A TAILORED APPROACH TO REDUCE DOSE OF ANTI-TNF DRUGS IS EQUALLY EFFECTIVE, BUT SUBSTANTIALLY LESS COSTLY THAN STANDARD DOSING IN PATIENTS WITH ANKYLOSING SPONDYLITIS OVER ONE YEAR: A MATCHED OBSERVATIONAL STUDY

J. Zavada, M. Uher, K. Sisol, S. Forejtova, K. Jarosova, H. Mann, J. Vencovsky, K. PavelkaInstitute Of Rheumatology, Prague Institute of Biostatistics and Analyses, Masaryk University, Brno, Czech RepublicObjectives: To compare efficacy, 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 over one year Methods: One year outcome was compared between two prospectively followed cohorts of AS patients treated in a single academic centre with either reduced doses (n=53), or standard doses (n=83) of anti-TNF drugs. Both treatment groups were matched for patients' age, gender, baseline activity, baseline function, duration of anti-TNF therapy and number of previous anti-TNF drugs. The change in measures of disease activity, physical function, and quality of life, as well as number of relapses, adverse events and costs of anti-TNF drugs were compared between both groups. The study covered the time period between 2007 and 2013 Results: In the reduced dosing group at baseline (after initial dose reduction) the median dose was 67% of standard dose, and 50% at 12 months; in 21% patients the dose was further decreased during one year of observation, while the same proportion of patients required a return to standard dosing regimen. All measures of activity and function, as well as their mean change, were comparable between both treatment groups at baseline and at 12 months of observation. The incidence of relapses, adverse events, severe adverse events, infections, infusion reactions and switches between anti-TNF drugs did not differ between both treatment groups. While the quality of life did not differ between both groups, the annual costs of anti-TNF therapy were substantially lower (by about one third) in the group with reduced dosing. Table 1 Standard dosing groupReduced dosing groupp-value Number of patients8353 Female n (%)19 (22.9%)13 (24.5%)0.826 Age (years)38.6 (33.5; 43.0)38.8 (33.4; 44.2)0.585 BASDAI baseline1.4 (0.4; 2.3)1.4 (0.5; 2.0)0.796 BASDAI 12 months1.8 (0.6; 2.8)1.5 (0.4; 2.8)0.453 CRP baseline2.5 (0.8; 4.8)2.2 (1.1; 4.7)0.713 CRP 12 months2.9 (1.1; 6.6)2.6 (1.4; 8.7)0.992 BASFI baseline1.5 (0.5; 3.0)1.6 (0.3; 2.5)0.644 BASFI 12 months1.6 (0.6; 3.3)1.4 (0.3; 2.7)0.481 Annual cost of anti-TNF therapy (€)12,000 (12,000; 12,000)7 784 (7,177; 8,391)<0.001 Incidence of events within 1year BASDAI >4 OR ΔBASDAI ≥1.513 (15.7%)12 (22.6%)0.383 Switch of anti-TNF drug6 (7.2%)2 (3.8%)0.404 Any AE16 (19.3%)6 (11.3%)0.219 Any SAE2 (2.4%)1 (1.9%)0.840 Infection9 (10.8%)4 (7.5%)0.524 Infusion reaction1 (1.2%)0 (0.0%)0.423 Values are given as median (interquartile range) unless otherwise specified. Mann-Whitney U test and chi-squared test are used when comparing continuous and categorical variables, respectively. Conclusions: A tailored approach to reduce doses of anti-TNF drugs in patients with AS after reaching low disease activity was a cost-effective strategy over one year of treatment. Acknowledgements: This work was supported by the project (Ministry of Health, Czech Republic) for conceptual development of research organization 00023728. Disclosure of Interest: None declared DOI: 10.1136/annrheumdis-2014-eular.3351Citation: Annals of the Rheumatic Diseases, volume 73, supplement 2, year 2014, page 719Session: Spondyloarthritis - treatment (Poster Presentations )