A Study of Apremilast in Pediatric Participants in Children With Mild to Moderate Plaque Psoriasis

Inclusion Criteria: * Participants must have a weight of ≥ 20 kg. * Participant must have an age and sex specific BMI value no lower in range than the fifth percentile on the growth chart for children and adolescents. * Participant is able to swallow the study medication tablet. * Diagnosis of chronic plaque psoriasis for at least 6 months prior to screening. * Has mild to moderate plaque psoriasis at screening and Study Visit 1 as defined by: * Psoriasis Area Severity Index score 2-15, * Body surface area 2-15%, and * Static Physician Global Assessment score of 2-3 (mild to moderate) * Disease inadequately controlled by or inappropriate for topical therapy for psoriasis. Exclusion Criteria: * Guttate, erythrodermic, or pustular psoriasis at screening and Study Day 1. * Psoriasis flare or rebound within 4 weeks prior to screening. * Active tuberculosis (TB) or a history of incompletely treated TB per local guidelines. * History of recurrent significant infections. * Active infection or infection treated with antibiotic treatment within 14 days of Study Day 1. * Any history of or active malignancy or myeloproliferative or lymphoproliferative disease. * Current use of the following therapies that may have a possible effect on psoriasis: * Conventional systemic therapy for psoriasis within 28 days prior to Study Day 1 (including but not limited to cyclosporine, corticosteroids, methotrexate, oral retinoids, mycophenolate, thioguanine, hydroxyurea, sirolimus, sulfasalazine, azathioprine, and fumaric acid esters). * Phototherapy treatment (ie, ultraviolet B \[UVB\], PUVA) within 28 days prior to Study Day 1. * Biologic therapy: * Etanercept (or biosimilar) treatment 28 days prior to Study Day 1 * Adalimumab (or biosimilar) treatment 10 weeks prior to Study Day 1 * Other TNF or IL-17 blockers (such as infliximab, certolizumab pegol, secukinumab, ixekizumab, brodalumab, or their biosimilars) within 12 weeks prior to Study Day 1 * Anti-IL-12 or anti-IL-23 treatment (such as ustekinumab, guselkumab, or tildrakizumab) within 24 weeks prior to Study Day 1. * Use of tanning booths or other ultraviolet light sources. * Answer "Yes" to any question on the Columbia-Suicide Severity Rating Scale during screening or at Study Day 1. * Female participant of childbearing potential with a positive pregnancy test assessed at screening and/or Study Day 1 by a serum and/or urine pregnancy test.