title: The Effect of Comedication With a Conventional Synthetic Disease-Modifying Antirheumatic Drug on Drug Retention and Clinical Effectiveness of Anti-Tumor Necrosis Factor Therapy in Patients With Axial Spondyloarthritis.
abstract: To explore the effect of comedication with conventional synthetic disease-modifying antirheumatic drugs (DMARDs) on drug retention and clinical effectiveness of tumor necrosis factor inhibitors (TNFi) in patients with axial spondyloarthritis (SpA).
  
  
  
  The study included all patients starting treatment with a TNFi in a large prospective cohort of axial SpA patients (Swiss Clinical Quality Management in axial SpA). Crude drug retention was analyzed using the Kaplan-Meier method, and in adjusted analyses, Cox proportional hazards regression was used to model TNFi discontinuation. We evaluated multiple disease activity measures and validated clinical response criteria over time.
  
  
  
  A total of 2,765 TNFi treatment courses were included from 1,914 patients with axial SpA, 20.4% in combination with a conventional synthetic DMARD. In unadjusted analyses, the monotherapy group had significantly shorter median TNFi retention time (32.7 months) compared to the cotherapy group (39.1 months) (P = 0.04). In multivariate adjusted analyses, the monotherapy group had significantly lower TNFi retention, with a hazard ratio (HR) of 1.17 (95% confidence interval [95% CI] 1.01-1.35). This effect was even larger when only infliximab-treated patients were considered, with an HR for monotherapy of 1.36 (95% CI 1.06-1.74). Clinical response rates were almost identical at 1 year, with a change in the Bath Ankylosing Spondylitis Disease Activity Index of -2.02 and -2.00 (P = 0.83) and a change in the Ankylosing Spondylitis Disease Activity Score using C-reactive protein of -1.14 and -1.12 (P = 0.45) in the monotherapy and cotherapy groups, respectively.
  
  
  
  We demonstrate an association between the combination of a TNFi with conventional synthetic DMARDs and improved drug retention in patients with axial SpA, particularly in the subgroup of patients with infliximab.
authors.affiliation: University Hospital of Geneva, Geneva, Switzerland.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Nissen
authors.affiliation: Zurich University Hospital, Zurich, Switzerland.
authors.forename: Adrian
authors.initials: A
authors.lastname: Ciurea
authors.affiliation: Bürgerspital, Solothurn, Switzerland.
authors.forename: Jürg
authors.initials: J
authors.lastname: Bernhard
authors.affiliation: Bethesda Hospital, Basel, Switzerland.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Tamborrini
authors.affiliation: St. Gallen Hospital, St. Gallen, Switzerland.
authors.forename: Ruediger
authors.initials: R
authors.lastname: Mueller
authors.affiliation: Balgrist University Hospital, Zurich, Switzerland.
authors.forename: Bettina
authors.initials: B
authors.lastname: Weiss
authors.affiliation: Zurich University Hospital, Zurich, Switzerland.
authors.forename: Martin
authors.initials: M
authors.lastname: Toniolo
authors.affiliation: Pascale Exer, MD:, Basel, Switzerland.
authors.forename: Pascale
authors.initials: P
authors.lastname: Exer
authors.affiliation: University Hospital of Geneva, Geneva, Switzerland.
authors.forename: Cem
authors.initials: C
authors.lastname: Gabay
authors.affiliation: University Hospital of Geneva, Geneva, Switzerland.
authors.forename: Axel
authors.initials: A
authors.lastname: Finckh
mesh_terms: D000328:Adult; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D000069285:Infliximab / Q000627:therapeutic use*; D008297:Male; D011446:Prospective Studies; D025241:Spondylarthritis / Q000188:drug therapy*; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D018501:Antirheumatic Agents; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab