title: The comparative effectiveness of abatacept versus anti-tumour necrosis factor switching for rheumatoid arthritis patients previously treated with an anti-tumour necrosis factor.
abstract: OBJECTIVE
  We compared the effectiveness of abatacept (ABA) versus a subsequent anti-tumour necrosis factor inhibitor (anti-TNF) in rheumatoid arthritis (RA) patients with prior anti-TNF use.
  
  
  METHODS
  We identified RA patients from a large observational US cohort (2/1/2000-8/7/2011) who had discontinued at least one anti-TNF and initiated either ABA or a subsequent anti-TNF. Using propensity score (PS) matching (n:1 match), effectiveness was measured at 6 and 12 months after initiation based on mean change in Clinical Disease Activity Index (CDAI), modified American College of Rheumatology (mACR) 20, 50 and 70 responses, modified Health Assessment Questionnaire (mHAQ) and CDAI remission in adjusted regression models.
  
  
  RESULTS
  The PS-matched groups included 431 ABA and 746 anti-TNF users at 6 months and 311 ABA and 493 anti-TNF users at 12 months. In adjusted analyses comparing response following treatment with ABA and anti-TNF, the difference in weighted mean change in CDAI (range 6-8) at 6 months (0.46, 95% CI -0.82 to 1.73) and 12 months was similar (-1.64, 95% CI -3.47 to 0.19). The mACR20 responses were similar at 6 (28-32%, p=0.73) and 12 months (35-37%, p=0.48) as were the mACR50 and mACR70 (12 months: 20-22%, p=0.25 and 10-12%, p=0.49, respectively). Meaningful change in mHAQ was similar at 6 and 12 months (30-33%, p=0.41 and 29-30%, p=0.39, respectively) as was CDAI remission rates (9-10%, p=0.42 and 12-13%, p=0.91, respectively).
  
  
  CONCLUSIONS
  RA patients with prior anti-TNF exposures had similar outcomes if they switched to a new anti-TNF as compared with initiation of ABA.
authors.affiliation: University of Massachusetts Medical School, Worcester, Massachusetts, USA.
authors.forename: Leslie R
authors.initials: LR
authors.lastname: Harrold
authors.affiliation: University of Massachusetts Medical School, Worcester, Massachusetts, USA.
authors.forename: George W
authors.initials: GW
authors.lastname: Reed
authors.affiliation: Albany Medical College, Albany, New York, USA.
authors.forename: Joel M
authors.initials: JM
authors.lastname: Kremer
authors.affiliation: Department of Immunology and Rheumatology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Curtis
authors.affiliation: Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Solomon
authors.affiliation: Departments of Medicine and Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, Maryland, USA.
authors.forename: Marc C
authors.initials: MC
authors.lastname: Hochberg
authors.affiliation: Department of Rheumatology, New York University Hospital for Joint Diseases, New York, USA.
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Greenberg
mesh_terms: D000069594:Abatacept; D000328:Adult; D000368:Aged; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy*; D001688:Biological Products / Q000627:therapeutic use; D005260:Female; D006801:Humans; D018796:Immunoconjugates / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D018501:Antirheumatic Agents; D001688:Biological Products; D018796:Immunoconjugates; D014409:Tumor Necrosis Factor-alpha; D000069594:Abatacept
keywords: Anti-TNF; DMARDs (biologic); Rheumatoid Arthritis