AB0302 Influence of Tapering Biological Therapies in Immunogenicity in A Cohort of Rheumatoid Arthritis with Low Disease Activity

BackgroundRecent studies propose the use of a tapering strategy (dose reduction or discontinuation) of tumor necrosis factor inhibitors (TNFi) in rheumatoid arthritis (RA) patients (pts) in low disease activity (LDA) or clinical remission (R) without losing the disease control. One concern, when lower doses are used, is the appearance of anti-drug antibodies (ADA) with the consequent loss of efficacy.ObjectivesTo evaluate the clinical influence of the tapering strategy of TNFi in a cohort of RA pts in LDA or R.MethodsOf a total of 283 RA pts under TNFi, 52 patients treated with Infliximab (Ifx), Adalimumab (Ada) or Etanercept (Etn) were selected. All pts were in LDA or R (DAS28 0.6). At flare, the biologic and non-biologic therapy could be intensified.ResultsIn our cohort of 52 pts, 26 (50%) pts were treated with Ada, 16 (31%) with Etn and 10 (19%) with Ifx. Forty one (79%) were women and 41 (79%) pts were ACPA+ and RF+. Most patients received methotrexate concomitantly (69%), 25 (48%) pts other DMARDs and 22 (42%) prednisone. The mean follow-up was 43.76±8months, without statistically significance among TNFi (p=0.595). At pre-visit, 40 (77%) pts were in R and 12 (33%) LDA. The majority of patients remained in LDA or R at final-visit: 26 (50%) in R, 14 (27%) in LDA, 12 (23%) with DAS28>3.2, p=0.97). When a subanalysis in each TNFi was performed, it was confirmed that most pts were in LDA or R at final-visit (p=0.59 in Ada, p=0.26 in Ifx and p=0.78 in Etn). No differences in CRP levels between visit-pre and final visit were seen. 25 patients (48%) had flares during follow-up (13 (52%) had 1 flare, 10 (40%) had 2 flares and 2 (8%) had 3 flares. Most patients with flares were in LDA or R at final-visit (R=9 (36%), LDA=5 (20%)). Only 2 pts with flares dropped out the TNFi and were ADA + at final visit. All patients were ADA negative at the pre-visit and only 6 (11%) were positive at final-visit, 4 of them withdrawed therapy for maintaining clinical remission. A statistically significant decrease was observed in drug levels between the pre-visit and post-visit (Ada: 5251.9±1205.9 vs 1507.2±322.7, p=0.001; Etn: 2735.2±347.4 vs 1114.9±