POS1325 COMPARISON OF THREE DIFFERENT ALGORITHMS FOR THE TREATMENT OF CHILDREN WITH POLYARTICULAR JIA: THE FIRST YEAR AFTER DIAGNOSIS

Background: Various treatment strategies are used for children with newly diagnosed polyarticular JIA. MTX is usually prescribed, sometimes in combination with high-dose intravenous glucocorticoid pulses (HDGC) or multiple intra-articular GC injections (IAGC). These different approaches were considered in the German consensus-based treatment protocols for polyarticular JIA1, they were also the leading therapies in patients with rheumatoid factor-negative polyarthritis (RF- PA) included in the JIA inception cohort ICON. Objectives: To compare the effectiveness of three different treatment strategies in nearly DMARD-naive patients with RF- PA. Methods: Patients with RF- PA who were included in the ICON cohort and received one of the following treatments within the first three months were considered for the analysis: Group 1: MTX + IAGC in >4 joints, Group 2: MTX + HDGC, Group 3: MTX, no IAGC in >4 joints, no HDGC. Propensity score-adjusted group differences in outcomes after one and two years were analysed by linear and logistic regression analyses. Results: The analysis included data from 150 patients (79% female, mean age 6.7±4.8 years) enrolled in ICON 1.6±1.9 months after the diagnosis of RF- PA, of whom 52 were in Group 1, 54 in Group 2 and 44 in Group 3. Disease activity did not differ significantly between the groups at treatment start (cJADAS-10 16.7±4.7, 15.8±5.7, 15.9±6.5, respectively). Of the total group, at 1- and 2-year follow-up (FU), 60.9%/60.1% and 52.3%/58.8% of patients had inactive disease (cJADAS ≤1/Wallace criteria2), 21.3% and 35.6% were in remission off drug2, and mean cJADAS-10 scores were 2.6±3.9 and 3.0±3.5, respectively. 60.5% and 67.0% had no functional limitations (CHAQ=0). Patients in Group 1 more often had an inactive disease (according to Wallace2) at the 1-year FU and tended to have inactive disease more often at 2-year FU than patients in Group 3 (78.1% vs. 45.2%, p=0.025; 73.3 vs. 49.1%, p=0.075, respectively). Group 2 patients (inactive disease in 56.1% and 53.4% at 1- and 2-year FU) did not differ significantly from either Group 1 or Group 3. In addition, Group 1 patients had a significantly better quality of life than patients of Group 2 at the 2-year FU (mean PedsQL 4.0 total score 90.4±9.3 vs. 83.8±11.2, p=0.031). At that time, Group 3 patients had a mean PedsQL 4.0 total score of 85.0±14.6, which was not significantly different from either Group 1 or 2. On the other hand, Group 1 patients tended to develop new uveitis more frequently within the first two years of treatment than patients in Groups 2 and 3 (13% vs. 2.2% and 3.6%, p=0.101 and 0.131, respectively). At the 2-year FU, patients in Group 1 also had a significantly lower mean height SDS than patients of Group 3 (-0.3±1.1 vs. 0.2±1.1, p=0.038). Mean height SDS was lowest (-0.5±0.8) in patients in Group 2 and significantly lower than in Group 3 (0.019). Mean body mass index SDS also differed significantly between the groups at 2-year follow-up. The mean BMI SDS was highest in Group 1 patients (0.2±0.8), differing significantly from Group 2 (-0.3±0.7, p=0.014) and Group 3 (-0.4±1.1, p=0.023). There were no significant differences in inactive disease (according to cJADAS) and functional status (CHAQ) between the three groups at 1- and 2-year FU. Over time, treatments were very different in the three groups. In Group 3, biologics were used significantly more often over time than in group 1 (54.0% vs. 18.3%, p=0.014), and Group 2 patients received bDMARDs in 36.1%. Conclusion: While patients with numerous early joint injections seem to achieve inactive disease more frequently and earlier, they have a slightly smaller body height and tend to develop uveitis slightly more often than patients with more intensive DMARD therapy. However, the differences are small between the groups. Further comparative effectiveness studies with higher patient numbers are needed to identify particularly effective and safe treatment strategies. References: [1]Horneff et al. Pediatric Rheumatology 2017;15:78. [2]Wallace et al. Arthritis Care Res (Hoboken) 2011;63:929-36. Acknowledgements: The ICON study is funded by a research grant of the Federal ministry of education and research (BMBF, FKZ 01ER0812, FKZ 01ER1504A-C). Disclosure of Interests: Kirsten Minden Speakers bureau: Pfizer, Abbvie, Consultant of: Novartis, Tobias Schwarz: None declared, Frank Dressler: None declared, Ivan Foeldvari Consultant of: Gilead, Novartis, Pfizer, Hexal, BMS, Sanofi, MEDAC, Johannes-Peter Haas: None declared, Gerd Horneff Speakers bureau: Pfizer, Consultant of: Novartis, Toni Hospach Consultant of: Novartis, Jasmin Kummerle-Deschner: None declared, Kirsten Moenkemoeller: None declared, Frank Weller-Heinemann Speakers bureau: Pfizer, AbbVie, SOBI, Roche, Novartis, Klaus Tenbrock: None declared, Martina Niewerth: None declared, Claudia Sengler: None declared, Dirk Foell: None declared, Jens Klotsche: None declared