(Updates with comments from FDA in seventh paragraph.)
June 12 (Bloomberg) -- Shire Plc will study its best- selling treatment for attention deficit hyperactivity disorder in preschool-age children as it seeks to expand the drug’s use.
Shire plans to begin the first of three studies on Vyvanse in 4- to 5-year-olds in the first half of 2015, the Dublin-based company said in a statement today. Given the Food and Drug Administration’s interest in reviewing safety and usage in young children, Shire submitted a proposed pediatric study request, which the FDA has now agreed to, Gwen Fisher, a Shire spokeswoman in Wayne, Pennsylvania, said by phone.
Vyvanse is approved in the U.S. for children ages 6 and older. It’s legal for doctors to prescribe the drug to younger children, and almost 400,000 prescriptions for children ages 5 and younger have been written in the 12 months through April, Fisher said. Shire estimates 3 percent to 5 percent of preschoolers have ADHD, she said.
At the same time, there are few studies that adequately show how well the drug works in the younger population, according to Shire.
“Shire is committed to continuing to add to the scientific body of knowledge about ADHD treatment options for patients,” Philip Vickers, Shire’s head of research and development, said in the statement. “Additional efficacy and safety data will help clinicians and parents make informed treatment decisions for preschool-age children with ADHD.”
Sales of Vyvanse, Shire’s top-selling ADHD drug, were $1.2 billion last year. The company said in February it halted development of the medicine to treat depression after studies showed it didn’t significantly ease symptoms. Shire has also said it plans to file an application to extend the use of Vyvanse to treat binge-eating disorder.
The FDA believes that drugs that may be used in children should be properly studied in them, Stephanie Yao, an agency spokeswoman, said in an e-mail. It’s important to get the necessary information about a product’s safety, dosing and efficacy for pediatric patients in the product labeling so that health-care providers can properly prescribe medicines and parents can monitor for side effects, she said.
Some psychologists have raised concerns that ADHD is over- diagnosed. Expanding the criteria used to diagnose the condition has led to a surge in drug prescriptions that may be unnecessary and possibly harmful, according to Rae Thomas, a senior research fellow at Bond University in Australia and a psychologist who has worked with children and families for more than 20 years.
ADHD medications are stimulants that can cause weight loss, liver damage and suicidal thoughts, and may suppress growth during puberty, while the long-term effects of the treatments are unknown, Thomas wrote in a paper published in the British Medical Journal last year.