Many multiple sclerosis patients have complained for years that commonly used MS drugs called beta interferons don’t do much to stop the disease from getting worse. Now, new research appears to back them up.

A study from researchers at the University of British Columbia and the UBC Hospital MS Clinic and Brain Research Centre found no strong evidence that the drugs had much of an impact on the long-term progression of the disease.

Beta interferons are the most widely used treatment for relapse-remitting MS, which is the most common form of MS in Canada, affecting about 85 per cent of patients.

In this form of the disease, new symptoms such as partial paralysis, numbness and lack of coordination can appear for or old ones can resurface or worsen. The relapses are followed by periods of weeks or months in which the patient fully or partially recovers.

For the study, the team looked at the health records of 2,656 British Columbia patients between 1985 and 2008. They included those with MS who were treated with beta interferons, as well as untreated MS patients.

The team reports in the Journal of the American Medical Association that beta interferons were not linked to a significant slowdown in disability progression in the patients.

The authors say while they could find little proof that the drugs had much impact on slowing the disabling effects of MS over time, the medications might still hold some benefits for patients.

"We know that this class of drugs is very helpful in reducing relapses, which can be important to patients,” study co-author Helen Tremlett said in a statement.

“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."

Dr. Joel Oger, a neurologist with the UBC Hospital MS Clinic, says when the drugs were studied in clinical trials, patients saw their number of relapses drop. As well, MRI tests showed reduced frequency of new lesions on their brains.

Oger says this "real life situation" study tends to confirm ”a more modern way of understanding MS.” By that he means that it’s possible that relapses may not be responsible for long-term disability in all patients and that another mechanism might be at work as well.

The researchers also say it is still possible that even if not all patients see long-term benefits from beta interferons, there are some who might.

“We are currently working toward identifying who those potential treatment responders might be," says Dr Afsaneh Shirani, who is the first author of the paper.

This study was funded jointly by the Canadian Institutes of Health Research and the U.S. National MS Society. The MS Society of Canada also provided some funding.

The research team is preparing for future studies to look at other classes of MS-modifying drugs. They say their hope is that the research will ultimately lead to an individualized approach to MS treatment.