The drug, T-0047, was placed on clinical hold by the FDA in response to the reports that progressive multifocal leukoencephalopathy (PML), a rare nerve disorder, was associated with Tysabri. Tysabri is marketed by Biogen Idec and Elan Pharmaceuticals and is a monoclonal antibody with a similar receptor target to T-0047.
Tanabe and GlaxoSmtihKline have been waiting to resume the study of T-0047 after the FDA and the EU approved the marketing of Tysabri in 2006. Tysabri was approved with the condition that it must be administered at registered infusion centers.
The resumed clinical trial is being conducted in Europe, Canada, Australia and New Zealand.