FRI0287 BIOLOGIC DRUG RESPONSE DOES NOT APPEAR RELATED TO RADIOGRAPHIC STATUS IN AXIAL SPONDYLOARTHRITIS: DATA FROM THE BSRBR-AS REGISTRY
Authors: X. Michelena, S. S. Zhao, S. Dubash, G. T. Jones, L. Dean, H. Marzo-Ortega
Journal: Annals of the Rheumatic Diseases (2020)

Background: The concept of axial spondyloarthritis (axSpA) incorporates the full range of inflammatory spinal disease. In the absence of specific immuno-genetic biomarkers, classification criteria differentiate two groups (non-radiographic [nr-axSpA] and radiographic axSpA [r-axSpA]) based on the presence of structural damage of the sacroiliac joints. Controversy remains as to whether nr-axSpA represents a milder form with biologic DMARD (bDMARD) treatment restrictions still in place in many countries. Table 1. Baseline characteristics of nr-axSpA and r-axSpA patients starting biologics. Variables Level nr-axSpA n=418 r-axSpA n=727 p-value Age , mean (SD), years 39.7 (12.4) 46.1 (13.4) &lt;0.001 Sex , n (%) Male 239 (57%) 529 (73%) &lt;0.001 Symptom duration , mean (SD), years 11.2 (10.9) 16.7 (12.9) &lt;0.001 Diagnostic delay , median (IQR), years 3.0 (1.0, 10.0) 3.0 (0.0, 11.0) 0.83 HLA-B27 (missing=325) 227 (73%) 387 (76%) 0.40 Inflammatory back pain , n (%) 384 (92%) 619 (92%) 0.95 Uveitis , n (%) 92 (22%) 205 (30%) 0.003 Crohn’s / Colitis , n (%) 55 (13%) 113 (17%) 0.11 Psoriasis , n (%) 79 (19%) 115 (17%) 0.43 Smoking status , n (%) Never smoked 148 (43%) 218 (38%) 0.040 Ex-smoker 95 (28%) 207 (36%) Current smoker 100 (29%) 154 (27%) NSAID use , n (%) 311 (75%) 560 (77%) 0.43 CRP , median (IQR), mg/dL 0.5 (0.1, 1.3) 0.9 (0.3, 2.5) &lt;0.001 BMI , mean (SD) 27.5 (5.6) 28.2 (5.8) 0.10 BASDAI , median (IQR) 6.7 (5.4, 7.8) 6.5 (5.0, 7.7) 0.12 BASFI , median (IQR) 5.9 (4.2, 7.8) 6.5 (4.4, 8.3) 0.043 VAS-G , mean (SD) 7.0 (2.0) 6.8 (2.0) 0.056 ASDAS-CRP , mean (SD) 2.8 (0.8) 2.8 (0.9) 0.32 ASQOL , median (IQR) 13.0 (9.0, 16.0) 13.0 (9.0, 15.5) 0.29 Biologic (to start ), n (%) Adalimumab 238 (57%) 436 (60%) 0.20 Etanercept 131 (31%) 220 (30%) Certolizumab 35 (8%) 47 (6%) Golimumab 5 (1%) 12 (2%) Secukinumab 7 (2%) 10 (1%) Infliximab 2 (&lt;1%) 2 (&lt;1%) Objectives: To describe the baseline characteristics and bDMARD response at one year in axSpA patients in the British Society for Rheumatology Biologics Register in Ankylosing Spondylitis (BSRBR-AS) according to radiographic status. Methods: BSRBR-AS is a national prospective cohort including participants who fulfil the ASAS classification criteria for axSpA. In this analysis, cross-sectional baseline data of patients starting bDMARDs including clinical, demographic and patient-reported outcomes (PROs) were compared. Follow-up data at one year was identified if 12±4 months from baseline and PROs completed within 2 months of visit date. Ankylosing Spondylitis Disease Activity Scores (ASDAS) for low disease status, clinically important improvement (CII) and major improvement (MI) were used to assess treatment response. Results: Baseline characteristics were available for 1,145 patients. Those with r-axSpA were more likely to be male, were older, and had longer disease duration (Table 1). Follow-up ASDAS was available in 290 patients. Two thirds of the patients achieved ASDAS low disease state at one year regardless of radiographic status (nr-axSpA: 64.2% vs r-axSpA: 66.1, Diff: -1.9%, 95% CI -13.7 to 9.8). Further, no significant differences were seen between the groups in attaining ASDAS CII (nr-axSpA: 50.7% vs r-axSpA: 44.7%, Diff: 6.0%, 95% CI -7.8 to 19.8%) or MI (nr-axSpA: 20% vs r-axSpA: 18.7%, Diff: 1.3%, 95% CI -9.7 to 12.3%). Conclusion: Although there appeared to be some differences in the baseline characteristics when exploring this cohort, according to radiographic status, which are likely related to the natural history of the disease; the level of biologic response was comparable between the groups supporting the concept of axSpA as a single disease entity. Acknowledgments: This project is supported by a FOREUM fellowship. Disclosure of Interests: Xabier Michelena: None declared, Sizheng Steven Zhao: None declared, Sayam Dubash: None declared, Gareth T. Jones Grant/research support from: Pfizer, AbbVie, UCB, Celgene and GSK., Linda Dean: None declared, Helena Marzo-Ortega Grant/research support from: Janssen, Novartis, Consultant of: Abbvie, Celgene, Eli Lilly, Janssen, Novartis, Pfizer, UCB, Speakers bureau: Abbvie, Celgene, Eli Lilly, Janssen, Novartis, Pfizer, Takeda, UCB DOI: 10.1136/±annrheumdis-2020-eular.3147