This is a phase 3, randomized (study drug assigned by chance), double-blind (neither physician nor participant knows the name of the assigned drug), multicenter (when more than one hospital works on a medical research study) placebo-controlled (an inactive substance that is compared with a medication to test whether the medication has a real effect in a clinical study) study in participants with palmoplantar pustulosis. The study will consist of 3 phases: screening phase (up to 6 weeks), treatment period (week 0 - week 60) and observational period (up to week 84). Participants will be assigned to 1 of 3 treatment groups (200 milligram [mg] guselkumab, 100 mg guselkumab or placebo group) using a stratified block randomization method in a 1:1:1 ratio at Week 0 and Group III (placebo) participants will be allocated in a 1:1 ratio to 1 of 2 treatment groups at Week 16. Participants will primarily be assessed for change from baseline in Palmo-Plantar Pustular Area and Severity Index (PPPASI) total score at Week 16. Safety will be monitored throughout the study.
The purpose of this study is to evaluate the efficacy and safety of guselkumab for the treatment of participants with palmoplantar pustulosis.