An Open-label Extension Study of Canakinumab in Patients With Systemic Juvenile Idiopathic Arthritis and Active Systemic Manifestations Manifestations and Response Characterization Study in Canakinumab Treatment-naïve Patients With Active SJIA With and Without Fever.

Inclusion criteria:

- Patients from study CACZ885G2305 or CACZ885G2301 who achieved an adapted ACR pediatric
30 response 15 days after their initial dose of canakinumab but clinically
deteriorated afterwards or a minimum ACR Pediatric 30 response was not maintained
after Day 15 and intervention is deemed necessary by the investigator, or Patients in
study CACZ885G2301 who are not eligible to enter Part II (withdrawal part) because
they were not able to meet the corticosteroid entry criteria , or Responder patients
in Part I or Part II who had not flared when CACZ885G2301 was stopped, or CACZ885G2301
patients who were responders in Part I but experienced a flare in Part II.

- Treatment-naïve patients need to meet the following criteria:

- Confirmed diagnosis of systemic juvenile idiopathic arthritis as per ILAR
definition that must have occurred at least 2 months prior to enrollment with
onset of disease < 16 years of age

- Male and female patients aged ≥ 2 to < 20 years of age

- Active disease at the time of enrollment defined as having 2 or more of the
following:

- Documented spiking, intermittent fever (body temperature > 38°C) for at
least 1 day during the screening period and within 1 week before first
canakinumab dose

- At least 2 joints with active arthritis

- AND C-reactive protein (CRP) > 30 mg/L (normal range < 10 mg/L) Rash
Serositis Lymphadenopathy Hepatosplenomegaly

- Naïve to canakinumab

Other protocol-defined inclusion criteria may apply

Exclusion criteria:

- History of allergy or hypersensitivity to study drug

- With active or recurrent bacterial, fungal or viral infections at time of enrollment

Other protocol inclusion/exclusion criteria may apply