UK drugmaker Shire Pharmaceuticals has filed a New Drug Application with US regulators seeking permission to market SPD465 for the treatment of adult attention-deficit hyperactivity disorder.

SPD465 is an extended-release form of Shire’s market-leading ADHD drug Adderall XR (mixed amphetamine salts), and has been designed to control symptoms for up to 16 hours. If it gets the seal of approval, SPD465 would be the longest acting treatment on the market, giving the product an edge over its sister product as well its competitors.

The agent is one of a few drugs in the ADHD arena the company is concentrating its efforts on to help reduce its reliance on the top seller Adderall XR, which raked $730 million last year but is nearing a generic battle in the USA.

Earlier this year, Shire reported promising clinical data from a Phase III trial of new ADHD candidate NRP104 (lisdexamfetamine dimesylate), developed with New River Pharmaceuticals. A pro-drug of amphetamine that promises to offer the efficacy of its parent without the potential for abuse, the product has already been tipped as a future blockbuster.