A Study to Evaluate the Efficacy and Safety of JNJ-77242113 (Icotrokinra) in Biologic-naïve Participants With Active Psoriatic Arthritis

Inclusion Criteria:

• Have a diagnosis of psoriatic arthritis (PsA) for at least 3 months before the firstadministration of study intervention and meet classification criteria for psoriaticarthritis (CASPAR) at screening

• Have active PsA as defined by: (a) At least 3 swollen joints and at least 3 tenderjoints at screening and at baseline (b) C-reactive protein (CRP) greater than orequal to (>=) 0.1 milligrams per deciliter (mg/dL) at screening from the centrallaboratory

• Have at least 1 of the PsA subsets: distal interphalangeal joint involvement,polyarticular arthritis with absence of rheumatoid nodules, arthritis mutilans,asymmetric peripheral arthritis, or spondylitis with peripheral arthritis

• Have active plaque psoriasis with at least one psoriatic plaque of >= 2 cm diameteror nail changes consistent with psoriasis

• A female participant of childbearing potential must have a negative highly sensitiveserum pregnancy test (Beta-hCG) at screening and a negative urine pregnancy test atWeek 0 prior to administration of study intervention

Exclusion Criteria:

• Has previously received any biologic disease-modifying antirheumatic drugs (DMARDs)for PsA or psoriasis

• Has a history or current signs or symptoms of severe, progressive, or uncontrolledrenal, hepatic, cardiac, vascular, pulmonary, gastrointestinal, endocrine,neurologic, hematologic, rheumatologic (with the exception of PsA), psychiatric,genitourinary, or metabolic disturbances

• Has known allergies, hypersensitivity, or intolerance to icotrokinra or itsexcipients

• Has other inflammatory diseases that might confound the evaluations of benefit oficotrokinra therapy, including but not limited to rheumatoid arthritis (RA),systemic lupus erythematosus, or lyme disease

• Participants with fibromyalgia or osteoarthritis symptoms that, in theinvestigator's opinion, would have potential to interfere with efficacy assessments