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Updated: Jun 1, 2026

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
Natalizumab and drug holiday in clinical practice: an observational study in very active relapsing remitting multiple
A Kerbrat1, E Le Page, E Leray
1Service de neurologie, CIC-P 0203 INSERM, centre hospitalier universitaire, Rennes, France.
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.
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