8.1.3 Applicability of G 2/88 and G 6/88 to process claims

In T 2192/22, the claims related to improved processes for purifying polypeptides of interest, by increasing the amount of a polypeptide of interest bound to a cation-exchange matrix relative to the amount of one or more impurities bound to the ion-exchange matrix..

The patent proprietor was of the view that the claim was such that its subject-matter should be recognised as novel under G 2/88 since it related to the use of a known compound for a new purpose not made available in the prior art – i.e. "the reduction of host cell proteins (HCPs) in the purification of a polypeptide of interest by cation-exchange chromatography".

The board however, concurred with the findings in T 892/94, that applying the concept of novelty developed in G 2/88 to claims for processes of producing a product, even when drafted as use for achieving a technical effect that results in an improved product could potentially result in a permanent monopoly of the use of a known substance for a known purpose. Such a permanent monopoly would arise from the repeated drafting of claims for a process of production including a new, possibly only subtly different, technical effect associated with this known process (T 1179/07).

In the present case, drafting the claim as a "use" of a chemical compound could not mask the fact that the claim defined a production/purification process and the new technical effect could 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 could not circumvent the fact that on analysis, the claim was directed to a use or process for the production of a product, here one having the "improved" property of having "reduction of host cell proteins".

Moreover, the alleged new technical effect of reduction of host cell proteins pertained to the product (the polypeptide) and could not be considered a technical limiting feature of the "use" according to G 2/88. Indeed, where an invention relates to a new technical effect of a physical entity that can only occur as part of a process for the production or manufacture of a product, such that this effect is inextricably linked to and cannot occur in isolation from the production process, a claim directed to that "use" of the physical entity to achieve that effect must be regarded as directed to the production process per se (T 1913/21).

The assessment of novelty in the present case was therefore done by answering the question of whether or not there was a disclosure forming part of the state of the art of a process having the same physical steps as the claimed process, i.e. purifying a polypeptide of interest by CEX chromatography, wherein at least one of the equilibration, loading and/or washing fluids contained a chemical structure with amino groups and/or cationic amino acid polymers, in a concentration of at least 7 mM. No other features were explicitly or implicitly implied by the wording of the claim. The board found that the prior art anticipated the claimed subject-matter and denied novelty.