Biosimilars are imitation drugs of biopharmaceuticals. They consist of complex threedimensional protein structures, which are synthesized by genetic modified cells (e.g. bacteria, yeast or mammal cells). They differ from low-molecular active compounds, like e.g. used in Generics, by its large and complex structures.
However, since these cells are more sensible in terms of temperature, nutrient supply, cell density etc. Biosimilars are strongly similar to the original active compound, but not identical in terms of its atoms (which means that they have tiny, analytical not measurable changes) compared to the original formula.
For this reason, the approval of Biosimilars requires preclinical and several clinical studies, where they are compared to the original formula. This in turn results in especially high requirements towards the production process as well as the product analytics.
As a consequence, Biosimilars are not considered to be identical copies with identical medicinal effects of the original formula. They rather represent its own medicinal class, which do not differ significantly from the original preparation in terms of prices.