LONDON, June 12 (Reuters) - London-listed drugmaker Shire PLC said it had agreed to a request from the U.S. regulator to test the use of its amphetamine-based drug Vyvanse in preschool children aged four and five with hyperactivity.
The FDA, the U.S. regulator, says the drug should be prescribed for patients aged six years or above.
Shire said the additional efficacy and safety data from the trials would help clinicians and parents make informed treatment decisions for preschool-age children with ADHD (attention deficit hyperactivity disorder).
The condition is increasingly diagnosed in U.S. schoolchildren, and worldwide sales of the drug grew 18 percent in the first quarter to $351 million.
Shire said the estimated prevalence of ADHD in the preschool population was three to five percent, and data suggested that only a small proportion of them responded adequately to behavioral therapy.
It said it anticipated beginning the first trial in its preschool pediatric clinical trial program in the first half of 2015. (Reporting by Paul Sandle; editing by Sarah Young)