On May 17, the Federal Circuit held in In re Baxter Int’l Inc. that patentability can be defeated in an Inter Partes reexamination despite the same patent being held valid by a court.

Fresenius USA Inc. challenged U.S. Patent Number 5,247,434 (the ‘434 patent) in the U.S. District Court for the Northern District of California seeking a declaratory judgment of invalidity for obviousness. The district court held the patent valid in favor of the patent owner, Baxter International Inc., with the validity being affirmed by a Federal Circuit panel in 2009.

During the litigation, Fresenius also filed an Inter Partes reexamination. The reexamination resulted in rejection of the claims based in-part on different art. The rejection was upheld by the Board of Patent Appeals and Interferences (BPAI), and that decision was also affirmed by the Federal Circuit.

Please see full alert below for more information.