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.
