OxyContin Manufacturer Sues Generics Makers for Patent Infringement

California – Purdue Pharma LP and Grunenthal GmbH filed a lawsuit against two generic drug makers, claiming their planned generic versions of OxyContin will infringe two patents that cover the “abuse-proof” version of the painkiller.

According to the complaints filed in New York on Friday, Watson Pharmaceuticals Inc., now owned by Actavis Inc., and Impax Laboratories Inc. filed abbreviated new drug applications with the U.S. Food and Drug Administration for a generic form of oxycodone hydrochloride extended-release tablets for seven different dosage strengths. Purdue and Grunenthal claim the planned generic forms will infringe at least one of two patents relating to the controlled-release version of OxyContin.

According to the FDA, OxyContin is a semi-synthetic opioid and a Schedule II controlled substance due to its high risk of addiction.

The patents-in-suit, both titled “Abuse-proofed dosage form” are owned by German-based Grunenthal, which licenses the patents to Connecticut-based Purdue. The patents protect a specific version of OxyContin that is coated in a plastic-like polymer to help prevent tampering and abuse of the drug. The polymer prevents the pill from being ground into a fine powder and becomes unusable if added to water, but it can still dissolve normally in the stomach.

Watson and Impax both sent a letter to Purdue in December 2012 informing the company of their plans to file ANDAs for a generic version of the painkiller and stating that the patents for the drug are not valid, unenforceable or are not infringed by their planned generics.

Purdue and Grunenthal claim the patents are valid and that the companies cannot reasonably conclude that the generic forms of the drug are not covered by the terms of the patents or that the generic versions would not infringe the patents.

OxyContin is a very profitable painkiller, making Purdue nearly $2.8 billion in U.S. sales in 2011. Purdue claimed that the infringement by the companies “will cause plaintiffs irreparable harm for which they have no adequate remedy at law and will continue unless enjoined by this court.”

Purdue requested a declaratory judgment that the planned generics will infringe the patents, an injunction prohibiting the companies from releasing generic versions of OxyContin until the patents expire in November 2023, costs and attorney fees.