Skip to content

    Multiple Sclerosis Health Center

    Font Size
    A
    A
    A

    Ingredient in New MS Drug Linked to Serious Brain Disease

    Reports found four psoriasis patients who took similar drug developed rare but sometimes deadly condition

    WebMD News from HealthDay

    By Brenda Goodman

    HealthDay Reporter

    WEDNESDAY, April 24 (HealthDay News) -- The active ingredient in a drug that's expected to become a popular treatment for multiple sclerosis has been linked to four European cases of a rare but sometimes fatal brain disease called progressive multifocal leukoencephalopathy (PML).

    The ingredient, dimethyl fumarate, is used in a drug called Fumaderm that was approved in Germany in 1994 to treat the skin condition psoriasis. It is also in a different but closely related medication called Tecfidera, which was just approved by the U.S. Food and Drug Administration in March for the treatment of multiple sclerosis (MS). It is known as a fumaric acid ester, which is commonly used as a food additive and has been used to treat psoriasis in Germany for 30 years.

    According to reports published in the April 25 issue of the New England Journal of Medicine, however, three patients who were taking Fumaderm to treat their psoriasis developed PML. One other patient developed the brain condition after taking a separate medication from a compounding pharmacy that also contained dimethyl fumarate.

    In a letter responding to the reports, Biogen, the company that makes both drugs, said Tecfidera may be safer because it contains only dimethyl fumarate, while Fumaderm also contains three other fumaric acid esters.

    The company also noted that none of the patients taking Tecfidera during clinical trials (then known as BG-12) developed PML. Since Tecfidera is a pill rather than an injection, and was effective and well-tolerated by patients in clinical trials, analysts have predicted it would soon become the top-selling multiple sclerosis treatment.

    But the German doctor who treated one of the psoriasis patients who got PML thinks there is still cause for concern.

    Dr. Jorg Schulz, a neurologist at Rheinisch-Westfaelische Technische Hochschule Aachen, a research university in Aachen, said the two drugs are virtually identical once they are broken down in the body.

    "The problem is that the studies with BG-12 covered a two-year period, but no longer periods," Schulz said, and he believes it may take prolonged treatment with the drug for PML to surface.

    1 | 2 | 3

    Today on WebMD

    nerve damage
    Learn how this disease affects the nervous system.
    woman applying lotion
    Ideas on how to boost your mood and self-esteem.
     
    woman pondering
    Get personalized treatment options.
    man with hand over eye
    Be on the lookout for these symptoms.
     
    brain scan
    ARTICLE
    worried woman
    ARTICLE
     
    neural fiber
    ARTICLE
    white blood cells
    VIDEO
     
    sunlight in hands
    ARTICLE
    marijuana plant
    ARTICLE
     
    muscle spasm
    ARTICLE
    Neuron
    ARTICLE