title: Low dose etanercept treatment for maintenance of clinical remission in ankylosing spondylitis.
abstract: OBJECTIVE
  To investigate the efficacy and safety of low-dose etanercept treatment after clinical remission of ankylosing spondylitis (AS) in the real world.
  
  
  METHODS
  Data on 134 AS patients who were treated with etanercept for more than 12 months and achieved clinical remission (BASDAI<4 and CRP<0.5 mg/dL) were extracted from a large single centre registry. Drug survival and incidence of adverse events in 100 patients who reduced the dose during follow up (low-dose group) were compared with 34 patients who maintained the initial dose (standard-dose group). For minimisation of selection bias between the two groups, the same analyses were performed in a propensity score-matched population.
  
  
  RESULTS
  Both groups showed similar BASDAI score and CRP levels during the follow-up. Drug survivals between the two groups were also comparable up to 4 years (vs. standard-dose group, adjusted HR=0.472, 95% CI 0.155-1.435). The same analysis performed after propensity score-matching showed concordant result. The incidence of injection site reactions in the low-dose group was significantly lower, and the incidence of other adverse events showed no differences between the two groups. In the low-dose group, dose reduction after more than 24 weeks of standard-dose treatment was associated with longer drug survival (adjusted HR=0.261, 95% CI 0.084-0.809).
  
  
  CONCLUSIONS
  Low-dose etanercept treatment after achieving clinical remission can be an alternative treatment option in terms of its comparable long-term efficacy and favourable safety in AS. More than 24 weeks of standard-dose treatment before dose reduction may be beneficial for longer drug survival in this strategy.
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jun Won
authors.initials: JW
authors.lastname: Park
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Young Im
authors.initials: YI
authors.lastname: Yoon
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jae Hyun
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jin Kyun
authors.initials: JK
authors.lastname: Park
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Eun Bong
authors.initials: EB
authors.lastname: Lee
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Yeong Wook
authors.initials: YW
authors.lastname: Song
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea. elee@snu.ac.kr.
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Lee
mesh_terms: D000068800:Etanercept / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage* / Q000009:adverse effects; D053208:Kaplan-Meier Estimate; D015999:Multivariate Analysis; D057216:Propensity Score; D016016:Proportional Hazards Models; D012042:Registries; D012074:Remission Induction; D056910:Republic of Korea; D013167:Spondylitis, Ankylosing / Q000175:diagnosis / Q000188:drug therapy*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D007166:Immunosuppressive Agents; D000068800:Etanercept