TY - JOUR T1 - Switching from natalizumab to alemtuzumab in patients with relapsing multiple sclerosis JF - Journal of Neurology, Neurosurgery & Psychiatry JO - J Neurol Neurosurg Psychiatry SP - 1376 LP - 1378 DO - 10.1136/jnnp-2019-320687 VL - 90 IS - 12 AU - Nevin John AU - Antonia Carroll AU - Wallace J Brownlee AU - Jeremy Chataway Y1 - 2019/12/01 UR - http://jnnp.bmj.com/content/90/12/1376.abstract N2 - Natalizumab is a disease-modifying therapy (DMT) used in relapsing-remitting multiple sclerosis (RRMS), licenced for use in patients with highly-active disease. It is an α4-integrin receptor antagonist that decreases activated T cell migration across the blood-brain barrier.1 Natalizumab carries a risk of progressive multifocal leucoencephalopathy (PML)—a risk that increases with duration of treatment; John Cunningham Virus (JCV) seropositivity and higher index values; prior use of immunosuppression.1 Patients may choose to withdraw from natalizumab to mitigate PML risk, or less commonly when natalizumab fails to control disease activity, or is poorly tolerated. Fingolimod has been commonly used as an option in those making the switch from natalizumab, but is associated with high rates of breakthrough clinical and/or radiological disease activity, although the risks may be lower with shorter washout periods.2 Rituximab has been suggested as an alternative to fingolimod in patients discontinuing natalizumab due to high PML risk, however, rituximab is not licenced for the treatment of RRMS and is not available in some countries for this indication.3 Alemtuzumab is a monoclonal antibody that binds to the CD52 surface protein on T and B lymphocytes, resulting in their depletion with subsequent repopulation, with comparable efficacy to natalizumab.1 Switching to alemtuzumab might be an alternative to fingolimod in patients stopping natalizumab but there is a paucity of clinical and safety data to guide this transition. Here, we present a single-centre experience in switching from natalizumab to alemtuzumab in RRMS.We retrospectively identified patients from the National Hospital for Neurology and Neurosurgery who switched from natalizumab to alemtuzumab from May 2015 to February 2018. We extracted data from the medical records: demographic characteristics, duration of natalizumab use, drug washout period, cerebrospinal fluid (CSF) examination results, JCV serology, clinical … ER -