T 1177/17 - Plausible and burden of proof

Key points

• The concept of 'plausibility' is often applied in the context that the applicant may only rely on post-published evidence of the technical effect if the application as filed makes that effect at least plausible. 
• In the present opposition case, the concept is used in connection with the burden of proof.
• The opponents allege that the technical effect is not made plausible by Example 1 of the patent.
• The Board decides that the technical effect is not plausible. " there is no evidence on file to show that [the compound] 2-FL, by itself, achieves the required NK cell stimulation that is necessary to attain the claimed antiviral effects." 
• " the [patentee] did not substantiate its submissions with any evidence other than the data reported in example 1. By contrast, it argued that it was down to the [opponents] to demonstrate that 2-FL did not provide for the claimed antiviral effects by means of NK cell stimulation. However, this argument cannot succeed, since the technical effects invoked by the [patentee] are not plausible over the whole scope of claim 1 of the main request" 
• The patent is revoked.

EPO T 1177/17 -  link



4.2.5 The subject-matter of claim 1 differs from the closest prior art in that the fucosyllactose is 2-FL.


4.3 Objective technical problem and solution


4.3.1 In order to formulate the objective technical problem, it is necessary to establish the technical effect(s) achieved by the aforementioned distinguishing feature.


[...]

4.3.3 While the appellants [opponent] did not dispute the validity of the data contained in example 1 of the patent in suit, they submitted that there was no evidence supporting the alleged link between the immunomodulatory effects of 2-FL shown in the mentioned example and the compound's activity against infections caused by the list of viruses recited in claim 1 of the main request.


4.3.4 Accordingly, it needs to be established whether the disclosure of example 1 renders the alleged, indirect antiviral activity of 2-FL by means of NK cell stimulation (see point 4.3.2 above) credible or at least plausible over substantially the whole scope of claim 1 of the main request.


4.3.5 Example 1 of the patent in suit pertains to a study in mice vaccinated with Influvac (an influenza vaccine; see paragraph 0048). The test animals received either a control diet or a diet supplemented with the following respective oligosaccharides: [...]


Diet supplementation with 2-FL resulted in a significant increase in NK cell number and activity compared with control-fed animals (see experimental data in Table 1 in paragraph 0052). Hence, in the board's judgement, example 1 credibly shows that dietary 2-FL augments the NK-cell-stimulating effects of the Influvac vaccine in the tested animals and thus contributes to the effective protection of these animals against infections caused by influenza viruses.

4.3.6 Claim 1, however, does not require 2-FL to be used in combination with a vaccine. Accordingly, the question arises as to whether 2-FL, by itself, can provide for the claimed indirect antiviral effects by means of NK cell stimulation, as alleged by the respondent.


4.3.7 In the board's judgement, it cannot. The board does not dispute that NK cells play an important role in the natural defence against viral infections, as indicated in paragraphs 0014 and 0041 of the patent in suit. The board also accepts that it is plausible that the claimed infections may be treated and/or prevented through an adequate degree of NK cell stimulation. However, there is no evidence on file to show that 2-FL, by itself, achieves the required NK cell stimulation that is necessary to attain the claimed antiviral effects.


4.3.8 At the oral proceedings, as before in the written proceedings, the respondent did not substantiate its submissions with any evidence other than the data reported in example 1. By contrast, it argued that it was down to the appellants to demonstrate that 2-FL did not provide for the claimed antiviral effects by means of NK cell stimulation.


4.3.9 However, this argument cannot succeed, since the technical effects invoked by the respondent are not plausible over the whole scope of claim 1 of the main request (see point 4.3.7 above).


4.3.10 Summing up the above considerations, the board finds that the technical effects relied upon by the respondent cannot be accepted as being achievable across the whole scope of claim 1 of the main request. As a consequence, these effects cannot be taken into account in the formulation of the objective technical problem posed.


4.3.11 In the absence of any other data demonstrating a particular technical effect linked to the distinguishing feature, the objective technical problem to be solved must be considered to be the selection of a specific fucosyllactose for the treatment and/or prevention of infections caused by RSV.


4.3.12 The proposed solution to this problem is 2-FL.


4.4 Obviousness


4.4.1 What remains to be decided is whether the proposed solution is obvious in view of the state of the art.


4.4.2 It is common ground that "fucosyl-lactose" referred to in D2 (see point 4.2.2 above) is a generic term comprising two different types of fucosyllactoses, 2-FL and 3-FL (see D4, page 980, left-hand column, first full paragraph). The skilled person is also aware of the fact that 2-FL is abundantly present in human breast milk (see paragraph 0014 of the patent in suit; D3, page 3, lines 3 to 4). In the light of this knowledge, the skilled person would consider 2-FL as a solution to the objective technical problem as defined in point 4.3.11 above and thus arrive at the claimed subject-matter in an obvious manner.


4.4.3 The respondent submitted that D2 did not contain any pointer for the skilled person to specifically select 2-FL to achieve the NK-cell-stimulating effects demonstrated in the patent in suit.


4.4.4 However, in view of the fact that the objective technical problem to be solved merely involves providing a specific fucosyllactose for the treatment and/or prevention of infections caused by RSV, this argument must fail. The proposed solution to this problem, i.e. 2-FL, is devoid of inventive merit for the reasons set out above.


4.4.5 In light of the above considerations the board comes to the conclusion that claim 1 of the main request does not meet the requirements of Article 56 EPC.