Shire plc, the global specialty biopharmaceutical company, announces that it has received a Paragraph IV Notice Letter from Watson Laboratories, Inc (“Watson”) advising of the filing of an Abbreviated New Drug Application (“ANDA”) for a generic version of Shire’s 4mg guanfacine hydrochloride extended release tablet, Intuniv.
Shire had previously reported in March 2010 of the receipt of a Paragraph IV Letter from Teva Pharmaceuticals USA, Inc. and in April 2010 of a Paragraph IV Letters from Actavis Elizabeth LLC and Anchen Pharmaceuticals, Inc, both regarding ANDAs for generic versions of Shire’s 1mg, 2mg, 3mg, and 4mg guanfacine hydrochloride extended release tablets.
Intuniv is protected by three FDA Orange Book listed patents: US Patent No. 5,854,290 (“the ’290 patent”) titled Use of Guanfacine in the Treatment of Behavioral Disorders; US Patent No. 6,287,599 (“the ’599 patent”) and US Patent No. 6,811,794 (“the ’794 patent”) both titled Sustained Release Pharmaceutical Dosage Forms with Minimised pH Dependent Dissolution Profiles. The three patents expire in 2015, 2020 and 2022, respectfully.
Shire is currently reviewing the details of Watson’s Paragraph IV Notice Letter which was directed to the ’290, ’599 and ’794 patents.
The Hatch-Waxman exclusivity period for Intuniv runs until September 2, 2012 therefore, ANDA for generic versions of INTUNIV cannot be approved prior to the end of that exclusivity period.
Under the Hatch-Waxman Act, Shire has 45 days from the receipt of the Notice Letter to determine if it will file a patent infringement suit. If Shire brings suit pursuant to the Hatch Waxman regulations, a stay of approval of up to 30-months will be imposed by the FDA on Watson’s ANDA.