AB1176 UTILITY OF REDOSER TOOL IN DOSE OPTIMIZATION OF BIOLOGICAL THERAPY IN PATIENTS WITH RHEUMATOID ARTHRITIS IN CLINICAL PRACTICE
Authors: A. M. Cabezas-Lucena, M. Morales-Águila, S. Manrique Arija, C. Fuego-Varela, L. Cano Garcia, N. Al Mashhadani
Journal: Annals of the Rheumatic Diseases (2020)

Background: Objectives: To describe the characteristics of patients with rheumatoid arthritis (RA) in dose reduction of biological therapy (BT) in clinical practice and identify possible factors associated with the time in dose reduction and verify the utility of REDOSER tool. Methods: Design: A retrospective, observational longitudinal study under conditions of clinical practice. Patients: RA in BT dose reduction between 2007- 2019 were selected. Inclusion criteria: RA according to ACR 2010 criteria which have been initiated BT dose reduction. Patients with BT are followed prospectively every 3-4 months in a specialized outpatient unit of BT dose reduction with a pre-established protocol for data collection and registered in a database. Variables : Primary: Time in reduction : was defined as the time in which patients maintained the BT optimization and Relapse at 12 and 24 months : percentage of patients who, after starting BT optimization, return to the previous or standard dose. Secondary variables : REDOSER: Appropriate, Doubtful and Inappropriate (If dose reduction was adequate according to the REDOSER tool applied retrospectively were evaluated). Other variables: Demographic, clinical-analytical: time of disease evolution, RF, anti CCP antibodies, Number of Tender Joints, Number of swollen joints, erosions, activity index (DAS28, SDAI, CDAI) and physical function (HAQ). Previous treatments. Statistical Analysis: descriptive, bivariate using x2 and T-Student among patients with and without relapse at 24 months and multivariate linear regression to identify independent variables associated with the time in BT dose reduction (DV: time in reduction). Results: 59 patients with RA were included. Table 1 shows the main characteristics of the subjects. The average (SD) of optimization in months was 17.9 (17.7). Ten patients (16.9%) relapsed at 12 months and 16 (27.1%) at 24 months. The mean (SD) of DAS28 and SDAI of patients who relapsed at 24 months was higher compared to baseline DAS28 (2.3 [0.9] vs. 1.5 [0.8]; p = 0.015) and SDAI (7.8 [6.3] versus 3.3 [1.6]; p 0.05). These patients who relapsed at 24 months compared to patients who did not have more erosions at the start of BT (p = 0.004), longer duration of disease (p = 0.072) and greater baseline activity of DAS28 (p = 0.017), of SDAI (p = 0.030) and CDAI (p = 0.036). After simulating the REDOSER tool to all patients at the beginning of the OBT, 28 patients (56%) were “Appropriate”, 20 (40%) “Doubtful” and 2 (4%) “Inappropriate” of which they continue in OBT at the conclusion of study 22, 10 and 0, respectively (p = 0.020). In the multivariant analysis, the independent variables that are associated with time in dose reduction of BT were baseline DAS28 (β = -0.660, 95% CI[2.7-14.0]; p=0.014) and age (β=-0.800, 95% CI [0.8-0.0]; p=0.038). Conclusion: The majority of the patients with RA who initiate BT dose reduction maintain the optimization after 24 months. REDOSER can be useful in clinical practice to assess the BT optimization in patients with RA. A longer time in BT dose reduction was associated with lower values of DAS28 at the beginning and younger age of the patients. Figure 1: Disclosure of Interests: None declared