Warner Chilcott Limited announced that one of its subsidiaries and Mayne Pharma International Pty Ltd have filed a second lawsuit against Mylan Pharmaceuticals Inc and Mylan in the District Court for the District of New Jersey for infringement of Mayne's US Patent No. 6,958,161 (the "161 Patent") which covers Doryx, a tetracycline-class oral antibiotic. The lawsuit is in response to the submission of an Abbreviated New Drug Application (ANDA) to the US Food and Drug Administration (FDA) by Mylan requesting approval to manufacture and sell a generic version of Doryx 150 mg delayed-release tablets prior to the expiration in 2022 of the '161 Patent.

Warner Chilcott previously announced, in December 2008, the filing of a lawsuit against Mylan in response to Mylan's submission of an ANDA requesting approval to manufacture and sell generic versions of Doryx 100 and 75 mg delayed-release tablets. Warner Chilcott markets and sells Doryx delayed-release tablets in 150, 100 and 75 mg strengths in the United States under a license agreement with Mayne.

Warner Chilcott and Mayne intend to vigorously defend the '161 Patent and pursue their legal rights. Warner Chilcott believes that the FDA will stay approval of Mylan's generic version of Doryx 150 mg delayed-release tablets for up to 30 months, while the case is pending in the District Court.