Federal Circuit Patent Updates - March 2018

Lourie, J. Reversing district court's dismissal of claims based on claim preclusion and the Kessler doctrine where plaintiff had asserted terminally disclaimed continuation patents against products previously found not to infringe parent patents. Although the new patents issued after the first action was commenced, they could be barred by claim preclusion, but the district court erred in presuming that the new patent claims were precluded based on a common specification and a terminal disclaimer. "Where different patents are asserted in a first and second suit, a judgment in the first suit will trigger claim preclusion only if the scope of the asserted patent claims in the two suites is essentially the same." However, "[a] although a terminal disclaimer does not conclusively show that a child patent involves the same cause of action as its parent, the terminal