Assessing the Withdrawal of Tysabri

Assessing the Withdrawal of Natalizumab - Journal Watch Neurology"The stunning chain of events concerning natalizumab has dealt a shocking blow to many patients who had pinned their hopes on what appeared to be an extremely effective new agent. It also has dashed the hopes of clinicians and discouraged hundreds of natalizumab investigators worldwide. Why PML emerged in patients without other opportunistic infections remains a mystery. JC virus, believed to reside in as many as 80% of clinically asymptomatic adults, probably is harbored in B cells within the bone marrow. It is frequently shed in urine. The mechanism by which it is activated to cause neurologic disease in natalizumab recipients remains unclear and is being investigated."...Dr. Miller is Professor of Neurology, Mount Sinai School of Medicine, and Medical Director, Corinne Goldsmith Dickinson Center for Multiple Sclerosis, New York City.