1.4. Removal or replacement of features from a claim
1.4.3 Omission of a feature presented as essential
For cases in which the amendment consists of the replacement or removal of a feature from an independent claim, the boards occasionally apply the test of decision T 260/85 (OJ 1989, 105). In T 260/85 it was stated that it was not permissible to delete from an independent claim a feature which the application as originally filed consistently presented as being an essential feature of the invention, since this would constitute a breach of Art. 123(2) EPC 1973. See also T 496/90, T 415/91, T 628/91, T 189/94, T 1032/96 (segment length parameters explained as essential), T 728/98 (OJ 2001, 319; concerning the deletion of the feature "substantially pure"), T 1040/98 (acoustic waveguide is described in the form of a bladder filled with a suitable material, throughout the description), T 1390/15 (consistent disclosure of solubility limit on the content of Mg and Cu) and T 1187/15 (consistent disclosure that heart rate can be derived from the blood pressure measurement). For recent decisions following this approach, see T 1099/21 and T 897/20.
In T 236/95 the board held that if the problem could not be solved without the features concerned, they could not be considered unimportant.
In T 784/97 the patent proprietor alleged that a prior art document would have made the skilled person aware that the disputed feature was not essential. The board held that whether or not a feature of an independent claim had to be seen as "essential" could not be a question of the prior art disclosure. Rather, what had to be decided was what a skilled person was taught by the originally filed documents.
In T 1515/11 the board confirmed that a feature could not be deleted from an independent claim if it had been consistently presented as an essential feature of the invention, since this would add subject-matter. In some cases there might be room for debate as to whether the application presents a feature as being essential to the invention or as being optional. However, there were also cases where, on purely formal grounds, the essentiality of a feature could not be doubted. One such case was where the applicant chose to include in an independent claim as filed a feature explicitly mentioning the problem, and affirming that the claimed subject-matter represents a solution to the problem. In particular, where a claim to a method included a feature explicitly defining that the method was carried out in a manner which solved the problem, to argue that this feature was not essential would be tantamount to arguing that in order to solve the problem, it was not essential to carry out the method in a way which solved the problem.
The board in T 648/10 confirmed the test set out in T 260/85. However, it observed that the EPC does not require the use of any particular tests when assessing whether subject-matter has been added. Instead, such tests are tools which may be helpful, in certain situations, in the assessment of whether subject-matter has been added.
- T 1535/23
In T 1535/23 the board observed that the Court of Appeal of the Unified Patent Court ("CoA UPC") in UPC_CoA_382/2024 applied the same test as the EPO to determine whether an amendment extended beyond the content of the application as filed. This test is known as the "gold standard" (see G 2/10).
The issue at stake in both T 1535/23 and UPC_CoA_382/2024 concerned the omission of a feature from a claim in the context of added matter. In T 1535/23 claim 1 of auxiliary request 5 essentially differed from independent claim 19 of the parent application as filed in that the specific surface area contained in independent claim 19 of the parent application as filed had been omitted and instead two characteristics of a powder X-ray diffraction pattern had been added. The board explained that the parent application as filed disclosed that the said specific surface area was an essential feature of the invention. All the independent claims of the parent application as filed required the said specific surface area, either directly or by reference to another independent claim. Furthermore, in the summary of the invention, the parent application as filed referred, in a first broad aspect, to a crystalline free base of palbociclib having the said specific surface area. Therefore, it was clear to the skilled person that the passages of the parent application as filed relied on by the respondent referred to embodiments all having this specific surface area. Hence, the board observed that the parent application as filed comprised no teaching that the specific surface area referred to in independent claim 19 of the parent application as filed was not an essential feature of the invention disclosed which could be omitted to characterise Form A of the freebase of palbociclib. The board concluded that the omission of the specific surface area in claim 1 of auxiliary request 5 added subject-matter beyond the content of the parent application as filed.
In turn, in UPC_CoA_382/2024 independent claim 1 of the patent related to an on-body glucose monitoring device comprising a sensor assembly and an enclosure with an electronics assembly. The point of dispute was whether the omission of an elastomeric sealing member for sealing the coupling between the sensor assembly and the electronics assembly in the wording of this independent claim added subject-matter. The CoA UPC found that even though a need for sealing was described in the application as filed, there was no described advantage or function of the use of the specific elastomeric material now omitted from the claim, other than that it provided sealing. Therefore, the skilled person understood from the application as filed that the exact method of sealing did not contribute to, and was thus not relevant for, the technical teaching of the invention as disclosed in the application as filed. The CoA UPC concluded that the omission of the use of an elastomeric sealing member from claim 1 of the patent did therefore not extend beyond the content of the application as filed.
The board explained that its conclusion in T 1535/23 was not in contradiction with the decision of the CoA UPC in UPC_CoA_382/2024. The fact that the CoA UPC acknowledged that the feature in question could be omitted without extending beyond the content of the application as filed while the board in T 1535/23 reached the opposite conclusion was based on different factual situations rather than on a difference in legal considerations. Both the CoA UPC and the board in T 1535/23, and the EPO in general, apply the same principle (the "gold standard") in judging whether an amendment extends beyond the content of the application as filed.