Additionally, A considered that the first medical use of these antibodies was not sufficiently disclosed either, given that the patent did not disclose any experimental data proving treatment effects. The Board did not agree with either of these arguments and ruled that both the claimed antibodies and their first medical use were sufficiently disclosed because the patent i) showed that antibodies carrying the triple mutation demonstrated the technical effects as mentioned in the claims, and ii) showed that the triple mutations could be introduced in known therapeutic antibodies without impairing their therapeutic effect. Thus, according to the Board, the patent enabled the skilled person to obtain antibodies or Fc fusion proteins having the functional features as required by the claims, and rendered it plausible that the mutated antibodies could be used as a medicament.
The European patent application no. 2691417 was opposed on all of the three the grounds of opposition (Art. 100 EPC). The OD decided that none of the grounds prejudiced the maintenance of the patent as granted and that, therefore, the opposition was rejected. The claims of the patent, relevant for the discussion of the ground under Art. 100(b) EPC, read:
The Opponent-Appellant (A) lodged an appeal against the decision of the OD, arguing that neither the claimed antibodies or Fc fusion proteins, nor their first medical use were sufficiently disclosed as required by Art. 83 EPC.
In the appeal, A stated that neither the claimed antibodies nor the Fc fusion proteins carrying the triple mutation were defined in terms of chemical structure, composition or other verifiable parameters, but solely by having certain functionalities, such as reducing antibody-dependent cellular cytotoxicity (ADCC, claim 2), reducing the binding affinity for an Fc receptor (claim 3), being a medicament (claim 7), and treating a disease by reducing an effector function (claim 8). Thus, A concluded that this type of functional definition not only covered the antibodies or Fc fusion proteins already known on the filing date, but also any antibody or Fc fusion protein not yet structurally defined and to be found in the future. As a result, the claim wording constituted a reach-through definition, which conflicted with sufficient disclosure.
According to A, the patent also did not disclose any experimental data proving treatment effect. For the medical use in claim 7 and 8, the skilled person would therefore conclude that the invention did not work in many cases, and that the desired results were not successfully achieved in a reliable way. With regard to claim 8, A further argued that the skilled person had to resort to trial-and-error experimentation on arbitrarily selected i) antibodies, ii) Fc fusion proteins and iii) diseases to establish whether they possessed the capability according to claim 8. As a result, A again concluded that an undue burden was placed on the skilled person to establish the therapeutic use.
Although the Board agreed that the claimed antibodies and Fc fusion proteins were, apart from the triple mutations, defined by their therapeutic effects, A did not provide any evidence that these effects were restricted to the particular antibodies used in the examples. Thus, the Board saw no reason for this to be the case and considered that the patent enabled the skilled person to obtain antibodies or Fc fusion proteins having the functional features as required by claims 2 and 3, without undue burden.
In view of the above finding with regard to the sufficient disclosure of the antibody and Fc fusion proteins as such, the Board stated that it remained to be analysed whether those compounds were suitable for use as a medicament. According to the Board, the patent showed that the triple mutations could be introduced into known therapeutic antibodies having an Fc region and that an antibody of this kind provided relevant medical effects, such as reduced Fc receptor affinity and reduced effector function, known to be useful in several therapeutic contexts. It was plausible that this finding also extended to Fc fusion proteins in which the Fc part was fused to a therapeutically effective protein and that the mutated antibodies or Fc fusion proteins could be used as a medicament in said known therapies without the mutations in the Fc region impairing the therapeutic effect.
Therefore, the Board considered that the only remaining question was whether claim 8 should be restricted to particular diseases. In order to answer this question, the Board consulted the Case Law of the Boards of Appeal. When performing the consultation, they explained that for the question whether the “medical use” aspect of the claim was sufficiently disclosed, the distinction between a new substance or a substance already being a part of the state of the art would be irrelevant as the skill required to use a known substance in medicine would be the same as that required for a substance provided by the patent for the first time.
After consulting decision G5/83 and T128/82, the Board summarized that none of these decisions concluded that sufficiency of disclosure for a broad first medical use claim required a limitation to a specific therapeutic use.
The Board could also not derive any requirement from the EPC whereby a patent would have to show that a compound would be suitable for each and every disease in order for a first medical use to be sufficiently disclosed. Instead, it would be sufficient to show that the compounds were suitable for at least one particular medical use, as was the case in the patent at issue.
Claim 8 defines the disease in functional terms and presupposes an existing (or future) treatment with an antibody or an Fc fusion protein. To put the invention into practice, it was therefore not necessary to identify a new compound or treatment, but only to establish whether there was a need for reduced effector functions in a known treatment. The appellant has not argued that the latter aspect would be an undue burden. The skilled person would therefore be able to identify the appropriate diseases without such undue burden.
In view of the above, the Board decided that the invention to which the claims relate was sufficiently disclosed in the patent, and set the decision under appeal aside.