Cephalon, Inc. and Eurand, Inc. announced that they have filed a lawsuit in US District Court in Delaware against Mylan Pharmaceuticals, Inc. and its subsidiary, Mylan, Inc., and Barr Pharmaceuticals, Inc. and its subsidiary, Barr Laboratories, Inc., for infringement of Eurand's US Patent Number 7,387,793. This patent claims extended-release formulations containing the muscle relaxant cyclobenzaprine, including Amrix (Cyclobenzaprine Hydrochloride Extended-Release capsules) and expires February 26, 2025.

The lawsuit is based upon Abbreviated New Drug Applications (ANDAs) filed by Mylan and Barr, each seeking US Food and Drug Administration (FDA) approval for a generic equivalent of the 15 mg and 30 mg strengths of Amrix to be sold in the United States. The Mylan ANDA alleges that the Amrix patent will not be infringed by its manufacture, use or sale of the product described in its ANDA and reserves its right to challenge the validity and/or enforceability of the Amrix patent. The Barr ANDA alleges that the Amrix patent is invalid, unenforceable and/or will not be infringed by its manufacture, use or sale of the product described in its ANDA. Amrix was approved by the FDA in February 2007 for short-term use as an adjunct to rest and physical therapy for relief of muscle spasm associated with acute, painful musculoskeletal conditions.

"We believe that the proposed Mylan and Barr ANDA products will be found to infringe the Amrix patent," said Jerry Pappert, executive vice president and general counsel of Cephalon. "The Amrix patent was approved by the United States Patent and Trademark Office and is presumed by law to be valid and enforceable. The patent position for this product is strong and we intend to vigorously defend the Amrix intellectual property."

"We believe our Orange Book-listed patent provides coverage for Amrix until 2025 and we intend to work diligently with Cephalon to protect this important product," said Manya S. Deehr, Eurand's chief legal officer.

The filing of this lawsuit is provided for by the Hatch-Waxman Act, a federal statute governing certain aspects of generic drug approvals. Under that statute, the filing of the lawsuit stays any FDA approval of the Mylan and Barr ANDAs until the earlier of a district court judgment in favor of Mylan or Barr or 30 months from the October 2008 receipt of the Mylan and Barr Paragraph IV certification letters.

Eurand developed Amrix based on its patented and proprietary drug delivery formulation technologies. Cephalon is the exclusive licensee and marketer of Amrix in the United States. Concurrent with the patent protection described above, Cephalon has a three-year period of marketing exclusivity preventing FDA approval of a generic version of Amrix until February 2010.

Founded in 1987, Cephalon, Inc. is an international biopharmaceutical company dedicated to the discovery, development and commercialization of innovative products in four core therapeutic areas: central nervous system, pain, oncology and addiction.

Eurand is a specialty pharmaceutical company that develops, manufactures and commercializes enhanced pharmaceutical and biopharmaceutical products based on its proprietary drug formulation technologies.