Inclusion Criteria:  - Candidates for systemic therapy with moderate chronic plaque psoriasis (PsO) (with or without psoriatic arthritis) at Screening and Baseline for at least 6 months prior to Baseline defined as:  Body Surface Area (BSA) >= 10% and <= 15%; and Psoriasis Area and Severity Index (PASI) >= 12; and Static Physician Global Assessment (sPGA) = 3 (moderate) based on a 5-point scale (0 to 4).  Exclusion Criteria:  Participant has any form of PsO other than chronic plaque PsO (e.g., pustular PsO, palmoplantar pustulosis, acrodermatitis of Hallopeau, erythrodermic, or guttate PsO). History of current drug-induced PsO or a drug-induced exacerbation of pre-existing psoriasis. History of active ongoing inflammatory skin diseases other than PsO and psoriatic arthritis that could interfere with the assessment of PsO (e.g., hyperkeratotic eczema). Prior exposure to risankizumab or apremilast.