This long-term, interventional, open-label extension study will evaluate the safety and efficacy of RoActemra/Actemra (tocilizumab) in patients from Poland and Russia with polyarticular-course juvenile idiopathic arthritis who completed the WA19977 study. Patients will receive RoActemra/Actemra 8 mg/kg every 4 weeks. The anticipated time on study treatment is 104 weeks.