Elan to begin new Tysabri tests
ELAN and US partner Biogen said yesterday they will begin a new series of tests of the companies' drug Tysabri.
The companies hope the tests will eventually involve 1,800 patients with multiple sclerosis (MS) in 27 countries. Elan and Biogen believe they have discovered why the drug does not work with some patients and now want to convince doctors that it should be used to treat people who have relatively mild versions of MS.
Tysabri, which has enjoyed sales of more than $1bn, is Elan's biggest-selling drug but it had to be pulled from the market in 2005 after three patients developed a rare brain infection. The US Food and Drug Administration allowed sales to resume in July 2006, after deciding benefits of slowing MS relapses outweighed possible risks. The new study will compare the benefits of Tysabri with rival treatments Copaxone and Rebif which are also used to treat MS. "Despite being on therapy, many MS patients still experience disease progression, resulting in loss of physical abilities and permanent damage to the central nervous system," said Richard Rudick who will run the trial. "Currently, there is limited data to inform decisions about how to switch in patients who have disease activity while on therapy."