The EPO Technical Board of Appeal (TBA) reviewed the law around novelty of use, and determined that in the case of CardioPolymer, Inc.'s European patent application (EP07837908.8), the claimed chemical entity did not qualify as a 'substance or composition' in accordance with Article 54(5) EPC and therefore was not eligible for purpose-related product protection.


The patent application relates to an alginate for treating a dilated left ventricle of a heart of a patient suffering cardiomyopathy. The alginate was found to be therapeutically useful when injected into the heart in a specific pattern. The alginate per se is known, however its therapeutic use in the heart was not.

The EPO Examining Division refused the application on the grounds of lack of novelty, and CardioPolymer, Inc. appealed.

The Decision

The main area of dispute was whether the claimed alginate qualified as a 'substance or composition' in accordance with Article 54(5) EPC, and therefore whether a new use of the alginate could impart novelty.

CardioPolymer Inc. argued that it would be 'absurd' not to consider the claimed alginate as a ‘substance or composition’. They argued that the effect of the invention was a combination of biochemical and physical properties, and whilst the specific injection pattern into the heart was important, the substance itself was equally important, such that the substance should be eligible for purpose-related product protection.

The Board disagreed. The Board confirmed that Article 54(5) EPC imparts novelty only to "substances or compositions" that are the active agent or ingredient of the particular specific medical use (referring to Article 31(1) of the Vienna Convention, the intended scope of the 'EPC 2000 claims' when they replaced ‘Swiss-style’ claims, and case law such as G5/83).

The Board set out an approach (similar to T1758/15) to determine whether a "substance or composition' is being used in a treatment:

It suggested establishing:

  • (a) The means by which the therapeutic effect is achieved; and
  • (b) Whether that which achieved the therapeutic effect is a chemical entity or composition of chemical entities.

In the present case, the alginate acts as a 'space occupying agent' (step a) and the therapeutic effect of the use is achieved by the ensemble of ‘space occupying’ physical structures formed of the alginate (step b). Such a material qualifies as a ‘viscous device’ rather than a substance or composition.

The alginate therefore does not qualify as a substance or composition within the meaning of Article 54(5) EPC, and the claims were found to lack novelty.


This case provides an important update on how the EPO is interpreting Article 54(5) EPC and their views on chemical entities that are not typical 'active agents' but may nevertheless impart a therapeutic effect. The two-step approach set out by the Board here provides applicants with some guidance for reviewing their own inventions in this space, and for now, it seems that the EPO’s position on the interpretation of Article 54(5) EPC is fairly strict.