Posts Tagged: "reexam"

Companies accused of patent infringement are increasingly looking at patent reexamination at the Patent Office as an attractive avenue for challenging the patent’s validity. Reexamination offers a number of well-known advantages as a forum for such validity challenges over District Court, among them the absence of a presumption of validity and a lower burden of proof. Less well-known, however, is the potential for reexamination to eliminate an accused infringer’s liability for past damages – even if the PTO confirms the validity of a patent in reexamination, the accused infringer might be entitled to “intervening rights,” effectively eliminating past damages, if the patent owner amends its claims to distinguish its invention over the prior art. This possibility of “intervening rights” received a big boost last week with the CAFC’s decision in Marine Polymer Techs. v. HemCon, finding that such rights may be created even without an amendment of the claims if the patent owner presents arguments in reexamination that “effectively amend” the claims.