Impax Laboratories, Inc. confirms that Alza Corporation has filed suit for patent infringement against Impax in the United States District Court for the District of Delaware in connection with Concerta (methylphenidate hydrochloride) extended-release 54 mg tablets.

Impax filed its Abbreviated New Drug Application (ANDA) for a generic version of Concerta with the US Food & Drug Administration (FDA) in November, 2002, and submitted Paragraph IV patent certifications in connection with two patents that were listed in the FDA's Orange Book in 2005. Following a court decision of patent invalidity with respect to one of the Concerta patents and submission of a major amendment to its ANDA, Impax amended its notice letter to the New Drug Application (NDA) holder and patent owners to provide amended bases for its paragraph IV certification.

Impax's generic Concerta products are part of the Company's Strategic Alliance Agreement with Teva Pharmaceuticals. Once the ANDA is approved by FDA, Teva will commercialize the products.

Concerta is indicated for the treatment of Attention Deficit Hyperactivity Disorder (ADHD) in children 6 years of age and older, adolescents, and adults up to the age of 65. According to Wolters Kluwer Health, US sales of Concerta 54 mg tablets were approximately $365 million for the 12 months ended September 30, 2010.

Impax Laboratories, Inc. is a technology-based specialty pharmaceutical company applying its formulation expertise and drug delivery technology to the development of controlled-release and specialty generics in addition to the development of branded products.