Whether the retroactive application of inter partes review to patents that were applied for before the America Invents Act violates the Fifth Amendment

QUESTIONS PRESENTED In 2011, Congress enacted a potent new mechanism for challenging patents through adversarial proceedings at the Patent Office known as inter partes review. See Leahy-Smith America Invents Act, Pub. L. No. 112-29, § 6(a), 125 Stat. 284, 299 (2011). Congress made that new mechanism applicable even to patents that were applied for and issued before the statute’s enactment. The Patent Office relied on that new procedure to revoke Arthrex’s patent claims, even though Arthrex applied for its patent and disclosed its invention to the public in reliance on the prior regime. While Arthrex’s case was pending on appeal, the Federal Circuit decided in another case between the same parties that the administrative patent judges who conduct inter partes reviews hold office in violation of the Appointments Clause. See Arthrex, Inc. v. Smith & Nephew, Inc., 941 F.3d 1320 (Fed. Cir. 2019). The Federal Circuit has repeatedly refused to apply that ruling to cases like this one where the appellant did not challenge the appointments in its opening brief on appeal. The questions presented are: 1. Whether the retroactive application of inter partes review to patents that were applied for before the America Invents Act violates the Fifth Amendment. 2. Whether a court of appeals can invoke forfeiture principles to refuse to address a constitutional claim in a pending appeal despite an intervening change in law. (i)