UPC: Inadmissible Extension due to Imprecise Calculation Base of Substance Proportions

In these revocation proceedings, the Central Division Munich addresses the precise requirements for the original disclosure of numerical ranges in composition claims. The patent in suit protects a method for processing sugar mixtures as well as sugar compositions. It is challenged on the grounds of added matter, lack of novelty, and lack of inventive step. The claimed sugar mixture requires that the amount of the marker molecule is in the range of at least 100 ppb to 0.5% of the total concentration. It is undisputed between the parties that the person skilled in the art – unless otherwise indicated – always understands percentages in a composition as being based on the total composition. This is confirmed by the description, according to which percentages are to be understood as weight/weight unless otherwise indicated. The defendant argues that a different calculation basis is derived from the description. The Court does not agree. Although the description serves as an aid to interpretation for the skilled person, and a patent may contain its own definitions of terms, the passages relied upon do not contain a clear deviating definition that would lead the skilled person to relate the marker amount to the total sugar concentration. The skilled person thus understands the claimed composition as calculating the proportion of the marker molecule based on the entire sugar mixture. This amendment adds technically relevant information that could not be derived from the original application, namely that a sugar mixture falls within the scope of the claim or not depending on the method of calculation – i.e., whether the proportion of the marker molecule is related to the total composition or merely to the sugar concentration. Thus, there is an inadmissible extension of the original disclosure. The patent proprietor is responsible for drafting patent claims such that the subject-matter of protection is sufficiently determined. This applies in particular to composition claims containing numerical ranges of components. In the case of such claims, the skilled person is entitled to expect the patent proprietor to specify the composition precisely and carefully. (CD Munich 24. 2. 2026, CFI 829/2024)