Ajinomoto Co., Inc. v. International Trade Commission, No. 18-1590 (Fed. Cir. 2019)Annotate this Case
Anjinomoto’s 655 patent claims E. coli bacteria that have been genetically engineered to increase their production of aromatic L-amino acids, such as L-tryptophan, during fermentation, as well as methods of producing aromatic L-amino acids using such bacteria. Ajinomoto filed a complaint against CJ with the International Trade Commission, alleging that CJ was importing certain products that infringed the patent. CJ used several strains of E. coli to produce L-tryptophan products, which it then imported into the United States. The Commission determined that CJ’s earlier strains did not infringe but that CJ’s two later strains did, and that the relevant claim of the 655 patent is not invalid for lack of an adequate written description. The Federal Circuit affirmed, upholding the Commission’s construction of “replacing the native promoter . . . with a more potent promoter.” The court rejected CJ’s claim of prosecution history estoppel and held that the 655 patent expressly provides four examples of “more potent promoters,” so that the Commission supportably found that a skilled artisan could make relatively predictable changes to the native promoter to arrive at a more potent promoter.