Protecting by patent a drug combining two known active ingredients: is it possible ?

More and more therapeutic treatments are based on the combination of two (or more) distinct active ingredients. It is possible to obtain patent protection for such a combination under certain conditions...

Grenoble, 30 December 2021 – More and more therapeutic treatments are based on the combination of two (or more) distinct active ingredients. It is possible to obtain patent protection for such a combination under certain conditions, including in cases where each of the active ingredients of the combination is already known to be involved in a mechanism related to the targeted disease. This is known as a combination invention.

The European Patent Office (EPO) distinguishes between the simple assembly of characteristics of the invention (juxtaposition) and the combination. For a combination invention to exist, the features (here the active ingredients) must be linked together by a functional interaction. This means that the active ingredients of the combination must influence each other to produce a combined technical effect that is different from the one they produce individually.

This combined technical effect can take many forms. The most favorable case is when the combination of active ingredients produces a synergistic effect. The EPO considers that two features interact synergistically with each other if their functions are linked and if they lead to an additional effect that goes beyond the sum of the effects produced by each of these features considered in isolation (see for example the decision of the EPO Board of Appeal T 1054/05). In the case of a combination of active ingredients, it may be sufficient to show that the effect of the combination is greater than that obtained with each of the active ingredients used alone, or even than the effect that a specialist in the field could have foreseen obtaining by combining them.

This combined technical effect can also be based on more indirect aspects, such as the reduction of harmful side effects, the optimization of the pharmacokinetics or bioavailability of at least one of the active ingredients, the possibility of administering the drug by a different route, the improvement of the patient’s compliance with the treatment, the reduction of the frequency of doses, etc.

Whatever the effect, it is generally preferable to include experimental data in the text of the patent application that will be filed, making this technical advantage credible.

To satisfy the criterion of inventive step, this technical effect (whether it is a synergy or any other advantage) must not be suggested by the prior art.

If these various conditions can be met, it may be possible to obtain protection for the combination as such (product claim), independently of any medical use. Protection via a particular medical use may also be envisaged (second therapeutic use claim), including a “kit-of-parts” protection (if the combined technical effect can be obtained even by administering the different active ingredients of the combination separately and/or sequentially; see e.g. decision T 9/81).

It is preferable to evaluate the satisfaction of these different criteria for each combination that you plan to protect, before filing a patent application. Regimbeau’s teams are at your disposal to advise you on a case-by-case basis on this subject.

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