AB0907 CHARACTERISTICS OF PATIENTS WITH SPONDYLOARTHRITIS WHO STARTED bDMARDs IN THE EARLY PERIOD (≤2 YEARS) - HURBIO REAL-WORLD DATA

Background: The concept of a 'window of opportunity' is well accepted in rheumatoid arthritis. Whether a similar approach applies to spondyloarthritis (SpA) remains uncertain. Objectives: This study aims to evaluate the characteristics of SpA patients started on biologic disease-modifying antirheumatic drugs (bDMARDs) within two years of symptom onset and compare them with patients started on bDMARDs later. Methods: Hacettepe University Rheumatology Biologic Registry (HUR-BIO) is a prospective, single center registry of rheumatic disease patients treated with bDMARDs. A total of 3161 SpA patients enrolled in the database were included in the study. Patient demographic characteristics, date of disease onset and diagnosis, HLA-B27 results and radiographic findings, if present, extra-articular lesions, synthetic DMARDs used before bDMARDs, bDMARD initiation date, number of tender/swollen joints at bDMARD initiation and at the last visit, ESR, CRP, and BASDAI, BASFI, VAS, and HAQ scores were recorded. Results: It was found that 665 of the 3161 SpA patients (51.3% male) included in the study were started on a bDMARD within a median of 11 months (6-18 months) after the onset of symptoms. Patients who started bDMARDs in the early period had an older age at symptom onset (32 years (25-41) vs. 27 years (21-35), p<0.001) and shorter disease duration according to symptom onset (9 years (5-11) vs. 16.5 years (12-23), p<0.001). Age at diagnosis was similar between the groups. Syndesmophyte, bamboo spine, and hip involvement were more common in patients with longer disease duration and later bDMARD initiation (p<0.001, p<0.001 and p=0.002, respectively). While there was no difference between the groups regarding extra-articular involvement, such as psoriasis and inflammatory bowel disease, uveitis was observed to be less common in patients started on early bDMARDs (6.8% vs. 13.3%, p<0.001). While the use of methotrexate (26% vs. 30%), salazopyrine (60% vs. 77%), and hydroxychloroquine (11% vs. 17%) was lower in the early bDMARD group than in the late bDMARD group, the use of steroids was higher (31% vs. 26%) (p=0.021, p<0.001, p<0.001 and p=0.021, respectively). The early and late bdMARD groups were similar for the first bDMARD selection [TNFi (98.5% vs. 98.1%) and IL-17i (%1.5 vs. 1.9%)]. There were no significant differences between groups in bDMARD switch rates (45.8% vs. 42.9%), drug adherence and disease activity indicators at first and last visit. Only the proportion of patients with a BASFI ≥4 at the time of bDMARD initiation was higher in the late bDMARD group (60.3% vs. 54.8%) (p=0.043). While the initial BASFI scores were similar between the groups, the BASFI score at the last visit was found to be lower in patients who started bDMARD early (2.3 (0.4-4.8) vs. 2.8 (0.9-5.3), p<0.001). Conclusion: This study showed no significant difference in medication adherence and disease activity in patients who started treatment earlier. However, this group had a lower rate of functional decline and a lower incidence of uveitis. Treatment decisions should be based not only on disease activity control but also on preserving the patient's functional ability. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.