Study to Evaluate Adverse Events and Change in Disease Activity in Participants Between 6 and 17 Years With Moderate to Severe Plaque Psoriasis Treated With Subcutaneous (SC) Injection of Risankizumab Who Have Completed Participation in Study M19-977

OptIMMize-2: A Phase 3 Multicenter, Single-arm, Open-label Extension Study to Assess the Safety, Tolerability, and Efficacy of Risankizumab in Subjects With Moderate to Severe Plaque Psoriasis Who Have Completed Participation in Study M19-977 (OptIMMize-1)

Psoriasis is a chronic, systemic, inflammatory disease in which skin cells build up and develop thick, red and white scaly patches on the skin. This study evaluates adverse events and change in disease activity with risankizumab in pediatric participants with moderate to severe plaque psoriasis who completed the study M19-977.

Risankizumab is an approved drug for treatment of moderate to severe plaque psoriasis in adults and is being studied in the pediatric population (6 to 17 years). A maximum of 132 participants will be enrolled in the study across approximately 50 sites worldwide.

Participants will receive subcutaneous injection of risankizumab every 12 weeks for 204 weeks and are followed up for safety for 20 weeks after last dose.

There may be higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the study at a hospital or clinic. The effect of the treatment will be checked by medical assessments, blood tests, checking for side effects and completing questionnaires.

Inclusion Criteria:

--Participants who have completed participation in study M19-977 and who meet all eligibility criteria for participation in Study M19-973 will be allowed to enroll in study M19-973.

Exclusion Criteria:

--Participants who have developed any discontinuation criteria as defined in Study M19-977.