In a recent decision published here, the Düsseldorf district court had to decide on a preliminary injunction requested based on a patent on a substance containing a mixture of two substances – Leflunomid and Teriflunomid. The claims required among other things that the amount of Teriflunomid should fall in a range between 0,3% and 50% of the amount of Leflunomid.
The allegedly infringing embodiments contained a priori only the first substance Leflunomid. However, the patentee argued that due to certain chemical processes occurring under regular storage conditions at a temperature of 25°C and a humidity of 60%, the amount of second substance Teriflunomid would increase and reach the threshold of 0,3% after 6 months for a first embodiment and after 9 months for a second embodiment.
The court found the product to infringe the patent directly and literally (no contributory infringement as one might have presumed). It referred to the earlier judgement with the title “Traktionshilfe” of the Düsseldorf Upper District Court (OLGDüsseldorf I-2 U 139/09) departing from the general rule according to which all the features of a claim must be realized in the moment of the use in cases where the circumstances will change in a reliable and predictable way such that the features of the claim will be realized soon (“demnächst”).
Interestingly, the Bundespatentgericht (BPatG) had rejected a novelty attack based on very similar arguments in the co-pending nullity procedure (which can be found here ). The BPatG found that even if the conversion of Leflunomid into Teriflunomid may actually have taken place under certain storage conditions prior to the priority date, this conversion was not the consequence of a methodical (planvoll) technical activity but rather uncontrolled such that the actual technical teaching to use product with a certain composition was not known. If achieving the claimed composition is the result of a certain choice of storage conditions and there is no evidence that this choice was actually made, the claimed composition is novel.
This highlights an important difference between the assessment of novelty and infringement which results from the focus on the technical idea rather than on the tangible features. According to the decision, a product may be infringing a patent accidentally, e.g. as the result of a natural decay/conversion process. If the same product (but not the decay process) was known before the priority date and the circumstances leading to the decay/conversion process are actually not inevitable, it would not be novelty destroying.