A biosimilar medicine is developed to be highly similar to the original biological medicine. The original biological medicine is a medicine that has already been approved and is used in the EU and referred to as the reference medicine. However, the biosimilar is not regarded as a generic of a biological medicine. Generic medicine is usually produced by chemical synthesis it is generally possible to obtain exactly the same molecule. A biosimilar and its reference medicine are essentially the same, though there may be minor differences in their active substances. These minor differences are due to the fact that these active substances are usually large and complex molecules and that they are made by living cells.
Biosimilar medicinal products come from living organisms (e.g. Chinese hamster ovary (CHO) cells, yeast, bacteria) that have been modified using recombinant DNA technology to produce the desired active substance of biological origin (e.g. insulin, growth hormone, monoclonal antibody). Due to the variability of the biological system, the complexity of biological molecules and complex manufacturing processes, there is a certain degree of variability in reference and biosimilar medicinal products. Some degree of variability is inherent to all biological medicines and minor differences may occur among different batches of the same biological medicine. Strict controls are always applied (study of physico-chemical properties, biological activity, impurities, sterility and stability) to ensure that potential differences are within the acceptable limits and that the differences do not affect safety or efficacy.
The biosimilarity with the reference product is established based on comprehensive head-to-head comparison of the biosimilar with the reference medicine to show that there are no clinically significant differences compared to the reference product in terms of quality, biological function, safety, efficacy and immunogenicity. In this context, it should be noted that biosimilars are approved according to the same standards of pharmaceutical quality, safety and efficacy that apply to all biological medicines approved in the EU (e.g. Good Manufacturing Practice, Good Clinical Practice, drug development according to the relevant EMA, ICH and WHO guidelines).
