A boon for Shire Pharmaceuticals this morning after it filed for approval to market its new attention-deficit hyperactivity disorder drug, Connexyn (guanfacine), in the USA - helping broaden its appeal for investors who have criticised the firm for being too reliant on its Adderall franchise in the same indication.

Connexyn (guanfacine), if approved, will become the first once-daily selective alpha 2A-adrenoceptor agonist for treating the often controversial field of attention-deficit hyperactivity disorder. For years, the drugs on offer were stimulant based, but with the advent of Eli Lilly's Strattera (atomoxetine) - the first non-stimulant therapy to be made available - other drugmakers have been keen to join the bandwagon and grow the market yet further. Adderall XR is the biggest drugs in the arena, with revenues in excess of $730 million last year, up 20%, and a record 26% of the US market.

Connexyn is a non-stimulant drug that Shire is hoping will be approved for use in children aged six to 17; in fact, it will be the second non-stimulant drug to be marketed, and Strattera comes with a black-box warning of sucidal thoughts in children. “Connexyn, if approved, would enhance our product portfolio as a new non-stimulant ADHD medication,” said Shire's Chief Executive Matthew Emmens. And it's not planning to rest on its laurels either: having recently launched the ADHD patch Daytrana, Shire is also seeking approval of two other offerings in the field - NRP104 and the adult ADHD therapy SPD465 - and is also investigating Connexyn in a second late-stage study in children with ADHD who also exhibit oppositional behaviour.

The US Food and Drug Administration has 10 months to review the application for Connexyn.