FRI0044 Dose Reduction of Biological Therapy in Rheumatic Diseases: A Two-Year Prospective Study
Authors: J. Inciarte-Mundo, M. Hernández, S. Cabrera-Villalba, V. Ruiz-Esquide, J. Ramírez, A. Cuervo, J. Cañete, R. Sanmarti
Journal: Annals of the Rheumatic Diseases (2015)

<h3>Background</h3> Dose reduction of biological therapy in patients with chronic arthritis (CA) with a good clinical response is a common pattern in clinical practice. However, most published studies are based on cross-sectional data in small groups of patients. <h3>Objectives</h3> To analyse the evolution of CA patients receiving low doses of biologics and to describe predictive factors associated with maintaining reduced doses of biological therapy. <h3>Methods</h3> Observational, longitudinal, prospective study that analysed the evolution of 153 patients treated with standard or reduced doses of biologics with a two-year follow up. Variables analysed were: age, sex, diagnosis and disease duration, previous treatment (sDMARD, bDMARD), current bDMARD and dosage, duration of biological treatment. In patients on reduced doses: concomitant therapy (sDMARD, steroids), ESR and CRP were collected. In rheumatoid arthritis (RA) patients, autoantibody status, erosions, and DAS-28 score were analysed. A logistic regression model was used to identify factors associated with maintaining the reduced dose after 2 years. The confidence interval of the area under the ROC curve was estimated by bootstrap technique to internally validate the predictive capacity of the model. <h3>Results</h3> 153 patients were included between June and November 2011: 82 RA, 29 ankylosing spondylitis (AS), 20 psoriatic arthritis (PsA) and 22 with other diagnoses: 70 patients (45.7%) were on reduced doses of biologics. This cohort was followed prospectively for 2 years. Of the 153 patients initially included, 142 remained on biologics at 2 years and 11 discontinued (6 on lower doses and 5 on standard doses: 3 due to adverse events (malignancies), 2 to pregnancies, 2 to prolonged remission, 1 to death and 3 lost to follow-up). After 2 years of follow-up, 56 patients remained on low-dose biological therapy (39.4%) and 8 (5.6%) required an increase in the dose to the standard regimen. By contrast, 19 patients receiving the standard dose were on reduced doses at two years. 75 (52.8%) patients were on a reduced dose after two years follow up. In patients (37 RA, 13 PsA) in whom the DAS-28 score was analysed (mean ± SD), 17.9% (8 AR, 2 PsA) had low disease activity (2.8±0.2) and 71.4% (29 AR 11, PsA) were in remission (1.9±0.5). Univariate analysis, showed that patients who remained on a reduced dose after 2 years had less use of concomitant steroids in 2011 [9% vs. 45% (p&lt;0.0001)] and lower ESR [8±6 vs. 2.9±1.5 (p&lt;0.0001)], CRP [0.1±0.2 vs. 0.3±1.1 (p&lt;0.0001)], and DAS-28 [2.3±0.3 vs. 2.9±1.5 (p&lt;0.0001)] in 2011. Multivariate analysis showed that lower use of concomitant steroids in 2011 in all patients [adjusted odds ratio (AOR) =0.15, 95% CI 0.05 to 0.52, p=0.0026] was independently associated with the maintenance of reduced doses. In RA patients, a lower DAS-28 score in 2011 was also a predictor of maintaining reduced doses [AOR =0.24, 95% CI 0.10 to 0.59, p=0.0018]. The area under the ROC curve was 85.5% [95% (74.2% -91.5%] <h3>Conclusions</h3> In our cohort, 87.5% of patients receiving reduced doses in 2011 remained on them after 2 years of follow up. Factors associated with the maintenance of a clinical response with reduced biological doses in the multivariate model were lower previous use of steroids and a lower DAS-28 score. <h3>Disclosure of Interest</h3> None declared