Predictors of Clinical Remission in Children With Polyarticular Juvenile Idiopathic Arthritis Treated With Abatacept

OBJECTIVE: To determine whether demographics, clinical measures, and disease activity predict inactive disease (ID) or clinical remission (CR) in patients with polyarticular course-juvenile idiopathic arthritis (pc-JIA) treated with abatacept. METHODS: Data were extracted from 2 phase III clinical trials in pc-JIA treated with intravenous (age 6-17 years; NCT00095173) and subcutaneous (age 2-17 years; NCT01844518) abatacept. Efficacy endpoints were Juvenile Arthritis Disease Activity Score 10 (JADAS) ID (score ≤2.7) and JADAS CR, (6 consecutive months of JADAS ID based on C-reactive protein [CRP] levels). Time-to-event analyses were performed. Kaplan-Meier analyses estimated time to achieve CR and ID. RESULTS: A total of 347/409 (84.8%) patients were included: 128/190 (67.4%) from the intravenous abatacept trial (excluded: 62 patients who switched to placebo) and 219/219 (100%) from the subcutaneous abatacept trial. In the multivariable model, baseline predictors of JADAS CR (hazard ratio [HR]) included younger age (≤10 years; 1.8), lower CHAQ-DI (≤0.75; 1.8), lower parent global assessment values (≤43.16; 2.1), and normal high-sensitivity CRP (<0.21; 1.6). Patients with minimal disease activity at days 57 or 85 were more likely to achieve both JADAS ID (HR [reference: minimal disease activity] 0.2-0.4 or 0.2-0.5, respectively) and CR (HR [reference: minimal disease activity] 0.1-0.5 or 0-0.3, respectively) earlier than patients with moderate or high disease activity during a 24-month period. CONCLUSION: Patients who achieve minimal disease activity within 3 months of abatacept treatment are more likely to achieve JADAS ID or CR earlier and maintain it for 24 months, regardless of administration route.