A Safety Study of 188-0551 Spray Versus Reference Listed Drug (RLD) in Adult Subjects With Plaque Psoriasis

Inclusion Criteria: * Subject is a male or non-pregnant female and is at least 18 years of age at the time of informed consent. * Subject has provided written informed consent. * Subject has moderate or severe psoriasis involving a minimum of 20% Body Surface Area (BSA). * Subject has an Investigator's Global Assessment (IGA) score of at least three (3 = moderate) at the Baseline Visit. Exclusion Criteria: * Subject is pregnant, lactating, or is planning to become pregnant during the study. * Subject has spontaneously improving or rapidly deteriorating plaque psoriasis. * Subject has a physical condition which, in the investigator's opinion, might impair evaluation of plaque psoriasis, adrenal axis function or which exposes the subject to an unacceptable risk by study participation. * Subject has had prolonged exposure to natural or artificial sources of ultraviolet radiation. * Subject is currently enrolled in an investigational drug or device study. * Subject has clinically significant abnormal labs at Visit 1/Screening that precludes topical steroid use, in the opinion of the investigator.