title: Post-approval trials of new medicines: widening use or deepening knowledge? Analysis of 10 years of etanercept.
abstract: OBJECTIVE
  To investigate the main aims of the post-approval randomized controlled trials (RCTs) on etanercept and the extent to which they were designed to gain more comparative information.
  
  
  METHODS
  A search of the literature (Medline, Embase), trial registries (Clinical Trials.gov, Controlled Trials.com), and market authorization reports from the Food and Drug Administration (FDA) and the European Medicines Agency (EMEA) was carried out to identify all RCTs. A comparison of trial data identified unpublished trials and multiple publications relating to the same study. All RCTs completed and/or published after initial market approval was regarded as post-approval.
  
  
  RESULTS
  Up until 2008, we found 84 post-approval trials, 11 (13%) trials on approved extensions of indication, another 30 (36%) trials on the approved indications, and 43 (51%) trials on indications not (yet) approved. Nearly half of the studies on indications not yet approved were initiated and funded by independent sponsors. After the initial approval of etanercept, six head-to-head trials were conducted on the approved indications. Overall, the main objectives of post-approval trials with etanercept were found to confirm efficacy and safety in new indications, and to gather additional information for optimal use on the approved indications.
  
  
  CONCLUSIONS
  Post-approval RCTs on etanercept focus more on studies searching for new indications than on deepening knowledge about use. Ten years after the market entry of etanercept, one of the reasonable demands of clinical practice, for more comparative information, still remains unanswered.
authors.affiliation: Division of Pharmacoepidemiology and Pharmacotherapy, Utrecht Institute for Pharmaceutical Sciences (UIPS), Faculty of Science, Utrecht, The Netherlands.
authors.forename: J C F
authors.initials: JC
authors.lastname: van Luijn
authors.forename: M
authors.initials: M
authors.lastname: Danz
authors.forename: J W J
authors.initials: JW
authors.lastname: Bijlsma
authors.forename: F W J
authors.initials: FW
authors.lastname: Gribnau
authors.forename: H G M
authors.initials: HG
authors.lastname: Leufkens
mesh_terms: D000328:Adult; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001168:Arthritis / Q000188:drug therapy*; D001171:Arthritis, Juvenile / Q000188:drug therapy; D015535:Arthritis, Psoriatic / Q000188:drug therapy; D001172:Arthritis, Rheumatoid / Q000188:drug therapy; D002648:Child; D017327:Clinical Trials, Phase IV as Topic; D000068800:Etanercept; D006801:Humans; D007074:Immunoglobulin G / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic; D018124:Receptors, Tumor Necrosis Factor / Q000627:therapeutic use*; D012107:Research Design; D013167:Spondylitis, Ankylosing / Q000188:drug therapy; D016896:Treatment Outcome
chemical_list: D018501:Antirheumatic Agents; D007074:Immunoglobulin G; D018124:Receptors, Tumor Necrosis Factor; D000068800:Etanercept