An Open-label, Ascending, Repeated Dose-finding Study of Sarilumab in Children and Adolescents With Polyarticular-course Juvenile Idiopathic Arthritis (pcJIA)

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 ≥2 and ≤17 years (or country specified age requirement)
at the time of the screening visit.

- Diagnosis of rheumatoid factor-negative or rheumatoid factor positive polyarticular
Juvenile Idiopathic Arthritis (JIA) subtype or oligoarticular extended JIA subtype
according to the International League of Associations for Rheumatology (ILAR) 2001
Juvenile Idiopathic Arthritis Classification Criteria with at least 5 active joints as
per American College of Rheumatology (ACR) definition for "active arthritis" at
Screening

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

Exclusion criteria:

- Body weight <10 kg or >60 kg for patients enrolled in the 3 ascending dose cohorts,
then body weight <10 kg for patients subsequently enrolled at the selected
dose-regimen.

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

- If non-biologic DMARD taken, dose stable for <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 0.5 mg/kg/day
(or 30 mg/day) within 2 weeks 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 pcJIA within 5 half-lives prior to the first
dose of sarilumab.

- 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.

- Lipid lowering drug stable for less than 6 weeks prior to screening.

- Exclusion related to tuberculosis (TB).

- 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).

- 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.