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Guerbet v. Bayer Pharma AG, Paris First Instance Tribunal, 23 March 2018, n°184/2015

In this ruling, the Paris First Instance Tribunal dismissed the invalidity claims brought by Bayer Pharma against Guerbet’s FR patent.

This decision includes a very detailed reasoning of the validity assessment, which notably follows the EPO problem-solution approach, which lead to the dismissal of the lack of inventive step claim. This is particularly interesting since French rulings are not usually extensively detailed, and French courts rarely disclose their problem-solution reasoning, leading sometimes to wonder whether they follow such reasoning at all. Moreover, whereas the EPO Opposition Division limited the corresponding EP, the French Court upheld it in its original granted version. This case is an example that French Courts can, and sometimes does, have (surprisingly) a more patent-friendly approach than the EPO.

Guerbet’s patent relates to a “Process for preparing a pharmaceutical formulation of contrast agents”. It relates to a process for preparing a liquid pharmaceutical formulation which is of use as a pharmaceutical contrast agent in medical imaging, in particular in magnetic resonance imaging (MRI), the contrast agent being a substance which makes it possible to visualize, by an increase in contrast, an anatomical structure (an organ for example) or a pathological condition (a tumour for example) which naturally shows little or no contrast, and which otherwise would be difficult to distinguish from the neighboring tissues.

The contrast agent at issue is a metal. Chelates are then used to bind with the metal, so as to form a “complex”. Said metal, when it is free, that is to say when it is not complexed with a chelate, is toxic to human beings such that it is impossible to inject it directly into the human body. For this reason, in order to prevent metal from “escaping” from the complexes after they have been administered and being found in the free state in the body, the pharmaceutical formulations described Guerbet’s patent also comprise between 0.002 and 0.4% mol/mol of excess “free” macrocyclic chelate. The role of this excess, as stated by the patent, is to “capture” the metal atoms that would be free. Thus, the role of the patent is to prevent an unwanted release of metal in the human body. The patent covers a product marketed as DOTAREM.

Bayer Pharma had raised several grounds for invalidity, including lack of inventive step.

The Tribunal starts by defining the technical problem of the invention as the one that aims to propose a process for the preparation of the DOTAREM product, which makes it possible to reliably determine the respective amounts of complex of chelate with the metal and of free chelate in low concentration in the pharmaceutical formulation, in order for it to be reproducible and for it to enable an application on an industrial scale.

The Tribunal then methodologically assesses which from the prior art documents presented by Bayer Pharma should be considered as the closest prior art documents. It then ultimately selects a combination of the DOTAREM notice and a US patent application.

The Tribunal then assesses inventive step in relation to the closest prior art. It starts by dismissing the claim from Bayer Pharma that, submit that Guerbet “does not demonstrate why a person skilled in the art would not have had a “reasonable expectation of success” by carrying out the processes of the prior art that were perfectly available to a person skilled in the art in order to achieve the processes of Claims 1 and 2 on the basis that without any evidence in support of such claim, Bayer is simply trying to reverse the burden of proof.

For the same reason, the Tribunal then dismisses the Claim from Bayer Pharma that Guerbet does not demonstrate an improved effect on the basis that there is no reason to wonder, for assessing the inventive step, whether or not there is an effect that is improved by this patent compared with other processes.

To conclude the assessment on inventive step, the Tribunal compares the invention with the closest prior art selected and finds that it is not merely the result of implementing operations known to a person skilled in the art, but is the arrangement of several steps corresponding to precise conditions which do not emerge from the data of the prior art.

The Tribunal also ordered Bayer Pharma to pay 90,000 euros in legal fees.

A copy of the decision (in English) can be found here.
A copy of the decision (in French) can be found here.

Headnote and translation in English: Raphaëlle Dequiré-Portier and Marie-Ange Pozzo di Borgo, GIDE LOYRETTE NOUEL