ArcelorMittal France v. AK Steel Corp.

In a decision invalidating reissue patent claims, the U.S. Court of Appeals for the Federal Circuit affirmed the district court’s application of the law-of-the-case doctrine and mandate rule, finding that the reissue claims were impermissibly broadened in violation of 35 U.S.C. § 251. ArcelorMittal France v. AK Steel Corp., Case No. 14-1189 (Fed. Cir., May 12, 2015) (Hughes, J.).

In 2010 ArcelorMittal sued AK Steel and others for infringement of a patent directed to a specific type of steel sheet that has a “very high mechanical resistance” after thermal treatment. The district court construed the claim term “a very high mechanical resistance” as “a tensile strength greater than 1500 MPa.” On appeal, after a jury trial, the Federal Circuit affirmed the district court’s construction of “a very high mechanical resistance” but reversed and remanded on other grounds.

While the appeal was pending, ArcelorMittal filed a reissue application in an attempt to overcome the district court’s unfavorable claim construction. The reissue application issued into a patent in 2013 and included the same independent claim as the original patent plus a number of dependent claims, including a dependent claim that claimed “[t]he coated steel sheet of claim […], wherein said mechanical resistance is in excess of 1000 MPa.” ArcelorMittal then amended its complaint on remand to substitute in the reissue patent. AK Steel moved for summary judgement on the ground that claims of the reissue patent “were invalid because they were impermissibly broadened in the reissue proceedings.” After the district court granted the motion, ArcelorMittal appealed.

ArcelorMittal argued that the reissue claims are not broader than the original claims because the issuance of the reissue patent demonstrates that the Patent Office believed the original claim term—“very high mechanical resistance”—was broader than previously construed.

The Federal Circuit, applying the principles of the law-of-the-case doctrine (which “posits that when a court decides upon a rule of law, that decision should continue to govern the same issues in subsequent stages in the same case”) and the mandate rule (which states that “an inferior court has no power or authority to deviate from the mandate issued by an appellate court”), explained that a court may only deviate from a decision in a prior appeal where “extraordinary circumstances” exist, which is rare.

ArcelorMittal argued that the issuance of the reissue patent is “new evidence” sufficient to constitute “extraordinary circumstances,” allowing it to deviate from the prior construction of the term “very high mechanical resistance.” The Federal Circuit disagreed, concluding that “[t]he successful prosecution of the reissue patent is not ‘new evidence’ sufficient to trigger the extraordinary circumstances exception to the mandate rule and the law-of-the-case doctrine. Permitting a reissue patent to disturb a previous claim construction of the original claims would turn the validity analysis under 35 U.S.C. § 251 on its head.”

As the Federal Circuit concluded, under the law-of-the-case doctrine, the district court was bound by its previous construction of the term “a very high mechanical resistance” notwithstanding the addition of the new dependent claim, explaining that the new claim improperly broadened the scope of the original claims outside the two-year period of broadening reissues and were therefore invalid.