retrospective cohort study, which means data from already collected sources were linked together in an anonymized form and studied. The study population included patients with MS who were treated with β-IFNs, the most widely used treatment for relapsing-remitting MS, as well as untreated MS patients.
These findings will be of interest to MS patients with this form of the disease, but researchers are quick to point out that this is just one measure of these disease modifying drugs and there is still potentially significant benefit to patients.
“What this study provides is additional information to patients and clinicians about the longer term effect of this class of drugs,” said Helen Tremlett, an Associate Professor in the Division of Neurology who holds the Canada Research Chair in Neuroepidemiology and Multiple Sclerosis. “We know that this class of drugs is very helpful in reducing relapses, which can be important to patients. We do not recommend that patients stop taking these medications, but these findings provide evidence, allowing more realistic expectations as to the anticipated benefits associated with drug treatment from the disability perspective.”
“It is still possible that some patients gain long-term benefit from β-IFNs,” said Afsaneh Shirani, the first author of the paper and a post-doctoral research fellow in the Faculty of Medicine and the Brain Research Centre at UBC and VCH Research Institute. “We are currently working toward identifying who those potential treatment responders might be.”
“Our study also encourages the investigation of novel treatments for MS,” she adds. “In addition, this study suggests that linked data from health administrative databases have enormous potential for research applications, despite all the challenges of record linkage.”
Relapsing-remitting MS is characterized by relapses or “flare-ups” during which time new symptoms can appear or old ones can resurface or worsen. The relapses are followed by periods of remission during which time the person can fully or partially recover. Relapsing-remitting MS is the most common form of MS affecting around 85% of MS patients in Canada.
“In clinical trial situations, it has been quite evident for years that patients receiving β-IFN treatment have reduced frequency of relapses as well as reduced frequency of new lesions seen on MRI,” says Joel Oger, a Professor of Neurology who works at the UBC Hospital MS Clinic. “This study following a large number of patients for a long time in ‘real life situation’ does not show an association of the β-IFNs with long-term disability, and tends to confirm a more modern way of understanding MS: relapses may not be responsible for long-term disability in all patients and another mechanism might be at work as well.”
The research team is preparing for future studies further examining this and other classes of disease modifying drugs. The hope is that the research will ultimately lead to an individualized approach to the treatment of MS.
The study was funded jointly by the Canadian Institutes of Health Research and the U.S. National MS Society. The researchers are also funded by the MS Society of Canada, the Michael Smith Foundation for Health Research, the Canada Research Chair program, the Natural Sciences and Engineering Research Council of Canada and the Christopher Foundation of Vancouver.