EP 2 707 383 B1 relates to methods of preventing and eliminating the formation of trisulfide bonds in proteins during protein production.
Claim 1 reads:
Use of an inhibitor of cysteine degradation for reducing the formation of trisulfide bonds in proteins, ……. and wherein the use comprises: culturing cells expressing said proteins in the presence of an effective amount of the inhibitor of cysteine degradation, whereby trisulfide linkage formation in said proteins is reduced relative to cells cultured in medium without the inhibitor of cysteine degradation.
The claim can be summarised as the “use of product X, having effect Y, on the production of product Z”.
Brief outline of the case
The OD decided maintenance according to a new MR.
Both opponents appealed.
The board revoked the patent for lack of N of the MRn over D3 and D24.
A request for referral to the EBA by the proprietor was rejected by the board.
Opponent’s 2 point of view
Claim 1 should be understood as relating to any use of pyruvate in protein production, regardless of whether or not such a use related to the reduced formation of trisulfide bonds.
In the case at hand, the purpose of claim 1 should be understood as that of protein production and not reducing the formation of trisulfide bonds, which is a mere technical effect of an old compound in an old use.
The effect of “reducing the formation of trisulfide bonds” was actually a technical effect underlying the known non-medical purpose, production of proteins, of the known chemical compounds listed in claim 1. Such subject-matter could not be novel.
The proprietor’s point of view
The proprietor argued that a novelty destroying document for the non-medical use of claim 1 had to disclose one of the cited pyruvates used for obtaining the same effect and that none of the documents explicitly disclosed “reducing the formation of trisulfide bonds”.
D3 and D24 made no mention of the problem of trisulfide bond formation in a method comprising culturing cells expressing proteins in the presence of an effective amount of the ICD.
For the proprietor, Opponent 2’s claim construction was wrong and it concluded that, put in terms of G 2/88, the invention concerned a new technical effect that led the skilled person to a new use, i.e. the use of such compounds to prevent trisulfide bond formation by inhibiting cysteine degradation.
The board’s decision
Application of G 2/88 and G 6/88
G 2/88 and G 6/88 are limited to claims directed to new non-medical uses of a known compound for a particular purpose, rather than to processes for production within the meaning of Art 64(2).
In order to be a limiting technical feature of the claim, the new purpose must relate to the use rather than to a property of the product.
The board held that, provided that a use claim in reality defines the use of a particular physical entity to achieve an “effect”, and does not define such a use to produce a “product”, the use claim is not a process claim within the meaning of Art 64(2).
It is further apparent that claims which, when correctly construed, are directed to processes resulting in products referred to in Art 64(2) are not subject to the special treatment established under G 2/88 and G 6/88, even if they contain the word “use“.
After reviewing a certain number of decisions quoted by the parties, the board concluded that there is a consistent line of jurisprudence, holding that the rationale of the EBA’s decisions G 2/88 and G 6/88 is limited to claims directed to new non-medical uses of a known compound for a particular purpose, and does not apply to processes for production within the meaning of Art 64(2).
Interpretation of the “use” in the present claim
The board determined whether or not the “use” in claim 1 is in fact a process to produce a product or if it is a use to achieve a new technical effect.
The claimed subject-matter comprises carrying out process steps, which result in the production of a product. Following the principles laid down in G 2/88 and G 6/88 and the jurisprudence implementing them, the claimed subject-matter must be regarded as a process for the production of proteins with a “reduced” number of trisulfide linkages, regardless of the fact that the claim is drafted as the “use” of a chemical compound.
The board considered that the proteins produced by the claimed process would be covered by Art 64(2) as “products directly obtained” by the claimed process.
In the present case, the choice of drafting the claim as a “use” of chemical compound cannot mask the fact that the claim defines a production process and the new technical effect can only take place in the context of this process.
The mere formatting of the claim to give the appearance that its subject-matter falls under the principles established by G 2/88 cannot circumvent the fact that on analysis, the claim is directed to a use or process for the production of a product, i.e. one having the ‘improved’ property of having ‘fewer’ trisulfide bonds.
Thus the new technical effect recited in the claim of reducing the formation of trisulfide bonds in proteins pertains to the product. the protein produced, and cannot be considered a technical limiting feature of the “use” according to G 2/88.
The lack of N
In view of the board’s claim construction, the reduction of the formation of trisulfide bonds in proteins is not a feature of the claimed subject-matter to be taken into account for assessing novelty.
D3 and D24 both disclose methods comprising culturing cells expressing said proteins in the presence of pyruvate, i.e. a compound defined in the paragraph [0042] of the patent as an inhibitor of cysteine degradation.
In view of the above considerations on claim construction, the subject-matter of claim 1 lacked N over the disclosure in documents D3 and D24.
Comments
From the present decision, it can be concluded that a clever claim drafting claiming the use of a known product (pyruvate), even if the effect is as such apparently novel (reduction of trisulfide bonds), in the manufacture of a further product (proteins) cannot be considered a technical limiting feature of the “use” according to G 2/88.
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