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