EPO referral to the Enlarged Board of Appeal (G2/21) – Post-published evidence of a technical effect
24 March 2023
In 2021, a referral was made to the Enlarged Board of Appeal (EBA) in case T116/18 concerning whether post-published evidence (i.e., information not available until after the filing date of a patent application) can be used to demonstrate a technical effect in the assessment of inventive step. The EBA issued its preliminary opinion in October and has now issued its formal decision, dated 23 March, confirming that post-published evidence can be considered in the assessment of inventive step and setting out guidance on when this would be appropriate.
Setting out the issues
In assessing inventive step, the EPO applies the “problem-solution approach”.
This involves identifying the “closest prior art”, establishing the “objective technical problem” to be solved based on the technical effect brought about by the distinguishing features over the closest prior art, and determining whether the claimed invention, starting from the closest prior art and the objective technical problem, would have been obvious to the skilled person.
The technical effect – and therefore the objective technical problem solved by the invention – can vary significantly depending on what is deemed by the EPO to be the closest prior art. However, EPO case law to date is divided on what evidence can be used to demonstrate that technical effect. If evidence of the technical effect in view of all possible closest prior art needs to be established in the application as filed, there is an argument that this presents an unreasonable burden on the patentee.
The Board of Appeal in T116/18 felt the need to refer the following three questions on post-published evidence to the Enlarged Board of Appeal:
- Should an exception to the principle of free evaluation of evidence (see e.g. G 3/97, Reasons 5, and G 1/12, Reasons 31) be accepted in that post-published evidence must be disregarded on the ground that the proof of the effect rests exclusively on the post-published evidence?
- If the answer is yes (the post-published evidence must be disregarded if the proof of the effect rests exclusively on this evidence), can the post-published evidence be taken into consideration if, based on the information in the patent application in suit or the common general knowledge, the skilled person at the filing date of the patent application in suit would have considered the effect plausible (ab initio plausibility)?
- If the answer to the first question is yes (the post-published evidence must be disregarded if the proof of the effect rests exclusively on this evidence), can the post-published evidence be taken into consideration if, based on the information in the patent application in suit or the common general knowledge, the skilled person at the filing date of the patent application in suit would have seen no reason to consider the effect implausible (ab initio implausibility)?
The Enlarged Board’s Decision
The answer to the first question is no. The EBA considers that there is a basic legal procedural right for post-published evidence to be considered. Specifically, evidence submitted by the proprietor to prove a technical effect may not be disregarded solely on the grounds that it was not public before the filing date of the patent in suit.
Even so, the EBA notes that the term “plausibility” relied upon in previous decisions (and used in referred questions 2 and 3) does not amount to a distinctive legal concept or specific patent law requirement under the EPC. The EBA therefore felt compelled to provide guidance on the use of post-published evidence for the reliance on demonstrating a purported technical effect.
In this regard, the EBA decision states that:
“A patent applicant or proprietor may rely upon a technical effect for inventive step if the skilled person, having the common general knowledge in mind, and based on the application as originally filed, would derive said effect as being encompassed by the technical teaching and embodied by the same originally disclosed invention”.
This is intended to tie the assessment of inventive step to the existing standard of what the skilled person would understand as the technical teaching of the invention at the filing date of the patent. The decision on whether post-published evidence may be relied upon should be based on the specific circumstances of each case.
The decision makes it clear that evidence may not be disregarded purely on the basis that it is post-published. Instead, assessing whether the claimed subject-matter involves an inventive step relies on establishing what the skilled person would understand at the filing date from the application as originally filed. This can include a technical effect encompassed by the technical teaching but supported by post-published evidence.
Advanced Engineering group
This publication is a general summary of the law. It should not replace legal advice tailored to your specific circumstances.
© Withers & Rogers LLP February 2023