Safety, Efficacy, and Tolerability of SNA-120 in Subjects With Pruritus Associated With Psoriasis Vulgaris

Inclusion Criteria: * Informed consent/assent and Health Insurance Portability and Accountability Act (HIPAA) authorization * Stable PV for at least 6 months prior to screening * Chronic pruritus of the PV plaques to be present for at least 6 weeks prior to screening * Mild to moderate PV at screening and baseline * Has a target plaque at baseline on the trunk and/or limbs * Subject's plaques are amenable to treatment with a topical ointment medication * Willing and able to comply with the study instructions and attend all scheduled study visits. * Willing to avoid prolonged exposure of the designated treatment plaques to ultraviolet radiation * Females of childbearing potential must have a negative pregnancy test at baseline before randomization and must agree to use highly effective contraception during the study * Men who are sexually active and can father children must agree to use highly effective forms of contraception during the study Exclusion Criteria: * Underlying conditions other than psoriasis that, in the opinion of the investigator, currently cause or influence pruritus of the overall skin * Positive hepatitis serology * Thyroid abnormalities that may impact itching * Subjects with spontaneously improving or rapidly deteriorating PV and/or pruritus * Current diagnosis of guttate, erythrodermic, exfoliative, or pustular psoriasis * Active psoriasis or itch affecting the palmar/plantar regions * Subjects with a clinical diagnosis of bacterial infection of the skin * Any major medical illness or symptoms of a clinically significant illness that may influence the study outcome * Any acute chronic medical or psychiatric condition or laboratory abnormality that would make them unsuitable for participation in this study * Known hypersensitivity to the study treatment excipients and /or polyethylene glycol, that contraindicates participation * Currently enrolled in an investigational drug or device study or has used an investigational drug or an investigational device treatment within 30 days of randomization/baseline (Note: Subjects who are enrolled in a long-term follow-up study and are not actively receiving an investigational drug or investigational device treatment may be eligible for participation in this study) * Female who is pregnant or lactating, or is planning to become pregnant during the study * Subjects participating in any previous SNA-120 (and/or CT327) clinical studies