A TAILORED APPROACH TO REDUCE DOSE OF ANTI-TNF DRUGS IS EQUALLY EFFECTIVE AND LESS COSTLY THAN STANDARD DOSING IN PATIENTS WITH ANKYLOSING SPONDYLITIS OVER TWO YEARS: A PROPENSITY SCORE-MATCHED COHORT STUDY

J. Zavada, M. Uher, K. Sisol, S. Forejtova, K. Jarosova, H. Mann, J. Vencovsky, K. PavelkaRheumatology, Institute of Rheumatology, Prague Institute of Biostatistics and Analyses, Masaryk University, Brno, Czech RepublicObjectives: To compare effectiveness, safety and costs of standard versus individually tailored reduced doses of anti-TNF drugs in patients with Ankylosing Spondylitis (AS) after achieving low disease activity. Methods: This was a single center prospective observational study performed within the national biologics registry. The anti-TNF dose tapering strategy was chosen by treating physicians, without pre-specified protocol. We used propensity score (PS) methodology to identify 2 cohorts of patients matched for relevant baseline characteristics (age, gender, baseline activity, baseline function, disease duration, duration of anti-TNF therapy - see table) who were treated with either reduced (n=53) or standard (n=83) doses of TNF inhibitors. Two years outcomes and costs of anti-TNF drugs were compared between both PS-matched cohorts. Results: In the reduced dosing group the median dose of TNF inhibitor corresponded to 0.67, and 0.58 of the standard dose initially, and at 24 months resp., and 23% of patients required return to standard dosing regimen. The hazard ratio (95% CI) of reduced versus standard dosing group for relapse and any adverse event was 1.25 (0.68; 2.28), and 0.61 (0.31; 1.19) resp. (Figure). The mean change per 2 years in BASFI, as well as BASDAI and CRP area under the curve (AUC) were no different between both groups, but the cost for anti-TNF drugs was substantially lower in the reduced dosing group (table). Table 1. Baseline data Standard dosing groupReduced dosing groupp-value Femalen (%)19 (22.9%)13 (24.5%)0.840 Age (years)Mean (SD)39.5 (9.3)41.0 (10.8)0.585 Disease duration prior to the start of anti-TNF therapy (years)Mean (SD)8.1 (7.0)9.2 (8.5)0.582 Duration of anti-TNF therapy (months)Mean (SD)37.4 (20.0)34.8 (18.6)0.443 CRP (mg/l)Mean (SD)4.4 (5.6)4.3 (7.8)0.713 BASDAIMean (SD)1.4 (0.9)1.4 (1.1)0.796 BASFIMean (SD)1.9 (1.4)1.8 (1.5)0.644 Anti-TNF agents  Etanerceptn (%)31 (37.3%)25 (47.2%)0.515  Adalumumabn (%)19 (22.9%)11 (20.8%)  Infiliximabn (%)33 (39.8%)17 (32.1%) 2 year outcomes of standard vs reduced dosing of TNFis  BASDAI area under the curve (AUC) during 24 monthsMean (SD)1.82 (1.17)1.66 (1.18)0.413  CRP AUC during 24 monthsMean (SD)6.59 (9.91)5.16 (6.83)0.338  Change in BASFI after 24 monthsMean (SD)0.21 (1.20)0.18 (1.63)0.690  Annual cost of anti-TNF therapy (€ )Mean (SD)120007805 (2433)<0.001  Difference in annual cost (€)Diff. (95% CI)reference−4195 (−4713; −3676)<0.001 Conclusions: In AS patients after reaching low disease activity a tailored approach to reduce doses of anti-TNF drugs produced similar clinical outcomes at 2 years, but was substantially less costly. Acknowledgements: Supported by project of MHCR for conceptual development of research organization 023728 Disclosure of Interest: None declared DOI: 10.1136/annrheumdis-2015-eular.2257Citation: Annals of the Rheumatic Diseases, volume 74, supplement 2, year 2015, page 749Session: Spondyloarthritis - clinical aspects (other than treatment) (Poster Presentations )