- Must have a diagnosis of psoriasis vulgaris (PASI >8) present for at least 1 year. Participants with an on-therapy PASI <=8 at Screening may be considered for inclusion. Participants must be discussed with the Sponsor prior to enrollment and the subject must have indicated that they are not satisfied with current therapy. To be included, participants must have a PASI >8 following washout of their current psoriasis therapy.