Preventing Extension of Oligoarticular Juvenile Idiopathic Arthritis JIA (Limit-JIA)

This is a research study to test whether a once-weekly injection of abatacept will prevent the progression of Juvenile Idiopathic Arthritis (JIA) to a more severe form. To evaluate the effectiveness of a 24-week course of treatment with abatacept plus usual care versus usual care to prevent polyarthritis (≥5 joints), uveitis, or treatment with other systemic medication within 18 months of randomization in children with recent-onset limited JIA.

Part I enrolled participants into a randomized open-label multicenter trial with a planned sample size of 306 JIA participants recruited from CARRA Registry sites. Participants were randomly allocated (1:1) to receive 24 weeks of abatacept plus usual care or usual care alone. Upon completion of 24 weeks of randomized treatment, each participant was to receive usual care and undergo follow-up for assessment of outcomes for an additional 12 months. Planned duration of the study for each participant was 18 months. Due to slow accrual and apparent loss of equipoise, enrollment into Part I was discontinued. Part I participants continued follow-up as planned. Part II is a non-randomized continuation of LIMIT-JIA with planned enrollment of 89 to reach 80 evaluable participants receiving to the abatacept arm. Participants will now receive 24 doses of abatacept plus usual care. Upon completion of 24 doses of treatment, each participant will receive usual care and undergo follow-up for assessment of outcomes for an additional 6 months. Planned duration of the study for each participant is 12 months. Part II will assess the efficacy of abatacept in prevention of disease extension by comparison of outcomes between participants enrolled in the abatacept arm and CARRA Registry patients who would have met major eligibility criteria for LIMIT-JIA.