ASAS definition of difficult-to-treat axial spondyloarthritis - ASAS D2T SpA


Despite the availability of several potent anti-inflammatory treatment options, only about 40 to 50% of patients with axial spondyloarthritis (axSpA) achieve the ASAS40 response and even lower proportion of patients (approximately 10-20%) achieve remission or inactive disease activity state within 16 to 24 weeks of treatment according to the data from randomized controlled trials with b- and tsDMARDs. There are several potential reasons for the non-response or partial response in axSpA, which can be related to the disease itself, but could also be related to factors other than biological non-response (e.g., chronic pain syndrome, concomitant degenerative disease, etc.).


Within the ASAS D2T SpA initiative we aim to develop a consensus definition of a difficult-to-treat axSpA that is primarily related to the biological nonresponse, i.e., active disease despite sufficient anti-inflammatory treatment. The definition is intended for clinical research focusing on characterization of those patients, identification of the mechanisms beyond the refractory disease and conducting interventional trials.


The project will include the following steps:

  • Literature review to identify potential elements or existing definitions of DT2 SpA.
  • Online survey among ASAS members related to the potential elements of the definition of a D2T SpA.
  • Development of the first draft of the definition based on the survey results by the steering committee.
  • Meeting of the task force with discussion of the proposed definition, amendments, development of the final version and voting.
  • Presentation of the final definition at the ASAS annual meeting and endorsement.

Timelines of the project: 2022 – ongoing


Project Team

PI: Denis Poddubnyy, Désirée van der Heijde

Steering committee:

Xenofon Baraliakos

Victoria Navarro Compan

Désirée van der Heijde

Denis Poddubnyy



Murat Torgutalp