There has recently been debate about the infringement of second medical use claims, in particular with regard to cross label use and skinny labelling. While the manufacturing and marketing as well as the use of the known drug may be off-patent, the manufacturing, marketing and use for the second medical purpose falls within the scope of protection of the patent. However, the practical enforcement of second medical use patents, in particular with regard to bringing evidence and in cases of cross label use is rather difficult in practice. The following article will take a closer look at the requirements for proving infringement in Germany.

Liability in general

There are only a few, but well established, cases in Germany on the question of infringement. In most cases, the party marketing the drug with instructions on the label that describe the patented use has been sued by the patent owner. Such a party might be liable for direct infringement because by adding the instructions, the drug is manifestly arranged for the use claimed in the patent ("sinnfällige Herrichtung").1 Such manifest arrangement is not necessarily made by the instructions on a label, although this is the most frequent way. Other ways may include the formulating, dosing or providing of ready-to-use preparations of a drug, provided that it is done to achieve the patented purpose.

However, a manifest arrangement requires that the purpose of use is closely linked to the product as marketed. There have been two recent cases where it has been found that information about the drug in marketing materials and flyers as well as explanations made by sales people, are not sufficiently attributable to the product.2 The courts denied direct infringement despite the sales people explaining that the product could also be used for the patented purpose were employees of the drug manufacturer. The courts argued that the drug had been marketed as such – in a way not being covered by the second medical use patent. As the flyers, marketing materials and explanations were not directly linked to the product, it is not certain that the customer would have taken them into consideration at all so it is not clear that the patented purpose of the second medical use patent would have been fulfilled.

In principle, the physician prescribing a drug could be liable for patent infringement, in particular if a drug is prescribed for "off-label" or "cross-label" use3 as he/she is not exempted from patent infringement under the German Patent Act4. However, there is so far no case law known where a physician would have been sued by a patent proprietor. The potential liability of the pharmacist also very much depends on the regulatory qualification of the drug.

Indirect infringement

It is interesting to note that indirect infringement has not been alleged in the two cases referred to above. The plaintiff did not allege indirect infringement might be due to the fact that according to established case law, only the offering and supply for the purpose of enabling the manifest arrangement of the product can constitute indirect infringement. This means that the offering or supplying for the purpose of the immediate use does not constitute indirect infringement.5

Liability for indirect infringement in general requires that the manufacturer must have known, or it must have been obvious from the circumstances, that the drug was suitable and intended to be used for the use of the invention (Section 10 German Patent Act). In particular, in cases of cross-label use, it is very much a question of finding facts and evidence to prove such knowledge or obviousness, respectively. There is no case law on this specific question in Germany yet, on whether and to what extent only indications for a potential cross-label use such as a higher number of sales can create the necessary subjective link, bearing in mind that the manufacture of the medicament as such is in the public domain and allowed.

In case there is indirect infringement, injunctive relief can only be requested with regard to the prohibition of enabling the patented use. Also, the claim for damages might be difficult to enforce: because the indirect infringer must pay the damage caused by the direct infringement, the patent proprietor must prove direct infringement. In practice, it turns out to be very difficult to bring evidence for the amount of damages when the product could be used for patented as well as for non-patented purposes.

Cross-label use

As explained above, the marketing and sale of a drug might constitute infringement if the drug has been manifestly arranged for the patented purpose. Given the recent case law on marketing flyers and advertisements, it is difficult to imagine a case where the cross-label use, for example the prescription of the drug for the patented use by a physician, is sufficiently attributable to the marketing and sale of the drug. Nonetheless, it is to be noted that recent case law neither reflects on the liability of the sales persons making such indications to customers nor examines the liability of physicians for a cross-label prescription.

Any new developments due to new EPC2000 claims?

There are discussions about the question of whether the scope of protection of EPC2000 claims (that is, second medical use claims made in the form "X for use in treating Y") would be different compared to purpose limited use claims / Swiss-type claims as they are not use claims, but product claims. With regard to EPC2000 claims there is no case law on infringement yet.6

The recent "Kollagenase I" decision7 of the German Federal Supreme Court related only to the patentability of second medical use claims. Hence, it did not reflect on the scope of protection of EPC2000 claims in contrast to purpose-limited use claims / Swiss-type claims. Nonetheless it is to be noted that the German Federal Supreme Court did in the end not distinguish between the different kinds of claim language.