A Study to Assess the Efficacy and Safety of PPC-06 (Tepilamide Fumarate)

Inclusion Criteria: * Generally healthy males or non-pregnant females age ≥18 years at the time of screening (or who have reached the state minimum legal age of consent). * Stable, moderate-to-severe plaque psoriasis diagnosed for at least 6 months prior to randomization (no morphology changes or significant flares of disease activity in the last 6 months in the opinion of the investigator or as reported by the subject). * Severity of disease meeting all 3 of the following criteria prior to randomization (at the Baseline \[Day 0\] visit): 1. PASI score of ≥12 2. Total body surface area (BSA) affected by plaque psoriasis of ≥10% 3. IGA score of \>3 * Must be a candidate for phototherapy and/or systemic therapy for psoriasis. Exclusion Criteria: * Subjects with non-plaque psoriasis (ie, predominantly inverse, erythrodermic, predominantly guttate, or pustular psoriasis). * Subjects with drug-induced psoriasis or subjects with drug-exacerbated psoriasis that has not resolved within 4 weeks prior to screening. * Subjects who have received systemic non-biologic psoriasis therapy or phototherapy (including either oral and topical psoralen and ultraviolet A (PUVA) light therapy, ultraviolet B, or self-treatment with tanning beds or therapeutic sunbathing) within 4 weeks prior to the Baseline Visit. * Subjects who had topical psoriasis treatment within the previous 2 weeks prior to the Baseline Visit. * Subjects with history of concurrent or recent use of any biologic agent within the following washout periods prior to baseline visit: * Etanercept - 35 days * Infliximab, adalimumab - 12 weeks * Ustekinumab - 24 weeks * Any other biologic agent \<5 half-lives prior to the Baseline Visit * Subjects with history of use of any investigational drug within 28 days prior to randomization, or 5 pharmacokinetic/ pharmacodynamic half-lives (whichever is longer).