A Repeated Dose-finding Study of Sarilumab in Children and Adolescents With Systemic Juvenile Idiopathic Arthritis (sJIA)

The total study duration per patient will be 166 weeks that will consist of a 4- week
screening, a 12-week core treatment phase, a 144-week extension phase, and a 6-week
post-treatment follow-up.

Inclusion criteria :

- Male and female patients aged ≥1 and ≤17 years (or country specified age requirement,
12-17 years for Russia) at the time of the screening visit.

- Diagnosis of systemic JIA subtype according to the International Associations against
Rheumatism (ILAR) 2001 Juvenile Idiopathic Arthritis (JIA) Classification Criteria
with the following features:

- 5 active joints at screening or

- 2 active joints at screening with systemic JIA fever >37.5 0C in the 3 days
preceding baseline or for at least 3 out of any 7 consecutive days during
screening despite glucocorticoids at a dose stable for at least 3 days.

- Patient with an inadequate response to current treatment and considered as a candidate
for a biologic disease modifying anti rheumatic drug (DMARD) as per investigator's
judgment.

Exclusion criteria:

- Body weight <10 kg or >60 kg for patients enrolled in the ascending dose cohorts, then
body weight <10 kg for patients subsequently enrolled at the selected dose.

- Uncontrolled severe systemic symptoms and/or Macrophage Activation Syndrome (MAS)
within 6 months prior to screening.

- History of or ongoing interstitial lung disease, pulmonary hypertension, pulmonary
alveolar proteinosis.

- If nonsteroidal anti-inflammatory drugs (NSAIDs) (including cyclo oxygenase-2
inhibitors [COX-2]) taken, dose stable for less than 2 weeks prior to the baseline
visit and/or dosing prescribed outside of approved label.

- If non-biologic DMARD taken, dose stable for less than 6 weeks prior to the baseline
visit or at a dose exceeding the recommended dose as per local labeling.

- If oral glucocorticoid taken, dose exceeding equivalent prednisone dose 1 mg/kg/day
(or 60 mg/day) within 3 days prior to baseline.

- Use of parenteral or intra-articular glucocorticoid injection within 4 weeks prior to
baseline.

- Prior treatment with anti-interleukin 6 (IL-6) or IL-6 receptor (IL-6R) antagonist
therapies, including but not limited to tocilizumab or sarilumab.

- Treatment with any biologic treatment for sJIA within 5 half-lives prior to the first
dose of sarilumab (the required off treatment periods and procedures may vary
according to local requirements).

- Treatment with a Janus kinase inhibitor within 4 weeks prior to the first dose of
sarilumab; and treatment with growth hormone within 4 weeks prior to the first dose of
sarilumab (the required off treatment periods and procedures may vary according to
local requirements).

- Treatment with any investigational biologic or non-biologic product within 8 weeks or
5 half-lives prior to baseline, whichever is longer.

- Exclusion related to tuberculosis.

- Exclusion criteria related to past or current infection other than tuberculosis.

- Any live, attenuated vaccine within 4 weeks prior to the baseline visit, such as
varicella-zoster, oral polio, rubella vaccines. Killed or inactive vaccine may be
permitted based on the Investigator's judgment.

- Exclusion related to history of a systemic hypersensitivity reaction to any biologic
drug and known hypersensitivity to any constituent of the product.

- Laboratory abnormalities at the screening visit (identified by the central
laboratory).

- Severe cardiac disease due to sJIA.

- Pregnant or breast-feeding female adolescent patients.

The above information is not intended to contain all considerations relevant to a patient's
potential participation in a clinical trial.