Ajinomoto Co., Inc. v. Int’l Trade Comm’n, Appeal No. 2018-1590 (Fed. Cir. Aug. 6, 2019)
Eli Lilly & Co. v. Hospira, Inc., Appeal No. 2018-2128 (Fed. Cir. Aug. 9, 2019)
Prosecution history estoppel typically forecloses a patent owner’s ability to claim infringement on equivalents in the territory between the original claim language and the finalized claim language. In two recent cases, however, the Federal Circuit showed its willingness to apply the tangential relation exception to prosecution history estoppel and find infringement under the doctrine of equivalents.