title: How to define responders in osteoarthritis.
abstract: BACKGROUND
  Osteoarthritis is a clinical syndrome of failure of the joint accompanied by varying degrees of joint pain, functional limitation, and reduced quality of life due to deterioration of articular cartilage and involvement of other joint structures.
  
  
  METHODS
  Regulatory agencies require relevant clinical benefit on symptoms and structure modification for registration of a new therapy as a disease-modifying osteoarthritis drug (DMOAD). An international Working Group of the European Society on Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) and International Osteoporosis Foundation was convened to explore the current burden of osteoarthritis, review current regulatory guidelines for the conduct of clinical trials, and examine the concept of responder analyses for improving drug evaluation in osteoarthritis.
  
  
  RESULTS
  The ESCEO considers that the major challenges in DMOAD development are the absence of a precise definition of the disease, particularly in the early stages, and the lack of consensus on how to detect structural changes and link them to clinically meaningful endpoints. Responder criteria should help identify progression of disease and be clinically meaningful. The ideal criterion should be sensitive to change over time and should predict disease progression and outcomes such as joint replacement.
  
  
  CONCLUSIONS
  The ESCEO considers that, for knee osteoarthritis, clinical trial data indicate that radiographic joint space narrowing >0.5 mm over 2 or 3 years might be a reliable surrogate measure for total joint replacement. On-going research using techniques such as magnetic resonance imaging and biochemical markers may allow the identification of these patients earlier in the disease process.
authors.affiliation: MRC Epidemiology Resource Centre, University of Southampton, Southampton, UK.
authors.forename: Cyrus
authors.initials: C
authors.lastname: Cooper
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Adachi
authors.forename: Thomas
authors.initials: T
authors.lastname: Bardin
authors.forename: Francis
authors.initials: F
authors.lastname: Berenbaum
authors.forename: Bruno
authors.initials: B
authors.lastname: Flamion
authors.forename: Helgi
authors.initials: H
authors.lastname: Jonsson
authors.forename: John A
authors.initials: JA
authors.lastname: Kanis
authors.forename: Franz
authors.initials: F
authors.lastname: Pelousse
authors.forename: Willem F
authors.initials: WF
authors.lastname: Lems
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Pelletier
authors.forename: Johanne
authors.initials: J
authors.lastname: Martel-Pelletier
authors.forename: Susanne
authors.initials: S
authors.lastname: Reiter
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Reginster
authors.forename: René
authors.initials: R
authors.lastname: Rizzoli
authors.forename: Olivier
authors.initials: O
authors.lastname: Bruyère
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D018771:Arthralgia; D019643:Arthroplasty, Replacement; D002358:Cartilage, Articular / Q000473:pathology; D018450:Disease Progression; D006801:Humans; D008279:Magnetic Resonance Imaging; D010003:Osteoarthritis / Q000175:diagnosis* / Q000188:drug therapy* / Q000453:epidemiology; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal
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