German Federal Supreme Court "Ankoppelungssystem" - admissibility of auxiliary requests

The nullity plaintiff has only attacked independent claim 1 of the patent, and not further sub-claims. In a nullity appeal proceeding, the patent owner made an attempt to defend the patent as granted, and in an auxiliary manner by including further features from granted sub-claims. The Supreme Court has decided hereto in a decision of March 1, 2017 (X ZR 10/15 „Ankopplungssystem“): „The defendant in a nullity action can only defend its patent to the extent that it is attacked by the nullity plaintiff. A limited defense of the patent in question by combining the attacked patent claim with features deriving from non-attacked sub-claims, or even one or more variants of non-attacked sub-claims is not admissible.” The Supreme Court does not see it as its task to render a judgment on a version of a patent to the extent that it is not attacked. Because the Supreme Court did not see claim 1 as granted to be based on an inventive step (in contrast to the first instance Patent Court), the patent owner has lost the proceedings over two instances. Consequently, the patent owner has to bear the costs of both instances. If only the independent claim 1 of a patent is attacked, the patent owner should try to defend the patent by including features from the description without reference to the sub-claims.