Biosimilars also known as follow-on biologics are biologic medical products whose active drug substance is made by a living organism or derived from a living organism by means of recombinant DNA or controlled gene expression methods. These terms are used to describe officially approved subsequent versions of innovator biopharmaceutical products made by a different sponsor following patent and exclusivity expiry on the innovator product. Reference to the innovator product is an integral component of the approval. After expiry of the patent of an approved recombinant drugs such as insulin, human growth hormone, interferons, erythropoietin, TNF blockers and others any other biotech company can copy and market these biologic drugs. However, unlike the more common small-molecule drugs, biologics generally exhibit high molecular complexity, and may be sensitive to changes in manufacturing processes. Nevertheless, it is well known that this also occurs in the original biologics which implies that the final product of these sophisticated processes which are not under a 100% control of the molecular engineers are known to undergo subtle changes over time.
Biosimilars are subject to an approval process by the European Medicines Agency and the Federal Drug Administration which requires substantial additional data to that required for chemical generics, although not as comprehensive as for the original biotech medicine, and this includes efficacy and safety data. This has been progressively replaced with a greater dependence on assays, from quality through to clinical, that show assay sensitivity sufficient to detect any significant difference in dose. However, the safe application of biologics depends on an informed and appropriate use by healthcare professionals and patients. Introduction of biosimilars also requires a specifically designed pharmacovigilance plan.
It is difficult and costly to recreate biologics. In contrast, small molecule drugs made up of a chemically based compound can be copied identically, they can be easily replicated and are considerably less expensive to reproduce. In order to be released to the public, biosimilars must be shown to be as close to identical to the parent biological product based on data compiled through clinical, animal and analytical studies. The results must demonstrate that they produce the same clinical results. EMA and FDA regulations as well as scientific considerations indicate that biosimilarity does not imply interchangeability. In Rheumatology the first biosimilar has recently been approved in Europe – a biosimilar to infliximab which has passed all tests and examens and that is produced by a Korean company.
Disclosure of Interest J. Braun Grant/Research support from: Abbvie, MSD, Pfizer, Consultant for: Abbvie, Celltrion, Janssen, MSD, Novartis, Pfizer, UCB, Conflict with: Abbvie, Celltrion, MSD, Novartis, Pfizer, UCB