PHILADELPHIA, May 1, 2013 /PRNewswire/ -- Shire plc (LSE: SHP, NASDAQ: SHPGY), the global specialty biopharmaceutical company, today announced that the US Food and Drug Administration (FDA) approved the prescription medication Vyvanse ® (lisdexamfetamine dimesylate) Capsules, (CII) as a maintenance treatment in children and adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD). Vyvanse is currently approved as a maintenance treatment in adults with ADHD. With this new approval, Vyvanse becomes the only stimulant approved for maintenance treatment in children, adolescents, and adults (patients ages 6 and above) with ADHD. The approval is based on results from a 32-week study: 26 weeks of open-label treatment with Vyvanse followed by a 6-week randomized withdrawal phase. The study was designed to evaluate the continued efficacy of Vyvanse in children and adolescents (aged 6 to 17 years). A significantly lower proportion of treatment failures occurred among Vyvanse patients (15.8%) compared to placebo (67.5%) at end point of the randomized withdrawal period, showing that significantly more patients treated with Vyvanse maintained ADHD symptom control compared with placebo. "It's important to help establish and maintain effective control of symptoms in patients with ADHD," said Valerie Arnold, MD, an investigator in the randomized withdrawal study . "With this study, physicians now have clinical data in children and adolescents ages 6 and above showing the effectiveness of Vyvanse as a maintenance treatment for ADHD. This additional approval of Vyvanse is welcome because children and adolescents with ADHD may have a need for extended treatment, and could benefit from a treatment option proven to maintain efficacy." Vyvanse is a Schedule II controlled substance. CNS Stimulants (amphetamines and methylphenidate-containing products) have a high potential for abuse and dependence. Assess the risk of abuse prior to prescribing and monitor for signs of abuse and dependence.