Washington, DC, October 20, 2004 – Shire Pharmaceuticals Group plc (NASDAQ: SHPGY, LSE: SHP.L, TSE: SHQ CN) announced today that ADDERALL XR® (an extended release, mixed salts amphetamine product) is effective and generally well-tolerated for adolescents with attention-deficit/hyperactivity disorder (ADHD). The short- and long-term study results of the multicenter Phase 3 study were presented today in Washington, DC.
"To date, well-designed, controlled studies of ADHD medications in adolescents have been extremely rare," said lead investigator Stephen Grcevich, M.D., Case Western Reserve University School of Medicine and President and Founder of The Family Center by the Falls, in Chagrin Falls, Ohio. "While the vast majority of safety and efficacy studies with ADHD medications have been conducted in school age children, and more recently, in adult populations, physicians are being asked with increasing frequency to treat adolescents with significant functional impairment associated with ADHD. For this reason, it is critically important to access this long-term data to guide physicians in our treatment of this specific population group."
ADHD is considered the most commonly diagnosed psychiatric disorder in children and adolescents, and affects approximately three to seven percent of all school-age children, or approximately two million children in the U.S. Results from follow-up studies of subjects with ADHD published over the past two decades suggest that up to 80 percent of children diagnosed with ADHD will continue to exhibit symptoms in adolescence and up to 65 percent in adulthood.-
The three main symptoms of ADHD include inattention, hyperactivity and impulsivity. If left untreated, these symptoms may seriously and adversely affect patients as well as their families and friends. Findings from a national survey, "Capturing America's Attention," released earlier this year found that adults with ADHD tend to report lower educational achievement, as approximately 17 percent of the adults surveyed with ADHD did not graduate high school, while only seven percent of those without ADHD did not graduate from high school. Untreated ADHD may also increase the risk for other problems, such as anti-social behavior, poor self-esteem and drug abuse, all of which can further impair social and family relationships, Grcevich explained.
After these adolescent patients completed a four-week placebo-controlled trial with ADDERALL XR, they entered into a six-month open-label extension study. Analysis of the four-week data revealed that ADDERALL XR, compared with placebo, produces statistically and clinically significant improvements in core ADHD symptoms in adolescents. Both ADDERALL XR-naïve adolescents as well as those who previously received ADDERALL XR showed continued symptomatic improvement during long-term ADDERALL XR treatment. ADDERALL XR was also found to be a well-tolerated once-daily treatment for the management of ADHD in adolescents.
Investigators measured adolescent patients' symptoms using two efficacy measures. The primary measure was the clinician-administered ADHD Rating Scale-IV (ADHD-RS) measured at baseline, weekly (short-term) and monthly (long-term) intervals. 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 (DSM-IV-TRTM). 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."
The initial 4-week study was divided into primary and secondary cohorts. The primary cohort was comprised of adolescents weighing over or equal to 165 lb who met DSM-IV- TRTM ADHD criteria for ADHD. Subjects received randomized doses of ADDERALL XR or placebo once daily for four weeks. At study endpoint, mean ADHD-RS total scores from the primary cohort receiving ADDERALL XR were significantly improved compared with placebo (P<0.0001). Statistically significant treatment effects compared with placebo of P<0.0001 for both the inattentive and hyperactivity/impulsivity subscales.
After completion of the initial 4-week study both primary and secondary cohort patients could opt to enroll in the long-term, 6-month, open-label extension study. Of the total 138 patients, 31 started ADDERALL XR for the first time in the 6-month open-label extension study, and 107 patients continued the ADDERALL XR treatment they had received in the short-term study. All patients choosing to continue treatment received ADDERALL XR at 10 mg/d during the first week of open-label treatment regardless of the ADDERALL XR dose received in the short-term study. The dose was subsequently increased or decreased in 10 mg/d or 20 mg/d increments for the duration of the 6-month open-label extension study, based upon the clinical judgment of the treating physician. 78 percent of all patients received ADDERALL XR for at least five months.
Long-term safety results were consistent with findings in the ADDERALL XR short-term adolescent study and previous studies of ADDERALL XR in school-aged children and adults with ADHD. Most adverse events were mild or moderate, and the most common adverse events in adolescents were stomach ache, loss of appetite, insomnia, nervousness and weight loss.
Adolescent patients participating in this study ranged from 13 to 17 years with a mean age of 14.4 years; the mean years since ADHD diagnosis was 5.3 years. Overall, 73 percent were Caucasian and 69 percent were male.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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