The purpose of this study is to evaluate the efficacy and safety of guselkumab (CNTO 1959) in the treatment of participants with moderate to severe plaque-type psoriasis (scaly skin rash) who had inadequate response to ustekinumab.

This is a randomized (assignment of study drug by chance), double-blind (participants nor study staff will know the identity of study drugs), multicenter study to evaluate efficacy and safety of guselkumab for the treatment of participants with moderate to severe plaque-type psoriasis who had an inadequate response to ustekinumab. The study will consist of a screening period, open-label and double-blind treatment periods, and a follow-up period. The treatment period will have 2 phases: an open-label treatment phase during which all participants will receive ustekinumab at Weeks 0 and 4 and a blinded treatment phase during which participants with an inadequate Investigator's Global Assessment response (IGA≥2) to ustekinumab at Week 16 will be randomized to receive either guselkumab or ustekinumab through Week 44. Participants with an IGA response of 0 or 1 (cleared or minimal disease) at Week 16 will continue to receive open-label treatment with ustekinumab every 12 weeks through Week 40. All participants will complete a follow-up phase through Week 52 for efficacy and through Week 60 for safety evaluations. The total duration of the study will be approximately 64 weeks (includes a 4-week screening period). Participants' safety will be monitored throughout the study.

Inclusion Criteria:

• Have a diagnosis of plaque-type psoriasis (with or without psoriatic arthritis for at least 6 months before the first administration of study drug
• 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) >=3 at Screening and at Baseline
• Have an involved body surface area (BSA) >= 10 percent (%) at Screening and at Baseline
• Be a candidate for phototherapy or systemic treatment for psoriasis (either naïve or history of previous treatment)

Exclusion Criteria:

• Has a 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 unstable cardiovascular disease, defined as a recent clinical deterioration (example [eg], unstable angina, rapid atrial fibrillation) in the last 3 months or a cardiac hospitalization within the last 3 months
• Currently has a malignancy or has a history of malignancy within 5 years before Screening (with the exception of a nonmelanoma skin cancer that has been adequately treated with no evidence of recurrence for at least 3 months before the first study drug administration, or cervical carcinoma in situ that has been treated with no evidence of recurrence for at least 3 months before the first study drug administration)
• Has previously received guselkumab or ustekinumab