In decision T 1252/20, the EPO has broadened the ability to protect known substances or compositions, for use in medicine.

In the UK and Europe, patent claims to ‘methods’ are not permitted if the method is surgical, therapeutic or diagnostic. The idea is to prevent medical practitioners from being sued for patent infringement whilst delivering care. A result of this policy is that infringement actions are shifted to a more commercial setting, where pharmaceutical and medical device companies operate.

Since methods of treatment, surgery or diagnosis are not patentable in Europe, one might think that R&D is not properly incentivised in those areas.

However, this is not the case. Patent protection is available for known ‘substances or compositions’ if a novel and inventive method is found for using them in medicine. This protection comes in the form of ‘first medical use’ or ‘second medical use’ claims. These have the format:

  1. ‘substance X for use as a medicament’ (for when the substance has never been used in medicine before) or

  2. ‘substance X for use in the treatment of disease Y’ (when existing medical uses of the substance were known, but the substance has now been found to also treat disease Y).

In essence, patentees obtain a special type of product claim, which is limited to the product when used in a new and inventive method.

The question is, what can X (the substance or composition) be?

When the law was created, pharmaceutical active ingredients were clearly at the forefront of the legislator’s mind. However, can X be a different type of substance which is not necessarily an ‘active ingredient’ in the narrow sense of the term?

For example, can one protect substances where it is the macroscopic 3D-structure which provides the technical effect? Or, must it be a ‘chemical’ mode of action which achieves the therapeutic effect?

Previous cases have involved:

  • A column containing a ligand (the ligand therapeutically interacted with blood running through the column to treat cancer) – patentable.
  • Collagen (injected so that it physically blocks radiation to sensitive organs) – not patentable.
  • A known dialysis membrane (but used for the treatment of cancer) – not patentable.
  • A neurostimulator device (for treating substance addiction)- not patentable.
  • A known synthetic lubricant (used to replace synovial fluid) –

The present case (T1250/20) involved a known peptide composition which, when injected into the body, self-aggregates to form a hydrogel. The hydrogel can be injected so that (once aggregated) it blocks blood supply to cancerous cells.

The patent claim didn’t mention a shape of the composition once aggregated. The shape of the aggregated substance in the body was not particularly important, in the way that the shape of a medical device would be. The peptide composition acts a bit like it is a device, but it is not a device as such.

The EPO held that previous case law (e.g. G5/83) did not provide a legal basis for limiting ‘substances or compositions’ to those which have a chemical mode of action to provide a therapeutic effect. After all, methods of treatment or surgery are prohibited from patentability, regardless of any mode of action. Therefore, medical use claims should not be so limited- the mode of action doesn’t matter.

Ignoring the mode of action resolves problems such as prodrugs, where it is not actually the administered compound which provides a therapeutic effect, but a metabolite of the compound once it is broken down by the body. Equally, certain materials will have different modes of action under different biological environments, or completely unknown modes of action.

In future, it seems likely that the deciding factors will be whether materials are claimed in chemical terms, and whether they lack any ‘device-like’ features such as limitations to their shape. Providing that these criteria are fulfilled, those materials should be protectable by medical use claims.

This case is important because materials used in medicine frequently have a physical interaction with the body to achieve their technical benefit. The decision therefore broadens the range of materials which can be protected using medical use claims.

This patentee friendly decision will be welcome for companies at the growing interface between medical devices, materials chemistry and therapeutic drugs.


Nick Bennett

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