In Marine Polymer Technologies v. HemCon, 672 F.3d 1350 (2012), the U.S. Court of Appeals for the Federal Circuit recently reaffirmed that a patentee cannot recover damages in a patent infringement case after amending its patent claims in re-examination. The Federal Circuit clarified, however, that a patentee is not barred from recovering damages in litigation if it argues for a narrow interpretation of its claims, so long as it does not change the claim language. This Federal Circuit en banc decision was much-awaited by in-house and patent litigation counsel given the uncertainty created by a Federal Circuit decision issued last year. In that earlier decision, a three-judge panel held that a patentee’s arguments made during re-examination — referred to by the court as “amendments in effect” — prevent recovery of damages. The recent Marine Polymer decision is a stern reminder that re-examination, if pursued in the face of litigation, must be carefully coordinated within an overall comprehensive patent litigation strategy.

Background

Re-examination is a proceeding whereby the U.S. Patent and Trademark Office decides whether the claims of an issued U.S. patent should be permitted to stand in light of prior art. In recent years, we have seen re-examinations initiated by companies threatened with or named as defendants in district court patent litigation. In a re-examination, the PTO may cancel patent claims that are deemed not patentable. Likewise, the patentee may need to amend its claims, for example making them narrower, to survive a re-examination. A re-examination may also conclude with the claims being unchanged and the patentability being confirmed and/or with new claims issuing. If patent claims are confirmed as patentable, it would naturally be more difficult to challenge their validity thereafter in litigation.