Kateryna Kon /
7 August 2019AmericasSarah Morgan

Fed Circ backs ITC on E. coli patent dispute

The US Court of Appeals for the Federal Circuit yesterday, August 6, affirmed a US International Trade Commission (ITC) decision to uphold a patent related to E. coli bacteria.

In the precedential decision, the Federal Circuit said that the ITC was correct to find that Japanese food and biotech company Ajinomoto’s patent was valid and that the importation of certain animal feed supplements was infringing.

Ajinomoto’s patent, US number 7,666,655, claims E. coli bacteria that have been genetically engineered to increase their production of aromatic L-amino acids, such as L-tryptophan, during fermentation.

In May 2016, Ajinomoto filed a complaint against South Korean food company CJ CheilJedang.

Ajinomoto accused CJ of infringing its patent by importing animal-feed-grade L-tryptophan products produced by a process covered by the ‘655 patent.

CJ had used several strains of E. coli bacteria to produce L-tryptophan products and, after
instituting an investigation, the commission determined that CJ’s earlier strains didn’t infringe but that CJ’s two later strains did.

The ITC also concluded that the relevant claim of the ‘655 patent wasn’t invalid for lack of an adequate written description.

Subsequently, Ajinomoto appealed against the ITC’s claim construction underlying the determination of no infringement by the earlier strains and CJ cross-appealed aspects of the determination of infringement by the later strains and the rejection of the invalidity challenge.

But yesterday, the court sided with the ITC.

Ajinomoto’s argument that the commission had erred in its claim construction and that the earlier strains were infringing was rejected by the Federal Circuit.

CJ had argued that its own on-E. coli yddG gene wasn’t an equivalent of Ajinomoto’s amino-acid sequence of the E. coli YddG protein.

The court said: “CJ argues that the two proteins do not perform the same function in the same way because the E. coli YddG protein exports aromatic L-amino acids such as L-tryptophan, whereas the non-E. coli YddG protein exports a different compound—namely, paraquat (also known as methyl viologen).”

In its finding, the court said that substantial evidence supported the ITC’s finding that both proteins perform the same function.

Finally, the court rejected CJ’s attempt to reverse the commission’s rejection of its invalidity challenge.

Circuit Judge Richard Taranto, on behalf of the court, said: “CJ’s argument both assumes too strict a legal standard and reads too much into its cited references. Adequate written description does not require a perfect correspondence between the members of the genus and the asserted common structural feature; for a functionally defined genus like the one at issue here, we have spoken more modestly of a ‘correlation between structure and function’.”

The Federal Circuit affirmed the ITC’s decision, without making a costs order.

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