(RxWiki News) Providing patients with realistic expectations of their treatment is important. How do both patients and doctors understand the effectiveness of the most widely prescribed multiple sclerosis medication, interferon beta?
A study published in the July issue of the Journal of the American Medical Association (JAMA) investigated the use of interferon beta to treat relapsing-remitting MS (RRMS).
Researchers found no evidence of interferon beta reducing disability progression for these patients.
"Talk with your physician about treatment expectations."
Afsaneh Shirani, MD, of the University of British Columbia, Vancouver, Canada, and colleagues collected data from 2656 people in British Columbia between 1985 and 2008. The data included 868 people with RRMS who were treated with interferon beta, 829 people who were not treated with interferon beta and 959 people whose data were recorded before the use of the drug to treat MS.
RRMS is the most common type of multiple sclerosis (MS). Interferon beta was approved for treating RRMS by the FDA in 1993.
The researchers compared the time from the start of interferon beta eligibility until a patient needed a cane to walk 100 meters without condition improvement for 150 days to evaluate effectiveness of the treatment.
This benchmark represents a sustained minimum of level six on the zero to ten Expanded Disability Status Scale (EDSS), the most common method used to measure disability in MS.
The first and last EDSS measurement varied between groups. The median follow-up times for the contemporary groups were 5.1 years for the treated group and 4.0 years for the untreated group, while the historic group was 10.8 years.
Of the treated group, 10.8 percent kept an EDSS score of six, compared with 5.3 percent for the contemporary untreated group and 23.1 percent for the historical untreated group. Adjustments were made to the rates due to differences in sex, age, disease duration and EDSS score.
Dr. Shirani and colleagues concluded that whether the patient had interferon beta exposure did not make a significant difference in reaching an EDSS score of 6 and therefore does not contribute to preventing long-term disability in patients with MS.
This study conflicts with previous studies that show interferon beta to reduce severity of relapses, disability and lesions in the brain for RRMS patients. Researchers were not sure how the drug worked, but they believed that it helped fight viral infections, inflammation and protects the insulated coating around nerves.
“While this study fails to demonstrate that interferon beta reduces physical disability longitudinally in one MS sample, patients must keep in mind that this is only one study examining one outcome variable,” said Nancy D. Chiaravalloti, PhD, Director of Neuropsychology & Neuroscience Research at Kessler Foundation.
“Other studies have demonstrated efficacy with interferon beta. More research is necessary to understand the conflicting results, including examining other aspects of the disease, such as lesion load, cerebral atrophy, and cognition.”
Dr. Chiaravalloti also stresses the importance of consulting with your physicians regarding any treatment decisions as multiple factors, such as other health conditions or lifestyle, are considered when recommending a treatment.
There are several potential conflicts of interest for the researchers of this study. Dr Shirani receives travel grants from the endMS Research and Training Network and the European Committee for Treatment and Research in Multiple Sclerosis.
Other researchers report similar travel grants as well as travel grants, consulting fees, research grants and/or educational grants from Aventis, Bayer, Biogen-Idec, BioMS, Corixa, Genentech, Novartis, Serono, Shering, Talecris, Teva-Neurosciences, BTG International, Medical Services Commission of British Columbia
This study was supported by grants from the Canadian Institutes of Health Research and the National Multiple Sclerosis Society. The study’s researchers also receive grants or research funding from the Multiple Sclerosis Society of Canada, the Michael Smith Foundation for Health Research, the Christopher Foundation, University of British Columbia and the Natural Sciences, Engineering Research Council of Canada, UK Multiple Sclerosis Trust.