Shire plc (LSE: SHP, Nasdaq: SHPGY), the global specialty biopharmaceutical company, today announced new findings on once-daily INTUNIV™ (guanfacine) Extended Release Tablets, the first selective alpha-2A agonist approved for the treatment of Attention Deficit Hyperactivity Disorder (ADHD), at a major psychiatric meeting. The primary objective of this study was to evaluate the efficacy of INTUNIV, dosed either in the morning or evening compared with placebo, when co-administered with stimulant medications used to treat ADHD in children and adolescents ages 6 to 17 with ADHD and suboptimal response to stimulant alone. The study met its primary end point, which was the change from baseline to end point in the ADHD Rating Scale-IV (ADHD RS-IV) total score.
"A considerable number of pediatric patients with ADHD experience a suboptimal response to stimulant treatment for their ADHD. Finding the right treatment while managing medication side effects may be complicated," said Timothy Wilens, M.D., staff in the pediatric psychopharmacology unit at Massachusetts General Hospital and associate professor of psychiatry at Harvard Medical School, who led the study. "We hope that these new data from a large multisite controlled study evaluating the efficacy and safety of extended-release guanfacine co-administered with stimulants for the treatment of ADHD in children and adolescents will be helpful to clinicians in the management of their patients with ADHD."
The US Food and Drug Administration (FDA) approved INTUNIV on September 2, 2009 as an ADHD treatment for children and adolescents ages 6 to 17, based on two pivotal monotherapy studies. These data presented today were included as part of a supplemental New Drug Application (sNDA) submitted to the FDA on April 28, 2010 to seek approval for INTUNIV as adjunctive treatment with long-acting oral stimulants for the treatment of ADHD in this patient population.
In the pivotal trials, INTUNIV alone provided significant efficacy across a range of ADHD symptoms that can be disruptive, such as inattentiveness/being easily distracted, impulsivity/interrupting others, hyperactivity/running around excessively, arguing with adults, and losing temper. INTUNIV is a non-scheduled medication and has no known potential for abuse or dependence. INTUNIV is available in US pharmacies in four dosage strengths: 1 milligram (mg), 2 mg, 3 mg, and 4 mg.
INTUNIV Co-Administered With a Stimulant Demonstrated Significant Symptom Improvement vs. Stimulant Alone
This 9-week, randomized, double-blind, placebo-controlled, parallel-group, dose-optimized phase III study enrolled patients aged 6 to 17 years with a diagnosis of ADHD and suboptimal response to treatment with a long-acting stimulant.
Throughout the study, patients continued to take their same once-daily dose of a long-acting stimulant and were randomized to three treatment arms: INTUNIV dosed in the morning, INTUNIV dosed in the evening, or placebo. A total of 455 patients were evaluated for efficacy and safety. The study consisted of 5 weeks of dose optimization and 3 weeks of dose maintenance. INTUNIV was optimized up to 4 mg per day.
The primary efficacy analysis was the change from baseline in ADHD-RS-IV total score at end point. ADHD-RS-IV is a standardized test for evaluating symptoms of ADHD and assessing response to treatment. At baseline, mean ADHD-RS-IV total scores were 37.6, 37.0, and 37.7 for the INTUNIV AM/stimulant, INTUNIV PM/stimulant, and placebo/stimulant treatment groups, respectively. At study end, mean ADHD-RS-IV total scores were 17.3, 16.1, and 21.7, respectively. Placebo-adjusted least squares (LS) mean change from baseline at end point for ADHD-RS-IV total score was a decrease of 4.5>.002) for the INTUNIV AM/stimulant and a decrease of 5.3 (P<.001) for the INTUNIV PM/stimulant.
In this study, no unique adverse events were observed with INTUNIV given with stimulant compared with those reported with either treatment alone. The most commonly reported treatment emergent adverse events (TEAEs) among patients treated with INTUNIV and a stimulant (greater than or equal to 5 percent) were headache, somnolence, upper respiratory tract infection, fatigue, insomnia, upper abdominal pain, dizziness, decreased appetite, cough, irritability, and nausea. The most commonly reported TEAEs among patients in the placebo/stimulant group were headache, upper respiratory tract infection, and irritability. The majority of TEAEs were mild to moderate in severity. The rate of discontinuation due to TEAEs was 2.7 percent in the INTUNIV AM/stimulant group, 3.9 percent in the INTUNIV PM/stimulant group, and 0.7 percent in the placebo/stimulant group. There were three serious adverse events reported among study participants (including one report of syncope) and all were considered unrelated to study drug. No deaths occurred during the study.
"Shire is committed to ADHD and continues to develop a range of ADHD treatments for health care providers and patients," said Michael Yasick, Senior Vice President of Shire's ADHD Business Unit. "We are pleased with the results of this trial and are currently working with the FDA to secure an indication for use of INTUNIV with stimulants in the treatment of ADHD."