On March 2nd 2020 Board of Appeal 3.3.02 of the EPO issued a decision (T 0709/17) providing guidance on the selection of suitable starting points when the closest prior art discloses various alternatives.
The Boards have repeatedly pointed out that the closest prior art for assessing inventive step is normally a prior art document disclosing subject-matter conceived for the same purpose or aiming at the same objective as the claimed invention and having the most relevant technical features in common, i.e. requiring the minimum of structural modifications.
In the case under discussion, document D7, which the parties and the Board considered to be the closest prior art, disclosed three alternative crystals with different morphology (particle size and crystal habits).
From these three alternative crystals, one (a) was characterized as “undesirable”, another one (b) was the object of the actual invention of D7 and the third one (c) was simply mentioned but clearly not preferred.
Appellants argued that both alternatives (b) and (c) were equally suitable starting points for the assessment of inventive step while the patentee contended that only (b), i.e. the object of the actual invention of D7, was a sensible starting point for the assessment of inventive step.
The Board concluded that, as argued by ABG IP, the skilled person would only have contemplated alternative (b), which was the actual invention of D7, as a suitable starting point for the assessment of inventive step.
Thus, the Board took the view that the mere disclosure of an alternative, not embodying the invention disclosed in a prior art document, is not a suitable starting point for the assessment of inventive step.
This decision provides useful guidance on the selection of suitable starting points when a document, which is considered the closest prior art, discloses several alternatives of different nature.
