T 0964/92 (Benzodioxane derivatives/EISAI) vom 23.08.1994

Inventive step (no - obvious alternative)
Common general knowledge
Identification of the technical problem and the closest state of the art

The question as to what extent a chemical structure can be modified without causing major changes in its biological activity is equally relevant to the question as to whether or not it is credible that all members of a certain group of chemical compounds solve a particular technical problem, e. g. whether they can be fairly assumed to be useful in a therapeutical treatment, and to the question of whether or not such an activity can be expected on the basis of the state of the art. If the answer to the former question can only be yes with respect to considerations forming part of the common general knowledge, then the question whether or not the solution of the same technical problem by providing the same group of compounds was obvious must be answered on the basis of the same considerations (No. 2.8. of the reasons).