T 2443/18 - (II) The CPA

Key points

•  In this opposition appeal, inventive step had to be decided for a second medical use claim. I focus on the discussion of the choice of the closest prior art. The patentee argued that “Document D3[] had the same object as the patent in suit [] For this reason, D3 was the closest prior art. It was also the only suitable starting point for the assessment of inventive step. In contrast, document D4 was inappropriate as a starting point.”
• The Board: “ If there were several workable routes, starting from different prior-art documents, which might have led the skilled person to the claimed subject-matter, the rationale of the problem-and-solution approach developed in the Boards' case law requires that all these possible routes be assessed before an inventive step can be acknowledged. Conversely, it is sufficient for denying inventive step if the claimed subject-matter lacks an inventive step in respect of one of the possible starting points [].”
• “It may happen that a piece of prior art is so remote from the claimed invention, in terms of intended purpose or technical features, that it can be argued in a prima facie assessment that the skilled person would not realistically have chosen it as a starting point and could not conceivably have modified it so as to arrive at the claimed invention. Such prior art might be referred to as "unsuitable". (Nonetheless, this would in principle not prohibit its consideration as a starting point in the problem-and-solution approach, which may in such a case be expected to result in a finding of non-obviousness.)”
• “If inventive step is to be denied, the choice of starting point needs no specific justification (see T967/97, Catchword II).”
  
  

T 2443/18

https://www.epo.org/law-practice/case-law-appeals/recent/t182443eu1.html

 If there were several workable routes, starting from different prior-art documents, which might have led the skilled person to the claimed subject-matter, the rationale of the problem-and-solution approach developed in the Boards' case law requires that all these possible routes be assessed before an inventive step can be acknowledged. Conversely, it is sufficient for denying inventive step if the claimed subject-matter lacks an inventive step in respect of one of the possible starting points (see T 967/97, Catchwords; T 1742/12, Reasons 6.6; Case Law of the Boards of Appeal of the European Patent Office, 9th edition 2019, I.D.3.1).

2.7 A promising starting point is typically a prior-art document that discloses subject-matter conceived for the same purpose or aiming at the same objective as the claimed invention and has the most relevant technical features in common. A further criterion is the similarity of the technical problem to be solved.

2.8 It may happen that a piece of prior art is so remote from the claimed invention, in terms of intended purpose or technical features, that it can be argued in a prima facie assessment that the skilled person would not realistically have chosen it as a starting point and could not conceivably have modified it so as to arrive at the claimed invention. Such prior art might be referred to as "unsuitable". (Nonetheless, this would in principle not prohibit its consideration as a starting point in the problem-and-solution approach, which may in such a case be expected to result in a finding of non-obviousness.)