SHIRE ANNOUNCES FILING OF SPD465 FOR THE TREATMENT OF ADULT ADHD

21 July 2006 – Basingstoke, UK and Philadelphia, US – Shire plc (LSE: SHP, NASDAQ: SHPGY, TSX: SHQ) announced today that it has submitted a new drug application (NDA) to the U.S. Food and Drug Administration (FDA) for SPD465, an investigational amphetamine compound for the treatment of Attention-Deficit/Hyperactivity Disorder (ADHD) in the adult population. The application is subject to a 12-month FDA review period. SPD465 has the same active ingredient as ADDERALL XR® (mixed salts of a single-entity amphetamine product), but is designed to provide ADHD symptom control for up to 16 hours. Upon approval, this novel product will be the first and only ADHD stimulant product that controls inattention, hyperactivity and impulsivity for up to 16 hours.