Day: August 1, 2019

Infringement under the Doctrine of Equivalents is Barred by Prosecution History Estoppel

The Federal Circuit recently affirmed dismissal of the patent owner’s lawsuit brought for patent infringement under the doctrine of equivalents in Amgen Inc. v. Coherus Biosciences Inc., 2018-1993 (Fed. Cir. July 29, 2019).  The case illustrates one of the potential difficulties a patent owner may encounter under the doctrine of equivalents.  Prosecution history estoppel is a defense to a charge of infringement under the doctrine of equivalents, and prevents a patent owner from recapturing subject