A Long-Term Study of Zasocitinib in Children and Teenagers With Plaque Psoriasis
Trial Parameters
Brief Summary
The main aim of this study is to see how well the medicine zasocitinib works, how safe it is, and how children and teenagers aged 4 to under 18 with moderate-to-severe plaque psoriasis respond to it. The study will be done in 2 parts: Part A will include both children and teenagers, while part B will only include children. At first, only teenagers who meet the study rules can participate in this study. Children may only start to participate once enough information has been collected from other studies with zasocitinib. Participants in Part A will initially be assigned to receive either zasocitinib or placebo for the first 16 weeks of treatment, then all participants will receive zasocitinib through the end of the study. All participants in Part B will be assigned to receive treatment with zasocitinib throughout the study. Participants will be in the study for up to 4 years and 2 months (217 weeks), including up to 35 days for the screening period, 208 weeks of treatment (Part A and Part B) and a 4-week safety follow-up period. During the study, participants will visit their study site multiple times.
Eligibility Criteria
Inclusion Criteria: 1. Participant has a diagnosis of chronic plaque psoriasis for greater than or equal to (\>=) 6 months prior to the screening visit. 2. Participant has stable plaque psoriasis defined as no significant flare or change in morphology (as assessed by the investigator) in psoriasis for \>=6 months before screening. 3. Participant has moderate-to-severe plaque psoriasis as defined by a Psoriasis Area and Severity Index (PASI) score \>=12 and a Static Physician's Global Assessment (sPGA) score \>=3 at screening and Day 1. 4. Participant has plaque psoriasis covering \>=10 percent (%) of total body surface area (BSA) at screening and Day 1. 5. Participant must be a candidate for phototherapy or systemic therapy. 6. Inclusion Criteria for Part A Cohort 1: The participant is male or female and aged 12 to less than (\<) 18 years, inclusive. 7. Inclusion Criteria for Part A Cohort 2 and for Part B: The participant is male or female and aged 4 to \<12 years, inclusive. 8. Inclu