title: Change in the clinical activity of multiple sclerosis after treatment switch for suboptimal response.
abstract: BACKGROUND
  Therapy for multiple sclerosis (MS) has a partial efficacy, and a significant proportion of treated patients will develop a suboptimal response with first-line disease-modifying drugs (DMD). Therapy switch in patients with MS can be a strategy after a treatment failure. We studied the change in clinical activity after switching of first-line DMD because of a treatment failure.
  
  
  METHODS
  Relapsing-remitting multiple sclerosis (RRMS) patients treated with interferon-beta (IFNB) or glatiramer acetate (GA) were divided into (i) patients without change in DMD, (ii) patients with a change in DMD because of a poor response, and (iii) those with a change in DMD without relation with response. Annualized relapse rate (ARR) and relapse-free proportions were analyzed.
  
  
  RESULTS
  We identified 923 patients with RRMS. Of the 180 who experienced a change because of suboptimal response, 90 switched to another first-line DMT, 38 to mitoxantrone, and 52 to natalizumab. Median ARR in the pre-DMD period on first DMD and second DMD was the following: 1, 1, and 0 for switchers from IFNB to another IFNB (P = 0.0001); 0.67, 1, and 0 for switchers from GA to IFNB (P = 0.01); 1, 1, and 0 for switchers from an IFNB to GA (P = 0.02); 1.1, 1.5, 0.2 for switchers from IFNB or GA to mitoxantrone (P = 0.0001); 0.9, 1, 0 for switchers from IFNB or GA to natalizumab (P = 0.0001).
  
  
  CONCLUSIONS
  In patients with RRMS who have a poor response, switch to another DMD may reduce the clinical activity of the disease.
authors.affiliation: Hospital Universitari Vall d'Hebron. Barcelona. Spain. jrio@vhebron.net
authors.forename: J
authors.initials: J
authors.lastname: Río
authors.forename: M
authors.initials: M
authors.lastname: Tintoré
authors.forename: J
authors.initials: J
authors.lastname: Sastre-Garriga
authors.forename: C
authors.initials: C
authors.lastname: Nos
authors.forename: J
authors.initials: J
authors.lastname: Castilló
authors.forename: C
authors.initials: C
authors.lastname: Tur
authors.forename: M
authors.initials: M
authors.lastname: Comabella
authors.forename: X
authors.initials: X
authors.lastname: Montalban
mesh_terms: D000328:Adult; D005260:Female; D000068717:Glatiramer Acetate; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use*; D016899:Interferon-beta / Q000627:therapeutic use*; D008297:Male; D009103:Multiple Sclerosis / Q000188:drug therapy* / Q000503:physiopathology*; D010455:Peptides / Q000627:therapeutic use*; D055502:Secondary Prevention; D017211:Treatment Failure; D055815:Young Adult
chemical_list: D007155:Immunologic Factors; D010455:Peptides; D000068717:Glatiramer Acetate; D016899:Interferon-beta