European Patent Office Appeal Board decision on ‘product-by-process’ bispecific antibody claim

European Patent Office Decision T0032/17 has some interesting points to note on the disclosure of technical features conferred by hybridoma deposit information and the burden of proof in relation to product-by-process claims in opposition proceedings.

The claim defined the monoclonal antibody by a functional feature (the antigens the antibody is able to recognise) and a process feature (the antibody being “produced from a hybridoma (…)”). The question arose as to whether the process feature conferred any additional technical features on the claimed antibody. The Opposition Division held that, as a consequence of the process feature, the claimed antibodies were characterised by a unique amino acid sequence because "deposit numbers allow to identify specific hybridomas" and "each antibody produced by a different hybridoma will have a different sequence (heavy and light chains) which renders the antibody unique.".

Citing T179/03, T412/93, T1120/00 and G2/12, the Board considered that the questions at issue were whether or not the process feature:

(a) gives rise to the specific amino acid sequence and chemical composition of the claimed antibodies and

(b) whether the skilled person is made aware of these structural characteristics of the antibodies by the teaching of the patent.

The Board found that the deposit information per se does not convey any technical information about the chemical composition or molecular structure of the antibodies produced by these hybridomas, such as their amino acid sequence, either explicitly or implicitly.

Further citing T179/03, the Board went on state that where a process feature is the only feature allegedly conferring novelty to a product, the burden of proof for showing the fact that the process feature results in a distinct and identifiable characteristic of the product - i.e. in the present case in the chemical composition and/or the specific amino acid sequences of the claimed antibodies - is on the patentee and not on the opponent(s).

The patent did not provide any information about the chemical composition or amino acid sequence of the antibodies produced by the deposited hybridomas, e.g. in the form of a sequence listing. Thus, the Board found that “it is apparent that the chemical composition and/or the amino acid sequence of the antibodies produced by the deposited hybridomas cannot be inferred by the skilled person from the teaching of the patent in suit”. The Board concluded that the process feature does not impart any identifiable technical feature on the claimed subject-matter and the sole technical feature defining the claimed monoclonal antibodies was the functional feature.

The patentee’s argument that the opponent could have determined the amino acid sequence of the antibodies produced by the deposited hybridomas did not succeed as the patentee was considered not to have discharged the burden of proof.

The full decision can be found here.