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

This is a Phase 2, randomized, double-blind, placebo-controlled, multicenter study designed
to assess the safety and efficacy of PPC-06 in subjects with moderate-to-severe plaque
psoriasis. Study subjects will be enrolled at approximately 75 sites in the United States
(US).

Approximately 400 subjects who meet the study entry criteria will be randomly assigned in a
1:1:1:1 ratio to 1 of the 4 treatment arms:

1. PPC-06 400 mg once daily (QD)

2. PPC-06 400 mg BID

3. PPC-06 600 mg BID

4. Placebo BID The maximum study duration for each subject will be approximately 29 weeks.

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).