LAUSR

There is a paucity of evidence based therapies for reactive arthritis(ReA). Data is limited for anti-TNF drugs usage [Table 1] with even less data on biosimilars.To find out the outcomes of etanercept biosimilars (ETN-b) use in ReAA retrospective review of patients meeting the Braun criteria5for probable ReA helped identify patients on ETN-b. Patients with less than 1 year follow-up and those who had received less than 5 doses of ETN were excluded. Biological naïve patients who had completed at least 1 year follow-up were included as controls. Baseline and current status was compared between these two groups.Of 94 identified ReA patients, 11(11.7%) had received ETN-b and 10 met the case definition. Five each had received one of two ETN-b. 30 were available as controls. All cases had been documented as refractory ReA. Amongst cases, 7 patients had resolution of ReA; 2 had relapsing courses and 1 persistent arthritis. Four were in remission off all drugs. Controls has similar proportions [Table 2]. There were no infections or adverse effects recorded during follow-up.Table 1.Anti-TNF use in reactive arthritisPlace (year)Anti-TNFNOutcomesRemarksPennsylvania, USA (2005)Etanercept1610 completed trial: 9 respondersSynovial histology improvement but not normalizedStrasbourg, France (2011)Infliximab(5) Etanercept(4) Adalimumab(1)10Rapidly effective in 9 patients (90%)5 had DFRRelapses responded to re- initiationBesançon, France (2016)Etanercept (9) infliximab (3) Adalimumab(3)155 had DFR9 developed chronic SpADelhi, India (2019)Infliximab(10), Adalimumab(3) Etanercept(1)9At median of 3.5 months: 4 had remission, 3 relapse, 1 adverse reactionBiologicals were not given regularlyCurrent studyEtanercept biosimilars10At median 7 months: 6 had DFRAll patients respondedDFR: drug free remissionTable 2.Comparison between etanercept group and biological naїve groupEtanercept group(n=10)Non-etanercept group(n=30)Non parametric tests of significanceAge at presentation (years)27(17.2-34.2)25(19-34.2)NSMales10 (100%)22 (55%)NSFollow-up (months)27(15-71.7)27(15-79.5)NSPreceding infectionDiarrhoea= 6Diarrhoea= 23NSUTI= 4UTI= 7Inflammatory backache311NSSmall joint involvement411NSMonoarticular/ oligoarticular/ polyarticular3/3/410/8/12NSAverage intra-articular injections1.90.3NSSulfasalazine922NSMethotrexate11NSDisease outcomeResolved = 7Resolved = 19NSRelapsing = 2Relapsing = 9Persistent = 1Persistent = 2Drug free remission4 (40%)12(40%)NSBASDAI at last follow-up0.3(0-0.8)0(0-1.4)NSHAQ-DI at last follow-up0(0-0.15)0.05(0-0.3)NSBASDAI: Bath Ankylosing Spondylitis Disease Activity Index; HAQ-DI: Health Assessment Questionnaire Disability Index; NS: not significantAll 10 patients responded. 40% achieved drug free remission. Thus, ETN-b appear safe and effective for ReA refractory to conventional therapy.[1]Flagg SD, Meador R, et al. Decreased pain and synovial inflammation after etanercept therapy in patients with reactive and undifferentiated arthritis: an open-label trial. Arthritis Rheum. 2005;53(4):613-7[2]Meyer A, Chatelus E, et al. Safety and efficacy of anti-tumor necrosis factor α therapy in ten patients with recent-onset refractory reactive arthritis. Arthritis Rheum. 2011 May;63(5):1274-80[3]Brinster A, Guillot X, et al. SAT0387 Anti Tnf Treatment of Reactive Arthritis. A Monocentric Experience. Ann Rheum Dis 2016;75:808[4]Gupta V, Mohta P, et al. A retrospective case series of 12 patients with chronic reactive arthritis with emphasis on treatment outcome with biologics. Indian J Dermatol Venereol Leprol. 2019 [in print][5]Braun J, Kingsley G, et al. On the difficulties of establishing a consensus on the definition of and diagnostic investigations for reactive arthritis. 1999.J Rheumatol. 2000;27(9):2185-92None declared