Last Month at the Federal Circuit
Last Month at the Federal Circuit

March 2014

Plain and Ordinary Meaning Applied Where Patentee Did Not Clearly Express an Intent to Redefine the Claim Term


Judges:  Rader, Linn (author), Wallach
[Appealed from D. Del., Judge Robinson]

In Butamax™ Advanced Biofuels LLC v. Gevo, Inc., No. 13-1342 (Fed. Cir. Feb. 18, 2014), the Federal Circuit vacated the district court’s grant of SJ of noninfringement, finding that the district court erred in its claim construction, and reversed the district court’s grants of SJ of invalidity.

Butamax™ Advanced Biofuels LLC (“Butamax”) owns U.S. Patent Nos. 7,851,188 (“the ’188 patent”) and 7,993,889 (“the ’889 patent”), which are directed to the production of isobutanol, useful as a fuel or food additive.  The ’188 patent is directed to a recombinant microbial host cell that uses a particular five-step biosynthetic pathway to produce isobutanol, and the related ’889 patent is directed to a method of producing isobutanol from a recombinant yeast microorganism that expresses the five-step biosynthetic pathway.  The second step of the biosynthetic pathway is a conversion that is catalyzed by a polypeptide enzyme known as keto-acid reductoisomerase, or “KARI.”

Butamax sued competitor Gevo, Inc. (“Gevo”) for infringement of the ’889 and ’188 patents, and moved for a preliminary injunction predicated on the ’889 patent.  The district court denied Butamax’s motion based on its construction of the KARI term as “an enzyme that is solely NADPH-dependent.”  Slip op. at 8 (quoting Butamax™ Advanced Biofuels LLC v. Gevo, Inc., 486 F. App’x 883, 883 (Fed. Cir. 2012)).  On a prior appeal, the Federal Circuit affirmed the denial of Butamax’s motion, but noted that the district court’s construction of the KARI term was “very questionable” and asked the district court “to reconsider its construction when it holds the Markman hearing.”  Id. (quoting Butamax™, 486 F. App’x at 883).  At the Markman hearing, the district court construed the term in the ’889 patent as “an enzyme known by the EC number 1.1.1.86 that catalyzes the conversion of acetolactate to 2,3-dihydroxyisovalerate and is
NADPH-dependent.”  Id. (citation omitted).  The district court then, inter alia, denied a motion by Butamax for SJ of literal infringement, granted Gevo’s motion for SJ of noninfringement under the DOE, granted Gevo’s motion for SJ of invalidity of claims 12 and 13 of the ’889 patent for inadequate written description, and also found claims 12 and 13 invalid for lack of enablement.  Butamax appealed.


“It cannot be disputed that the patentees offered a definition of KARI.  It is disputed, however, whether this definition ‘clearly expresses an intent’ to redefine KARI in a way that differs from the plain and ordinary meaning . . . and, if so, the extent of any such difference.”  Slip op. at 13.

On appeal, the Federal Circuit noted that the primary dispute between the parties was whether the claimed KARI must be “NADPH-dependent.”  The Court concluded that the plain meaning of KARI itself did not impose this limitation, and further that the patentees did not act as their own lexicographers by defining KARI to be NADPH-dependent.  The Court reasoned that while the patentees offered a definition for KARI, it did not clearly express an intent to redefine the term KARI as being NADPH-dependent.  The Court also agreed with Butamax that the references in the specification to other enzymes as using certain cofactors like NAD+ or NADH and/or NADPH did not imply that the patentees intended to limit KARI to exclude use of NADH.

The Federal Circuit disagreed with Gevo’s contention that the reference in claim 1 of the ’188 patent to an Enzyme Commission (“EC”) number for KARI required KARI to be NADPH-dependent.  The Court noted that the EC number referred to a mutant in which NADH could substitute for NADPH, and that Gevo described its own mutant enzymes (which it contended are not NADPH-dependent) by reference to that same EC number.  The Court stated it could not conclude that the reference to the EC number was an expression of a clear intent to redefine KARI.  The Court also noted that the district court’s claim construction improperly excluded a preferred embodiment, which was also the subject of a dependent claim, and that the prosecution history did not warrant any limitation of the claimed KARI as being NADPH-dependent.  The Court thus construed the enzyme term without imposing the limitation that it be NADPH-dependent.

Turning to the district court’s grants of SJ of infringement and invalidity, the Court first vacated the SJ of infringement and directed the district court to reconsider the question under the new claim construction.  The Court then reversed the SJ of invalidity of claims 12 and 13 of the ’889 patent, finding that the ’889 patent provided adequate written description for these claims.  The Court reasoned that Butamax identified sufficient evidence that at least created a genuine dispute of material fact.  The Court also reversed the district court’s judgment that these claims were invalid for lack of enablement, reasoning that “the judgment was a scrivener’s error.”  Id. at 26.

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