Comparative effectiveness and persistence of TNFi and non-TNFi in juvenile idiopathic arthritis: a large pediatric rheumatology center in US

Objective: To evaluate the persistence and effectiveness of tumor necrosis factor inhibitors (TNFi) vs non-TNFi among newly diagnosed JIA patients after initiation of biologic disease-modifying anti-rheumatic drug (bDMARD).

Methods: Using longitudinal patient-level data extracted from electronic medical records (EMR) in a large Midwestern pediatric hospital from 2009-2018, we identified JIA patients initiating TNFi and non-TNFi. Treatment effectiveness was assessed based on disease activity. Inverse probability of treatment weighting (IPTW) of propensity score was used to estimate the treatment effectiveness and Kaplan-Meier analysis were conducted to assess persistence.

Results: Of 667 JIA patients, most (92.0%) were prescribed one of the class of TNFi as their initial biologic treatment. Etanercept was the most frequently prescribed (67.1%) treatment, followed by adalimumab (27.5%). Only around 5% of patients were prescribed off-label bDMARDs as their first-course treatment; however, >20% were prescribed off-label biologics as their second-course therapy. 7.3% of patients received four or more bDMARDs. The median persistence of the first-course bDMARD is 320 days, with TNFi being significantly longer than the non-TNFi (395 vs 320 days, p= 0.010). The cJADAS reduction was significant greater of TNFi users (6.6, 95% CI 5.7-7.5) compare to non-TNFi users (3.0, 95% CI 1.5-4.6, p< 0.0001) at 6-month follow-up visit.

Conclusion: Persistence was significantly longer among patients initiating TNFi as their first biologic therapy than those receiving non-TNFi. Patients with TNF therapy had significant greater reduction of cJADAS at the 6-month follow-up visit compared with patient in non-TNF cohort.

Keywords: Anti-TNFi; Biological Therapy; Juvenile Idiopathic Arthritis; Prescribing Patterns; Treatment Outcome.