title: Safety and efficacy of natalizumab in Belgian multiple sclerosis patients: subgroup analysis of the natalizumab observational program.
abstract: 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.
authors.affiliation: Neurology Department, Cliniques Universitaires St-Luc, Avenue Hippocrate 10, 1200, Woluwe-Saint-Lambert, Belgium, vincent.vanpesch@uclouvain.be.
authors.forename: Vincent
authors.initials: V
authors.lastname: van Pesch
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Bartholomé
authors.forename: Véronique
authors.initials: V
authors.lastname: Bissay
authors.forename: Olivier
authors.initials: O
authors.lastname: Bouquiaux
authors.forename: Michel
authors.initials: M
authors.lastname: Bureau
authors.forename: Jo
authors.initials: J
authors.lastname: Caekebeke
authors.forename: Jan
authors.initials: J
authors.lastname: Debruyne
authors.forename: Inge
authors.initials: I
authors.lastname: Declercq
authors.forename: Dany
authors.initials: D
authors.lastname: Decoo
authors.forename: Pierre
authors.initials: P
authors.lastname: Denayer
authors.forename: Eric
authors.initials: E
authors.lastname: De Smet
authors.forename: Marie
authors.initials: M
authors.lastname: D'hooghe
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Dubois
authors.forename: Michel
authors.initials: M
authors.lastname: Dupuis
authors.forename: Souraya El
authors.initials: SE
authors.lastname: Sankari
authors.forename: Karine
authors.initials: K
authors.lastname: Geens
authors.forename: Daniel
authors.initials: D
authors.lastname: Guillaume
authors.forename: William
authors.initials: W
authors.lastname: van Landegem
authors.forename: Andreas
authors.initials: A
authors.lastname: Lysandropoulos
authors.forename: Alain Maertens
authors.initials: AM
authors.lastname: de Noordhout
authors.forename: Robert
authors.initials: R
authors.lastname: Medaer
authors.forename: Annick
authors.initials: A
authors.lastname: Melin
authors.forename: Katelijne
authors.initials: K
authors.lastname: Peeters
authors.forename: Rémy Phan
authors.initials: RP
authors.lastname: Ba
authors.forename: Cécile
authors.initials: C
authors.lastname: Retif
authors.forename: Pierrette
authors.initials: P
authors.lastname: Seeldrayers
authors.forename: Anoek
authors.initials: A
authors.lastname: Symons
authors.forename: Etienne
authors.initials: E
authors.lastname: Urbain
authors.forename: Patrick
authors.initials: P
authors.lastname: Vanderdonckt
authors.forename: Erwin
authors.initials: E
authors.lastname: Van Ingelghem
authors.forename: Ludo
authors.initials: L
authors.lastname: Vanopdenbosch
authors.forename: Erwin
authors.initials: E
authors.lastname: Vanroose
authors.forename: Bart
authors.initials: B
authors.lastname: Van Wijmeersch
authors.forename: Barbara
authors.initials: B
authors.lastname: Willekens
authors.forename: Christiana
authors.initials: C
authors.lastname: Willems
authors.forename: Christian
authors.initials: C
authors.lastname: Sindic
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D001530:Belgium / Q000453:epidemiology; D015331:Cohort Studies; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use*; D007391:International Cooperation; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000188:drug therapy*; D000069442:Natalizumab; D011358:Product Surveillance, Postmarketing; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D007155:Immunologic Factors; D000069442:Natalizumab