Irvine, Calif., February X, 2018 – Knobbe Martens, one of the leading intellectual property law firms in the United States, has received a U.S. District Court ruling in Iceutica Pty Ltd., et al. v. Lupin Limited, et al. dismissing all claims of patent infringement against client Lupin Limited and Lupin Pharmaceuticals, Inc. (“Lupin”).

Judge Marvin Garbis of the U.S. District Court for the District of Maryland concluded that plaintiffs iCeutica Pty Ltd. and Iroko Pharmaceuticals, LLC, which filed the lawsuit in February 2017, were barred from asserting that Lupin’s products (generic forms of Vivlodex®) infringed plaintiffs’ patents under the doctrine of equivalents. Plaintiffs had asserted that Lupin’s products infringed the claims of U.S. Patent Nos. 9,526,734 (“’734 patent”) and 5,649,318 (“’318 patent”). The claims require a certain particle size which Lupin’s products did not literally infringe.

In its Motion for Summary Judgment, Lupin argued that prosecution history estoppel applied, legally barring Plaintiffs from asserting that Lupin’s products infringed under the doctrine of equivalents. During prosecution of the ’734 and ’318 patents, plaintiffs had repeatedly narrowed the particle size limitations to overcome the prior art and had argued that the claimed particle size was a distinguishing feature over the prior art. In opposition to Lupin’s Motion for Summary Judgment, plaintiffs argued that prosecution history estoppel did not apply as any amendments made during prosecution were merely tangential to the alleged equivalent.

Judge Garbis heard oral argument on the motion in December 2017 and issued his opinion on February 1. He ruled in favor of Lupin finding that both argument-based and amendment-based prosecution history estoppel applied. As plaintiffs could not prove literal infringement of the particle size limitation and were barred from asserting infringement under the doctrine of equivalents, Judge Garbis dismissed the case.