A Study of the Efficacy and Safety of Apremilast (CC-10004) in Subjects With Moderate to Severe Plaque Psoriasis of the Scalp

The study will consist of four phases:

- Screening Phase - up to 35 days

- Double-blind Placebo-controlled Phase- Weeks 0 to 16 Subjects will receive treatment
with one of the following:

- apremilast 30 mg tablets orally BID or

- placebo tablets (identical in appearance to apremilast 30 mg tablets) orally BID

- Apremilast Extension Phase - Weeks 16 to 32

- All subjects will be switched to (or continue with) apremilast 30 mg BID at Week
16. All subjects will maintain this dosing through Week 32.

- Observational Follow-up Phase

- Four-week Post-Treatment Observational Follow-up Phase for all subjects who
complete the study or discontinue from the study early.

Inclusion Criteria:

Subjects must satisfy the following criteria to be enrolled in the study:

- Males or females, ≥ 18 years of age at the time of signing the informed consent
document

- Be willing and able to adhere to the study visit schedule and other protocol
requirements.

- Have a diagnosis of moderate to severe plaque psoriasis of the scalp at screening and
baseline

- Must be a candidate for phototherapy and/or systemic therapy for either body or scalp
psoriasis lesions.

- Have moderate to severe plaque psoriasis at screening and baseline

- Must be in good health (except for psoriasis) as judged by the Investigator, based on
medical history, physical examination, 12-lead electrocardiogram (ECG), clinical
laboratories, and urinalysis

- Must meet laboratory criteria

- Females of childbearing potential (FCBP)* must have a negative pregnancy test at
Screening and Baseline. While on investigational product and for at least 28 days
after taking the last dose of investigational product, FCBP who engage in activity in
which conception is possible - must use one of the approved contraceptive** options
described below:

Option 1: Any one of the following highly effective methods: hormonal contraception (oral,
injection, implant, transdermal patch, vaginal ring); intrauterine device (IUD); tubal
ligation; or partner's vasectomy; OR Option 2: Male or female condom (latex condom or
nonlatex condom NOT made out of natural [animal] membrane [for example, polyurethane]; PLUS
one additional barrier method: (a) diaphragm with spermicide; (b) cervical cap with
spermicide; or (c) contraceptive sponge with spermicide.

*A female of childbearing potential is a sexually mature female who 1) has not undergone a
hysterectomy (the surgical removal of the uterus) or bilateral oophorectomy (the surgical
removal of both ovaries) or 2) has not been postmenopausal for at least 24 consecutive
months (that is, has had menses at any time during the preceding 24 consecutive months).

** The female subject's chosen form of contraception must be effective by the time the
female subject is randomized into the study (for example, hormonal contraception should be
initiated at least 28 days before randomization).

Exclusion Criteria:

The presence of any of the following will exclude a subject from enrollment:

- Other than psoriasis, history of any clinically significant uncontrolled disease.

Any condition, including the presence of laboratory abnormalities, which would place the
subject at unacceptable risk if he/she were to participate in the study.

- Pregnant or breast feeding

- Hepatitis B surface antigen positive at Screening

- Anti-hepatitis C antibody positive at Screening

- Active tuberculosis (TB) or a history of incompletely treated TB

- Clinically significant abnormality on 12-lead Electrocardiogram (ECG) at screening

- History of positive human immunodeficiency virus (HIV), or have congenital or acquired
immunodeficiency (eg, common variable immunodeficiency disease)

- Active substance abuse or a history of substance abuse within 6 months prior to
signing the informed consent form.

- Bacterial infections requiring treatment with oral or injectable antibiotics, or
significant viral or fungal infections, within 4 weeks of signing the informed consent
form.

- Malignancy or history of malignancy, except for treated (i.e., cured) basal cell or
squamous cell in situ skin carcinomas or treated (i.e., cured) cervical
intraepithelial neoplasia (CIN) or carcinoma in situ of the cervix with no evidence of
recurrence within 5 years of signing the informed consent.

- Prior history of suicide attempt at any time in the subject's life time prior to
signing the informed consent and randomization, or major psychiatric illness requiring
hospitalization within the last 3 years prior to signing the informed consent.

- Psoriasis flare/rebound within 4 weeks of signing the informed consent form or between
the Screening and Baseline Visits.

- Topical therapy within 2 weeks prior to randomization; Conventional systemic therapy
for psoriasis within 4 weeks prior to randomization; Intralesional corticosteroids on
the scalp within 2 weeks prior to randomization; Phototherapy treatment of body or
scalp psoriasis lesions within 4 weeks prior to randomization; Biologic therapy
between 12 weeks to 24 weeks prior to randomization

- Use of any investigational drug beginning 4 weeks prior to randomization, or 5
pharmacokinetic/pharmacodynamic half-lives, if known (whichever is longer)

- Prolonged sun exposure or use of tanning booths or other ultraviolet (UV) light
sources

- Prior treatment with apremilast

- History of allergy or hypersensitivity to any components of the Investigational
product (IP)