Shire has been boosted by the news that US regulators have given the green light to its new attention-deficit hyperactivity disorder drug Intuniv.

The US Food and Drug Administration has approved Intuniv (guanfacine) extended-release tablets for the treatment of ADHD in children and adolescents aged 6 to 17. The drug, which is not a controlled substance and does not have a known mechanism for potential abuse or dependence, will be the first selective alpha-2A receptor agonist for the treatment of ADHD, Shire noted.

Trials of Intuniv have demonstrated improvement in a range of ADHD symptoms across a full day, the company noted, such as inattention, arguing with adults, hyperactivity, impulsivity, and losing one’s temper. The once-daily drug is expected to be available in US pharmacies in November and will be marketed by Shire’s 600-strong ADHD sales team.

The approval comes just over a month after the FDA issued a complete response letter for Intuniv following labelling discussions between Shire and the agency. At that time, Shire stressed that the FDA did not identify safety concerns in the letter or request new clinical studies and the problem of the labelling language has now been resolved.

Intuniv joins Vyvanse (lisdexamfetamine dimesylate) at the head of Shire’s ADHD franchise in the USA, and the firm will be hoping that it can help soften the blow of declining sales of its blockbuster Adderall XR (mixed amphetamine salts) which is now facing generic competition from Teva Pharmaceutical Industries’ copycat version. Second-quarter sales of Adderall XR sales crashed 77% to $67.4 million.