A Study of Ustekinumab or Guselkumab in Pediatric Participants With Active Juvenile Psoriatic Arthritis

Inclusion Criteria:

• Diagnosis of juvenile psoriatic arthritis (jPsA) by Vancouver criteria withexclusion 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 andat 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 ofswelling, loss of motion with pain or tenderness or both pain and tenderness meetthe criteria for an active arthritic joint

• Have active disease despite previous non-biologic disease modifying anti-rheumaticdrug (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 12weeks or evidence of intolerance; NSAID therapy is defined as taking an NSAID for atleast 4 weeks or evidence of intolerance

• Concurrent use of methotrexate, sulfasalazine, leflunomide, oral corticosteroids orNSAIDs is permitted but must be on stable dose

• Participants must be up to date with all immunizations in agreement with currentlocal immunization guidelines for immunosuppressed patients

• Prior use of anti-TNFα agents, IL-17 inhibitors and other biologics (exceptnon-responders to IL-23 inhibitors) and JAK inhibitors are permitted with sufficientwashout 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