This is an informal case summary prepared for the purposes of facilitating exchange during the 2025 WIPO IP Judges Forum.
Session 2: Pharmaceutical Patents
Federal Court of Justice, Germany [2013]: Case No. BGH X ZR 141/10 – PNGase
Date of judgment: October 29, 2013
Issuing authority: Federal Court of Justice (Bundesgerichtshof)
Level of the issuing authority: Final Instance
Type of procedure: Judicial (Commercial)
Subject matter: Patents (Inventions)
Plaintiff: R.
Defendant: G.
Keywords: Inventive step, Expectation to succeed, Costs and efforts for research
Basic facts: Citing lack of patentability, the plaintiff challenged the validity of a patent for a purified nucleic acid comprising a nucleotide sequence encoding an enzyme having PNGase activity produced by the bacterium Flavobacterium meningosepticum.
The enzyme PNGase F was used in the prior art for structural analyses of glycoproteins. This enzyme occurs in Flavobacterium meningosepticum together with the enzyme Endo F. These enzymes split off the carbohydrate chains of glycoproteins. However, Endo F splits at a different point than PNGase F. Experts therefore aimed to work with PNGase F that was completely free of Endo F.
The skilled person knew that Flavobacterium meningosepticum contains a nucleotide sequence as a genetic code on the basis of which this bacterium produces the enzyme PNGase F. The skilled person was therefore motivated to determine this nucleotide sequence in order to use it to produce PNGase F without Endo F in another organism, even though there was little need for this in view of other production methods.
Based on the idea of being able to produce PNGase F in another organism, the skilled person was generally aware of the path to such a further development from inter alia standard works and various articles. Various difficulties could arise along this path, but the skilled person was also aware of how to overcome them.
The Federal Patent Court ruled that the invention did not involve an inventive step. The known methods for purifying the enzymes of Flavobacterium meningosepticum to obtain PNGase F free of Endo F were associated with high costs and time expenditure. The skilled person therefore considered recombinant production in another organism to be an obvious solution. The skilled person had access to the gene bank specific to Flavobacterium meningosepticum and thus to the starting materials required for a cloning strategy. Technical difficulties may have arisen in the process. However, overcoming these did not require any inventive effort.
Held: The Federal Court of Justice, having the power to review findings of fact as well as law, reversed the decision of the Federal Patent Court and dismissed the action for invalidation of the patent in suit, finding that it was not obvious to follow the path to determine the nucleotide sequence encoding the enzyme PNGase F.
Relevant holdings in relation to pharmaceutical patents: By finding the DNA sequence using the path known to them, the skilled person would have determined the nucleotide sequence for PNGase F. However, the skilled person would only have had reason to follow this path if there were sufficient expectations of success for determining this sequence and, beyond that, for being able to produce PNGase F in another host organism free of Endo F.
Whether an expectation of success can be considered sufficient to render pursuing a path toward the desired result obvious does not depend solely on the probability of success. Rather, what is decisive is an overall assessment that takes into account the urgency of solving the technical problem and the expected technical or economic benefits, as well as the effort and costs of the necessary work, the lack of alternatives, the nature, scope, and impact of difficulties that may arise along the way, and, finally, the risk that such difficulties could make achieving the objective considerably more difficult or even unattainable.
In view of the various risks involved in determining a method for producing PNGase F in another organism, the skilled person has to weigh the time and effort that would have been required for this development. Such projects would normally represent a significant part of a doctoral thesis. Conducting such a lengthy series of experiments, fraught with risks that would only become apparent at the end, therefore the project of recombinant heterologous production of PNGase F would hardly seem an obvious further development.
Relevant legislation: Section 56 of the European Patent Convention (EPC)