A Study to Evaluate the Efficacy and Safety of Bimekizumab Compared to Ustekinumab in Children and Adolescents From 6 Years to Less Than 18 Years of Age With Moderate to Severe Plaque Psoriasis

Inclusion Criteria:

Study participant must be 6 to <18 years of age, inclusive, at the time of signing the informed consent/assent according to local regulation
Study participant has had a diagnosis of moderate to severe plaque psoriasis (PSO) for at least 3 months prior to the Screening Visit

Study participant meets the following at both the Screening and Baseline Visits:

Body surface area (BSA) affected by PSO ≥10%
. Investigator's Global Assessment (IGA) score ≥3 (on a scale from 0 to 4)
. Psoriasis Area and Severity Index (PASI) score ≥12 OR

PASI score ≥10 plus at least 1 of the following:

i) Clinically relevant facial involvement ii) Clinically relevant genital involvement iii) Clinically relevant hand and foot involvement

Study participant is a candidate for systemic PSO therapy and/or photo/chemotherapy and for treatment with ustekinumab per labeling
Study participant has body weight ≥15 kg and body mass index for age percentile of ≥5 at Screening

Exclusion Criteria:

Primary failure (no response within 12 weeks) to 1 or more interleukin-17 (IL-17) biologic response modifiers (eg, brodalumab, ixekizumab, secukinumab) OR more than 1 biologic response modifier other than an IL-17
Study participant has a presence of guttate, inverse, pustular, or erythrodermic PSO or other dermatological condition that may impact the clinical assessment of PSO
Study participant has a history of inflammatory bowel disease (IBD) or symptoms suggestive of IBD
History of active tuberculosis unless successfully treated, latent TB unless prophylactically treated
Study participant has an active infection or history of infections (such as serious infection, chronic infections, opportunistic infections, unusually severe infections)
Study participant has previously received bimekizumab
Study participant has previously received ustekinumab
Study participant has received drugs outside the specified timeframes relative to the Baseline Visit or receives prohibited concomitant treatments
Study participant has the presence of active suicidal ideation, or positive suicide behavior
Study participant diagnosed with severe depression in the past 6 months (prior to Screening) should be excluded
Study participant has a history of psychiatric inpatient hospitalization within the past year before enrolling into the study