Fed. Cir. affirms dismissal based on claim preclusion.  In a prior suit, the district court found that Senju’s patent claims were invalid, but Senju instituted a re-examination and obtained an amended version of one claim and several new claims. Senju filed a new suit based on the re-examined claims.

Senju Pharm. Co., Ltd. v. Apotex Inc., ___ F.3d ___ (Fed. Cir. Mar. 31, 2014) (Newman, PLAGER, O’Malley (dissenting)) (D. Del: Robinson) (3 of 5 stars)

Claim preclusion barred the second suit directed at the same ANDA filing.  The only dispute was whether the two suits involved the same “cause of action,” i.e., “whether the same patent, or more precisely the same patent rights, were involved in both suits.”  Slip op. at 9.  Interpreting Aspex Eyewear, 672 F.3d 1335, the Fed Cir held that reexamined claims “do not in and of themselves create a new cause of actions that did not exist before” because “a so-called ‘reexamined patent’ is the original patent” and “does not involve the filing of a new patent application nor the issuance of a new patent.”  Id. at 13.  Moreover, reexamined claims may not be broader than those in the original patent, so “in the absence of a clear showing that such a material difference in fact exists in a disputed patentable reexamination claim, it can be assumed that the reexamined claims will be a subset of the original claims and that no new cause of action will be created.”  Id. at 15.  Here, the only change was the addition of limiting words, so there was no new cause of action.

Dissent:  Judge O’Malley argued that “[a]lthough reexamined claims cannot be broader in scope than original claims, they sometimes grant broader rights than original claims” because they may be valid and thus confer a right to exclude that the original, invalid claims do not.  Dissent at 2.  She distinguishedApex because the prior judgment there involved a finding of non-infringement, not invalidity.  She would have thus remanded for a determination of whether the re-examined claims were substantially the same as the original claims.