• Participants parent's or legal representative(s) written informed consent and child's assent, if appropriate, must be obtained before any study related activity or assessment is performed. Of note, if the participant reaches age of consent (as per local law) during the study, they will also need to sign the corresponding study ICF (Informed Consent Form).

• Males and females ≥2 years old to \<18 years old at the time of screening.

• Confirmed diagnosis of JPsA according to the modified International League of Associations for Rheumatology (ILAR) classification criteria that must have occurred at least 6 months prior to screening.

• Active JPsA disease defined as ≥3 active joints (swollen or if not swollen must be both tender and limited range of motion) at baseline (BSL).

• Inadequate response (≥1 month) or intolerance to ≥1 Non-Steroidal Anti-Inflammatory Drug (NSAID) at screening.

• Inadequate response (≥2 months) or intolerance to ≥ 1 Disease Modifying Anti-Rheumatic Drug (DMARD) at screening.

• Concomitant use of the following second-line agents such as disease-modifying and/or immunosuppressive drugs to treat the JPsA will be allowed:

‣ Stable dose of methotrexate (MTX) (maximum of 20 mg/ m2 BSA/ week) for at least 4 weeks prior to the BSL visit, with folic/folinic acid supplementation (according to standard medical practice of the center).

⁃ Stable dose of an oral corticosteroid (CS) at a prednisone equivalent dose of \<0.2 mg/kg/day or up to 10 mg/day maximum, whichever is less, for at least 7 days prior to BSL.

⁃ Stable dose of no more than one NSAID for at least 1 week prior to BSL.