The European Medicines Agency (EMA) has temporarily restricted the use of alemtuzumab. It should only be started in patients with relapsing-remitting multiple sclerosis that is highly active despite treatment with at least two disease modifying therapies, or where other disease-modifying therapies cannot be used.  The restriction follows new reports, some fatal, of cardiovascular adverse effects that occur within 1-3 days of receiving alemtuzumab, and immune-mediated adverse effects:
Bleeding in the lungs, myocardial infarction, stroke, cervicocephalic arterial dissection
Autoimmune hepatitis (with damage to the liver) and haemophagocytic lymphohistiocytosis
Healthcare professionals should consider stopping alemtuzumab in patients who develop signs of these conditions. Existing patients who benefit from alemtuzumab therapy may continue treatment in consultation with their doctor. Patients should be informed of the signs and symptoms of these conditions, and advised to seek immediate medical attention should they occur. 
Restrictions to alemtuzumab indications are a temporary measure while the EMA safety review is ongoing. At the conclusion of the review, the EMA will consider whether additional measures and changes to the authorised use of alemtuzumab are required.
Alemtuzumab, a monoclonal antibody directed against the CD52 antigen, is approved for use in adult patients with relapsing-remitting multiple sclerosis. It acts through antibody-dependent cellular cytolysis and complement-mediated lysis following cell surface binding to T and B lymphocytes.See Management: approach See Management: treatment algorithm
Demyelinating central nervous system condition clinically defined by two episodes of neurological dysfunction (brain, spinal cord, or optic nerves) that are separated in space and time.
Classically presents in white women, aged between 20 to 40 years, with temporary visual or sensory loss. However, may affect either sex and any age or ethnic group, and may have variable neurological symptom location and/or duration.
May have subtle changes in vision, ambulation, and reflexes on examination that provide evidence of previous attacks (which may not have been noticed by the patient).
Magnetic resonance imaging (MRI) of the brain is sensitive, but very susceptible to over-interpretation in the absence of clinical correlation. Spinal MRI is abnormal less often, but lends greater specificity when present with brain lesions.
Treatment of the condition can be divided into three parts: treatment of the acute attack; prevention of future attacks by reducing triggers and use of disease-modifying therapies; and symptomatic treatments of neurological difficulties such as spasticity, pain, fatigue, and bladder dysfunction.
Multiple sclerosis (MS) is defined as an inflammatory demyelinating disease characterised by the presence of episodic neurological dysfunction in at least two areas of the central nervous system (brain, spinal cord, and optic nerves) separated in time and space. 
Mellen Center for MS Treatment and Research
Cleveland Clinic Foundation
MAW has received payment for participating on the speakers' bureaus of Biogen, Genzyme, and Novartis. MAW also serves on the editorial board for the International Journal of MS Care.
Dr Mary Alissa Willis would like to gratefully acknowledge Dr Lael A. Stone, a previous contributor to this topic. LAS declares that she has no competing interests.
Project Leader for Neurology
ARG declares that he has no competing interests.
Associate Professor of Neurology
Department of Clinical Neurological Sciences
London Health Sciences Centre
SAM declares that she has no competing interests.
The London Multiple Sclerosis Clinic
Schulich School of Medicine
University of Western Ontario
Clinical Neurological Sciences Department
London Health Sciences Centre
MK declares that he has no competing interests.
Department of Neurology
AC declares that he has no competing interests.
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