FDA updates Tysabri label relating to anti-JCV

The US Food and Drug Administration on Friday approved a product label change for Tysabri (natalizumab), co-marketed by US biotech firm Biogen Idec (Nasdaq: BIIB) and Ireland-based Elan Corp (NYSE: ELN) that will help enable individual benefit risk assessment for patients with multiple sclerosis (MS).

The new label identifies anti-JCV antibody status as a risk factor for developing an infrequent but serious brain infection known as progressive multifocal leukoencephalopathy (PML). This marks the third risk factor identified to help physicians and people with MS have more confidence in their treatment decisions when considering TYSABRI, a highly effective treatment for relapsing forms of MS.

Could push sales up to as much as $3 billion by 2016, says analyst