Biogen Idec applies to update Tysabri labelling

Biogen Idec has applied for permission to update the labelling of its multiple sclerosis drug Tysabri in the US and Europe.

In association with partner Elan, the company is hoping to amend the drug's Summary of Product Characteristics to include anti-JC virus antibody status as a potential factor in stratifying the risk of progressive multifocal leukoencephalopathy (PML).

Both companies have stated their commitment to isolating and addressing risk factors for the rare brain infection among the Tysabri patient population.

Applications have therefore been submitted to the US Food and Drug Administration and European Medicines Agency to request a review and approval of the proposed changes to the product's labelling.

Tysabri has been approved in more than 45 different countries to date and is ratified in Europe for use among patients with relapsing-remitting forms of multiple sclerosis.

According to Biogen Idec's most recent financial report, sales of the treatment saw an increase during the third quarter of 2010.