The following is excerpted from a September 12, 2011 article by Heather Morehouse Ettinger, Ph.D. of McDermott Will & Emery posted at the National Law Forum:
Addressing whether an amendment narrowing the claim scope during the prosecution limited the patentee’s ability to capture a generic’s different, but potentially equivalent, product as infringing, the U.S. Court of Appeals for the Federal Circuit affirmed a decision on summary judgment, finding that prosecution history estoppel applied and barred the application of the doctrine of equivalents (DOE). Duramed Pharmaceuticals, Inc. (Teva Women’s Health) v. Paddock Laboratories, Inc., Case No. 10-1419 (Fed. Cir., July 21, 2011 (Lourie, J.).
The district court granted Duramed’s motion for summary judgment of non-infringement, finding that the narrowing of the claims to recite a particular moisture barrier coating in view of the prior art was substantially related to patentability and, therefore, under Festo, a presumption of prosecution history estoppel applied. The district court further found that Duramed had not overcome this presumption, and thus the DOE could not be applied, because the prior art illustrated that polyvinyl alcohol moisture barriers were foreseeable. Duramed appealed.
The Federal Circuit affirmed, agreeing with the district court that, under Festo, because Duramed narrowed the scope of the claims during prosecution, a presumption of prosecution history estoppel applied.
Read the full article here.