A Study to Evaluate the Efficacy, Safety, and Pharmacokinetics of Subcutaneously Administered Guselkumab for the Treatment of Chronic Plaque Psoriasis in Pediatric Participants

Inclusion Criteria:

- Have a diagnosis of chronic plaque-type psoriasis for at least 6 months (with or
without psoriatic arthritis [PsA]), prior to first administration of study
intervention, defined as having at screening and baseline, Investigator Global
Assessment (IGA) greater than or equal to (>=) 3, Psoriasis Area and Severity Index
(PASI) >=12, >=10% body surface area (BSA) involvement and at least one of the
following: very thick lesions, clinically relevant facial, genital, or hand/ foot
involvement, PASI>=20, >20% BSA involvement, or IGA=4

- Be a candidate for phototherapy or systemic treatment of plaque psoriasis (either
naive or history of previous treatment)

- Have plaque psoriasis considered by the investigator as inadequately controlled with
phototherapy and/or topical therapy after an adequate dose and duration of therapy

- Be considered, in the opinion of the investigator, a suitable candidate for etanercept
therapy, according to their country's approved Enbrel product labeling

- Be otherwise healthy on the basis of physical examination, medical history, and vital
signs performed at screening. Any abnormalities, must be consistent with the
underlying illness in the study population and this determination must be recorded in
the participant's source documents and initialed by the investigator

- Must have acceptable evidence of immunity to varicella and measles, mumps, and rubella
(MMR), which includes any one of the following: documentation of age-appropriate
vaccination that includes both doses of each vaccine (unless local guidelines specify
otherwise) or documentation of past infection by a healthcare provider or in the
absence of previous 2 criteria, participants must have positive protective antibody
titers to these infection prior to the first administration of study intervention. For
participants who have not completed the recommended vaccination schedule for varicella
and MMR, and the subsequent vaccination falls within the next 4 years, an accelerated
vaccination schedule must be completed prior to study enrollment if available and
required or strongly recommended for the location. If varicella or MMR vaccines are
utilized, it is necessary for 2 weeks to elapse between the vaccination and receipt of
study intervention

Exclusion Criteria:

- Currently has nonplaque forms of psoriasis (example [eg], erythrodermic, guttate, or
pustular)

- Has current drug-induced psoriasis (eg, a new onset of psoriasis or an exacerbation of
psoriasis from beta blockers, calcium channel blockers, or lithium)

- Has previously received guselkumab or etanercept

- Has a history of chronic or recurrent infectious disease, including but not limited to
chronic renal infection, chronic chest infection (eg, bronchiectasis), recurrent
urinary tract infection (recurrent pyelonephritis or chronic non-remitting cystitis),
fungal infection (mucocutaneous candidiasis), or open, draining, or infected skin
wounds or ulcers

- Has a known history of lymphoproliferative disease, including lymphoma; a history of
monoclonal gammopathy of undetermined significance (MGUS); or signs and symptoms
suggestive of possible lymphoproliferative disease, such as lymphadenopathy or
splenomegaly