Abstract on EPC2000 Art 087(1) for the decision T0411/19 of 15.11.2022

In T 411/19 appellant II (opponent 2) argued that the subject-matter of claim 1 was not entitled to the earliest priority date because the application from which priority was claimed (P1) did not sufficiently disclose the suitability of the claimed compounds for the claimed therapeutic use, i.e. for the treatment of macular oedema or retinal vein occlusion. The board recalled that, according to the established case law of the boards, a claimed second medical use met the requirements of Art. 83 EPC if the patent disclosed the suitability of the product for the claimed therapeutic application, if this was not known to the skilled person at the relevant date. In the board's opinion, this standard applied to priority documents equally because the priority document had to disclose the invention claimed in the subsequent application in such a way that it could be carried out by a person skilled in the art. The question to be answered in determining if the subject-matter of claim 1 could validly claim priority from P1 was therefore whether P1 disclosed that the claimed compounds were suitable for treating macular oedema and retinal vein occlusion. The board observed that it had not been disputed that P1 disclosed Kunitz domain peptides according to the general formula of claim 1 of the patent and stated that these were useful in the treatment of ophthalmic disorders in humans and animals. Macular oedema and retinal vein occlusion were both mentioned in lists of treatable ophthalmic disorders. There was therefore a literal disclosure of the subject-matter of claim 1. The board noted, however, that P1 contained no experimental data or other evidence of any kind that went beyond a mere allegation that the peptides defined in that document were indeed suitable for treatment of any of the ophthalmic disorders listed. That the peptides mentioned were suitable was not at all self-evident because it was the essence of the contribution to the art of the invention purportedly made in P1. In the absence of such evidence, it could not be concluded that P1 provided even an initial plausibility that the claimed compounds were suitable for treating the disorders in question. Appellant I had referred to certain passages as providing a link between particular plasma kallikrein inhibitors and the ophthalmic disorders. The board was of the view that these were no more than a summary of the background knowledge in the art on proteases, including kallikreins and their inhibitors and did not at all constitute evidence that peptides defined in P1 were suitable for treatment of any ophthalmic disorder by inhibiting plasma kallikrein. The board concluded that P1 did not disclose the invention of claim 1 in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art. The invention claimed in claim 1 of the main request was therefore not the "same invention" in the sense of Art. 87(1) EPC as the invention disclosed in P1. It could therefore not validly claim priority from P1.