AB0228 LONG-TERM EFFECTIVENESS, DRUG SURVIVAL OF BIOLOGIC THERAPIES IN PATIENTS WITH ACTIVE RHEUMATOID ARTHRITIS AND SPONDYLOARTHRITIS AND PREDICTIVE FACTORS OF DRUG DISCONTINUATION DUE TO DISEASE REMISSION
Authors: K. Preedeekanit, A. Koolvisoot
Journal: Annals of the Rheumatic Diseases (2021)

Background: Rheumatoid arthritis (RA) and spondyloarthropathies (SpA) are chronic rheumatic diseases that can progress to disability if left uncontrolled. Biologic therapies can induce remission in patients with inadequate response or intolerance to conventional synthetic disease-modifying antirheumatic drugs (csDMARDs). Due to the safety and economic concern, updated treatment recommendations now consider biologics discontinuation in patients with persistent remission. However, available data are still limited. Objectives: To evaluate the biologics effectivenss, drug survival, rate of discontinuation in real-life practice and to identify predictors of biologics discontinuation due to remission in RA and SpA. Methods: A total of 87 patients with RA and 49 patients with SpA, starting biologics between January 2005 and October 2020, were recruited from the Rheumatic Disease Prior Authorization (RDPA) registry of Siriraj hospital. Baseline data were recorded. Time-dependent rates in achieving remission were calculated. Cumulative probability of biologics discontinuation and predictive factors of drug discontinuation due to remission were analyzed. Results: The biologics used in RA patients were Etanercept (49.4%), Rituximab (44.8%), and Infliximab (5.7%). The 1- and 5- year remission rates were 8.5% and 23.9%, respectively. Drug survival rates were 33.6% for Etanercept, 40.7% for Rituximab, and 36% for Infliximab at five years. The main reasons for drug discontinuation were disease remission (32.1%), inadequate response (32.1%), and side effects (15.1%). Rituximab had the highest discontinuation rate due to remission (56.4%). There was no predictive factor for biologics discontinuation due to remission. SpA patients were treated with Etanercept (83.6%) and Infliximab (16.4%). The 1- and 5- year remission rates were 67.4% and 66.7%, respectively. Drug survival rates were 50.3% for Etanercept and 0% for Infliximab at five years. Biologics withdrawal due to side effects occurred in 16%, inadequate response in 10%, and disease remission in 10% of patients. The predictive factor for biologics discontinuation due to remission was disease duration &lt; 5 years (Hazard ratio 6.92, 95%CI 1.10, 43.29) Conclusion: Biologic therapies are effective in patients with active RA and SpA despite csDMARDs treatment. The highest drug survival rates are Rituximab in RA and Etanercept in SpA. Infliximab has the shortest drug retention rate in SpA. Drug discontinuation due to remission is more successful in RA patients, particularly in the Rituximab group. The best predictor for biologics discontinuation due to remission in SpA is the disease duration of fewer than five years. Table 1. Effectiveness, Drug Survival and Causes of Biologic Discontinuation in RA and SpA RA % (87 cases ) Biologics Total % (N) 5-year Remission rate % 5-year Drug survival rate % Discontinuation % (N 53 cases) Total % (53) Remission Inadequate response Side effect Non-adherence/ Refer Death Etanercept 49.4 (43) 23.9 33.6 50.9(27) 14.8(4) 44.4(12) 22.2(6) 11.1(3) 7.4(2)* Infliximab 5.7 (5) 36 5.7 (3) 0(0) 33.3(1) 33.3(1) 33.3(1) (0) Rituximab 44.8 (39) 40.7 43.4 (23) 56.5(13) 17.4(4) 4.3(1) 13.0(3) 8.7(2) SpA %(49 cases ) Biologics Total % (N) 5-year Remission rate % Drug survival rate % Discontinuation % (N 23 cases) Total % (23) Remission Inadequate response Side effect Non-adherence/ Refer Death Etanercept 83.6 (41) 66.7 50.3 78.3(18) 22.2(4) 22.2(4) 33.3(6) 22.2(4) 0(0) Infliximab 16.4 (8) 0 21.7 (5) 20(1) 20(1) 40(2) 20(1) 0(0) *Cause of death: sudden cardiac death (1), intraabdominal infection (1 ) Cause of death: pneumonia (1), Lung cancer (1 ) Disclosure of Interests: None declared