Tysabri found effective in Crohn’s trial
In the latest Crohn's trial, a statistically significant number of patients who had active inflammation showed improvement after taking Tysabri for periods of eight and 12 weeks.
The release of part of the trial results highlights the potential effectiveness of Tysabri in autoimmune diseases beyond multiple sclerosis (MS), the condition Tysabri was approved for in November by the FDA.
Tysabri was pulled off the market in February after an MS patient in a long term trial of Tysabri died of the rare brain disease progressive multifocal leukoencephalopathy (PML) and another patient was suspected of having the condition. The second case was later confirmed, though that patient survived, and a third patient who took Tysabri in a trial for Crohn's disease was posthumously diagnosed as having died from the disease. Three other potential PML cases with possible links to Tysabri are also under investigation.
PML normally occurs only in patients with compromised immune systems. Biogen and Elan have been examining the possibility that the drug made patients susceptible to PML by changing the way certain white blood cells function.
Biogen and Elan are planning to meet with regulators at the end of the summer to discuss whether Tysabri can return to the market.
Last week, Biogen IDEC closed a deal with Genentech to sell a California plant built to manufacture the Tysabri.
Tysabri had been expected to generate more than $1 billion in annual revenue.