UPC CoA confirms “gold standard” for added matter in Sibio v Abbott

Sibio Technology Limited v Abbott Diabetes Care Inc. [UPC-CoA-884/2025] – Court of Appeal of the UPC, Luxembourg (Kalden, Rombach, Simonsson, van der Burg, Rydman) – 13 August 2026

The Court of Appeal of the Unified Patent Court (UPC) recently issued its decision on the validity of Abbott’s patent EP3831283 for an on-body glucose monitoring device.  In its assessment of added subject-matter, the Court conducted a detailed review of the technical teaching of the patent as a whole, leading it to determine that the omission of a feature from claim 1 did not result in new technical information being added beyond the scope of the application as filed.  The Court applied essentially the same legal test as that used by the EPO (the “gold standard”, G2/10), also emphasising the importance of assessing the functional and structural relationships between the omitted and claimed features.  We consider whether this indicates a deviation from the EPO’s notoriously strict approach to added matter.

Background

In March 2024 Abbott Diabetes Care Inc. filed an application with the UPC Local Division for a preliminary injunction (PI) and other provisional measures against Sibio Technology Limited, alleging that Sibionics’ GS1 CGM (continuous glucose monitoring) product infringed EP’283.  The application was refused for the reason that claim 1 was more likely than not invalid due to the omission of an elastomeric sealing member or elastic material from claim 1, resulting in added matter.  The Court of Appeal (CoA) reversed the first instance decision, finding that the skilled person would derive other modes of sealing directly and unambiguously from the application as filed.  The preliminary injunction was therefore granted (UPC_CoA_392/2024).

In parallel, Sibio filed a revocation action against EP’283, alleging invalidity due to added matter and lack of novelty and inventive step.  The oral hearing on this action was held by the Paris Central Division in June 2025 (UPC_CFI_231/2023). The Court noted that while the Court of Appeal’s decision on the provisional measures was not binding, its reasoning could not be disregarded.  It held that, inter alia, the omission of an elastomeric seal from claim 1 did not result in added matter.

In the present case, the CoA maintained its view taken in the PI case, upholding the decision of the First Instance Court.  The reasons for the decision offer further insight into the approach to added matter in the UPC.

The Court of Appeal’s test for added matter

The CoA set out that in order to determine whether there is added matter, it must ascertain:

“what the skilled person would derive directly and unambiguously using his common general knowledge and seen objectively ad relative to the date of filing, from the whole of the application as filed, whereby implicitly disclosed subject-matter, i.e. matter that is a clear and unambiguous consequence of what is explicitly mention, shall also be considered as part of its content.”

The decision explicitly notes that this test is the same as the “gold-standard” established by the EPO’s Enlarged Board of Appeal in G2/10 (paragraph 30).

Sibio maintained that including features in claim 1 relating to a recess, without also including the elastomeric sealing in the recess, constitutes added matter, either because it is an intermediate generalization or because the omitted feature is essential to the invention.  However, in the Court’s view, no separate categories of added matter exist, since there is only one relevant test.

It was also the Court’s view that “the technical effect that the invention aims to achieve, and whether an omitted feature contributes thereto, is relevant for the assessment of added matter”.  In particular, the CoA emphasised the relevance of whether the skilled person would consider there to be “a structural or functional relationship between the omitted feature and the other features of the claimed embodiment”, i.e. “an inextricable link”.

The absence of an inextricable link between the omitted elastomeric sealing and the claimed features of the device is central to the Court’s finding in this case.  In view of the application as a whole, the CoA held that the skilled person would not consider the elastomeric sealing to have a role in establishing electrical connections in the device.  On the other hand, the skilled person would recognise that sealing the electrical contacts from the environment was essential, but could be achieved by any type of sealing forming part of the common general knowledge, particularly in the absence of any preference stated in the application for one type of sealing over another.  Therefore, the omission of an elastomeric seal from claim 1 did not convey new technical information.

Deviation from EPO practice?

Some commentators have suggested that the UPC’s approach, with its emphasis on the teaching of the application as a whole, is more “holistic” than the EPO’s.  However, according to the BoA case law, an intermediate generalisation is justified “in the absence of any clearly recognisable functional or structural relationship among the features of the specific combination, or if the extracted features is not inextricably linked with those features” (see e.g. T1067/97).

For example,  in T2047/22, the Board rejected the appellant’s (opponent) argument that Merck’s patent for applicator for inserting a medical implant contained added matter.  The appellant argued that the recitation in claim 1 of a cannula holder “slidably received inside the housing”, taken from the description, constituted an intermediate generalisation.  The Board disagreed, noting that the skilled person would infer that alternatives to the omitted features could be used and, as such, they were not inextricably linked to the claimed features.

Similarly, in T507/22, the Board rejected the opponent’s argument that claim 1 directed to a casting installation contained added matter due to omission of a cooling nozzle and vibrator in relation to the claimed guide roll.  Although the application as filed disclosed all three features in the same sentence, (“there may be provided a guide roll…., a cooling nozzle…, and a vibrator…..”), the Board found that they did not have an inextricable functional or structural linkage and, therefore, the intermediate generalisation was allowable.

The above cases are also consistent with T1762/21, in which the Board stated:  “The person skilled in the art is presented with subject-matter extending beyond the application as filed when an amended claim includes only some features of an originally disclosed combination and the features left out of the claim were understood, by the person skilled in the art, to be inextricably linked to the claimed ones. This is the case if the person skilled in the art would have regarded the omitted features to be necessary for achieving the effect associated with the added features. In such a situation, the amended claim conveys the technical teaching that the effect can be obtained with the claimed features alone, which is in contrast with and extends beyond the originally disclosed subject-matter that the whole combination of features was needed.”

Therefore, while the EPO often considers importing into a claim a feature that is only explicitly disclosed in combination with other omitted features to add matter, the EPO case law also acknowledges that there are circumstances in which such amendments are allowable.

The UPC Court of Appeal’s decision in Sibio v Abbott does therefore not seem inconsistent with established EPO practice.  What is apparent, both before the EPO and the UPC, is that whether or not an amendment is considered to constitute an unallowable intermediate generalisation will be highly dependent on the specific facts of the case.  Applicants are advised to carefully consider, at the time of drafting, what the application explicitly and implicitly teaches the skilled person about the functional and structural relationships between the technical features of the invention.

This article was prepared by Partner and Patent Attorney Jennifer Bailey.