In Marine Polymer Technologies, Inc. v. Hemson, Inc., No. 2010-1548 (Fed. Cir. Mar. 15, 2012), the Federal Circuit en banc held that intervening rights for an accused infringer arise only when a patentee actually changes the text of a claim during reexamination.  Here, a jury found that the defendant had infringed a valid patent and awarded the patentee $29.4 million.  On appeal, a Federal Circuit panel reversed the jury award based on intervening rights acquired by the defendant during reexamination because the patentee made arguments during reexamination that affected the claim scope.  The patentee asked the Federal Circuit to review the panel’s decision en banc.  Sitting en banc, the Federal Circuit vacated the earlier panel’s reversal of the jury award.  The Federal Circuit reasoned that the plain and unambiguous language “amended or new” in 35 U.S.C. § 307(b) is a term of art in patent prosecution and requires “formal changes to the actual language of the claim.”  The Federal Circuit said that a claim cannot be “amended” without changing the claim language itself.  The Federal Circuit rejected the accused infringer’s argument that disavowal or disclaimer by the patentee, without more, can “amend” a claim by changing the claim scope.