A Study of Guselkumab in the Treatment of Participants With Moderate to Severe Plaque-Type Psoriasis

Inclusion Criteria:

Have a diagnosis of plaque-type psoriasis (with or without psoriatic arthritis) at least 6 months before the first administration of study agent
Have a Psoriasis Area and Severity Index (PASI) greater than or equal to (>=) 12 at Screening and at Baseline
Have an Investigator's Global Assessment (IGA) score >=3 at Screening and at Baseline
Have an involved body surface area (BSA) >=10 percent (%) at Screening and at Baseline
Must be a candidate for either systemic therapy or phototherapy for psoriasis

Exclusion Criteria:

Participants with nonplaque forms of psoriasis (for example, erythrodermic, guttate, or pustular) or with current drug-induced psoriasis (for example, a new onset of psoriasis or an exacerbation of psoriasis from beta blockers, calcium channel blockers, or lithium)
Participants who have ever received guselkumab or adalimumab
History or current signs or symptoms of severe, progressive, or uncontrolled renal, hepatic, cardiac, vascular, pulmonary, gastrointestinal, endocrine, neurologic, hematologic, rheumatologic, psychiatric, or metabolic disturbances
Has any condition that, in the opinion of the investigator, would make participation not be in the best interest (for example, compromise the well-being) of the participant or that could prevent, limit, or confound the protocol-specified assessments
Is pregnant, nursing, or planning a pregnancy (both men and women) within 5 months following the last administration of study drug