FRI0265 Immunogenicity of Anti-TNF Antagonists in Patients with Rheumatoid Arthritis or Polyarticular Psoriatic Arthritis in Clinical Remission or Low Disease Activity: The Inmunoremar Study. (10th June 2014)

• Record Type: Journal Article
• Authors: Sanmarti, R.; Inciarte, J.; Estrada Alarcόn, P.; Garcia Manrique, M.; Gonzalez Navarro, A.; Narvaez, J.; Rodríguez-Moreno, J.; Gomez-Centeno, A.; Yagüe, J.
• Is Part Of: Annals of the rheumatic diseases. Volume 73:Supplement 2(2014)
• Page Start: 479
• Page End: 479
• Publication Date: 2014-06-10
• Subjects: Rheumatism -- Periodicals; 616.723005
• DOI: 10.1136/annrheumdis-2014-eular.4682
• Languages: English
• ISSNs: 0003-4967

Abstract

Abstract : Objectives: To determine serum trough levels and anti-drug antibodies ( Ab ) in patients with rheumatoid arthritis ( RA ) or polyarticular psoriatic arthritis ( PsA ) in clinical remission ( CR ) or low disease activity ( LDA ) on treatment with adalimumab ( ADA ), etanercept ( ETN ) and infliximab ( IFX ) and correlate serum trough levels and Ab with loss of CR o LDA after 1-year of follow-up. Methods: Prospective, multicenter study of patients diagnosed with RA or PsA attended by 3 hospital outpatient clinics in Catalonia, Spain treated with ADA, ETN or IFX for ≥3 months in CR or with LDA measured by DAS28-ESR at ≥2 consecutive visits. We determined Ab and serum trough levels (commercial ELISA Kit Promonitor®, Progenika SA) at 0, 4, 8 and 12 months. Variables collected: demographic data; disease activity (different articular indexes), diagnosis; disease duration; biologic drug; reduced dose, and concomitant DMARDs therapy. Study entry data (Visit 0) are presented. Results: 165 patients (RA 92 [55.8%], PsA 73 [44.2%]), 65.5% female, mean age 57±12 years were included. 121 (73.3%) patients were in CR, 44 (26.7%) with LDA, 63 on ADA, 83 ETN, and 19 IFX. Mean treatment duration was 65.2±40.7 months. 75 patients (45%) were receiving low doses of biologics, and 98 (59.4%) concomitant DMARD (84% methotrexate). In 3 patients (1.8%, 2 in CR and receiving DMARD) significant Ab levels were found, with undetectable serum trough levels (2RA and 1PsA): 2 anti-IFX (10%) and 1 anti-ADA (1.6%). Another patient receiving ADA had low Ab titers and detectable serum drug levels. Mean serum levels of all TNF antagonists were non-significantly different between RA and PsA, monotherapy or combined treatment. Patients with reduced dosage had significantly-lower levels of ADA and ETN than those receiving standard doses. No differences between patients in CR or LDA were observed. According to the ELISA cut-off for appropriate drug serum levels (ADA: >1.274μg/ml, and ETN :>1.242μg/ml) (Chen DY et al. Ann Rheum Dis 2014;0:1-9), 19% and 30.1% of patients treated with ADA and ETA, respectively, had suboptimal levels (30% with ADA and 46.2% with ETA on dose reduction). There were no differences between DAS28-CPR, DAS28-ESR, SDAI, CDAI, ESR or CRP values in patients with suboptimal or appropriate serum levels. Conclusions: The frequency of anti-drug antibodies is very low in patients with RA and PsA treated with TNF antagonists in CR or with LDA. A significant percentage of patients had suboptimal drug serum trough levels. Prospective follow-up will determine whether these serum levels may predict loss of CR or LDA. Disclosure of Interest: R. Sanmarti Grant/research support: Unrestricted grant from Pfizer, J. Inciarte Grant/research support: Grant from Hospital Clinic of Barcelona (Premi Emili Letang 2013), P. Estrada Alarcόn: None declared, M. Garcia Manrique: None declared, A. Gonzalez Navarro: None declared, J. Narvaez Grant/research support: Unrestricted grant from Pfizer, J. Rodríguez-Moreno Grant/research support: Unrestricted grant from Pfizer, A. Gomez-Centeno Grant/research support: Unrestricted grant from Pfizer, J. Yagüe Grant/research support: Unrestricted grant from Pfizer DOI: 10.1136/annrheumdis-2014-eular.4682