Long-Term Maintenance of Clinical Responses by Individual Patients With Polyarticular-Course Juvenile Idiopathic Arthritis Treated With Abatacept.

OBJECTIVE: To investigate the frequency and trajectories of individual patients with polyarticular-course juvenile idiopathic arthritis (pJIA) achieving novel composite endpoints on abatacept.

METHODS: Data from a clinical trial of subcutaneous abatacept (NCT01844518) and a post hoc analysis of intravenous abatacept (NCT00095173) in patients with pJIA were included. Three endpoints were defined and evaluated; combined occurrence of low disease activity (LDA) measured by the Juvenile Arthritis Disease Activity Score, 50% improvement in JIA-American College of Rheumatology criteria (ACR50), and patient-reported outcomes (PRO). PROs included visual analog scale (VAS) of minimal pain (pain-min) and Childhood Health Assessment Questionnaire-disability index score of 0 (CHAQ-DI0). In this post hoc analysis, maintenance of month 13 and 21 endpoints (LDA+pain-min, LDA+CHAQ-DI0, and ACR50+pain-min) in those who achieved them at month 4 was determined.

RESULTS: Composite endpoints (LDA+pain-min, LDA+CHAQ-DI0, and ACR50+pain-min) were achieved at month 4: 44.7%, 19.6%, and 58.9% of the 219 patients treated with SC abatacept, respectively. Of those who achieved LDA+pain-min at month 4, 84.7% (83/98) and 65.3% (64/98) maintained LDA+pain-min at months 13 and 21, respectively. The proportions of patients meeting LDA+pain-min outcomes increased from 44.7% (98/219) at month 4 to 54.8% (120/219) at month 21. The frequency of patients who met LDA+CHAQ-DI0 increased from 19.6% (43/219) at month 4 to 28.8% (63/219) at month 21.

CONCLUSIONS: Among individual patients with pJIA treated with abatacept who achieved one of the combined clinical and PRO composite endpoints, many maintained them over 21 months of abatacept treatment.