FDA Approval for Elan's Potential Blockbuster MS-Drug Tysabri
Dublin - The global market for MS-drugs will be reshuffled following the FDA's approval of the new MS-drug Tysabri, formerly Antegren, by Irish Elan Corp. and its partner Biogen Idec Inc. Tysabri is the first humanized monoclonal antibody approved for the treatment of MS. It inhibits adhesion molecules on the surface of immune cells. Research demonstrated that the new medicament works by preventing immune cells from migrating from the bloodstream into the brain where they can cause inflammation and potentially damage nerve fibers and their insulation.
“Physicians we spoke to are optimistic that this drug will end up being a mainstay in MS treatment,” said Michelle Grady, senior analyst with Decision Resources. Other analysts are similarly optimistic and expect Tysabri to be an emerging blockbuster with potential earnings to peak over $3.5 billion. The actual world market, by 2013, will more than double from its present level of about $4 billion, and Tysabri's competitors - mainly interferon- drugs, which actually take 98% of the market - will have less than half, with Tysabri accounting for fully a third.
In clinical studies, the new MS drug reduced the rate of clinical relapses by 66% relative to placebo in a mono therapy. Furthermore the combination of Tysabri with Biogen's blockbuster Avonex resulted in a 54% reduction in the rate of clinical relapses over the effect of Avonex alone. The only potential hitch is Tysabri's monthly intravenous route of administration. Analysts wondered whether mild patients who tend to be younger women would like to go to an infusion center instead of taking interferone- drugs, which can be self-administered.