July 2024 EPO Board of Appeal Decision No. T 0629/22
Although G 2/21 addressed the circumstances in which post-filed evidence may be used to support a technical effect in respect of an inventive step, the Enlarged Board of Appeal did not provide any guidance on assessing contradictory evidence provided by different parties. This was a critical issue in T 0629/22.
Vegan Cheese Product Claim
T 0629/22 concerned European patent no. 3422865 (subject-matter: vegan cheese and preparation thereof).
The product claim was distinguished from the prior art according to the type and amount of starch used in the vegan cheese. However, the technical effect (improved “melt-stretch” characteristics) was shown in examples only to be achieved using a particular method. This method used heating to induce gelatinisation of the starch and was considered essential by the Board of Appeal for achieving the technical effect.
The Board found that it would not be credible that a product formed without the heating step would have the purported technical effect (melt-stretch or stringiness).
The product claim was thus held to lack inventive step.
Product-by-Process Claim
The Board of Appeal then assessed the inventiveness of the product-by-process claim for the vegan cheese, in which the manufacturing steps (including the heating step) were specified.
The patentee argued that the inclusion of the heating step meant that all cheeses falling within the scope of the claim would have the purported technical effect. This assertion was further backed up using post-filed data as evidence.
The opponent submitted contradictory data as evidence that cheeses prepared according to the specified method did not have the required levels of stringiness (i.e., alleging that the technical effect was missing).
Accordingly, contradictory post-filed data from the patentee and the opponent had to be assessed by the Board in reaching a conclusion.
The Board was convinced that the difference in findings could be put down to a difference in experimental design, e.g., the use of different tests of stretch e.g., spatula vs fork. The Board was thus satisfied that the technical effect relied on by the patentee was credible, even in the face of contradictory data from the opponent.
Conclusion
This decision confirms that the credibility (or “plausibility”) test threshold favours the patentee. The decision suggests that the technical effect of a claim may be adjusted post-hoc according to the experimental evidence available to the patentee.
