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T 166/18 – Sumitomo Chemical Company, Limited v Syngenta Limited

Further to our previous article of September 2021, the Board of Appeal has now confirmed its referral of three questions to the Enlarged Board regarding the use of post-published data in establishing an inventive step.

Background

In our previous article, we discussed the expected referral to the Enlarged Board of Appeal in case T 116/18, wherein the Board of Appeal decided greater clarity was required concerning the use of post-published data when considering inventive step.

The Board decided the patent would be found to involve an inventive step, and thus would be valid, if the post-published data could be considered, but that the patent would be found to lack an inventive step, and thus would not be valid, if the post-published data could not be considered. Both parties agreed with the Board that there was a need to refer the question of whether or not the post-published data could be relied upon to satisfy the plausibility requirement.

The written decision of the Board of Appeal has now been published, and confirms the anticipated referral to the Enlarged Board of Appeal under case G 2/21, as well as the Board’s reasoning for referring three questions to the Enlarged Board.

Summary

The written decision of the Board confirms that the three questions to be referred are:

  1. 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 evidence of the effect rests exclusively on the post-published evidence?
  2. 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)?
  3. 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)?

These questions are largely similar to the expected referral questions set out in our previous article. However, it should be noted that the relevant date is now given as the “filing date”. The Board noted that, in this case, the post-published data were filed by the patent Proprietor after the filing date of the presently contested patent, and thus scenarios wherein the data were filed after the priority date but before the filing date would not be directly comparable with this case.

Full details of the Board’s reasoning for the referral and selection of each of the questions is provided below. However, in summary the Board considered that previous decisions fell into three distinct and incompatible categories, rendering the correct approach ambiguous. Additionally, the Board was uncertain of the legal basis for considering plausibility and whether the consideration of plausibility is compatible with the long-standing problem-solution approach at the EPO.

Reasoning: the three lines of plausibility case law

In its decision, the Board stated that it believes there exist three diverging strands of case law as to how plausibility should be assessed, and that the case law decisions cited by the parties could be divided into these categories:

1. The “ab initio plausibility” line of case law,
2. The “ab initio implausibility” line of case law, and
3. The “no plausibility” line of case law.

The Board believes that its questions set out above are essentially asking:

1. Should plausibility be assessed at all, or should the “no plausibility” standard be applied?
2 & 3. If so, (2) should the “ab initio plausibility” standard be applied, or (3) should the “ab initio implausibility” standard be applied, instead?

Each of the three lines of plausibility case law is now set out in more detail below.

1. The “ab initio plausibility” line of case law

The “ab initio plausibility” line of case law holds that post-published data can only be taken into account if the specification as filed includes sufficient data to show ab initio that the invention solves the objective technical problem. Therefore, whilst post-published data may be taken into account to back-up such a disclosure in the application as filed, such data may not be considered if this amounts to the only data provided that demonstrates the objective technical problem has been solved by the claimed invention.

The Board cited a number of decisions that it considered fell into the “ab initio plausibility” line of case law. Firstly, the Board referred to decision T 1329/04, in which the Proprietor had claimed a new polypeptide it had developed (denoted “GDF-9”) belonged to the TGF-β superfamily, but had not included any data in its application as filed that suggested it would be appropriate to assign this protein to this superfamily, such as structural data or evidence of its mode of action. As such, the post-published data filed by the Proprietor to demonstrate that GDF-9 does indeed act as a growth differentiation factor was not considered admissible since it could not be determined from the application as filed that GDF-9 is a growth differentiation factor. Therefore, the Board concluded that the patent lacked an inventive step on the grounds that the claimed technical effect was not rendered plausible by the application as filed.

The Board in the present case also referred to decision T 609/02, in which it had been decided that “post-published (so-called) expert evidence (if any) may be taken into account, but only to back-up findings in the patent application… and not to establish sufficiency of disclosure on their own.”

Additionally, the Board referred to T 488/16, wherein the Board in that case had decided that “a mere verbal statement that “compounds have been found active” in the absence of any verifiable technical evidence is not sufficient to render it credible that the technical problem the application purports to solve… is indeed solved.”

2. The “ab initio implausibility” line of case law

The “ab initio implausibility” line of case law holds that post-published data is only disregarded if there is a reason for the skilled person to doubt the plausibility of the invention set out in the application as filed. Therefore, this line of case law allows post-published data to be taken into account even if there is insufficient data provided in the application as filed to demonstrate that the claimed technical effect is achieved across the entire scope of the claims.

Again, the Board cited a number of decisions that it considers fall into this category. In T 919/15, the patent in question claimed two herbicide compounds in combination with each other, wherein one compound was from a family of compounds having a first general formula and the other compound was from a family of compounds having a second general formula. The alleged technical effect of the claimed invention was that the two compounds act synergistically with each other. However, the application as filed only contained data showing that certain combinations, i.e. not all possible combinations, of these herbicide compounds yielded a synergistic effect.

Post-published data filed by the patent Proprietor in an attempt to demonstrate that a synergistic effect is observed for combinations of compounds across the entire scope of the claims was accepted by the Board. The Board decided the evidence provided in the application as filed for some combinations of compounds was sufficient to render it plausible that all combinations of compounds across the scope of the claims would act synergistically. The Board additionally considered it decisive that the skilled person would have had no reason to doubt that synergy would be observed for all combinations of compounds encompassed by the claims, and thus decided the post-published data filed by the Proprietor could be considered under such circumstances.

3. The “no plausibility” line of case law

The “no plausibility” line of case law holds that plausibility is not a suitable test for assessing inventive step and thus post-published data should be considered regardless of the circumstances under which it is filed.

The Board noted that in decision T 31/18, it was decided that preventing a patent Proprietor from relying on post-published data would be incompatible with the established problem-solution approach to assessing inventive step. The Board in T 31/18 noted an Applicant would, at the time of filing a patent application, be required to anticipate all possible formulations of the objective technical problem, despite perhaps not even knowing what the closest prior art may be, and would need to include data in the patent application accordingly. Based on this, the Board in T 31/18 decided a patent Proprietor should be able to rely on post-published data whenever it considers this appropriate in support of its inventive step arguments.

The Board in the present case noted a similar conclusion was reached in T 2371/13.

Conclusion

The Board noted that three very different standards have been applied when determining whether or not post-published data can be considered in the assessment of inventive step. At one extreme, the “ab initio plausibility” standard requires an absolute disclosure in the application as filed of data demonstrating that the objective technical problem is solved by the claimed invention, whilst at the other extreme, the “no plausibility” standard permits a patent Proprietor to rely on post-published data regardless of the data contained in the application as filed. The Board noted the “ab initio implausibility” standard falls somewhere between these two extremes.

The Board noted that a strict application of the “ab initio plausibility” standard would ultimately result in patents only being granted for the Examples given in the application as filed, i.e. specific embodiments of the invention for which data is provided, and would render it almost impossible for a patent Proprietor to overcome inventive step objections based on a reformulation of the objective technical problem in view of a newly-identified closest prior art document.

In contrast, the Board noted that application of the “no plausibility” standard may permit filing of speculative patent applications, i.e. applications for “inventions” the Applicant has not actually created at the time of filing but expects to be able to provide data in support of at a later date (so-called “armchair inventions”).

Separately, the Board noted that it is unclear what the legal basis is for preventing a patent Proprietor from relying on post-published data. In particular, the Board expressed concern that such prevention may contravene the Principle of Free Evaluation of Evidence that permits a patent Proprietor to rely on whatever evidence it sees fit.

The Board also noted in its decision that Article 56 EPC states an inventive step will be acknowledged if, having regard to the state of the art, the invention would not have been obvious to a person of skill in the art. The Board noted the strict “ab initio plausibility” standard does not take into account the content of the prior art despite being used to assess inventive step, so this standard cannot be provided for under Article 56 EPC.

In its decision, the Board also referred to a review article, in which the author had noted the word “plausibility” is not recited anywhere in the EPC.

Finally, the Board referred to A. Slade, “Plausibility: a conditio sine qua non of patent law?”, I.P.Q. 2020, 3, 180-203, in which the author thereof had suggested neither Article 56 EPC (inventive step) nor Article 83 EPC (sufficiency of disclosure) provide the required legal basis for the concept of plausibility. Instead, the author thereof suggested plausibility is, in fact, provided for under Article 52(1) EPC (patentable inventions), on the grounds that an invention must be rendered plausible by the application as filed in order for it to be considered an “invention” at all.

Final comments

It is clear from the decision that the Board of Appeal in this case does not consider there to be an appropriate standard for the assessment of plausibility and its relationship to determining whether or not post-published data may be taken into account for the assessment of inventive step.

Additionally, the Board is uncertain where legal basis can be found in the EPC for considering plausibility and whether this is compatible with the long-established problem-solution approach for considering inventive step at the EPO.

It now falls to the Enlarged Board of Appeal to deliberate on the matter and provide an answer.

We will of course report further on all future developments in this case.

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