EP 2 188 302 B1 relates to methods and means for preventing the reduction of disulfide bonds during the recombinant production of disulfide-containing polypeptides.
Brief outline of the case
The patent was maintained according to a new MR.
Opponents 1, 2, 4, 7, 8, 9 and 11 appealed.
The board revoked the patent for added matter.
The opponents’ point of view
For the opponents, the feature “following fermentation” was ambiguous. It described multiple technically logical scenarios, for example: following some fermentation, i.e. once fermentation has started, following production of a recombinant antibody molecule by fermentation, i.e. once at least one antibody molecule has been produced by a recombinant host cell, following the termination of all fermentation, i.e. when all the CCF was harvested or the cells were lysed, or as the proprietor argued, following the end of a stage in an industrial antibody production method that was associated with the bulk of the antibody.
The application did not directly and unambiguously disclose that the method step, supplementing the culture fluid with a Trx inhibitor, used to achieve the purpose took place following fermentation. In other words, the application taught that the effect was achieved following fermentation, but it did not disclose that the intervention taken to achieve this effect occurred following fermentation.
The expression “following completion of the cell culture process” was not the same as “following fermentation“. At best, there was similarity between “following completion of the cell culture process” and one specific interpretation of “following fermentation“, i.e. following termination of all fermentation.
The only interpretation of “following fermentation” that fitted consistently with the original application was “after harvest“.
It disclosed that the intervention of supplementing a Trx inhibitor, could be done before and/or after harvest. The claim, however, defined a new, specific period during which the intervention should be applied: after fermentation but before harvesting.
The proprietor’s point of view
The skilled person, avoiding artificial and semantic constructions and with a mind willing to understand, would not interpret “following fermentation” as “during fermentation“, “following some fermentation“, or “following the start of fermentation“, as suggested by the opponents. The normal implicit meaning was “after the end of fermentation“.
The term “following fermentation” in claim 1 referred to a time in an antibody production process, which time was after the end of the growth and production phases.
When the relevant passages of the description as originally filed passages were read together, from a practical and reasonable standpoint, and in the context of the application as a whole, it was directly and unambiguously derivable that the invention included a method in which the pre-harvest CCF was supplemented with a Trx inhibitor following fermentation.
The board’s decision
The expression “following fermentation” in the context of the claim does not provide the skilled person with a clear point in time or time period at which a Trx inhibitor is to be supplemented to the CCF.
Multiple technically sensible interpretations exist. For example, the expression could mean “following the start of fermentation“, “following some fermentation“, “following production of an antibody molecule by fermentation”, “following a discrete round of fermentation”, “following the end of a production phase in industrial antibody production”, or “following termination of all antibody synthesis”. The board found none of these interpretations illogical or not technically sensible.
The claim itself does not contain a definition of the expression “following fermentation“. Even if the description of the application as filed or the patent is taken into account as a further means of interpretation, it does not provide an explicit definition of “following fermentation” either.
The skilled person therefore only learns that proteins can be processed and purified “following fermentation“, but not when this time period starts.
The expression “following fermentation, supplementing the pre-harvest cell culture fluid (CCF)” is ambiguous in the context of claim 1, and not limited to a “time in an antibody production process, which time is after the end of the growth and production phases”, as argued by the proprietor.
Therefore only an explicit disclosure in combination with the other features of the claim would allow all possible interpretations to be directly and unambiguously derived from the application as filed This is obviously not the case.
The board noted that, “following fermentation” is not the same as “following completion of the cell culture process“. In view of the claim interpretation by the board, the ambiguous term “following fermentation” in the context of supplementing the CCF does not necessarily mean that the culture process has been completed. In contrast, the cell culture process, in the context of antibody production, is generally completed with the harvest or lysis of the cells.
Moreover, “following completion of the cell culture process” and “following fermentation” are not synonyms in the context of fed-batch or continuous cell culture processes where culture medium (with or without the cells) is continuously or intermittently introduced into and removed from the culturing vessel. Such processes are explicitly mentioned in the application as filed, and the interpretation of a term or an expression in the application as filed therefore needs to be technically sensible for continuous cell culture processes as well.
The term “using” is substantially broader then “supplementing” and includes, for example, processes in which the Trx inhibitor is added at an earlier stage, remains present in the culture fluid and is used “following completion of the cell culture process”.
The board concluded that the application as filed does not disclose a process in which, following fermentation, the CCF is supplemented with a Trx inhibitor.
Comments
An unclear or ambiguous feature can indeed lead to an infringement of Art 123(2).
In T 1791/16, Reasons 11, it was held that, If a claim is ambiguous/unclear, all technically reasonable claim interpretations must be considered. If one of those interpretations contains matter that extends beyond the content of the application as originally filed, it must be concluded that added subject-matter is present.
In T 470/21, Reasons 2.1, it was held that, a reasonable interpretation of a claim is to be taken into consideration for the assessment of Art 123(2) but added that Art 69(1) may be used to interpret the scope of protection under Article 123(3) EPC, but it is not used to determine whether the requirements of Art 123(2) are met.
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