title: Observational study on efficacy, safety, and drug survival of anakinra in rheumatoid arthritis patients in clinical practice.
abstract: BACKGROUND
  The efficacy and safety of anakinra, a recombinant human interleukin 1 (IL1) receptor antagonist used in rheumatoid arthritis, has been documented in five randomised controlled studies. However, long term post-marketing efficacy data are lacking.
  
  
  OBJECTIVE
  To evaluate the efficacy, safety, and drug survival of anakinra in clinical practice.
  
  
  METHODS
  All patients with rheumatoid arthritis who started anakinra in six hospitals between May 2002 and February 2004 were included in a two year prospective, in part retrospective, cohort study. Efficacy was assessed using the 28 joint disease activity score (DAS28) and the EULAR response criteria. Safety was evaluated using the common toxicity criteria. Drug survival and prognostic factors were analysed using Kaplan-Meier and Cox proportional hazard analyses.
  
  
  RESULTS
  After three months, 55% of the patients (n = 146) showed a response (43% moderate, 12% good). A subset of patients continuing anakinra after 18 months had a sustained clinical response compared with patients who switched to other disease modifying antirheumatic drug treatment (DAS28 improvement, 2.46 v 1.79). Drug survival was 78%, 54%, and 14% after three, six, and 24 months, respectively. The reason for discontinuation was lack of efficacy in 78% and adverse events in 22%. Except for higher drug survival in women (odds ratio = 0.51, 95% confidence interval, 0.27 to 0.97), no prognostic factors were found. Adverse events were reported 206 times in 111 patients, the most common being injection site reactions (36%). Serious adverse events occurred in 12% of the patients, with one classified as related.
  
  
  CONCLUSIONS
  The short term efficacy and safety profile of anakinra are comparable to those found in randomised clinical studies. However, the drug survival of anakinra after two years is low, mostly because of lack of efficacy.
authors.affiliation: Sint Maartenskliniek, Nijmegen, The Netherlands. alfons@denbroeder.org
authors.forename: A A
authors.initials: AA
authors.lastname: den Broeder
authors.forename: E
authors.initials: E
authors.lastname: de Jong
authors.forename: M J A M
authors.initials: MJ
authors.lastname: Franssen
authors.forename: M E C
authors.initials: ME
authors.lastname: Jeurissen
authors.forename: M
authors.initials: M
authors.lastname: Flendrie
authors.forename: F H J
authors.initials: FH
authors.lastname: van den Hoogen
mesh_terms: D000368:Aged; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy*; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein; D008297:Male; D008875:Middle Aged; D017472:Receptors, Interleukin-1 / Q000037:antagonists & inhibitors*; D012795:Sialoglycoproteins / Q000009:adverse effects / Q000627:therapeutic use*; D013921:Thrombocytopenia / Q000139:chemically induced
chemical_list: D018501:Antirheumatic Agents; C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D017472:Receptors, Interleukin-1; D012795:Sialoglycoproteins