title: Spanish consensus on the use of natalizumab (Tysabri®)-2013.
abstract: BACKGROUND
  Natalizumab treatment has been shown to be very efficacious in clinical trials and very effective in clinical practice in patients with relapsing-remitting multiple sclerosis, by reducing relapses, slowing disease progression, and improving magnetic resonance imaging patterns. However, the drug has also been associated with a risk of progressive multifocal leukoencephalopathy (PML). The first consensus statement on natalizumab use, published in 2011, has been updated to include new data on diagnostic procedures, monitoring for patients undergoing treatment, PML management, and other topics of interest including the management of patients discontinuing natalizumab.
  
  
  METHODS
  This updated version followed the method used in the first consensus. A group of Spanish experts in multiple sclerosis (the authors of the present document) reviewed all currently available literature on natalizumab and identified the relevant topics would need updating based on their clinical experience. The initial draft passed through review cycles until the final version was completed.
  
  
  CONCLUSIONS
  Studies in clinical practice have demonstrated that changing to natalizumab is more effective than switching between immunomodulators. They favour early treatment with natalizumab rather than using natalizumab in a later stage as a rescue therapy. Although the drug is very effective, its potential adverse effects need to be considered, with particular attention to the patient's likelihood of developing PML. The neurologist should carefully explain the risks and benefits of the treatment, comparing them to the risks of multiple sclerosis in terms the patient can understand. Before treatment is started, laboratory tests and magnetic resonance images should be available to permit proper follow-up. The risk of PML should be stratified as high, medium, or low according to presence or absence of anti-JC virus antibodies, history of immunosuppressive therapy, and treatment duration. Although the presence of anti-JC virus antibodies is a significant finding, it should not be considered an absolute contraindication for natalizumab. This update provides general recommendations, but neurologists must use their clinical expertise to provide personalised follow-up for each patient.
authors.affiliation: Instituto de Neurociencias Clínicas, Servicio de Neurología, Hospital Regional Universitario Carlos Haya, Fundación Pública Andaluza para la Investigación de Málaga en Biomedicina y Salud, Málaga, España. Electronic address: oscar.fernandez.sspa@juntadeandalucia.es.
authors.forename: O
authors.initials: O
authors.lastname: Fernández
authors.affiliation: Servicio de Neurología, Hospital Universitario Puerta de Hierro, Madrid, España.
authors.forename: J A
authors.initials: JA
authors.lastname: García-Merino
authors.affiliation: Servicio de Neurología, Hospital Clínico Universitario San Carlos, Madrid, España.
authors.forename: R
authors.initials: R
authors.lastname: Arroyo
authors.affiliation: Servicio de Neurología, Hospital Universitario Ramón y Cajal, Madrid, España.
authors.forename: J C
authors.initials: JC
authors.lastname: Álvarez-Cermeño
authors.affiliation: Servicio de Neurología, Hospital Universitario Virgen Macarena, Sevilla, España.
authors.forename: G
authors.initials: G
authors.lastname: Izquierdo
authors.affiliation: Servicio de Neurología, Hospital Clinic, Instituto de Investigaciones Biomédicas August Pi i Sunyer, Barcelona, España.
authors.forename: A
authors.initials: A
authors.lastname: Saiz
authors.affiliation: Servicio de Neurología, Hospital Universitario de Donostia, San Sebastián, España.
authors.forename: J
authors.initials: J
authors.lastname: Olascoaga
authors.affiliation: Servicio de Neurología, Hospital de Basurto, Bilbao, España.
authors.forename: A
authors.initials: A
authors.lastname: Rodríguez-Antigüedad
authors.affiliation: Servicio de Neurología, Hospital Clínico Universitario Santiago de Compostela, Santiago de Compostela, España.
authors.forename: J M
authors.initials: JM
authors.lastname: Prieto
authors.affiliation: Servicio de Neurología, Hospital Clínico Universitario San Carlos, Madrid, España.
authors.forename: C
authors.initials: C
authors.lastname: Oreja-Guevara
authors.affiliation: Servicio de Neurología, Hospital Universitario Ntra. Sra. de la Candelaria, Tenerife, España.
authors.forename: M A
authors.initials: MA
authors.lastname: Hernández
authors.affiliation: Servicio de Neurología, Hospital de Sant Joan Despí Moisès Broggi, Barcelona, España.
authors.forename: E
authors.initials: E
authors.lastname: Moral
authors.affiliation: Servicio de Neurología, Hospital Universitario Virgen de la Arrixaca, Murcia, España.
authors.forename: J
authors.initials: J
authors.lastname: Meca
authors.affiliation: Centre d'Esclerosi Múltiple de Catalunya (CEMCAT), Hospital Universitari Vall d'Hebron, Barcelona, España.
authors.forename: X
authors.initials: X
authors.lastname: Montalbán
mesh_terms: D000328:Adult; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use; D006801:Humans; D007155:Immunologic Factors / Q000009:adverse effects / Q000627:therapeutic use*; D007968:Leukoencephalopathy, Progressive Multifocal / Q000139:chemically induced; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000188:drug therapy*; D000069442:Natalizumab / Q000009:adverse effects / Q000627:therapeutic use*; D017410:Practice Guidelines as Topic; D012307:Risk Factors; D013030:Spain
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D007155:Immunologic Factors; D000069442:Natalizumab
keywords: Consenso; Consensus; Esclerosis múltiple; España; Multiple sclerosis; Natalizumab; Riesgo; Risk; Spain