Shire has unveiled plans for two head-to-head studies comparing its attention-deficit hyperactivity disorder drug Vyvanse with Johnson & Johnson's rival product Concerta.

The Dublin-based firm is initiating two Phase IV trials to compare Vyvanse (lisdexamfetamine dimesylate) with Concerta (methylphenidate) extended-release-tablets to explore differences in efficacy in adolescents ages 13 to 17 with ADHD. Together, the two trials will enrol approximately 1,000 patients, and results are expected by the second half of 2013.

Shire recently completed a Phase III, eight-week study of Vyvanse in the treatment of ADHD in children and adolescents in which Concerta was an active reference arm. The company notes that while "formal comparisons between Vyvanse and Concerta were not planned as part of that study…the data do suggest this as an area for further investigation".

Jeffrey Jonas, head of R&D for Shire’s specialty pharmaceuticals and regenerative medicine businesses, said that the firm's "investment in this innovative programme underscores our commitment to improving patient care by providing prescribers with additional information on which to base treatment decisions". The company quoted Jeffrey Newcorn of the Mount Sinai School of Medicine as saying that doctors need access to information on comparative efficacy and “I expect the data from these studies may aid prescribers in making individualised treatment decisions for their adolescent patients with ADHD".

The approach is a somewhat risky one, given that Concerta has recently gone off-patent and if the studies do not prove the superiority of Vyvanse, Shire could lose market share to cheap generics of methylphenidate that are now available.