T 1708/18 - Standard of proof for anticipation by inherent feature

Key points

• Claim 5 is directed to: "An isolated antibody that binds specifically to the isolated polypeptide of SEQ ID NO:2 or SEQ ID NO:4."
• In other words, no structure of the antibody is specified at all in the claim.
•  "The opposition division considered that the subject-matter of claim 5 was novel over the disclosure of each of the documents cited by the opponents, including document D3"
• "According to the opposition division, the opponents "did not show beyond doubt that one of the antibodies disclosed in documents D3, D5, D6, ... or D35 is able to bind the antigen of SEQ ID NOs:2 or 4". "
• The Board: "The question of whether or not a given known antibody binds to a particular polypeptide is a question of fact. It is correct that the inherent binding property of the antibody concerned must be demonstrated by the party making the allegation, i.e., in the case at hand, the burden to prove that the antibody disclosed in document D3 binds to the PCSK9b and/or PCSK9c polypeptides lay with the opponents"
• " however, the standard of proof generally applied at the EPO for deciding on an issue of fact is the balance of probabilities."
• "According to this standard, the EPO must base its decisions on statements of fact which, based on the available evidence, are more likely than not to be true"
• As a comment, see also  T 0768/20: "“the board wishes to point out that the practical relevance of the distinction between the "balance of probabilities" standard and the "beyond reasonable doubt" standard is often overestimated. Both standards are only fulfilled if the deciding body is persuaded that the alleged fact is true, which is not a matter of "just tipping the balance slightly".
• "The board is not persuaded by the arguments of the opposition division and the patent proprietor that, by way of exception, a higher standard must apply in the present case."
• "the opposition division appears to mix up two issues which are distinct and unrelated: i) the issue of which standard of disclosure applies when assessing the legal question of novelty, and ii) the issue of which standard of proof applies when assessing evidence and factual questions. The fact that the standard of disclosure required for a finding of lack of novelty (or for allowing an amendment to the application under Article 123(2) EPC) is the standard of a direct and unambiguous disclosure is immaterial to the question of which standard of proof applies when considering evidence and factual issues in the context of novelty (or inventive step)."
• The Board notes that T 464/94 held that: "In the board's view, it is not justifiable to decide whether a document is prejudicial to novelty on the basis of probability. When a patent is revoked for lack of novelty, the department concerned has to be sure, having taken all the facts and arguments put forward during the proceedings into consideration, that the revocation is justified. In case of doubts, further clarification of the factual situation must be carried out; otherwise, the patent cannot be revoked for lack of novelty".
• As a comment, see Guidelines G-VI,6, "the lack of novelty may be ... implicit in the sense that, in carrying out the teaching of the prior-art document, the skilled person would inevitably arrive at a result falling within the terms of the claim. An objection of lack of novelty of this kind is raised by the examiner only where there can be no reasonable doubt as to the practical effect of the prior teaching".
• "this board notes, however, that it is not clear whether the deciding board [in T 464/94] was referring in this statement to the assessment of legal issues in the context of novelty, such as the question of whether the skilled person would have directly and unambiguously derived a specific piece of information from a document, or to the assessment of factual questions, such as whether particular information was published on a specific date, whether a given process resulted in a particular product or whether the product concerned had a specific property. This board is therefore not persuaded that the board in decision T 464/94 indeed adopted an approach to the assessment of factual questions that was different from that which this board intends to follow.'
• "The factual question to be decided upon in the present case is whether it is more likely than not that a known PCSK9 antibody would bind specifically to the PCSK9b and/or the PCSK9c polypeptide. In assessing this question, any evidence submitted by the parties is considered by the board and such evidence does not necessarily have to be in the form of "wet lab" experiments, as argued by the patent proprietor."
• "The question must be answered in the affirmative in the board's opinion, for the reasons set out in the following."
• "The polyclonal antibody disclosed in document D3 recognises an epitope determined by the linear sequence of a peptide (see point 24. above), which is fully contained within the PCSK9b and PCSK9c polypeptides (see point 25. above). In view of this factual assessment, the board considers that it is more likely than not that this antibody, the availability of which had not been questioned, also specifically binds to the PCSK9b or PCSK9c polypeptides, at least in a so-called "Western blot"[]." 
• The patent is revoked.
• As a comment, the Board seems correct in that the current case law is not entirely consistent about the standard of proof with respect to prior art.

EPO 

The link to the decision is provided after the jump.

https://www.epo.org/law-practice/case-law-appeals/recent/t181708eu1.html