The objectives of this study are to assess the pharmacokinetics, pharmacodynamics, safety, and tolerability of SB414 in subjects with mild to moderate plaque psoriasis.

This is a phase 1b, multi-center, double-blind, randomized, vehicle-controlled study to be conducted in approximately 36 adult subjects with mild to moderate chronic plaque psoriasis. After obtaining informed consent, subjects will be randomized to active or vehicle treatment arms. Subjects will apply the study product (SB414 6% or Vehicle cream) twice daily to all affected areas of psoriasis on the trunk and/or extremities for 4 weeks.

Inclusion Criteria:

• Be male or female, 18-70 years old, and in good general health;
• Have a clinical diagnosis of stable chronic plaque psoriasis of mild to moderate severity based on the PSGA, involving 2-15% BSA (excluding the scalp/face), present for > 6 months;
• Must have at least 2 target plaques on trunk and/or extremities at least 5 cm2 with a TPSS > 5 and thickness sub-score > 2. Target plaques cannot be located on the groin, hands, feet, neck, face, elbows, knees, ankles or scalp;
• Be willing to not use any other systemic agents used to treat psoriasis or apply any other topical products (medicated or over-the-counter) to the treatment sites on the trunk and/or extremities during the study;
• Women of childbearing potential (WOCBP) must have a negative UPT prior to randomization and must agree to use an effective method of birth control during the study and for 30 days after their final study visit.

Exclusion Criteria:

• Have inverse (i.e.: axillae, groin) or facial psoriasis only, erythrodermic psoriasis, guttate psoriasis, pustular psoriasis, drug-induced psoriasis, and /or psoriatic arthritis requiring treatment with disease modifying antirheumatic drugs (DMARDs);
• Concurrent or recent use of topical or systemic medications without a sufficient washout period;
• Are immunocompromised, including those who are known HIV positive or received immunosuppressive treatment within the past 6 months;
• Female subjects who are pregnant, nursing mothers, or planning to become pregnant during the study.