To encompass and embody: Applying the abstract principles of G 2/21

It is now some weeks since we received the EBA's decision in G 2/21 on the standard of evidence required for inventive step (often referred to as the "plausibility" referral). As previously summarised (IPKat), G 2/21 does not change the evidence standard for inventive step. Instead, the main contribution of G 2/21 is the introduction of an additionally nuanced test for assessing the disclosure standard for a purported technical effect.  G 2/21 also does not provide practical guidance on how this test should be implemented and leaves a number of key questions for the Boards of Appeal to answer. 

G2/21: "Encompassing and embodying"

G 2/21 does not change the status quo with respect to the disclosure requirement for a technical effect relied on for inventive step. In G 2/21 the EBA confirms that, when relying on a technical effect for inventive step, it is necessary to ask what a skilled person would have understood from the application as filed in view of the common general knowledge (CGK) (r.93). This language mirrors the sufficiency requirement (Article 83 EPC) (IPKat).

On the question of whether post-filed evidence can be used to support inventive step, the EBA found that there was no bar to the submission of new evidence. However, once evidence has been submitted it can still be ignored as inconsequential to the question at hand. With regards to new evidence supporting a purported technical effect, the EBA found that new evidence could not alter the requirement for the technical effect to be understandable to a skilled person from the application as filed in view of CGK. Arguably, post-filed evidence of a fact that is neither disclosed in the application as filed, nor derivable from CGK, is definitionally irrelevant to the question of what a skilled person would understand from the application as filed in view of the CGK. The possible exception to this is new evidence pertaining to what the CGK would have been when the application was filed. 

Contemplating the abstract principles

G 2/21 then added some nuance to what it means for a technical effect to be understandable from the application as filed:

"The relevant standard for the reliance on a purported technical effect when assessing whether or not the claimed subject-matter involves an inventive step concerns the question of what the skilled person, with the common general knowledge in mind, would understand at the filing date from the application as originally filed as the technical teaching of the claimed invention. The technical effect relied upon, even at a later stage, needs to be encompassed by that technical teaching and to embody the same invention".

G 2/21 is not about plausibility

From G 2/21, it seems that the EBA dislikes the term "plausibility", or particularly its evolution into a catch-word that has gained a life of its own in the national courts and IP commentary (r.92).  However, despite being commonly referred to as the plausibility referral, G 2/21 is not really about plausibility. Whilst plausibility is mentioned throughout G 2/21, this is only because the terminology of plausibility is commonly used in connection with discussions about the standard of evidence for inventive step. A reference to "plausibility" is a way for Boards of Appeal to signal that there is a higher level of underlying doubt with regards to certain types of invention, particularly those defined by very broad claims and/or those in challenging technical fields (IPKat). In such cases, the Boards of Appeal assess whether the purported technical effect of a claimed invention would be "plausible" to a skilled person, from the application as filed and in view of common general knowledge. 

The question of whether or not "the terminological notion of plausibility" needs to be employed because of the breadth of the claim or the nature of the technical field, is separate to the question of the standard of disclosure required to support a technical effect (r.72) (IPKat). The disclosure standard remains the same regardless of the type of invention. Particularly, it is still necessary to ask what a skilled person would understand from the application as filed, in view of common general knowledge. From G 2/21, we now have the additionally nuanced requirement that the technical effect is encompassed by the technical teaching and embodies the same invention as the technical teaching of the invention, as understood by a skilled person from the application as filed at the filing date in view of CGK. 

Outstanding questions

The EBA provides no practical guidance as to what it means for a technical effect to be "encompassed by the technical teaching" and to "embody the same invention" as the application as originally filed. It is seemingly clear from this language that a technical effect relied on for inventive step cannot be completely divorced from the original technical teaching of the application as filed. What is not clear from the reasoning in G 2/21 is whether the application as filed must explicitly mention the technical effect. Would an implicit understanding that the claimed invention embodies the technical effect be sufficient? It is also not clear from G 2/21 how new data disproving a technical effect should be treated. 

Unknown prior art

The question at the heart of the referral in G 2/21 was whether a technical effect relied on for inventive step must be explicitly disclosed in the application as filed. A common scenario in which a patentee may want to rely on a technical effect that is not explicitly disclosed in the application as filed is when the closest prior art was not known to the patentee at the filing date. The EPO often requires direct comparisons to be made between the prior art and the claimed invention. For example, to support inventive step for a new antibody, it may be necessary to show that a claimed antibody has higher potency than prior art antibodies binding the same target. The EPO will also often require the potency of the claimed antibody and the prior art antibody to be measured by exactly the same assay, in order that they are directly comparable. However, if the prior art is obscure, the patentee may not have been aware of it at the time of filing. The question becomes whether the patentee can submit additional data directly comparing the antibodies in order to support inventive step. 

This Kat is not clear on how to assess whether new comparative data for e.g. an antibody, could be said to be "encompassed by the technical teaching" and to "embody the same invention" as the technical teaching understood by the skilled person from the application as filed. However, the EBA in G 2/21 does not state that an explicit disclosure of the technical effect is necessary. G 2/21 may be interpreted as permitting implicit disclosures of a purported technical effect, provided these could be understood by a skilled person from the application as filed in view of CGK. Crucial to this question is whether the skilled person is given hindsight knowledge of the technical effect (IPKat). 

The relevance of new negative data

In the referring decision in G 2/21, the Board of Appeal had to consider not just whether new data supporting a technical effect could be considered post-filing, but also whether new data disproving a technical effect could be similarly considered. The Opponent in the case in question submitted new evidence at opposition that contradicted the evidence provided in the application as filed. However, the EBA in G 2/21 did not directly address the question of how much weight should be given to this evidence. Nonetheless, from the EBA's reasoning, it appears to this Kat that post-filed negative evidence relating to a technical effect should face a similar test to positive data, and should be ignored if irrelevant to what a skilled person would understand from the application as filed in view of CGK at the filing date. In other words, the new data should not be considered if it would not be known or understood by a skilled person from the application as filed in view of CGK.

There may also be an interaction here with the evidence requirement in inventive step and sufficiency, that there are no substantiated doubts supported by verifiable facts about the invention. Can new data from an opponent provide substantiation to new doubts about an invention, or must these doubts already be inherent in the application as filed in view of CGK? The wording in G 2/21 suggests the EBA would favour the latter possibility. In other words, the opponent must demonstrate that a skilled person would have doubts about the purported technical effect based solely on the application as filed in view of CGK.   

Final thoughts

The Boards of Appeal are now faced with the unenviable task of implementing G 2/21. It will be interesting to see how Boards of Appeal tackle the issue of implicit technical effect in view of prior art not known to the patentee at the filing date, and the relevance of new negative data against a purported technical effect. Both of these questions were relevant in the referring decision in G 2/21, T 0116/18. Will the Board of Appeal in this case now be any clearer as to how to proceed? 

Further reading

When generating antibodies for a target is more than routine (T 0435/20) (24 April 2023)

Plausibility demystified - a review of EPO case law before G 2/21 (24 Feb 2023)