The information that is made publicly available before a patent’s priority date forms part of the prior art. In July, the Enlarged Board of Appeal (EBoA) of the European Patent Office (EPO) published its decision regarding G1/23, providing further clarity on the scope of prior art and the meaning of “available to the public”.
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FreepikThe decision addresses a key question under Article 54(2) of the European Patent Convention (EPC), namely whether the public disclosure of a product that cannot be reverse engineered should still be regarded as part of the prior art.
Background to the decision
The case arose from the interlocutory decision T438/19 which examined whether an invention relating to a complex polymer could be regarded as novel and/or inventive when a similar product, Engage® 8400, had already been made commercially available before the filing date of the patent application.
Though Engage® 8400 only differed from the claimed invention in its aluminium content, the internal composition and manufacturing process of the product was not publicly known, and any attempt to reverse engineer the product would have required undue burden.
This created uncertainty about whether the marketed product was indeed “available to the public” for the purpose of assessing novelty and inventive step.
In its assessment, the EBoA revisited an earlier judgment (G1/92), which set out that a product “made available to the public” under Article 54(2) EPC forms part of the state of the art if it can be analysed and reproduced by a person skilled in the art without undue burden.
The EBoA explained that the composition or internal structure of a product will form part of the state of the art if a skilled person can determine it, even if there was no particular reason to examine the product at the time.
Patrick O’Brien 9 Dec 2025 Article 54(2) EPC
Article 54(2) EPC states that:
The state of the art shall be held to comprise everything made available to the public by means of a written or oral description, by use or in any other way, before the date of filing of the European patent application...
Article 54(2) EPC, much like South Africa’s counterpart in Section 25(6) of the Patents Act, is intentionally broad, placing no restriction on the form a disclosure must take for it to be considered part of the state of the art. The emphasis is not on how a product is made available to the public, but rather the fact that the product was in fact made publicly available.
The Impact of G1/23
The EBoA held that once a product has been marketed or otherwise made available to the public, it forms part of the prior art, regardless of whether it can be reproduced by a skilled person. Any technical information that can be derived from such a product is likewise considered part of the state of the art.
The judgment highlighted that, unlike G1/92, which required analysability and reproducibility, there is no need for a product to be reproducible for it to form part of the prior art. Public availability alone is enough: if a product can be analysed, it forms part of the state of the art and cannot be patented, even where reproduction is not possible.
However, a product’s public availability does not extend to any hidden technical effect it may possess. A product already on the market may still obtain patent protection under a new or subsequent medical use.
Further, in considering G1/23, the T141/24 judgment clarified that a product is only publicly available once it is publicly accessible and that a product sold subject to confidentiality obligations will not qualify as being made available to the public.
Merlene Engelbrecht 16 Jan 2026 Local reflections: South African equivalents to the European decision
In South Africa, Section 25(6) of the South African Patents Act defines the state of the art as matter that has been made available to the public in any manner. The similarity between South African patent law and the European position is immediately apparent.
In McCauley Corporations Ltd v Brickor Precast (Pty) Ltd 1989 BP 314 (CP), the court weighed the meaning of “made available to the public”. MacArthur J held that the key enquiry is simply “whether the material was available to the public”. The disclosure must be non-confidential, allowing public access to that material before the priority date of the invention.
In Merck Sharpe Dohme Group and Another v Cipla Agrimed (Pty) Ltd 2016 (3) SA 22 (SCA), the Supreme Court of Appeal held that “in order to constitute anticipation, the prior disclosure must not only identify the subject-matter of the claim in the latter patent, but must also do so in a way that enables the skilled person to make or obtain it”.
Therefore, an “enabling disclosure” is not limited to a written, oral, or otherwise explicit disclosure. An enabling disclosure could encompass a publicly available product analysable by a person skilled in the art.
As noted by the EboA, the major concern is not whether the product can be reproduced exactly, but whether the knowledge gained from the analysis of the product would provide a skilled person with sufficient information to produce something falling within the scope of the later patent.
It is therefore arguable that the concept of “enabling disclosure” as referred to in the Merck Sharpe Dohme Group case aligns closely with the position adopted by the EboA in G1/23.
Lessons learned
The G1/23 decision marks an important development in how European patent law treats publicly sold products. It confirms that public availability alone is enough to place a product within the state of the art.
For businesses and innovators, the key lesson is timing. Patent protection should be secured before any product is released into the market.
Relying on confidentiality, complexity or the belief that a product cannot be reverse engineered is no longer a safe strategy. If the product can be analysed in any meaningful way it may already fall within the state of the art.
The decision highlights the need for earlier and more deliberate intellectual property planning. Innovators should review their product development timelines, assess what information may become public and ensure that their patent filing strategy is aligned with any commercial launch.
A cautious and proactive approach will be essential to avoid unintentionally surrendering valuable patent rights.
