Impax Laboratories, Inc. confirms that it has initiated a challenge of patents listed by Daiichi Sankyo, Inc. in connection with its Welchol (Colesevelam HCl) for Oral Suspension, 3.75 gm/packet and 1.875 gm/packet.

Impax filed its Abbreviated New Drug Application (ANDA) containing a paragraph IV certification for a generic version of Welchol 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 owners of its paragraph IV certification.

On Daiichi Sankyo, Inc. and Genzyme Corporation filed suit for patent infringement against Impax in the United States District Court for the District of Delaware. This action formally initiates the patent challenge process under the Hatch-Waxman Act.

Once the ANDA is approved by FDA, Global Pharmaceuticals, Impax's generic division, will commercialize the products.

Welchol is indicated as an adjunct to diet and exercise to reduce elevated low-density lipoprotein cholesterol (LDL-C) in patients with primary hyperlipidemia (Fredrickson Type IIa) as monotherapy or in combination with an hydroxymethyl-glutaryl-coenzyme A (HMG CoA) reductase inhibitor, reduce LDL-C levels in boys and postmenarchal girls, 10 to 17 years of age, with heterozygous familial hypercholesterolemia as monotherapy or in combination with a statin after failing an adequate trial of diet therapy, and improve glycemic control in adults with type 2 diabetes mellitus. According to Wolters Kluwer Health, US sales of Welchol for Oral Suspension were approximately $39 million for the twelve-month period ending September 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.