Long-term study proves ADDERALL XR is a safe and effective option to treat adults with ADHD

Phase III study presented at American Psychiatric Association Meeting

Shire Pharmaceuticals Group plc (NASDAQ: SHPGY, LSE: SHP.L, TSE: SHQ CN) announced that adults with attention-deficit/hyperactivity disorder (ADHD) experienced significant ADHD symptom control when treated with once-daily ADDERALL XR (a mixed salts amphetamine product). The 18-month interim analysis of a two-year Phase III trial led by Harvard investigators was discussed today during a platform presentation at the American Psychiatric Association (APA) annual meeting in New York City.

"Adults with ADHD can benefit from treatment with ADDERALL XR over the long-term because it can improve their ability to maintain focus, concentrate, and pay attention for longer periods of time, which may enable them to achieve more in professional, academic and social settings," said lead investigator Joseph Biederman, M.D., professor of psychiatry at Harvard Medical School.

Up to 65 percent of children with ADHD may still exhibit symptoms into adulthood and an estimated 4.4 percent of the U.S. adult populations are affected by ADHD. If left untreated, ADHD may seriously and adversely affect patients as well as their families, friends and coworkers. The disorder's symptoms of inattention and impulsivity, if untreated, can result in poor performance in the workplace and may increase adults' risk for other problems, such as drug abuse, anti-social behavior, and poor self-esteem, all of which can further impair social and family relationships, Biederman explained.

After these adult patients completed a four-week placebo-controlled trial with ADDERALL XR, they entered into a two-year extension study. The 18-month interim analysis of this extension study revealed that they maintained a significant reduction in their ADHD symptoms when treated with ADDERALL XR. For many patients, this sustained reduction in ADHD symptoms was at doses equivalent to those used in the initial four-week study, which reinforced previous findings that patients do not build up a tolerance to the effects of ADDERALL XR, says Biederman. ADDERALL XR was found to be significantlyefficacious across all doses.

Investigators measured patients' symptoms using a validated ADHD Rating Scale (ADHD-RS), in which scores are considered severe, moderate or mild. The ADHD-RS assesses the 18 individual items related to ADHD that are listed within in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Nine of these items assess inattentive symptoms and the other nine items assess hyperactive and impulsive symptoms. Sample rating categories include "avoids tasks that require sustained mental effort" and "talks excessively." Patients with more severe ADHD improved the most on ADDERALL XR treatment in the four-week placebo controlled study.