The Munich Local Division revoked EP 3 346 403 in its entirety for added matter and, for that reason and for lack of actual infringement, dismissed the infringement action brought by the proprietor. The decision clarifies that the mere disclosure of breast cancer samples in experimental data does not amount to a disclosure of an invention limited to breast cancer. Not everything mentioned in the original disclosure can serve as a basis for a claim amendment.
The claimant asserted direct and indirect infringement of EP 3 346 403, which relates to a method for quantifying gene expression in FFPE breast cancer tissue using OAZ1 as an endogenous reference gene. The defendants lodged a counterclaim for revocation. In response, the claimant filed three auxiliary requests.
The Court decided both the infringement action and the counterclaim for revocation in a single decision.
The Court revoked the patent for added matter, holding that claim 1 as granted extended beyond the content of the parent application as filed.
A central issue was whether the parent application directly and unambiguously disclosed:
The Court answered both questions in the negative.
The Court accepted that breast cancer tissue samples were disclosed in the parent application. In particular, breast cancer samples formed part of a larger set of 60 FFPE samples used in Experimental Example 7 to validate the expression stability of 13 candidate endogenous reference genes.
However, the Court drew a sharp distinction between disclosure of subject-matter and disclosure as belonging to the invention. The application as filed consistently presented the technical problem as the identification of universally applicable reference genes, explicitly not limited to specific tissue types or specific diseases. The experimental use of breast cancer samples was therefore understood as part of a broader validation dataset, not as a teaching that the invention was directed to breast cancer.
Against that background, the skilled person would not directly and unambiguously derive from the application as filed that the claimed method was limited to FFPE breast cancer tissue. The fact that breast cancer tissues were included among several tissue and cancer types did not amount to a disclosure that breast cancer defined or characterised the invention.
The Court further held that the parent application did not disclose OAZ1 as the sole endogenous reference gene for normalising the expression level of a target gene.
While OAZ1 was disclosed as one of 13 novel reference genes, it was not singled out in the claims of the parent application, nor was it disclosed in any example as being used alone for normalisation in a gene expression quantification method. The application consistently discussed the identification and validation of a set of candidate reference genes with favourable properties across a wide range of tissues.
In addition, the Court noted that the application referred to prior art teaching both single-gene and multi-gene normalisation strategies. Against that background, the absence of any disclosure of a method using OAZ1 alone reinforced the conclusion that the specific combination claimed in EP 3 346 403 was not directly and unambiguously derivable.
All auxiliary requests failed for the same reasons, as they retained both the breast cancer limitation and the exclusive use of OAZ1.
Independently of revocation, the Court dismissed the infringement action.
Based on its claim construction, the Court held that claim 1 required normalisation of the target gene expression level only to the expression level of OAZ1. The attacked embodiment normalised target gene expression to the average expression level of three reference genes, namely OAZ1, CALM2 and RPL37A.
There was no intermediate step in which normalisation was carried out against OAZ1 alone. The Court rejected the claimant’s late argument that the calculation was mathematically equivalent, emphasising that infringement depends on the actual technical implementation, not on hypothetical mathematical reformulations.
The Court also observed that CALM2 and RPL37A were expressly described in the patent as insufficiently stable and were not among the selected guide genes, which further excluded infringement even under a broader reading.
