A Study of Guselkumab Administered Subcutaneously in Bio-naive Participants With Active Psoriatic Arthritis Axial Disease

Eligibility Criteria

• * Have a diagnosis of psoriatic arthritis (PsA) for at least 6 months prior to the first administration of study intervention and meet classification criteria for psoriatic arthritis (CASPAR) criteria at screening
• * Have active PsA as defined by: a) at least 3 swollen joints and at least 3 tender joints at screening and at baseline and b) C-reactive protein (CRP) greater than or equal to (\>=) 0.3 milligram/deciliter (mg/dL) at screening from the central laboratory, and despite previous non-biologic disease modifying antirheumatic drug (DMARD), apremilast, and/or nonsteroidal anti-inflammatory drug (NSAID) therapy
• * Have magnetic resonance imaging (MRI)-confirmed PsA axial disease (positive MRI spine and/or sacroiliac \[SI\] joints, shown by a Spondyloarthritis Research Consortium of Canada \[SPARCC\] score of \>= 3 in either the spine or the sacroiliac joints)
• * Have a Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score of at least 4, and have a spinal pain score (on a visual analog scale \[VAS\]) of at least 4
• * Have active plaque psoriasis, with at least 1 psoriatic plaque of \>= 2 centimeter (cm) diameter and/or nail changes consistent with psoriasis, or documented history of plaque psoriasis
• * Has known allergies, hypersensitivity, or intolerance to guselkumab or its excipients
• * Has other inflammatory diseases that might confound the evaluations of benefit of guselkumab therapy, including but not limited to rheumatoid arthritis (RA), ankylosing spondylitis (AS)/non-radiographic-axial spondyloarthritis (this does not include a primary diagnosis of PsA with spondylitis), systemic lupus erythematosus, or Lyme disease
• * Has previously received any biologic treatment
• * Has ever received a Janus kinase (JAK) inhibitor including but not limited to tofacitinib, baricitinib, filgotinib, peficitinib, decernotinib, upadacitinib or any other investigational JAK inhibitor
• * Has received any systemic immunosuppressants (example, azathioprine, cyclosporine, 6 thioguanine, mercaptopurine, mycophenolate mofetil, hydroxyurea, tacrolimus) within 4 weeks of the first administration of study intervention