Oct. 29, 2009 (PR Newswire) --

HONOLULU, Oct. 29 /PRNewswire-FirstCall/ -- Shire plc (LSE: SHP, Nasdaq: SHPGY), the global specialty biopharmaceutical company, announced new study results on INTUNIV(TM) (guanfacine) Extended Release Tablets, at a major psychiatric medical meeting today. The primary objective of this study was to assess the change from baseline on the oppositional subscale of the Conners' Parent Rating Scale-Revised: Long Form (CPRS-R:L) in patients ages 6 to 12 with a primary diagnosis of Attention-Deficit/Hyperactivity Disorder (ADHD) with the presence of oppositional symptoms at baseline. INTUNIV met the primary objective demonstrating significant efficacy in reducing symptoms as measured by the oppositional subscale. Some of the symptoms measured by this scale include deliberately doing things that annoy others, refusing to comply with adults' requests, and being touchy or easily annoyed by others.

According to the Centers for Disease Control and Prevention (CDC), approximately 7.8 percent of all US school-aged children have been diagnosed with ADHD at some point in their lives. ADHD is a complex neurobehavioral disorder, which includes symptoms and behaviors such as inattentiveness, running around or climbing excessively, and being excitable or impulsive, many of which can be disruptive.

"The disruptive nature of ADHD can impact social and academic settings for those patients diagnosed with the disorder," said F. Randy Sallee, MD, PhD, Professor of Psychiatry at the University of Cincinnati and Cincinnati Children's Hospital Medical Center in Cincinnati, Ohio. "This study showed that INTUNIV is an effective option for treating a range of ADHD symptoms."

INTUNIV, a once-daily formulation of guanfacine, was approved by the US Food and Drug Administration (FDA) on September 2, 2009 as the first selective alpha-2A agonist for the treatment of ADHD. Although the mechanism of action is not known, guanfacine, the active ingredient in INTUNIV, is thought to selectively stimulate alpha-2A adrenoreceptors in the prefrontal cortex. Stimulation of the postsynaptic alpha-2A receptors is thought to strengthen working memory, reduce susceptibility to distraction, improve attention regulation, improve behavioral inhibition, and enhance impulse control.

Once-daily INTUNIV is expected to be available in US pharmacies in November and will come in four dosage strengths (1 mg, 2 mg, 3 mg, and 4 mg). INTUNIV is not a controlled substance and has no known potential for abuse or dependence.

INTUNIV Demonstrated Significant Symptom Reduction in Patients Diagnosed with ADHD and the Presence of Oppositional Symptoms

This randomized, placebo-controlled, flexible-dose study was conducted in 214 patients ages 6 to 12 over a nine-week period. INTUNIV demonstrated significant ADHD symptom improvement in the primary and secondary measures as demonstrated on the Oppositional Subscale of the CPRS-R:L and the ADHD Rating Scale-IV (ADHD-RS-IV), respectively.