Today Biogen Idec (NASDAQ: BIIB) and Elan Corporation, plc (NYSE: ELN) announced that they have submitted applications to the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) requesting updates to the TYSABRI ® (natalizumab) labels. The applications request an expanded indication that would include first-line use for people living with certain relapsing forms of multiple sclerosis (MS) who have tested negative for antibodies to the JC virus (JCV). A formal assessment of both applications is ongoing. These submissions are supported by risk stratification data and a risk algorithm that enables physicians and individuals living with MS to make informed decisions when considering treatment with TYSABRI. If approved, a first-line label will allow all appropriate anti-JCV antibody negative patients to consider TYSABRI early in the course of treatment, regardless of the level of disease activity or prior treatment history. TYSABRI is a highly efficacious treatment that has been shown to slow disability progression by 42 – 54 percent and reduce annualized relapse rates by 68 percent. “Our anti-JCV antibody test, STRATIFY JCV ®, helps to determine the most appropriate patients for TYSABRI and the data collected to date supports our recent filing for first-line use,” said Alfred Sandrock, M.D., Ph.D., senior vice president, Development Sciences and Chief Medical Officer, Biogen Idec. “Many appropriate patients are already benefiting from TYSABRI. A first line approval would allow people with MS access to a highly efficacious treatment earlier in the course of the disease, potentially leading to better outcomes. This is an important consideration for people with MS who may want or need more efficacy.” Currently in the U.S., due to an increased risk of an opportunistic viral infection, progressive multifocal leukoencephalopathy (PML), TYSABRI is generally recommended for people living with relapsing forms of MS whose disease is not responding to, or who are unable to tolerate, an alternative therapy regardless of JCV status. In the EU, TYSABRI is approved for highly active relapsing-remitting MS (RRMS) in adult patients who have failed to respond to beta interferons or have rapidly evolving, severe RRMS.