presented positive safety data and new patient rates for multiple sclerosis drug Tysabri, at the annual meeting of the American Academy of Neurology in Chicago Tuesday.
At the end of the first quarter, the companies said there were 15,300 patients on the drug in the U.S., and more than 10,200 taking it outside of the U.S. -- overall a 25% rise since the last sequential quarter.
The company noted that more than 36,700 patients have been treated with the drug, and more than 9,900 have taken it for at least one year.
Notably, the companies said there were no new cases of progressive multifocal leukoencephalopathy (PML), a rare and typically fatal brain virus that prompted the drug to be temporarily removed from the market in 2005.
Biogen and Elan said they are making progress toward their public goal of reaching 100,000 patients on Tysabri by the end of 2010.
Bear Stearns analyst Mark Schoenebaum said in a note to investors that the weekly worldwide patients are accelerating nicely and have tracked above his estimates. New patients are adding at a rate of 385 per week, or a 14% increase from the new patient rate at the end of the fourth quarter.