In Fresenius, USA Inc. v. Baxter International, Inc., the Federal Circuit interpreted the ex parte reexamination statutes (35 USC §§ 301-307) as providing that the final cancellation of claims in a reexamination proceeding is binding on concurrent litigation proceedings, as long as the litigation is still pending. This decision validates the use of ex parte reexamination to launch a collateral attack on patents in litigation. While many defendants hesitate to bring an ex parte reexamination because of the very limited role they would have in the proceedings, because ex parte reexamination is not limited by the timing requirements of inter partes review and post grant review proceedings, and does not carry the same litigation estoppel, it may be worthy of a second look under appropriate circumstances.
When the Federal Circuit denied the Request for Panel Rehearing and Rehearing en banc in In re Baxter, the court let stand its two decisions that affirmed conflicting rulings on the validity of the same patent. In Fresenius USA, Inc. v. Baxter Int’l, Inc., 582 F.3d 1288 (Fed. Cir. 2009), the court affirmed the district court decision that upheld the validity of claims 26-31 of U.S. Patent 5,247,434, while in its May 17, 2012 decision in In re Baxter, the court affirmed the USPTO Board decision that the claims were invalid as obvious. Parallel litigation and USPTO proceedings involving the same patent may become more rare now that the America Invents Act (AIA) has replaced inter partes reexamination with inter partes review and placed restrictions on parallel litigation proceedings, but still could arise from pending inter partes reexamination proceedings or from ex parte reexamination proceedings, which are not subject to the same restrictions.Continue reading this entry