German Federal Court of Justice decided on Doctrine of Equivalence in the field of chemistry and confirms indicative effect of statements during patent prosecution

In the recent judgment Pemetrexed of June 14, 2016 (X ZR 29/15), the Federal Court of Justice had to decide for the first time on an infringement case under the Doctrine of Equivalence relating to the medical use of a chemical compound. In this context, it was also discussed whether statements during patent prosecution can have an indicative effect.

In short

The Court confirms an earlier Court decision and states that it is admissible to consider statements during patent prosecution for claim interpretation. According to the Court, this also applies to statements by the Examiner during prosecution. However, such indications should not be used as sole basis for claim interpretation.

With the present Decision, the FCJ Federal Court of Justice has clearly strengthened the indicative role of patent prosecution for claim interpretation in Germany, in particular in the context of the Doctrine of Equivalence. Accordingly, it is recommendable to prosecute EP and DE patent cases diligently with respect to statements on the interpretation of features, in order to avoid a negative indicative effect in a later patent infringement case in Germany.

The Case

The patent which is subject of the present infringement case relates the use of pemetrexed disodium in the manufacture of a medicament for use in combination therapy for inhibiting tumor growth in mammals.

The allegedly infringing product comprises the dipotassium salt of pemetrexed.

In addition to the statements on the indicative role of statements during patent prosecution, the Court has clarified that an infringement under the Doctrine of Equivalence may in priciple also apply to features relating to chemical compounds.

In the Decision, the Court further considers a plurality of aspects to be taken into account for assessing equivalence, and emphasizes that there is a difference in whether a selection was made during patent prosecution to claim one of two more alternatives, or, whether – as in the present case – the potentially infringing equivalent is not explicitly disclosed in the patent, but is only encompassed by a generic term disclosed in the patent.

Moreover, the Court indicates that second medical use claims in general, including Swiss type medical use claims, such as the claim in question, are to be interpreted as purpose-restricted compound claims. This claim interpretation has to be considered in the present case for assessing a potential contributory infringement.

The Federal Court of Justice has set aside the Decision of the Higher Regional Court of Dusseldorf. Accordingly, the Higher Regional Court of Dusseldorf will have to reconsider the infringement case taking into account the rules set by the Federal Court of Justice, in particular regarding the Doctrine of Equivalence and contributory infringement of second medical use claims.