T 0326/22 - Functional antibody claims

Key points

• The reports of the death of functional antibody claims are greatly exaggerated (see epi Information 2024/4), as this case shows.
Claim 1 reads: ""1. An isolated monoclonal antibody or immunologically active fragment thereof that binds to human CD47, wherein the antibody or immunologically active fragment thereof binds to a discontinuous epitope on CD47, wherein the discontinuous epitope comprises amino acids residues Y37, K39, K41, K43, G44, R45, D46, D51, H90, N93, E97, T99, E104, and E106 of CD47 when numbered in accordance with SEQ ID NO: 147,
and wherein the antibody or immunologically active fragment thereof prevents CD47 from interacting with signal-regulatory-protein a (SIRPalpha)
and does not cause a significant level of agglutination of cells after administration.""
• Hence, the definition of the claim is purely functional. The SEQ ID refers to the structure of the epitope (target), not the structure of the antibody itself.
• For sufficiency:  In these circumstances the issue to be assessed is whether the skilled person based on the patent application's teaching taking common general knowledge into account can reliably and without inventive skill find those antibodies in the pool of generated CD47 antibodies that show the functional properties indicated in claim 1."" 
• "as long as the generation of these further CD47 antibodies requires nothing but routine work that may be tedious and time consuming, the method of generating these antibodies cannot be regarded per se as being based on undue burden (T 431/96, Reasons 6)."
•  "the patent application provides the skilled person with the sequence information of the six CDRs of the 2A1 antibody and of various derivatives thereof including their full variable light and heavy chain sequences (Table 1 on pages 32 and 33, paragraphs [00111] and [00112]). Antibodies with these sequences fulfil the functional properties indicated in claim 1. It is also uncontested that varying these sequences and obtaining further antibodies are routine and hence impose no undue burden on the person skilled in the art. Thus, in agreement with the appealed decision (point 14.1 of the Reasons), the board considers that the skilled person in following this route routinely arrives at further antibodies with the functional properties of claim 1."
• "Example 11 of the patent application mentions that X-ray crystallography ("XRC") was used for determining the epitope structure on CD47 bound by the chimeric antibody 2A1-xi and discloses the epitope's structural information (see also Figure 11C). "
• It is unclear to me if the patent provides for an assay for the feature of the binding to the specified epitope and if the skilled person can easily screen for antibodies having that property, other than obtained by varying the example antibody 2A1.
• After a detailed technical analysis: "In view of the considerations above, it is credible that the skilled person by applying the teaching of the patent application and taking common general knowledge into account would arrive without undue burden at further antibodies falling within the scope of claim 1. "
• On inventive step: "Compared to the full-length B6H12 and 5F9 antibodies of document D1, the objective technical problem to be solved resides thus in the provision of an improved CD47 antibody."
• "Document D1 provides no pointers for the skilled person to select the epitope on CD47 as defined in claim 1 for solving the technical problem formulated above. Thus the claimed antibodies are based on an inventive step over the disclosure of the full-length monospecific and bispecific B6H12 and 5F9 antibodies of document D1."
• The claim request is held to comply with the EPC.

EPO 

The link to the decision can be found after the jump.

https://www.epo.org/en/boards-of-appeal/decisions/t220326eu1