Apremilast Pediatric Study in Children With Active Oral Ulcers Associated With Behçet's Disease

Key Inclusion Criteria * Male or Female participants 2 to \< 18 years of age at randomization. * Diagnosed with BD meeting the ISGBD criteria at any time prior to the screening visit. * Oral ulcers that occurred ≥ 3 times within the 12-month period prior to the screening visit. * Participant must have ≥ 2 oral ulcers at both the screening visit and on day 1. * Participant has had prior treatment with ≥ 1 non-biologic BD therapy, such as, but not limited to, topical corticosteroids or systemic treatment. Key Exclusion Criteria * Behçet's disease-related active major organ involvement - pulmonary (eg, pulmonary artery aneurysm), vascular (eg, thrombophlebitis), gastrointestinal (eg, ulcers along the gastrointestinal tract), or CNS (eg, meningoencephalitis) manifestations, or ocular lesions (eg, uveitis) requiring immunosuppressive therapy; however: * Previous major organ involvement is allowed if it occurred ≥1 year prior to the screening visit and is not active at time of enrollment * Participants with mild BD-related ocular lesions not requiring systemic immunosuppressive therapy are allowed * Participants with BD-related arthritis and BD-skin manifestations are also allowed. * Previous exposure to biologic therapies for the treatment of BD oral ulcers, previous biologic exposure is allowed for other indications (including other manifestations of BD).