RecruitingPhase 4Drug trialStudy to Evaluate the Safety, Efficacy, and Pharmacokinetics of Budesonide Extended-release Tablets in Pediatric Subjects Aged 5 to 17 Years With Active, Mild to Moderate Ulcerative ColitisThis is a randomized, double-blind, placebo-controlled, multicenter, study to evaluate the efficacy, safety, and pharmacokinetics (PK) of budesonide extended-release tablets for the induction of remission in pediatric subjects, with active, mild to moderate ulcerative colitis (UC). Subjects will be permitted to continue taking background oral or rectal 5-aminosalicylate (5-ASA) products.