Multiple Sclerosis Medication May Not Slow Disease Progression

New research raises questions about the efficacy of one of the most commonly prescribed drugs used to treat relapsing-remitting multiple sclerosis.

Although the immunomodulator interferon beta is recognized as a standard treatment for relapsing-remitting multiple sclerosis (MS) and is thought to reduce the rate of MS relapse as well as slow the progression of disability, a new study published in the July 18, 2012, issue of JAMA challenges this widely-accepted belief.

According to researchers from the University of British Columbia, led by Afsaneh Shirani, MD, treatment with interferon beta is not associated with a reduction in disability progression.

Investigators came to this conclusion after analyzing prospectively collected data from 1985 to 2008. Patients with relapsing-remitting MS treated with interferon beta (n = 868) were compared with untreated contemporary (n = 829) and historical (prior to the approval of interferon beta) (n = 959) cohorts. Researchers measured the time from initiation of interferon beta treatment to a confirmed and sustained score of 6 on the Expanded Disability Status Scale (EDSS). A score of 6 occurs when patients require a cane to walk 100 meters.

After adjusting for sex, age, disease duration, and EDSS score, the outcome rates for reaching a sustained EDSS score of 6 were 10.8% in the group treated with interferon beta, 5.3% in the contemporary untreated group, and 23.1% in the historical untreated group.

“The ultimate goal of treatment for MS is to prevent or delay long-term disability. Our findings bring into question the routine use of interferon beta drugs to achieve this goal in MS,” the authors wrote.

Dr. Shirani and colleagues are hopeful that their study results will encourage the investigation of novel therapeutics and new mechanisms of action to treat MS.

The finding that interferon beta may not be as effective a treatment as previously believed makes the need for new and effective therapeutics for MS that much more urgent. Thanks to a 1-year grant funded through the Department of Defense’s Congressionally Directed Medical Research Programs, a company named SRI International is now developing a novel therapy for MS.

The grant will support the development of an oral MS therapeutic that targets miR-326, a MicroRNA found to stimulate T-helper 17 (Th17) cells. Patients with MS have high levels of miR-326, and Th17 is thought to play a major role in causing autoimmune diseases such as MS.