"Extrapolar" in the field of drug development and registration, means authorizing a product by the regulatory authority for an indication in which clinical trials have not been required during its development, because they would not provide added value, or for ethical reasons. In this case, the efficacy and safety data from clinical situations studied during development are “extrapolated” or “extended”.
La extrapolation It has a scientific basis, so its practice should not raise suspicions regarding the risk-benefit. In addition, one of the guarantees regarding the scientific criteria that support it is the extensive experience of the EMA in the extrapolation of data related to original biological products.
In the case of biosimilars, the extrapolation means that the marketing holder does not need to prove that comparative clinical trials have been carried out in all the indications for which authorization is requested.
Thus, it is the laboratory that must request the extrapolation of the data from efficacy and safety from one indication to another and justify why you believe that this extrapolation is acceptable in a guaranteed regulatory framework.
In this way, the Extrapolation is possible if both products are comprehensively shown to be comparable physicochemically and in biological activity (in vitro and in vivo tests) and that their efficacy, safety and immunogenicity are equivalent in sufficiently sensitive indications or clinical conditions.
It should be noted that the fundamental principles that govern the biosimilar extrapolation are the same as those applied to the originals. Biosimilar medicines can therefore be authorized with an equivalent guarantee for certain diseases of the original based on the "totality of the evidence" provided by the marketing laboratory.
Practical experience with biosimilars that are already on the market, allows us to affirm to date that the therapeutic response is equivalent to that of the original product in any of the authorized indications. They have been authorized, or not, by extrapolation.
