A Study to Evaluate the Drug Levels, Efficacy and Safety of Deucravacitinib in Pediatric Participants With Moderate to Severe Plaque Psoriasis

The purpose of this pediatric study is to evaluate the drug levels, efficacy and safety of Deucravacitinib in pediatric participants aged 4 to \<18 years with moderate to severe plaque psoriasis. This study includes two cohorts; Cohort 1 (age 12 to \<18 years) and Cohort 2 (age 4 to \<12 years), with two parts; for each cohort. Part A will evaluate the drug levels of BMS-986165 to enable selection of 2 dose levels to be studied in Part B. Part B will assess the efficacy and safety of two dose levels in pediatric participants with moderate to severe plaque psoriasis. The 5-year long-term extension (LTE) period will observe the long-term safety and tolerability of deucravacitinib in pediatric participants with psoriasis who have completed Parts A or B of the study.

Inclusion Criteria * Males and females aged 12 to \<18 years for Cohort 1. Males and females aged 4 to \<12 years for Cohort 2. * Plaque psoriasis for at least 6 months. * Moderate to severe disease. * Candidate for phototherapy or systemic therapy. * Must have completed the Week 52 treatment period in Part A or B for long-term extension (LTE) period. Exclusion Criteria * Participants weighing ≤ 30.0 kg at screening for Cohort 1 (age 12 to \< 18 years), Part A and Part B. Participants weighing ≤ 18.0 kg at screening for Cohort 2 (age 4 to \< 12 years), Part A and Part B. * Other forms of psoriasis. * History of recent infection. * Prior exposure to deucravacitinib (BMS-986165) or active comparator. * Evidence of active TB for LTE period. * Other protocol-defined inclusion/exclusion criteria apply.