AB0655 Anti-TNF Alpha Dose Reduction in Ankylosing Spondylitis Patients
Authors: A. Ortolan, M.S. Chimenti, M. Lorenzin, P. Frallonardo, F. Sunzini, P. Conigliaro, R. Perricone, L. Punzi, R. Ramonda
Journal: Annals of the Rheumatic Diseases (2016)

<h3>Background</h3> Anti-Tumor Necrosis Factor (TNF)alpha drugs play a fundamental role in Ankylosing Spondylitis (AS) therapy. Nevertheless their use is associated to potential side effects, such as a higher frequency of infection, and high healthcare costs. On these bases, a dose reduction strategy (lengthening drug administration interval) is often attempted in clinical practice. <h3>Objectives</h3> 1) to retrospectively compare the features of anti-TNFalpha-treated AS patients who could lengthen the administration interval (group A) with those of patients who needed to maintain standard dosage (group B); 2) to evaluate the impact of dose reduction on infection frequency; 3) to evaluate cost-savings in group A. <h3>Methods</h3> All AS patients attending the spondyloarthritis outpatients clinic- Rheumatology Unit of University of Padova and of University of Rome "Tor Vergata" between January 2011 to April 2015 who were treated with anti-TNFalpha (infliximab, adalimumab, etanercept) at a standard dose for at least 6 months with a good control of disease activity (ASDAS &lt;2.1) were prescribed a dose reduction regimen. Some patients were able to maintain the new regimen (group A), while others were not because of symptom flare-up (group B). Disease activity (ASDAS, BASDAI), inflammatory (CRP), functional and (BASFI) and metrologic (BASMI) indexes were recorded at baseline (t0), after 6 months (t6), then once a year (t12, t24, t36, t 48) for a 4-year follow-up. <h3>Results</h3> Data from 96 AS patients (25 females, 26.04%; mean age 47.62±13.39 years) were examined. Drug administration interval, which could be lengthened in 66 (68.75%) patients (group A) without flare-ups or functional worsening, was associated to an improvement in ASDAS [t0=2.1 (1.49) vs t48=1.00 (0.29); p&lt;0.0001]; BASDAI [t0=39 (49.6) vs t48=9.5 (14); p&lt;0.0001]; BASFI [t0=22 (35) vs t48=1 (11); p&lt;0.0001]. At the end of the observation period (t48), group A showed better physical functioning and lower disease activity compared to group B [BASFI A vs B =1 (36.18) vs 17.5 (7.3), ASDAS 1 (0.3) vs 1.6 (1.15); CRP 2.15 (2.1) vs 3.1 (7.3) mg/L]. At t0 group A had a less severe inflammatory status [CRP A vs B 2.9 (3.3) vs 4.7 (6.4) mg/L; p=0.0134], and a negative family history for spondiloarthritis (p=0.0318), while no significant difference was observed for smoking, psoriasis, peripheral arthritis, dactylitis, uveitis, enthesitis in more than 4 sites and HLA B27. The number of patients who developed infections during the observation period was significantly lower in group A (p=0,007); the average cost saving at t48 for group A vs group B was: 7.060 vs 14.820 € for infliximab; 6357 vs 13.260 € for etanercept; 11840 vs 12.917 € for adalimumab. <h3>Conclusions</h3> Lenghtening anti-TNFalpha administration interval appears to be a valid approach in patients with a less severe inflammatory status, and a negative family history of spondyloarthritis. Dose reduction regimen is associated to lower infection frequency and less expense for National Health Care System. <h3>References</h3> Arends S, van der Veer E, Kamps FB, et al. Patient-tailored dose reduction of TNF-α blocking agents in ankylosing spondylitis patients with stable low disease activity in daily clinical practice. Clin Exp Rheumatol. 2015;33:174–80. <h3>Disclosure of Interest</h3> None declared