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 (JIA) achieving novel composite end points on abatacept. METHODS: Data from a clinical trial of subcutaneous abatacept (NCT01844518) and a post hoc analysis of intravenous abatacept (NCT00095173) in patients with polyarticular-course JIA were included. Three end points were defined and evaluated: combined occurrence of low disease activity (LDA) measured by the Juvenile Arthritis Disease Activity Score; 50% improvement in American College of Rheumatology criteria for JIA (ACR50); and patient-reported outcomes. Patient-reported outcomes included visual analog scale score of minimal pain (pain-min) and Childhood Health Assessment Questionnaire disability index score of 0 (C-HAQ DI0). In this post hoc analysis, maintenance of month 13 and 21 end points (LDA+pain-min, LDA+C-HAQ DI0, and ACR50+pain-min) in those who achieved them at month 4 was determined. RESULTS: Composite end points (LDA+pain-min, LDA+C-HAQ DI0, and ACR50+pain-min) were achieved at month 4 (44.7%, 19.6%, and 58.9% of the 219 patients treated with subcutaneous abatacept, respectively). Of those who achieved LDA+pain-min at month 4, 84.7% (83 of 98) and 65.3% (64 of 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 of 219) at month 4 to 54.8% (120 of 219) at month 21. The frequency of patients who met an LDA+C-HAQ DI score of 0 increased from 19.6% (43 of 219) at month 4 to 28.8% (63 of 219) at month 21. CONCLUSION: Among individual patients with polyarticular-course JIA treated with abatacept who achieved 1 of the combined clinical and patient-reported outcomes composite end points, many maintained them over 21 months of abatacept treatment.

Subcutaneous Abatacept in Patients With Polyarticular-Course Juvenile Idiopathic Arthritis: Results From a Phase III Open-Label Study.

OBJECTIVE: To investigate the pharmacokinetics, effectiveness, and safety of subcutaneous (SC) abatacept treatment over 24 months in patients with polyarticular-course juvenile idiopathic arthritis (JIA). METHODS: In this phase III, open-label, international, multicenter, single-arm study, patients with polyarticular JIA (cohort 1, ages 6-17 years and cohort 2, ages 2-5 years) in whom treatment with ≥1 disease-modifying antirheumatic drug was unsuccessful received weight-tiered SC abatacept weekly: 10 to <25 kg (50 mg), 25 to <50 kg (87.5 mg), ≥50 kg (125 mg). Patients who had met the JIA-American College of Rheumatology 30% improvement criteria (achieved a JIA-ACR 30 response) at month 4 were given the option to continue SC abatacept to month 24. The primary end point was the abatacept steady-state serum trough concentration (Cminss ) in cohort 1 at month 4. Other outcome measures included JIA-ACR 30, 50, 70, 90, 100, and inactive disease status, the median Juvenile Arthritis Disease Activity Score in 71 joints using the C-reactive protein level (JADAS-71-CRP) over time, safety, and immunogenicity. RESULTS: The median abatacept Cminss at month 4 (primary end point) and at month 24 was above the target therapeutic exposure (10 µg/ml) in both cohorts. The percentage of patients who had achieved JIA-ACR 30, 50, 70, 90, or 100 responses or had inactive disease responses at month 4 (intent-to-treat population) was 83.2%, 72.8%, 52.6%, 28.3%, 14.5%, and 30.1%, respectively, in cohort 1 (n = 173) and 89.1%, 84.8%, 73.9%, 58.7%, 41.3%, and 50.0%, respectively, in cohort 2 (n = 46); the responses were maintained to month 24. The median (interquartile range) JADAS-71-CRP improved from baseline to month 4: cohort 1, from 21.0 (13.5, 30.3) to 4.6 (2.1, 9.4); cohort 2, from 18.1 (14.0, 23.1) to 2.1 (0.3, 4.4). Improvements were sustained to month 24, at which time 27 of 173 patients (cohort 1) and 11 of 22 patients (cohort 2) had achieved JADAS-71-CRP remission. No unexpected adverse events were reported; 4 of 172 patients (2.3%) in cohort 1 and 4 of 46 (8.7%) in cohort 2 developed anti-abatacept antibodies, with no clinical effects. CONCLUSION: Weight-stratified SC abatacept yielded target therapeutic exposures across age and weight groups, was well tolerated, and improved polyarticular JIA symptoms over 24 months.