The Irish and U.S. makers of Tysabri reported Thursday that the drug — currently suspended from sale because of a possible link to a deadly disease — has produced positive results in an advanced trial for patients with Crohn’s disease.
Elan Corp. of Ireland and Biogen Idec Inc. of Massachusetts have jointly developed Tysabri to suppress the symptoms of multiple sclerosis, which attacks the body’s central nervous system, and Crohn’s, which inflames the gastrointestinal system.
Tysabri went on sale late last year in the United States after testing strongly on MS sufferers, but was withdrawn Feb. 28 after being linked to two patients who contracted a rare and usually fatal brain disease called progressive multifocal leukoencephalopathy, or PML. One of those patients died. On March 30, Elan and Biogen announced that a Crohn’s sufferer who had been taking Tysabri also had died of PML.
The Boston Globe and Wall Street Journal this month reported possible fourth and fifth cases of PML in Tysabri users, but Elan and Biogen have both declined to comment on those reports.
Elan and Biogen said Thursday that a third-phase trial of 510 Crohn’s sufferers in 114 locations, called “Encore,” had produced a reduction in symptoms within 12 weeks of treatment.
“The results of the Encore study are encouraging because patients treated with Tysabri achieved a significant improvement in symptoms of this devastating, chronic immune disease,” said Lars Ekman, president of research and development at Elan.
Ekman said the trial results were being forwarded to U.S. Food and Drug Administration officials in hopes of encouraging a decision on whether Tysabri can be returned to the market.