Shire's Vyvanse has taken one step closer to becoming the first stimulant on the US market for the maintenance treatment of young people with attention-deficit hyperactivity disorder (ADHD).

The drugmaker said Wednesday that US regulators have agreed to review a supplemental New Drug Application for the drug, which seeks approval for its use as a maintenance treatment in children and adolescents aged six to 17 years.

The filing is based on clinical data from a Phase IIIb clinical study which assessed the long-term efficacy and safety of Vyvanse (lisdexamfetamine dimesylate) as a maintenance therapy.

Vyvanse is already cleared in the US for the treatment of ADHD in patients ages six to 17 and in adults as part of a total treatment plan, as well as a maintenance treatment for adults with the condition.

A decision from the US Food and Drug Administration on the firm's current sNDA is expected by April 29, 2013.