A Study of Subcutaneously (SC) Administered Tocilizumab (TCZ) in Participants With Polyarticular-Course Juvenile Idiopathic Arthritis (pJIA)

Inclusion Criteria: * Ages 1 year (12 years for participants in Russia) up to and including 17 years at screening * Diagnosis of pJIA according to International League of Associations for Rheumatology classification * Rheumatoid factor (RF)-positive pJIA * RF-negative pJIA * Extended oligoarticular JIA with a polyarticular course * History of inadequate clinical response (in the opinion of the treating physician) to or inability to tolerate methotrexate (MTX) * Participants currently receiving TCZ by the intravenous (IV) route of administration and with well-controlled disease do not require a period of discontinuation of IV TCZ and should have their first dose of SC TCZ administered on the date that their next IV TCZ infusion would be due. Participants participating in the study may be either naive to TCZ therapy or may be switching from IV to SC. The total number of participants switching from IV TCZ must account for no more than 50 percent (%) of the total participant number. To account for the baseline TCZ concentrations in these participants, information on the last 4 IV TCZ infusions prior to baseline will be collected * Concurrent treatment with disease-modifying antirheumatic drugs (DMARDs) (including MTX), nonsteroidal anti-inflammatory drugs (NSAIDs), and oral corticosteroids are permitted at the discretion of the investigator * Females of childbearing potential and non-sterile males with female partner of childbearing potential must agree to use effective contrace…