Clinical Trial Finder

Inclusion Criteria:

• - Diagnosis of juvenile psoriatic arthritis (jPsA) by Vancouver criteria with exclusion of enthesitis-related arthritis (ERA).

Diagnosis made >=3 months (that is, 90 days) prior to screening.

• - Active disease in at least greater than or equal to (>=) 3 joints at screening and at week 0 (defined as swelling or loss of motion with pain and/or tenderness.

Swelling alone meets the criteria for an active arthritic joint. In the absence of swelling, loss of motion with pain or tenderness or both pain and tenderness meet the criteria for an active arthritic joint.

• - Have active disease despite previous non-biologic disease modifying anti-rheumatic drug (DMARD) and/or non-steroidal anti-inflammatory drug (NSAID) therapy: Non-biologic DMARD therapy is defined as taking a non-biologic DMARD for at least 12 weeks or evidence of intolerance; NSAID therapy is defined as taking an NSAID for at least 4 weeks or evidence of intolerance.

• - Concurrent use of methotrexate, sulfasalazine, leflunomide, oral corticosteroids or NSAIDs is permitted but must be on stable dose.

• - Participants must be up to date with all immunizations in agreement with current local immunization guidelines for immunosuppressed patients.

• - Prior use of anti-TNFα agents, IL-17 inhibitors and other biologics (except non-responders to IL-23 inhibitors) and JAK inhibitors are permitted with sufficient washout period.

Exclusion Criteria:

• - Participants with enthesitis-related arthritis (ERA) - Have a history of latent or active granulomatous infection, including tuberculosis (TB), histoplasmosis, or coccidioidomycosis prior to screening.

• - Have a history of, or ongoing, chronic or recurrent infectious disease.

• - Has evidence of herpes zoster infection within 8 weeks prior to Week 0.

- Have a known history of hepatitis C infection or test positive at screening

Juvenile psoriatic arthritis is a complex, chronic, progressive, debilitating musculoskeletal disease with significant remaining medical need. There is a need for medications which have a similar efficacy profile and a similar safety profile relative to currently available treatment for jPsA which include anti-tumor necrosis factor alpha (TNF alpha) inhibitors and secukinumab. STELARA (ustekinumab) is a fully human immunoglobulin G (IgG) 1 kappa monoclonal antibody (mAb) which binds with high affinity to the p40 subunit common to both interleukin (IL)-12 and IL 23 preventing IL-12/23p40 binding to the IL 12 Rb1 cell surface receptor shared by both cytokines. Through this mechanism of action, ustekinumab effectively neutralizes IL-12 T helper 1- and IL-23 T helper 17-mediated cellular responses. TREMFYA (guselkumab) is a fully human IgG1 lambda (G1 lambda) mAb that binds to the p19 subunit of human IL-23 with high affinity. The binding of guselkumab to IL-23 blocks the binding of extracellular IL-23 to the cell surface IL-23 receptor, inhibiting IL-23-specific intracellular signaling and subsequent activation and cytokine production. This study consists of Screening period (up to 6 weeks), Treatment period (up to 52 weeks) and a final safety visit at Week 68. The total duration of the study is up to 68 weeks.

Arms

Experimental: Cohort 1: Ustekinumab

Participants will receive a weight-based dose of ustekinumab subcutaneously (SC) at Week 0, Week 4 and then every 12 weeks up to Week 52.

Experimental: Cohort 2: Guselkumab

The dose of guselkumab will be based on the participant's weight. Participants will receive guselkumab SC at Weeks 0 and 4 followed by either every 4 weeks (Q4W) (with historical radiographic evidence of joint damage) or every 8 weeks (Q8W) (without historical evidence of joint damage) dosing with the last dose at Week 52. Participants at high risk of joint damage can also be considered for Q4W dosing per investigator.

Interventions

Drug: - Ustekinumab

Ustekinumab will be administered as subcutaneous injection.

Drug: - Guselkumab

Guselkumab will be administered as subcutaneous injection.