Impax Laboratories, Inc., a technology based specialty pharmaceutical company, confirmed that the company has initiated a challenge of patents listed in the Orange Book in connection with Toviaz (fesoterodine fumarate extended-release tablets, 4 mg and 8 mg).

Impax filed its Abbreviated New Drug Application (ANDA) containing a paragraph IV certification for a generic version of Toviaz with the US Food & Drug Administration (FDA). Following receipt of the notice from the FDA that Impax’s ANDA had been accepted for filing, Impax notified the New Drug Application holder and patent owner of its paragraph IV certification.

On June 28, 2013, Pfizer Inc. and UCB Pharma GmbH filed suit for patent infringement against Impax in the United States District Court for the District of Delaware. This action formally initiated the patent challenge process under the Hatch-Waxman Act.

Once the ANDA is approved by the FDA, Global Pharmaceuticals, Impax’s generic division, intends to commercialize the product.

Toviaz reduces spasms of the bladder muscles. Toviaz is used to treat overactive bladder with symptoms of urinary frequency, urgency, and incontinence. According to IMS Health (NSP), US sales of Toviaz, 4 mg and 8 mg were approximately $159 million for the 12 months ended May 2013.

Impax Laboratories, Inc. (Impax) 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 central nervous system disorder branded products.