6.8. Post-published documents

Sufficiency of disclosure must, in principle, exist at the effective date of a patent, while post-published documents may be used as evidence that the disclosure is reproducible without undue burden only under certain circumstances.

In T 116/18 (OJ 2022, A76) the issue of post-published evidence led to a referral to the Enlarged Board (see decision G 2/21, OJ 2023, A85). In essence, this referral was concerned with inventive step (Art. 56 EPC) – the patent proprietor had cited a piece of post-published evidence to demonstrate that the problem was solved and that the alleged technical effect was achieved. The referral contains a definition by the board of the term "post-published evidence". The board identified three main lines of case law: T 1329/04, T 609/02, T 488/16, T 415/11, T 1791/11 and T 895/13 of 21 May 2015 date: 2015-05-21 ("ab initio plausibility" – plausibility was ultimately not established in these decisions); T 919/15, T 578/06, T 2015/20, T 536/07, T 1437/07, T 266/10, T 863/12, T 184/16 ("ab initio implausibility" – plausibility was ultimately established in these decisions); T 31/18, T 2371/13 ("no plausibility" line of case law).

In G 2/21 (OJ 2023, A85) the Enlarged Board noted in points 10 and 11 of the Reasons that the board in T 116/18 had explicitly found that the ground for opposition pursuant to Art. 100(b) EPC was not relevant for deciding on the appeal. According to the Enlarged Board, the referred questions could therefore not be rephrased by adding a reference to sufficiency of disclosure and Art. 83 EPC. The Enlarged Board was nevertheless aware of the case law, in particular concerning second medical use claims where the notions of "plausibility" had been used ; the Enlarged Board quoted the main case law (points 73-77 of the Reasons) and stated that the scope of reliance on post published evidence was much narrower under sufficiency of disclosure (Art. 83 EPC) compared to the situation under inventive step (Art. 56 EPC). The Enlarged Board stated that in order to meet the requirement that the disclosure of the invention be sufficiently clear and complete for it to be carried out by the person skilled in the art, the proof of a claimed therapeutic effect has to be provided in the application as filed, in particular if, in the absence of experimental data in the application as filed, it would not be credible to the skilled person that the therapeutic effect is achieved. A lack in this respect could not be remedied by post-published evidence (point 77 of the Reasons).

The fact that experimental data were not published until after the filing date of the application is not prejudicial to their nature as evidence of physical phenomena, which occur independently of any publication date (T 416/14). See also G 2/21, point 91 of the Reasons, according to which evidence submitted by a patent applicant or proprietor may not be disregarded solely on the ground that such evidence, on which the effect rests, had not been public before the filing date of the patent application in suit and was filed after that date.

Even though sufficiency of disclosure must, in principle, be established at the priority date, post-published documents can be used as evidence that the claimed concept can be put in practice. Accordingly, the board decided to consider documents in spite of their late filing (T 1164/11 related to an invention going against generally accepted scientific principles).

In T 2070/13 the board observed that D16 – a patent specification – failed to provide any guidance as to how anti-adherence might be determined; the document was post-published with respect to the patent in suit and its disclosure was thus of no relevance to the sufficiency of disclosure thereof.

See also T 2037/22 (proof of a claimed technical effect which is not a therapeutic effect).

See also in this chapter II.C.7.2. "Level of disclosure required for medical use – credible effect". The case law before G 2/21 can be found in the CLB, 10th edn. 2022.