title: MRI-based analysis of the natalizumab therapeutic window in multiple sclerosis.
abstract: The recommended natalizumab dosage is 300 mg every 4 weeks. We evaluated radiological activity at various times from the last natalizumab infusion by examining 386 magnetic resonance imaging (MRI) scans from 166 natalizumab-treated patients with relapsing-remitting MS. Of 113 scans performed >4 weeks after last natalizumab infusion, 26 were active (i.e. had ≥1 contrast-enhancing lesions). Risk of radiological activity increased by 1.34 fold for each week of delay with respect to the recommended 4-week dosing interval, compared with schedule-adherent patients (p<0.0001). Our data suggest that an increased MRI activity ≥7 weeks from the last infusion of natalizumab should be considered in cases of therapy discontinuation.
authors.affiliation: UO Neurology, Multiple Sclerosis Centre, Fondazione Istituto San Raffaele G. Giglio, Italy.
authors.forename: Luigi M E
authors.initials: LM
authors.lastname: Grimaldi
authors.forename: Luca
authors.initials: L
authors.lastname: Prosperini
authors.forename: Gaetano
authors.initials: G
authors.lastname: Vitello
authors.forename: Giovanna
authors.initials: G
authors.lastname: Borriello
authors.forename: Federica
authors.initials: F
authors.lastname: Fubelli
authors.forename: Carlo
authors.initials: C
authors.lastname: Pozzilli
mesh_terms: D000293:Adolescent; D000328:Adult; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage*; D001921:Brain / Q000187:drug effects* / Q000473:pathology*; D016009:Chi-Square Distribution; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000008:administration & dosage*; D007263:Infusions, Parenteral; D016014:Linear Models; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D055118:Medication Adherence; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000188:drug therapy* / Q000473:pathology*; D000069442:Natalizumab; D016017:Odds Ratio; D011237:Predictive Value of Tests; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D007155:Immunologic Factors; D000069442:Natalizumab