SPondyloarthritis: EARly Definition (ASAS-SPEAR): Analysis of Symptom Duration Thresholds Using Pooled Data from Randomized Controlled Trials

Spondyloarthritis (SpA) is a term used to describe a group of connective tissue diseases that cause prominent joint inflammation and affects 0.5%-2% of the population. It includes a wide spectrum of manifestations, including a presentation with predominantly axial manifestations (i.e. pain and swelling in the spine and the joints that connect the bottom of the spine to the pelvis), namely axial spondyloarthritis (axSpA), and with predominantly with peripheral manifestations, peripheral spondyloarthritis (pSpA). As a result of significant advances in the field of SpA, researchers started using the term ‘early SpA‘ to refer to the first phase of the disease. Nevertheless, no consensual definition has been established. In this respect, the Assessment of SpondyloArthritis international Society (ASAS) identified the need to establish a standardized definition for the term ‘early SpA’ in a research setting, since it had been widely used with many arbitrary definitions. Hence, the ASAS-SPEAR (SPondyloarthritis EARly definition) project aims at proposing a consensus definition of ‘early SpA’ to be employed in research. As a first step of this project, a systematic literature review (SLR) was conducted. This review had as objectives: 1) to identify all possible definitions used in the literature to define ‘early SpA’, including ‘early axSpA’ and ‘early pSpA’; 2) to summarize the evidence on the relationship between symptom/disease duration or the presence of radiographic damage and clinical treatment response in patients with axSpA. Two abstracts summarizing the results of the systematic literature review (SLR) will be presented at EULAR 2022 Congress (2, 3). In addition, a full manuscript has been submitted for publication, another is in preparation.
The main conclusions of the SLR were that there is substantial heterogeneity in the definitions of ‘early SpA’ in the current literature, and that evidence on whether the duration of symptoms is related with different treatment outcomes is scarce and mostly inconclusive. Of note, when early was defined by disease duration or radiographic damage, no association with clinical treatment response was found. The results of this SLR were discussed among all ASAS members in the 2022 ASAS annual meeting. A voting took place, in which there was a consensus to pursue a definition of ‘early axSpA’. Additionally, the group voted this definition to be based on symptom duration. Currently, a Delphi survey among ASAS members is being conducted to decide on the details of this definition, as for example the final cut-off of this symptom duration (e.g. less than 2 years).
To inform the final decision on the ‘early axSpA’ definition, one of the steps of the ASAS-SPEAR project is to conduct analyses to assess treatment outcomes according to the different thresholds of symptom duration in patients included in randomized controlled trials (RCT). In this sense, it is relevant to know whether patients who are treated earlier or later in the course of their disease (with a definition based on symptom duration) have different outcomes or response to treatment. This information is not readily available for most of the conducted trials as it is not part of the regulatory requirements. Relying on an SLR with published data only is subject to publication bias. We therefore want to systematically obtain data through the sponsors or authors from eligible trials. The latter are identified through the SLRs conducted in the context of the ASAS-EULAR recommendations for the management of axSpA (previously published SLRs and also the recent SLR performed as the basis of the ongoing, 2022 update of the recommendations).