['psoriasis']
['risankizumab', 'placebo for risankizumab']

        Inclusion Criteria:

          -  Have a diagnosis of chronic plaque psoriasis (with or without psoriatic arthritis) for
             at least 6 months before the first administration of study drug. Duration of diagnosis
             may be reported by the patient.

          -  Have stable moderate to severe chronic plaque psoriasis with or without psoriatic
             arthritis at both Screening and Baseline (Randomisation):

               1. Have an involved body surface area (BSA) ≥10% and

               2. Have a Psoriasis Area and Severity Index (PASI) score ≥12 and

               3. Have a Static Physician Global Assessment (sPGA) score of ≥3.

        Exclusion Criteria:

          -  Patients with

               1. non-plaque forms of psoriasis (including guttate, erythrodermic, or pustular)

               2. current drug-induced psoriasis (including an exacerbation of psoriasis from beta
                  blockers, calcium channel blockers, or lithium)

               3. active ongoing inflammatory diseases other than psoriasis and psoriatic arthritis
                  that might confound trial evaluations according to investigator's judgment

          -  Previous exposure to BI 655066
      