Patent Law

Ajinomoto Co., Inc. v. International Trade Commission (Fed. Cir. 2010)

The ITC held that Ajinomoto's patents were invalid for failure to satisfy the best mode requirement of 35 U.S.C. 112. On appeal, the Federal Circuit affirmed.

The two asserted patents relate to methods of producing L-lysine using GM E. coli and include fairly broad claims. L-lysine is used in animal feed and is now a multi-billion-dollar market. The patent discloses one way to create the L-lysine producing E. coli. However, by the time they filed the patent application, the inventors had identified another, better strain. The evidence showed that Ajinomoto intentionally withheld that information.

The best mode doctrine requires that the inventor disclose the preferred embodiment of the invention and any preferences that materially affect properties of the claimed invention, but only to the extent that information is subjectively known by the inventor at the time the application was filed. There are four major caveats to the law of best mode. (There is no duty to supplement the best mode disclosure during prosecution). The scope of the required best mode disclosure is commensurate with the scope of the claims. [updated] This has been termed the "two-way street" of the best mode requirement: "the best mode requirement is a ?two-way street,? for which a patentee?s obligations are no broader than the right to exclude." Thus, "the best mode does not extend to unclaimed, non-novel subject matter."

Here, Ajinomoto was tripped-up by the breadth of its claims. Ajinomoto's asserted claim recited the step of "cultivating a bacterium belonging the genus Escherichia . . . having mutation to desensitize feedback inhibition of L-lysine." It was easy then for the the court to hold that Ajinomoto should have recited its preferred host strain.

By defining the invention to include the host strains, we do not read the Commission?s decision as requiring the disclosure of any and all preferences related to the production of lysine, as Ajinomoto claims. The Commission simply defined the scope of the claimed invention to include ?cultivating a bacterium? as recited by the asserted claims. Also, the Commission did not, as Ajinomoto asserts, require the disclosure of all subject matter having to do with the claim term ?bacterium.? The Commission simply required the disclosure of the preferred and, for the ?698 patent, only bacterial strain that the inventors used to practice the claimed invention.

Ajinomoto unsuccessfully argued that this result was contrary to the precedent of Christianson v. Colt Industries Operating Corp., 822 F.2d 1544 (Fed. Cir. 1987), AllVoice, Zygo, and Bayer.

Patent Reform: The Patent Reform Act of 2010 would eliminate the invalidity defense of failure to satisfy the best mode and therefore would flip the verdict in a case such as this.