Prior Use Referred to the EPO’s Enlarged Board of Appeal
Home / News / Prior Use Referred to the EPO’s Enlarged Board of Appeal

Prior Use Referred to the EPO’s Enlarged Board of Appeal

The issue of anticipation by prior use has been referred to the Enlarged Board of Appeal for consideration in decision T438/19.

The EPO’s longstanding approach to prior use was established around 20 years ago in Enlarged Board of Appeal decision G1/92. In short, a product sold commercially or otherwise in the public domain will constitute prior art against later-filed patent applications only if the skilled person is able to reverse-engineer the product to determine its internal composition or structure, and reproduce the product. Recently, in decision T438/19, the referring board has come to the view that this general principle is in need of clarification.

The facts under consideration by the referring board concern a published prior art document (cited as D1), which in an example refers to a commercially available polymer, ENGAGE® 8400. There was a dispute as to whether and to what extent the polymer could be analysed and reproduced by the skilled person. In this context the referring board has identified three key issues, which in its view require clarification from the Enlarged Board:

First, if a product which cannot be analysed is put on the market, is the product itself excluded from the state of the art, or is it more correct to say that the existence of the product is part of the state of the art but the internal structure of the product is excluded from the state of the art? This distinction may have consequences for inventive step. For example, in the case under consideration, it may be relevant to the issue of whether or not the relevant example within D1 can constitute a starting point for a consideration of inventive step, to be combined with secondary documents which provide further information regarding the ENGAGE® 8400 polymer.

Secondly, for a commercial product to form part of the state of the art, is it necessary that a skilled person can analyse all aspects of the product to bring the product into the prior art, or is it sufficient to be able to do enough analysis to confirm that the product is a product according to the relevant claims? There is an early case which takes the latter approach (T952/92), but the referring board found some contradictory case law, and thus felt that clarification from the Enlarged Board is necessary.

Thirdly, similar to the second issue but focussed on reproducibility: is it necessary that a skilled person having analysed the product is able to reproduce an identical product, or is it sufficient if the skilled person can prepare a variant within the scope of the relevant claims?  Again, T952/92 favoured the latter approach, but the referring board felt that there was sufficient divergence in the case law to merit a referral to the Enlarged Board.

The exact questions put to the Enlarged Board are reproduced below.

  1. Is a product put on the market before the date of filing of a European patent application to be excluded from the state of the art within the meaning of Article 54(2) EPC for the sole reason that its composition or internal structure could not be analysed and reproduced without undue burden by the skilled person before that date?
  1. If the answer to question 1 is no, is technical information about said product which was made available to the public before the filing date (e.g. by publication of technical brochure, non-patent or patent literature) state of the art within the meaning of Article 54(2) EPC, irrespective of whether the composition or internal structure of the product could be analysed and reproduced without undue burden by the skilled person before that date?
  1. If the answer to question 1 is yes or the answer to question 2 is no, which criteria are to be applied in order to determine whether or not the composition or internal structure of the product could be analysed and reproduced without undue burden within the meaning of opinion G 1/92? In particular, is it required that the composition and internal structure of the product be fully analysable and identically reproducible?