POS1305 TREATMENT RESPONSE TO TUMOR NECROSIS FACTOR INHIBITORS IN ADULTS WITH JUVENILE IDIOPATHIC ARTHRITIS: DATA FROM THE NOR-DMARD STUDY

Abstract

Background:Juvenile idiopathic arthritis (JIA) can cause considerable pain and disability in childhood and adulthood. Studies exploring the efficacy of medications in adult JIA patients are limited, although tumor necrosis factor inhibitors (TNFi) have been increasingly used in this patient group.Objectives:To explore the efficacy of TNFi ± comedication on disease activity in adult JIA patients, compared to a weighted rheumatoid arthritis (RA) cohort.Methods:Data from NOR-DMARD, a longitudinal observational study including patients > 18 years starting or switching DMARD treatment, was used [1]. Patients with a clinical JIA diagnosis, or patients with other inflammatory joint diseases diagnosed before 16 years were identified from the study population. RA patients were included for comparative purposes.Disease activity measurements and remission rates among patients starting treatment with TNFi ± comedication were collected at baseline, 3 and 6 months. Changes in disease activity and absolute remission rates after 3 and 6 months were calculated. Remission rates and change in disease activity from baseline were compared between JIA patients and a weighted RA cohort with weights based on age and gender, using linear and logistic regression for continuous and categorical variables, respectively.Results:281 JIA patients (68.9% female, mean (SD) age 32.1 (11.1) years, mean (SD) diagnosis duration 23.5 (12.2) years) and 1374 RA patients (71.6% female, mean (SD) age 52.7 (14.5) years, mean (SD) diagnosis duration 9.5 (10.0) years) were included in the analyses. Age, gender distribution and disease duration differed significantly between cohorts.Both groups had a significant improvement across all disease activity measures after 3 months (Table 1), which was maintained after 6 months across all measures except MHAQ. The RA group had a significantly greater 3- and 6-month improvement in SJC28. Both groups had an overall 6-month increase in absolute remission rates. The JIA group had a significantly higher 3-month DAS28 remission rate (Figure 1). This difference was not significant after 6 months, as remission rates from 3 to 6 months in the JIA group declined across all measures.Table 1.BaselineChange to 3 monthsChange to 6 monthsJIA*RA*Diff.§JIA*RA*Diff.§JIA*RA*Diff.§ESR, mm/h18.7 (18.9)25.5 (22.0)1.3 (-2.3 to 4.9)-7.4 (15.8)-7.6 (16.6)-0.3 (-4.4 to 3.8)-7.4 (16.8)-8.5 (18.2)0.0 (-5.7 to 5.7)SJC282.5 (3.6)5.5 (5.4)1.6 (1.3 to 2.0)-1.4 (3.4)-3.1 (4.7)-1.0 (-1.7 to -0.3)-1.6 (3.2)-3.5 (5.1)-1.0 (-1.9 to -0.1)TJC 284.0 (5.6)6.6 (6.4)1.3 (0.4 to 2.3)-1.8 (3.9)-3.1 (5.9)-0.6 (-1.4 to 0.2)-1.8 (3.9)-3.9 (6.2)-1.0 (-2.0 to 0.1)DAS283.6 (1.4)4.5 (1.6)0.3 (0.1 to 0.6)-1.2 (1.3)-1.2 (1.4)-0.0 (-0.3 to 0.3)-1.2 (1.3)-1.5 (1.4)-0.2 (-0.6 to 0.2)SDAI16.8 (10.6)23.1 (14.3)2.4 (0.3 to 4.5)-7.7 (9.9)-10.9 (12.7)-2.0 (-4.2 to 0.2)-7.9 (8.6)-13.2 (13.6)-2.8 (-5.8 to 0.2)PGA51.4 (26.3)49.9 (25.5)-4.0 (-8.5 to 0.5)-20.6 (26.7)-17.0 (26.7)2.7 (-2.2 to 7.6)-21.6 (25.3)-19.1 (28.7)3.4 (-3.0 to 9.8)MHAQ0.6 (0.5)0.7 (0.5)0.0 (-0.1 to 0.1)-0.24 (0.42)-0.22 (0.42)0.0(-0.1 to 0.1)-0.23 (0.40)-0.25 (0.45)0.0 (-0.1 to 0.1)*Mean (SD)§ Weighted group difference, RA coefficient (95 % confidence interval)Figure 1.Mean 3- and 6-month remission rates with error bars (SE)Conclusion:TNFi was equally effective in reducing disease activity in the JIA and RA cohort after 3 and 6 months, and in inducing remission after 6 months. Absolute remission rates in the JIA group declined from 3 to 6 months across all measures, and studies with longer duration are needed to explore the long-term efficacy of TNFi in the patient groups.