POS0948 PREVALENCE AND ADJUDICATION RATES FOR IMAGING BASED JUXTA-ARTICULAR BONE FORMATION INCLUSION CRITERIA AND BONE EROSION STRATIFICATION IN PSORIATIC ARTHRITIS CLINICAL TRIALS

• Published in: Annals of the rheumatic diseases Vol. 83; no. Suppl 1; p. 710
• Main Authors: Syed, F., Pereira, S., Dasari, R., Warner, S.
• Format: Journal Article
• Language: English
• Published: Kidlington BMJ Publishing Group Ltd and European League Against Rheumatism 01.06.2024; Elsevier Limited
• Subjects: Bone; Bone growth; Bone imaging; Clinical Trial; Clinical trials; Imaging; Osteogenesis; Osteophytes; Psoriatic arthritis; Scientific Abstracts
• ISSN: 0003-4967; 1468-2060
• DOI: 10.1136/annrheumdis-2024-eular.2947

Background:Psoriatic arthritis (PsA) is a progressive disease with multiple manifestations including juxta-articular bone formation (JBF) and bone erosions (ERO). To recruit the right subjects in a clinical trial as well as to stratify them for monitoring treatment effects, JBF (as part of the CASPAR criteria) and bony joint erosions are used as radiological criteria.Objectives:We aim to ascertain the relative percentage of PsA subjects that would display JBF, erosions or both to understand the relative prevalence of these radiological manifestations which are used as eligibility or stratification criteria in Phase II/III clinical trials. We also wanted to ascertain the adjudication rates on central reading for these hallmarks. For prospective PsA clinical trial planning it is important to understand the percentage of subjects likely to be eligible by central imaging review based on the JBF and erosion status.Methods:Data from a total of four Phase III trials (n= 4,902) were evaluated. Subjects from two trials (n= 1,654) were assessed for presence or absence of at least one juxta-articular new bone formation (JBF+ or JBF-) in the digits of either the hands or feet. Subjects from three trials (n= 4,361) were assessed for presence or absence of at least one erosion (ERO+ or ERO-) in either the hands or feet. Trials with a double read plus adjudication model were used to derive adjudication rates. For JBF adjudication rates, we used data derived from two trials (n= 1,654). For erosion adjudication rates or determining the adjudication rate for JBF as well as erosions, we used data derived from 1 trial (n= 1,113).Results:Trials requiring JBF as a component of the CASPAR inclusion criteria had 26.4% JBF+ and 73.2% were JBF-. 49.4% of subjects were ERO+ and 50.5% (2,200 of 4,361) were ERO-. The adjudication rate for JBF only was 37.5%, for erosions only was 42.0%.Table 1.Prevalence of radiologic featuresRadiologic FeatureTotal # of subjects+ Status (#/%)-Status (#/%)Juxta-articular Bone Formation (JBF)1,654437/ 26.4%1,211/ 73.2%Erosions4,3612,156/ 49.4%2,200/ 50.5%Table 2.Adjudication ratesAdjudication featureTotal # of subjectsAdjudication (#/%)JBF only1,654620/ 37.5%Erosion only1,113468/ 42.0%Conclusion:Overall, central independent review determined a quarter of subjects were JBF+ (26.4%) and approximately half of the subjects had at least one erosion (49.4% ERO+). The adjudication rates for both JBF and ERO alone were high (37.5% JBF only and 42.0% ERO only). The adjudication rate may be attributed to reader variability especially when looking at subtle erosions or discriminating true JBF versus reparative bone formation and/or osteophytes which can mimic JBF. The relatively high adjudication rate for either of these features supports a double read plus adjudication model to address these differences. Given CASPAR criteria and erosions are used for eligibility and stratification in PsA trials it is important to take these findings into consideration for study design and sample size considerations for Screening and Randomization in PsA clinical trials.REFERENCES:NIL.Acknowledgements:NIL.Disclosure of Interests:None declared.