Equivalence: the swinging pendulum

While countries like the UK are often described as “literal countries” when it comes to their courts’ traditional reluctance to rule in favour of equivalence, Germany has remained a country where equivalence was always a possibility for patent owners who sought to enforce their patents.

In 2002, Germany’s Federal Court of Justice (Supreme Court) issued a string of very important decisions reaffirming and reshaping the criteria for claim construction and equivalent patent infringement. These decisions were largely understood to mean that there was a tendency in the court to limit the use of the doctrine of equivalence. Several later decisions seemed to reinforce that perception.

In 2011, the Supreme Court issued two decisions (Occluder and Diglyceride composition) in which the rule was developed that, in principle, equivalence had to be excluded if the patent specification mentioned several possibilities of how a technical effect could be achieved but only one had actually been included in the patent claim. In that situation, the “selection” of the one possibility included in the patent claim should be regarded as a deliberate “decision” that excluded, in the eyes of the court, other potentially effective subsitutes from being eligible as equivalent to the claimed solution.

New ruling

In a decision issued in June 2016, the Supreme Court again had the opportunity to refine that rule.

The case was a patent infringement case involving a patent concerning the use of pemetrexed disodium for use in combination therapy for inhibiting tumour growth in mammals. The Düsseldorf Court of Appeal ruled that the Occluder rule could also be applied in cases where a specific chemical composition “pemetrexed dipotassium” (whose classification as “equivalent” to the one claimed in the patent was in question) was not expressly disclosed in the patent specification but belonged to the same type of chemical compositions that was disclosed in the patent.

In such a situation, the Düsseldorf court held, the disclosure of a type of chemical composition had to have the same legal effect as a list of all specific compositions belonging to that type that were known at the priority date.

The Supreme Court dissented on this point, reversed the Düsseldorf court’s ruling and remanded the case back for further trial.

The Supreme Court held that the Occluder rule could not be applied to the set of facts that underlay the Düsseldorf court’s decision. While the Düsseldorf court itself had expressly recognised that, on the face of it, the facts differed from the facts underlying the Occluder rule, an analogous application was not appropriate, the Supreme Court held.