Acta Neurologica Belgica

, Volume 114, Issue 3, pp 167–178

Safety and efficacy of natalizumab in Belgian multiple sclerosis patients: subgroup analysis of the natalizumab observational program


    • Neurology DepartmentCliniques Universitaires St-Luc
  • Emmanuel Bartholomé
    • CHU Tivoli
  • Véronique Bissay
    • UZ Brussel
  • Olivier Bouquiaux
    • CHA Libramont
  • Michel Bureau
    • Clinique Reine Astrid
  • Jo Caekebeke
    • OLVZ Aalst
  • Jan Debruyne
    • UZ Gent
  • Inge Declercq
    • Europaziekenhuizen, Site Sainte-Elisabeth
  • Dany Decoo
    • AZ Alma
  • Pierre Denayer
    • A.I.T. Tournai
  • Eric De Smet
    • Revalidatie and MS-Centrum
  • Marie D’hooghe
    • MS Center
  • Bénédicte Dubois
    • UZ Leuven
  • Michel Dupuis
    • Clinique St. Pierre
  • Souraya El Sankari
    • Neurology DepartmentCliniques Universitaires St-Luc
  • Karine Geens
    • AZ Klina
  • Daniel Guillaume
    • Centre Neurologique
  • William van Landegem
    • GZA St. Augustinus
  • Andreas Lysandropoulos
    • Hopital Erasme
  • Alain Maertens de Noordhout
    • C.H.R. Citadelle
  • Robert Medaer
    • C.N.L. N.V
  • Annick Melin
    • Cliniques Saint Joseph
  • Katelijne Peeters
    • Jessaziekenhuis campus Salvator
  • Rémy Phan Ba
    • Hopital Universitaire du Sart-Tilman
  • Cécile Retif
    • CHU St. Pierre
  • Pierrette Seeldrayers
    • CHU de Charleroi, Hopital Civil
  • Anoek Symons
    • ZNA Middelheim
  • Etienne Urbain
    • Grand Hôpital de Charleroi, Site Notre Dame
  • Patrick Vanderdonckt
    • AZ Groeninge
  • Erwin Van Ingelghem
    • AZ Damiaan
  • Ludo Vanopdenbosch
    • AZ Sint Jan Brugge
  • Erwin Vanroose
    • Ziekenhuis Oost-Limburg
  • Bart Van Wijmeersch
    • Revalidatie and MS-Centrum
  • Barbara Willekens
    • UZ Antwerpen
  • Christiana Willems
    • Jessaziekenhuis campus Salvator
  • Christian Sindic
    • Neurology DepartmentCliniques Universitaires St-Luc
Original Article

DOI: 10.1007/s13760-014-0308-9

Cite this article as:
van Pesch, V., Bartholomé, E., Bissay, V. et al. Acta Neurol Belg (2014) 114: 167. doi:10.1007/s13760-014-0308-9


Natalizumab (Tysabri®) is highly efficacious in controlling disease activity in relapsing multiple sclerosis (MS) patients. As it is one of the more recent therapies for MS, there remains a need for long-term safety and efficacy data of natalizumab in a clinical practice setting. The Tysabri observational program (TOP) is an open-label, multicenter, multinational, prospective observational study, aiming to recruit up to 6,000 patients with relapsing-remitting MS from Europe, Canada and Australia. The objectives of this study are to collect long-term safety and efficacy data on disease activity and disability progression. We report here the interim results of the 563 patients included in TOP between December 2007 and 2012 from Belgium. This patient cohort was older at baseline, had longer disease duration, higher neurological impairment, and a higher baseline annualized relapse rate, when compared to patients included in the pivotal phase III AFFIRM trial. Nevertheless, the efficacy of natalizumab was comparable. The annualized relapse rate on treatment was reduced by 90.70 % (p < 0.0001) with a cumulative probability of relapse of 26.87 % at 24 months. The cumulative probabilities of sustained disability improvement and progression at 24 months were 25.68 and 9.01 %, respectively. There were no new safety concerns over the follow-up period. Two cases of progressive multifocal leukoencephalopathy were diagnosed. Our results are consistent with other observational studies in the post-marketing setting.


Multiple sclerosisNatalizumabObservational studyTherapeutic efficacySafety

Supplementary material

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Supplementary material 1 (DOCX 99 kb)
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Supplementary material 2 (DOCX 97 kb)
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Supplementary material 3 (DOCX 73 kb)
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Supplementary material 4 (DOCX 58 kb)
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Supplementary material 5 (DOCX 58 kb)

Copyright information

© Belgian Neurological Society 2014