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Patents Invalidated for Failing to Disclose Best Mode

March 08, 2010

Decision icon Decision

Last Month at the Federal Circuit - April 2010

Judges: Newman, Lourie (author), Linn

[Appealed from: ITC]

In Ajinomoto Co. v. International Trade Commission, No. 09-1081 (Fed. Cir. Mar. 8, 2010), the Federal Circuit affirmed the final determination of the ITC finding two patents, U.S. Patent Nos. 5,827,698 (“the ’698 patent”) and 6,040,160 (“the ’160 patent”), invalid for failure to comply with the best mode requirement.  The Federal Circuit also upheld the ITC’s final determination finding the ’698 patent unenforceable due to inequitable conduct.

Ajinomoto Co., Inc. (“Ajinomoto”), owner of both the ’698 and ’160 patents, filed suit before the ITC alleging that the Global Bio-Chem Technology Group Company Limited family of corporations (collectively “GBT”) infringed claim 15 of both of these patents.  Claim 15 of the ’698 patent recites a method for producing L-lysine by cultivating L-lysine produced by Escherichia coli (“E. coli”) having a mutant lysine decarboxylase gene, the ldc mutation.  Claim 15 of the ’160 patent recites a method for producing L-lysine by cultivating L-lysine produced by E. coli having a mutation to desensitize feedback inhibition of L-lysine, the dapA mutation.  The ’160 patent claims priority to a PCT application filed November 1994, which claims foreign priority to a Japanese application filed in 1993.

The ’698 patent describes inserting the ldc mutation into the WC196 strain of E. coli, the strain disclosed in the specification and deposited by the inventors in an international depository.  Similarly, the ’160 patent describes inserting the dapA mutation into two host strains, B-399 and W3110(tyrA).  But for both patents, it was undisputed during litigation that the actual strain used by the inventors when they filed their patent applications differed—WC80-196S (having an additional sucrose utilization gene) for the ’698 patent and AE-70 for the ’160 patent, both strains having additional undisclosed genetic mutations, including a lysC mutation.

Ajinomoto filed a complaint at the ITC in April 2006, alleging violation of section 337 vis-à-vis infringement of the ’698 and ’160 patents by GBT’s importation and sale of lysine feed products.  The ITC instituted an investigation, and GBT eventually admitted infringement of both patents before trial.  In July 2008, the ALJ rendered his initial determination finding no violation of section 337 due to invalidity of the patents—best mode violations in both patents—rendering the patents unenforceable for inequitable conduct.  In response, Ajinomoto petitioned to the ITC for review.  The ITC issued notice that it had chosen to review but had taken no position on the ALJ’s finding regarding the ’160 patent and did not review the remainder of the ALJ’s decision, thereby upholding the ALJ’s invalidity and unenforceability finding.  Ajinomoto then appealed to the Federal Circuit, arguing that the ITC made legal errors in defining the scope of its claimed inventions and the scope of the best mode requirement. 

The Federal Circuit first rejected Ajinomoto’s argument regarding claim scope, holding that while not every preference constitutes a best mode for purposes of 35 U.S.C. § 112, the preferred embodiment of the invention must be disclosed.  Accordingly, the Court reasoned that inventors had a duty to disclose their preferred host strains for practicing their inventions.  The Court pointed to claim language in both the ’698 and ’160 patents reciting, respectively, “cultivating an isolated microorganism” and “cultivating a bacterium belonging [to] the genus Escherichia,” as evidence that the claimed inventions included not only the genetic mutations used by the inventors but also the bacterial host strains containing those mutations.  Because the claimed bacterial host strains were within the claim scope, the Court concluded that the best mode requirement obligated Ajinomoto to disclose its best bacterium for carrying out the inventions.  And since Ajinomoto failed to disclose the bacterium used and preferred by the inventors, the Court found that the claims were invalid for violating the best mode requirement.

The Federal Circuit then turned to Ajinomoto’s argument that even if the best mode requirement extends to the bacterium used to practice claim 15 of the ’698 patent, the ITC erred in its application of the best mode requirement.  Ajinomoto contended that there was no best mode violation for not disclosing the unclaimed host strain used in their invention, and also argued that the inventors met the best mode requirement for the ’698 patent because the inventors publicly deposited a strain containing one of the additional undisclosed genetic mutations, the lysC mutation.

The Federal Circuit rejected each of these arguments as well, agreeing with the ITC that the inventors violated the best mode requirement by concealing the identity of their preferred host strain and other genetic alterations they introduced into their E. coli.  The Court held that the best mode requirement cannot be satisfied by the deposit of a nonpreferred strain.  Specifically, the Court found that the inventors preferred the strain WC80-196S but had only deposited the strain WC80-196, which lacked the undisclosed sucrose utilization gene used by the inventors.  Furthermore, the Court noted that the inventors did not even use WC80-196 when practicing their own invention.  The Court found that the deposited strain contained the lysC mutation but that the specification contained no disclosure of that fact, and one skilled in the art would not have known that the strain had such an alteration.  Accordingly, the Court concluded that the deposited strain having the lysC mutation failed to enable one of skill in the art to practice the inventors’ preferred embodiment.

Lastly, with regard to the ’160 patent, Ajinomoto separately argued that the ITC erred in invalidating claim 15 because, even if Ajinomoto concealed its best host strain as of the filing date of its 1993 Japanese application, the only result would be that Ajinomoto cannot rely on that application for priority purposes under 35 U.S.C. § 120.  Instead, Ajinomoto attempted to alter its priority date of the ’160 patent to the November 1994 PCT priority date on appeal.  The Federal Circuit rejected this argument, instead agreeing with the government and GBT that Ajinomoto had waived its right to rely on its PCT application’s filing date.  The Court reasoned that Ajinomoto had expressly relied on the Japanese priority date throughout litigation, which foreclosed GBT from offering prior art publicly available between the Japanese priority date and the PCT application filing date.  Ajinomoto’s reliance on the Japanese priority date had also foreclosed any attempt by GBT to attack Ajinomoto’s PCT’s application’s compliance with the best mode requirement.  The Court concluded that a patentee cannot reverse a finding of invalidity by unveiling after trial an alternative priority date upon which it would now like to rely.