Biogen Idec/ Elan reveal new Tysabri safety data

US firm Biogen Idec and Irish drugmaker Elan have published two-year data from several Phase III clinical trials evaluating the drug Tysabri (natalizumab) in patients with relapsing forms of multiple sclerosis, in the New England Journal of Medicine. The findings had been previously presented at US and International medical meetings during 2005.

The results of the AFFIRM Phase III monotherapy trial and the Phase III SENTINEL combination study, during which Tysabri was added to Avonex (interferon beta-1a) , were included with information from the earlier safety evaluations in the supplemental Biologics License Application the firm submitted to the US Food and Drug Administration in September 2005.

Earlier this year, however, the FDA said it would extend its assessment of the compound following the company's recall of the drug, after it was linked of three cases of progressive multifocal leukoencephalopathy (Marketletter January 16, 2006). Since then, both firms have worked with PML experts to evaluate the safety data from the 3,000 plus patients that have received the drug. The companies added that an independent adjudication committee concluded that there were no cases of PML in the patient population, other than the three already reported.