Shire said that the lawsuit results from an Abbreviated New Drug Application (ANDA) filed by Teva for generic versions of 1mg, 2mg, 3mg and 4mg guanfacine hydrochloride extended release tablets, Intuniv, which seeks to market such generic products before the expiration of the ’599 and ’794 patents.
Teva’s ANDA did not challenge, and the lawsuit does not currently assert the patent (US Patent No 5,854,290, Use of Guanfacine in the Treatment of Behavioral Disorders) which expires in 2015. The regulatory exclusivity period for Intuniv runs through September 2, 2012.
Intuniv is a once-daily, extended release formulation of guanfacine, designed to provide steady delivery of drug throughout the day. Intuniv is not a controlled substance and has no known potential for abuse or dependence.
Guanfacine, the active ingredient in Intuniv, is thought to work directly by binding selectively to alpha-2A adrenergic receptors located in the prefrontal cortex – an area of the brain that has been linked to ADHD.