title: Natalizumab reduces clinical and MRI activity in multiple sclerosis patients with high disease activity: results from a multicenter study in Switzerland.
abstract: BACKGROUND
  Natalizumab has been recommended for the treatment of relapsing-remitting multiple sclerosis (RRMS) in patients with insufficient response to interferon-beta or glatiramer acetate (disease-modifying treatments-DMT) or in aggressive MS. The pivotal trials were not designed to investigate natalizumab monotherapy in these patient populations.
  
  
  OBJECTIVE
  To investigate the efficacy of natalizumab after treatment failure of previous DMT and in highly active MS.
  
  
  METHODS
  A retrospective, multicenter study in Switzerland. Three major MS centers reported all RRMS patients who initiated natalizumab>or=12 months prior to study conduction.
  
  
  RESULTS
  85 RRMS patients were included (72% female, mean age 37.3 years, mean Expanded Disability Status Scale 3.1; 88.2% were pretreated with DMT), and mean treatment duration with natalizumab was 18.4+/-2.6 months. 79% of the patients were relapse-free during the observational period. The annualized relapse rate decreased from 2.0+/-0.6 to 0.27+/-0.2, and 92.9% were progression-free after 12 months (p<0.001). The mean number of gadolinium-enhancing lesions decreased from 1.2+/-1.2 to 0.1+/-0.1 at 12 months' follow-up (91.7% reduction).Discontinuation rate was 11.8% (7.1% for antibody positivity).
  
  
  CONCLUSIONS
  Patients who initiate natalizumab after previous high disease activity experience a marked reduction of clinical and MRI disease activity.
authors.affiliation: Department of Neurology at Cantonal Hospital St. Gallen, St. Gallen, Switzerland. Norman.Putzki@kssg.ch
authors.forename: Norman
authors.initials: N
authors.lastname: Putzki
authors.forename: Ozgür
authors.initials: O
authors.lastname: Yaldizli
authors.forename: Robert
authors.initials: R
authors.lastname: Bühler
authors.forename: Guido
authors.initials: G
authors.lastname: Schwegler
authors.forename: Daniela
authors.initials: D
authors.lastname: Curtius
authors.forename: Barbara
authors.initials: B
authors.lastname: Tettenborn
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000188:drug therapy*; D000069442:Natalizumab; D012189:Retrospective Studies; D013557:Switzerland
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000069442:Natalizumab