Study of Guselkumab Versus Placebo for the Treatment of Low Body Surface Area Moderate Plaque Psoriasis

Prior treatment

• Participants will not be eligible if they have ever received prior biologic (or biosimilars of) for the treatment of psoriasis, psoriatic arthritis (PsA), or any other indications that could impact the assessment of psoriasis. Prior biologics (or biosimilars of) may include, but not limited to, tumor necrosis factor (TNF)-inhibitors (for example: adalimumab, etanercept, infliximab, or certolizumab or biosimilars), interleukin (IL)-17 inhibitors (for example: secukinumab, ixekizumab, brodalumab, or bimekizumab), and IL-12/23 inhibitors (for example: ustekinumab), or IL-23 inhibitor (for example: guselkumab, risankizumab or tildrakizumab)

Other illness

• Has a history of chronic or recurrent infectious disease, including, but not limited to, chronic renal infection, chronic chest infection (for example, 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

Lab values

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

Other

• Has a nonplaque form of psoriasis (example, erythrodermic, guttate, or pustular) at screening or randomization
• For participants with palmoplantar involvement, confounding diagnoses, including, but not limited, to palmoplantar pustulosis, eczematous dermatitis, contact/irritant dermatitis, acquired keratoderma, etcetera, should be confirmed and excluded

• All participants must have a diagnosis of plaque psoriasis (with or without psoriatic arthritis) for at least 6 months before first administration of study intervention
• All participants must meet the following disease severity criteria at screening and at baseline: (a) Overall Investigator's Global Assessment (IGA) 3 (moderate) plaque psoriasis; (b) Body Surface Area (BSA) 2-15 percent (%) with at least 1 plaque outside of special sites; (c) Involvement of at least 1 special site with at least moderate severity. Qualifying sites include scalp with scalp-specific IGA greater than or equal to (\>=) 3, face with facial psoriasis IGA \>=3, intertriginous with intertriginous psoriasis IGA \>=3, or genital with static physician global assessment of genitalia (sPGA-G) \>=3
• All participants be inadequately controlled with or intolerant of at least 1 prior topical therapy (including, but not limited to, corticosteroids, retinoids, vitamin D, or vitamin D/steroid and retinoid/steroid combinations, tacrolimus, pimecrolimus, anthralin/dithranol, coal tar preparations, tapinarof, roflumilast, etcetera) for the treatment of psoriasis at both screening
• All participants be a candidate for phototherapy or systemic treatment for psoriasis