The patent concerns a combination treatment of diabetes containing pioglitazone and glimepiride (brand name: DUETACT®).

The Opponents objected:

• - Added matter of the combination in the application as initially filed which covered numerous further combinations

The Board of Appeal considered that there was no added matter as pioglitazone was presented as the most preferred compound within the insulin sensitivity enhancer which lead the Board apply the one dimensional selection case law for the second component.

• - Inventive step

The main difficulty concerned the relevance of the tests to be used to show an improved effect.

The Court confirmed their position that in case of a combination, the demonstration should be based on closest combinations in the prior art, not synergy.

With regard to the test itself, the question solved was that of plausibility of the test due to the different potency of the compounds used in the tests.