Pharmacokinetics, Efficacy and Safety of Abatacept Administered Subcutaneously (SC) in Children and Adolescents With Active Polyarticular Juvenile Idiopathic Arthritis (pJIA) and Inadequate Response (IR) to Biologic or Non Biologic Disease Modifying Anti-rheumatic Drugs (DMARDs)

Inclusion Criteria:

- JIA subjects (male or female), ages 2-17 years with active disease who had an
insufficient therapeutic response or intolerance to at least one non biologic DMARD or
Tumor Necrosis Factor (TNFα) antagonists for at least 3 months prior to screening

- Subjects with TNFα inadequate response (or prior biologic) will be restricted to 30%
of the population

- Subjects must have a history of at least 5 joints with active disease and must have
currently active articular disease with ≥2 active joints and ≥2 joints with limitation
of motion.

Exclusion Criteria:

- Subjects with other rheumatic diseases or major chronic inflammatory/immunologic
diseases, active uveitis, systemic JIA with active systemic features (within a period
of 6 months prior to enrollment), persistent Oligoarthritis JIA, or failed 3 or more
TNFα antagonists or other biological DMARDs will be excluded.

- Active systemic disease: (ie, extra-articular features of systemic JIA including
fever, rash, organomegaly) within a period of 6 months prior to randomization.

- Subjects who have failed more than two TNFα antagonists or other biologic DMARDs