Test could ID which patients should get MS drugs

In another potential step toward personalized medicine, researchers have developed a test that predicts whether multiple sclerosis patients will respond to beta interferon drugs. The $6 billion drug class--which includes Biogen Idec's Avonex, Merck KGaA's Rebif, and Bayer's Betaferon--works in patients with one subtype of MS, but not in the other, researchers say.

The two subtypes are driven by two different immune cells: IL1 and IL17. Patients with the IL1p type respond to beta interferon therapy, while those with the IL17 type don't, says Stanford neurology professor Lawrence Steinman, one of the researchers in the Nature-published study. "A lot of people are taking beta interferons who should not be, and it may make them actually worse," Steinman tells Bloomberg.

The test measures blood levels of both cells to determine which type of the disease affects a patient. That way, doctors would know whether to prescribe a beta interferon drug. That sort of clarity could cut into beta interferon sales, but could also show that the drugs are more effective than previously thought. A diagnostic might also steer more patients toward other types of MS meds, such as Biogen's Tysabri or Teva Pharmaceutical Industries' Copaxone.

Alfred Sandrock, Biogen's SVP for neurology research tells the Wall Street Journal that the study "could be a very useful advance for MS patients," and adds the company plans to collaborate with Steinman on related research. The Stanford doctor says it would be a year or two before an actual blood test would be submitted to FDA for approval.

- see the Bloomberg story
- read the article in the WSJ