Cofactor Key Factor as Gevo Dodges Injunction

June 26th, 2012 by Eric Lane Leave a reply »

Biobutanol maker Gevo dodged a bullet with a big win last week in its expanding patent war with Butamax Advanced Biofuels (Butamax) (see previous posts herehere, here, here, here, and the post on Butamax’s opening shot).

While Butamax did have exactly one week of satisfaction after the District Court for the District of Delaware issued a Temporary Restraining Order prohibiting any new sales of Gevo’s bio-based isobutanol, the bigger victory went to Gevo when the court denied Butamax’s motion for a preliminary injunction.

Butamax had requested the court enjoin Gevo from infringing U.S. Patent No. 7,993,889, entitled “Fermentive production of four carbon alcohols” (’889 Patent).  The ’889 Patent is directed to a more cost efficient method of producing isobutanol directly from pyruvate via a particular production pathway using recombinant microbial host cells.

To determine whether Butamax was likely to succeed on the merits (and thus deserving of preliminary injunctive relief) the court zeroed in on the heart of the infringement question, which turns on the interpretation of a key claim term.

More particularly, the parties disputed the meaning of the term “acetohydroxy acid isomeroreductase enzyme,” also known as a “KARI.”  KARI is the enzyme used in one of the steps of claim 1 of the ’889 Patent.

A KARI needs a cofactor that donates electrons to enable it to catalyze a reaction, and the issue was whether a KARI is defined with respect to NADPH or NADH cofactors.

Critical to resolution of this issue, the ’889 Patent expressly defines acetohydroxy acid isomereductase as:

an enzyme that catalyzes the conversion of acetolactate to 2,3-dihydroxyisovalerate using NADPH (reduced nicotinamide adenine dinucleotide phosphate) as an electron donor

The court noted that the ’889 Patent specifically states that other enzymes use “NADH and/or NADPH as an electron donor.” 

Guided by the statements in Butamax’s ’889 Patent, the court construed acetohydroxy acid isomeroreductase as being defined with respect to NADPH only:

Accordingly, the court interprets the term acetohydroxy acid isomeroreductase in the manner in which plaintiff defined it, namely, as an enzyme that is solely NADPH-dependent (as opposed to NADH-dependent or NADH and NADPH-dependent).

Because Gevo uses an NADH-dependent enzyme, the court found it unlikely that Butamax would prevail on infringement of the ’889 Patent:

[B]y defining the KARI as exclusively NADPH-dependent, plaintiff has placed defendant’s use of an NADH-dependent, or primarily NADH-dependent enzyme, outside the scope of claim 1.

As to validity of the ’889 Patent, the court observed that claims 1 and 14 have been rejected as anticipated by the U.S. Patent and Trademark Office upon reexamination.

The patent examiner based his rejection on the inherent capability of enzymes in yeast cells to carry out the anabolic pathway claimed in the ’889 Patent:

[Y]east converting pyruvate to isobutanol inherently possesses the enzymes capable of carrying out isobutanol synthetic pathway reactions found in claim 1.

Due to the questionable validity of the ’889 Patent and Gevo’s strong non-infringement position, the court denied Butamax’s motion for a preliminary injunction.

A couple of days after the preliminary injunction decision, the court issued an opinion on Butamax’s motion on the pleadings in which it denied Butamax’s motion for a judgment that it does not infringe Gevo’s U.S. Patent Nos. 8,017,375 and 8,017,376.

The court found the infringement claims “particularly ill suited for disposition on a motion of judgment” because of the complexity of the technology but did indicate it might be willing to entertain focused discovery to expedite resolution of the claim.

So Butamax has stumbled out of the gate, but will no doubt continue the race.

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