Natalizumab and drug holiday in clinical practice: an observational study in very active relapsing remitting multiple sclerosis patients

J Neurol Sci. 2011 Sep 15;308(1-2):98-102. doi: 10.1016/j.jns.2011.05.043. Epub 2011 Jun 12.


Background: In order to reduce the risk of progressive multifocal leucoencephalopathy when using natalizumab for more than 12 months, a 6-month drug holiday has been discussed. However, the consequences on short term disease activity have been poorly assessed.

Objective: The aim of this study was to assess clinical and radiological disease activity within 6 months after stopping natalizumab in very active relapsing remitting Multiple Sclerosis (RRMS) patients.

Methods: In 8 hospitals from Western France, we retrospectively collected clinical and MRI data from consecutive RRMS patients treated with natalizumab for at least 6 months, and who stopped the drug for various reasons except therapeutic failure. Patients didn't receive any other disease modifying treatment after discontinuing natalizumab.

Results: A total of 27 patients with very active RRMS before natalizumab start (mean annualized relapse rate of 2.3, MRI activity in 21 of 27 patients) were studied. Within 6 months after discontinuing natalizumab, 18 patients (67%) experienced clinical relapse and 3 additional patients had radiological activity, without clinical relapse. Four patients (15%) experienced a rebound activity, with severe relapse and 20 or more gadolinium enhancing lesions on MRI.

Conclusion: Such observational data didn't support the concept of drug holiday when using natalizumab in very active RRMS.

Publication types

  • Comparative Study
  • Multicenter Study

MeSH terms

  • Activities of Daily Living
  • Adult
  • Antibodies, Monoclonal, Humanized / administration & dosage*
  • Drug Administration Schedule
  • Female
  • France / epidemiology
  • Humans
  • Male
  • Middle Aged
  • Multiple Sclerosis, Relapsing-Remitting / drug therapy*
  • Multiple Sclerosis, Relapsing-Remitting / epidemiology
  • Multiple Sclerosis, Relapsing-Remitting / physiopathology
  • Natalizumab
  • Retrospective Studies
  • Secondary Prevention
  • Time Factors
  • Young Adult


  • Antibodies, Monoclonal, Humanized
  • Natalizumab