The U.S. Court of Appeals for the Federal Circuit renders a split decision regarding sham patent litigation (Tyco Healthcare / Mutual Pharmaceutical)

The U.S. Court of Appeals for the Federal Circuit has remanded for further consideration antitrust claims accusing a patent holder of filing a sham infringement suit and a sham citizen petition with the Federal Drug Administration. The case is Tyco Healthcare Group LP v. Mutual Pharmaceutical Co. (Fed. Cir., Aug. 6, 2014). This split decision has significant implications both for patent holders planning to assert infringement claims and for infringement defendants considering antitrust counterclaims. Background Sandoz Limited applied for several patents directed to formulations and features of, and methods of treatment with, temazepam, a drug used to treat insomnia. In 2001, Tyco Healthcare Group LP and Mallinckrodt, Inc. ("Tyco") acquired the patents from Sandoz, and currently markets