Research Studies

Inclusion Criteria * Subjects must satisfy the following criteria to be enrolled in the study: * Subject must be male or female, &#8805;18 years of age at the time of signing the informed consent form (ICF). * Subject must understand and voluntarily sign an ICF prior to any study-related assessments / procedures being conducted. * Subject is willing and able to adhere to the study visit schedule and other protocol requirements. * Subject must have a diagnosis of chronic plaque psoriasis for at least 6 months prior to signing the ICF. * Subject must have a diagnosis of mild to moderate plaque psoriasis at both Screening and Baseline as defined by: o sPGA score of 2-3 (mild to moderate) o BSA 2-15% o PASI score 2-15 * Subject must be inadequately controlled with, or intolerant of at least one topical therapy (including topical corticosteroids, topical retinoid or vitamin D analog preparations, calcipotriene and betamethasone dipropionate ointment or foam, tacrolimus, pimecrolimus, or anthralin/dithranol) for the treatment of psoriasis at both Screening and Baseline. * Subject has not had prior exposure to biologics for the treatment of psoriatic arthritis, psoriasis, or any other indication that could impact the assessment of psoriasis. * Subject must be in good health (except for psoriasis) as judged by the investigator, based on medical history, physical examination, clinical laboratories, and urinalysis. * Subject must meet the following laboratory criteria: o White blood cell count &#8805;3000/mm3 (&#8805;3.0 x 109/L) and < 14,000/mm3(< 14 x 109/L) o Platelet count &#8805;100,000/&#956;L (&#8805;100 x 109/L) o Serum creatinine &#8804;1.5 mg/dL (&#8804;132.6 &#956;mol/L) o Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase [SGOT]) and alanine aminotransferase (ALT) (serum glutamic pyruvic transaminase [SGPT]) &#8804;2 x upper limit of normal (ULN) o Total bilirubin &#8804; 2 mg/dL (34 &#956;mol/L) * Females of childbearing potential (FCBP)1 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 contraceptive2 options described below: o 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&#8217;s vasectomy; OR o Option 2: Male or female condom (latex condom or non-latex 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. Exclusion Criteria * The presence of any of the following will exclude a subject from enrollment: * Subject has any significant medical condition, laboratory abnormality, or psychiatric illness that would prevent the subject from participating in the study. * Subjects has 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. * Subject has any condition that confounds the ability to interpret data from the study. * Subject is pregnant or breast feeding. * Subject has hepatitis B surface antigen or anti-hepatitis C antibody positive at Screening. * Subject has active tuberculosis (TB) or a history of incompletely treated TB. * Subject has history of positive human immunodeficiency virus (HIV), or has congenital or acquired immunodeficiency (e.g., common variable immunodeficiency disease). * Subject has active substance abuse or a history of substance abuse within 6 months prior to signing the ICF ****See Detailed Eligibility for more criteria***

Exclusion Criteria (cont) * Subject has bacterial infections requiring treatment with oral or injectable antibiotics, or significant viral or fungal infections, within 4 weeks of signing the ICF. Any treatment for such infections must have been completed at least 4 weeks prior to randomization. * Subject has malignancy or history of malignancy except for: o treated (i.e., cured) basal cell or squamous cell in situ skin carcinomas; o treated (i.e., cured) cervical intraepithelial neoplasia (CIN) or carcinoma in situ of the cervix with no evidence of recurrence. * Subject has 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. * Subject has psoriasis flare/rebound (defined as a sudden worsening of psoriasis which requires administration of prohibited medications) within 4 weeks of signing the ICF or between the Screening and Baseline Visit. * Subject has current or planned concurrent use of the following therapies that may have a possible effect on psoriasis during the course of the treatment phase of the trial: o Topical therapy within 2 weeks of randomization (including but not limited to topical corticosteroids, topical retinoid or vitamin D analog preparations, tacrolimus, pimecrolimus, or anthralin/dithranol). An unmedicated skin moisturizer (e.g., Eucerin?) will be also permitted for body lesions only. Subjects should not use these topical treatments within 24 hours prior to the clinic visit. o Conventional systemic therapy for psoriasis within 4 weeks prior to randomization (including but not limited to cyclosporine, corticosteroids, methotrexate, oral retinoid, mycophenolate, thioguanine, hydroxyurea, sirolimus, sulfasalazine, azathioprine, or fumaric acid esters). o Phototherapy treatment of body within 4 weeks prior to randomization (i.e., ultraviolet B [UVB], psoralen and ultraviolet A [PUVA] radiation). o Use of any investigational drug beginning 4 weeks prior to randomization, or 5 pharmacokinetic/pharmacodynamics half-lives, if known (whichever is longer). * Subject has evidence of skin conditions that would interfere with clinical assessments. * Subject has prolonged sun exposure or use of tanning booths or other ultraviolet (UV) light sources. * Subject had prior treatment with apremilast. * Subject has history of allergy or hypersensitivity to any components of the investigational product (IP).