title: Patient subgroup analyses of the treatment effect of subcutaneous interferon β-1a on development of multiple sclerosis in the randomized controlled REFLEX study.
abstract: The REFLEX study (NCT00404352) established that subcutaneous (sc) interferon (IFN) β-1a reduced the risks of McDonald MS (2005 criteria) and clinically definite multiple sclerosis (CDMS) in patients with a first clinical demyelinating event suggestive of MS. The aim of this subgroup analysis was to assess the treatment effect of sc IFN β-1a in patient subgroups defined by baseline disease and demographic characteristics (age, sex, use of steroids at the first event, classification of first event as mono- or multifocal, presence/absence of gadolinium-enhancing lesions, count of <9 or ≥9 T2 lesions), and by diagnosis of MS using the revised McDonald 2010 MS criteria. Patients were randomized to the serum-free formulation of IFN β-1a, 44 μg sc three times weekly or once weekly, or placebo, for 24 months or until diagnosis of CDMS. Treatment effects of sc IFN β-1a on McDonald 2005 MS and CDMS in the predefined subgroups were similar to effects found in the intent-to-treat population. McDonald 2010 MS was retrospectively diagnosed in 37.7 % of patients at baseline. Both regimens of sc IFN β-1a significantly reduced the risk versus placebo of McDonald 2005 MS and CDMS, irrespective of McDonald 2010 status at baseline (risk reductions between 29 and 51 %). The effect of sc IFN β-1a was not substantially influenced by baseline patient demographic and disease characteristics, or baseline presence/absence of McDonald 2010 MS.
authors.affiliation: Department of Medicine, University of Ottawa, 501 Smyth Road, Ottawa, ON, K1H 8L6, Canada, mfreedman@toh.on.ca.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Freedman
authors.forename: Nicola
authors.initials: N
authors.lastname: De Stefano
authors.forename: Frederik
authors.initials: F
authors.lastname: Barkhof
authors.forename: Chris H
authors.initials: CH
authors.lastname: Polman
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Comi
authors.forename: Bernard M J
authors.initials: BM
authors.lastname: Uitdehaag
authors.forename: Florence
authors.initials: F
authors.lastname: Casset-Semanaz
authors.forename: Brian
authors.initials: B
authors.lastname: Hennessy
authors.forename: Lorenz
authors.initials: L
authors.lastname: Lehr
authors.forename: Bettina
authors.initials: B
authors.lastname: Stubinski
authors.forename: Dominic L
authors.initials: DL
authors.lastname: Jack
authors.forename: Ludwig
authors.initials: L
authors.lastname: Kappos
mesh_terms: D000328:Adult; D003627:Data Interpretation, Statistical; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D055103:Hypodermoclysis; D000068556:Interferon beta-1a; D016899:Interferon-beta / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D009103:Multiple Sclerosis / Q000145:classification / Q000175:diagnosis / Q000517:prevention & control; D010919:Placebos; D062706:Prodromal Symptoms; D012189:Retrospective Studies; D012306:Risk; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D010919:Placebos; D016899:Interferon-beta; D000068556:Interferon beta-1a