Interferon Beta has for years been a widely used disease-modifying drug for treatment of multiple sclerosis.  But a study published this month in the  Journal of the American Medical Association, concluded that the medication is ineffective at slowing the progression of MS. Researchers from the University of British Columbia did not find "evidence that administration of interferon beta was associated with a reduction in disability progression in patients with relapsing-remitting MS" (Shirani et al, 2012).

So what does that mean?  First, some background. Drugs in the interferon beta class--Betaseron, Avonex and Rebif--were thought to "decrease the number of attacks of weakness and slow the progression of the disease."  It was believed that this class of drugs worked as an anti-inflammatory in MS patients, preventing the breakdown of the "blood-brain barrier," which is a common effect of the disease (Neurology, 1996).  But this most recent study indicates that, though some patients may benefit from treatment with interferon beta, the drugs’ abilities to prevent or delay long-term disability in MS patients now seem questionable. 

[QUIZ: Relapsing-Remitting MS: Symptoms and Relapses]

And that raises the question of why the shortcomings of these drugs weren’t determined sooner. Back in 1996 a study found that interferon beta drugs "could slow the progressive, irreversible, neurological disability of relapsing multiple sclerosis," ultimately concluding that the drugs had a" significant beneficial impact in relapsing multiple sclerosis patients by reducing the accumulation of permanent physical disability, exacerbation frequency, and disease activity" (Jacobs et al, 1996).  The recent study clearly disputes that. How could the drugs be thought to be so effective 16 years ago, but ineffective now?

Here’s how the two studies differed:

• The 1996 study followed patients for only two years, as opposed to the 23 years over which data was collected in 2012.
• The 1996 test studied only 301 patients; the 2012 study looked at 2,656 patients.
• In 1996, the benchmark EDSS score was 1.0 – defined as "no disability, minimal signs in one functional system." (Higher
  scores indicated greater disability.)  In 2012, the benchmark was a point of greater disability, creating a broader scale of outcomes across the tested population.

And what about the cost of two decades of interferon beta use? 

In 2006, researchers from the Karolinska Institute in Stockholm found that the annual cost of multiple sclerosis is roughly $47,000 per patient, including both direct medical care and indirect costs through lost productivity (Kobelt et al, 2006).  Of this total, 34 percent of costs went towards disease-modifying drugs.  Some of the more expensive drugs cost up to $25,000 per year, and the newest disease-modifying drug (Gilenya) costs even more—almost $48,000 per year (Goldberg et al, 2009; von Schaper, 2010).