Clarifying the application of the indefiniteness standard set forth in the Supreme Court’s Nautilus case, a divided U.S. Court of Appeals for the Federal Circuit denied a combined petition for rehearing and rehearing en banc while also criticizing the panel’s jurisdiction to hear the appeal. The Dow Chemical Co. v. Nova Chemicals Corp. et al., Case Nos. 14-1431, -1462 (Fed. Cir., Dec. 17, 2015) (Prost, C.J.) (Wallach, J.; Dyk, J., concurring) (Moore, J.; Pauline, J.; Newman, J.; O’Malley J.; Taranto, J., concurring-in-part) (O’Malley, J.; Reyna, J., dissenting-in-part).

At issue were two Dow patents directed to improved ethylene polymer compositions for use in making thinner films without comprising their strength. The claims at issue require “a slope of strain hardening coefficient greater than or equal to 1.3.” At trial, the defendants argued the claims are indefinite for failing to teach one skilled in the art how to measure “strain hardening.” A jury found the asserted claims to be infringed and not invalid. The Federal Circuit affirmed the decision, but remanded the case back to district court to address supplemental damages. The district court granted supplemental damages, and both parties appealed to the Federal Circuit. While the appeal was pending, the Supreme Court decided Nautilus, Inc. v. Biosig Instruments, Inc., which set forth a new standard for indefiniteness. Applying the new Nautilus standard, the Federal Circuit found the claims indefinite and reversed the supplemental damages award.

Dow’s filed a combined petition for rehearing and rehearing en banc, which was denied. Judge Moore, joined by Judge Pauline, Newman, O’Malley and Taranto in full (Chen in part) concurred with the denial in order to clarify the impact of the panel’s opinion on the law of indefiniteness. First, contrary to Nova Chemical’s claims, “the panel did not and cannot stand for the proposition that extrinsic evidence cannot be relied upon to determine, whether in light of the state of knowledge of the skilled artisan at the time, a patent’s specification is sufficiently definite.” In rejecting Dow’s claim that the panel changed the law of indefiniteness, Judge Moore explained that, consistent with Supreme Court and prior Federal Circuit precedent, findings of fact that rely upon extrinsic evidence on the issue of indefiniteness must be given deference on appeal. Judge Moore’s concurring opinion also noted that the burden of proving indefiniteness remains with the party challenging validity.

Chief Judge Prost, joined by Judges Wallach and Dyk, filed a separate concurrence, agreeing with Judge Moore, that the standard for establishing the invalidity of a patent is clear and convincing evidence and that the burden rests on the accused infringer. The concurring opinion also explained that if a skilled person would choose an established method for measurement, that may be sufficient to defeat indefiniteness, even if such method is not set forth in haec verba in the patent.

Judge O’Malley, joined by Judge Reyna, dissented with respect to jurisdiction, criticizing the original panel’s reliance on Nautilusbecause “the panel could not reopen a validity determination that had been the subject of a final judgment that was affirmed on appeal, and as to which the Supreme Court declined review,” even in light of the change in law for indefiniteness as a result of Nautilus.