Shire reported positive data from a Phase III study evaluating lisdexamfetamine dimesylate (LDX) in the long-term maintenance of attention deficit/hyperactivity disorder (ADHD) in patients aged 6–17 years. The study data will support the European marketing authorization application for LDX, which was accepted for review earlier this year. The drug is already approved in the U.S. and Canada under the brand name Vyvanse® for treating ADHD in 6–17 year old patients as well as adults, and in Brazil (as Venvanse™) for treating children aged 6–12 years.
The newly reported data come from a study in 276 patients, originally designed as an extension to the European Phase III efficacy and safety trial with LDX. Participants were treated with one of three doses of LDX during an open-label period of at least 26 weeks, before starting on a six-week double-blind randomized withdrawal period, in which subjects were treated using either LDX or placebo. The results confirmed a lower rate of treatment failure (13.5%) among the LDX cohort, compared with the placebo cohort (65.8%). Most of the placebo-treated patients who exhibited symptom relapse did so within two weeks of switching from LDX therapy.
In its Q1 2012 results released last month, Shire said it anticipates that global sales of Vyvanse will reach over $1 billion in 2012. The drug achieved sales of $260 million in the first three months of the year, up 29% on Q1 2011. Just last month the firm reported positive data from a placebo-controlled Phase II study evaluating LDX capsules in adults with binge eating disorder. Additional studies in larger patient cohorts are under way.