“When U.S. Patent No. 5,952,714 issued in September 1999, the Patent Act provided only two avenues for challenging the validity of the patent’s claims: ex parte reexamination and district court litigation. Shortly thereafter, Congress added a third method, inter partes reexamination, but deliberately chose to exclude older patents from the new proceeding. More than 10 years later, Congress replaced inter partes reexamination with a fundamentally different proceeding, inter partes review, and made it apply retroactively to all prior patents. The questions presented are as follows:
1. Does the retroactive application of inter partes review to a patent that issued before the passage of the Leahy–Smith America Invents Act, Pub. L. No. 11-29, 125 Stat. 284 (2011), violate the Takings Clause of the Fifth Amendment?
2. “Does the retroactive application of inter partes review to a patent that issued before the passage of the Leahy–Smith America Invents Act, Pub. L. No. 11-29, 125 Stat. 284 (2011), violate the Due Process Clause of the Fifth Amendment?”
