Duramed Pharm., Inc. v. Paddock Labs, Inc.

by
Plaintiff, a pharmaceutical company, owns a patent that claims conjugated estrogen pharmaceutical compositions for use in hormone replacement therapies. Plaintiff alleged infringement of the patent based on defendant's Abbreviated New Drug Application for a generic version of plaintiff's hormone replacement therapy product, arguing the doctrine of equivalents. The district court entered summary judgment for defendant. The Federal Circuit affirmed. Plaintiff failed to rebut the presumption of prosecution history estoppel based on unforeseeability. The doctrine of prosecution history estoppel prevents a patent owner from recapturing, through the doctrine of equivalents, subject matter surrendered to acquire the patent. Because plaintiff narrowed the scope of the patent's claims in response to a prior art rejection, a presumption of prosecution history estoppel applies. View "Duramed Pharm., Inc. v. Paddock Labs, Inc." on Justia Law