Summary
A distinction between "Breakthrough-drug" and "Me-too-drug" within one therapeutic class of medication is usually not clinically relevant. The concept of a class effect, which would mean, that one "Me-too drug" could be substituted with another one from the same therapeutic class, is only proven for very few drug classes. Usually an individual risk/benefit assessment has to be performed for each specific drug. Even if a class effect has been established, doctors should not be forced to switch their patients to the cheapest drug within the same class. Patient specific factors such as compliance have to be considered first. However at the onset of a new therapy regimen, the drug with the lowest price should be used.