The Scope of a Swiss Claim

The Court of Appeal has now had a chance to look at Swiss claims in infringement proceedings, with some interesting results. Monsanto -v- Merck came before the Court of Appeal on an appeal from a decision to strike out the allegation that the Swiss claim was infringed. Monsanto alleged infringement of a patent for a non-steroidal anti-inflammatory drug (NSAID). One common side-effect of NSAIDs is gastric irritation and the patented class of product was said to reduce this side-effect. Although this was a new chemical class and so protectable per se, the patent also included at claim 20, a Swiss claim. The Swiss claim was in the form: "Use of a compound of claim 1 for preparing a medicament for treating inflammation or an inflammation/associated disorder". Merck intended to release a drug in which the active ingredient was known as MK-966. This was a "Keto form". Monsanto's claim 1 specifically covered the Enol form but not the Keto form and Monsanto contended that, after the Keto form had been administered to a patient, a significant amount of the Enol form would be produced. Moreover, Monsanto claimed that the Enolate form was also covered by the claim and that an Enolate anion (which produced both the Enol and Keto forms of MK-966) and the Enol form itself were present during production. They therefore alleged that claim 20 was infringed and, because a process claim is also infringed by importing and keeping the direct product of the process, that the final product also infringed this claim. The matter came before Pumfrey J on an application for disclosure of documents (previously called "discovery") and directions. He questioned whether any disclosure relating to the manufacturing process was really necessary and suggested that a strike out application be brought. Pumfrey J felt that this was a clear case of construction. He stated "the presence of the compound in question during the course of manufacture of the active ingredient is, accordingly, in my judgment, not use of the compound in question for preparing the medicament". In other words, Pumfrey J took the position that a Swiss claim was directed to the process step of using the active ingredient to make the medicament and accordingly struck out Monsanto's allegations that Claim 20 was infringed. The Court of Appeal took a completely different approach to the construction of the Swiss claim. The Court of Appeal held that the entire manufacturing process must be considered. Even if the infringing element was not the active ingredient, if it had been present at any stage during the manufacturing process, then there could be infringement. Consequently, the issue as to whether or not claim 20 had been infringed had to be understood in the context of the patent as a whole and a view on infringement could only be reached after the Court had heard the expert evidence and so been able to assume "the mantle of the man skilled in the art"