Mylan sues Warner Chilcott, Mayne Pharma over Doryx

(Reuters) - Mylan Pharmaceuticals Inc, the world's No. 3 generic drugmaker, sued Warner Chilcott Plc and Australia-based Mayne Pharma Group Ltd alleging they tried to restrict generic competition to their acne drug Doryx.

Warner Chilcott and Mayne made minor changes with no therapeutic benefit to Doryx to delay approval of competing generic versions of the drug, Mylan said in the lawsuit.

U.S. health regulators require that a generic version of a drug is similar to the original.

Mylan did not immediately respond to a request for comment. Mayne could not be reached outside of regular business hours.

The generic drugmaker in late April won a patent suit against Warner Chilcott, allowing Mylan to launch its copy of Doryx.

Mylan is seeking unspecified damages and legal costs in the anti-trust lawsuit filed in the U.S. District Court for the Eastern District of Pennsylvania.

Warner Chilcott and Mayne said they were reviewing Mylan's complaint and intend to vigorously defend the allegation.

The companies received approval to sell the disputed 150 mg dose of Doryx in 2008.

Mayne does not expect to incur any material financial liabilities related to the suit, the company said in a statement early Monday.

Ireland-based Warner Chilcott is currently exploring strategic options amid declining sales of Doryx and its osteoporosis drug Actonel.

Doryx sales for the quarter ended March 31 were $30 million, down 55 percent from a year ago.

(Reporting by Zeba Siddiqui in Bangalore; Editing by Sriraj Kalluvila)