FDA does not approve the company's supplemental Biologic License Application for subcutaneously delivered natalizumab for the treatment of relapsing multiple sclerosis. Rationale has not been publicly released. 
Approved in UK .
Approved in EU 
Current licensed indication for Tysabri IV is as use single disease modifying therapy in adults with highly active relapsing remitting multiple sclerosis for patients with highly active disease despite a full and adequate course of treatment with at least one disease modifying therapy (DMT) or patients with rapidly evolving severe relapsing remitting multiple sclerosis defined by 2 or more disabling relapses in one year, and with 1 or more Gadolinium enhancing lesions on brain MRI or a significant increase in T2 lesion load as compared to a previous recent MRI .
Recommended for EU approval by CHMP - approval covers the same indications as the original product. Treatment [...] is to be initiated and continuously supervised by specialised physicians experienced in the diagnosis and treatment of neurological conditions, with timely access to MRI. Home treatment is not recommended .
Currently pre-registration in the EU. Has been filed using centralised procedure .