Generics, biologics,
biosimilars: who’s who?

Unlike generic medicines, manufactured through chemical synthesis, biologic medicines contain one or more active principles produced or derived from a biologic source, include a wide range of products like vaccines, allergens or recombinant proteins. 4

Most biologics, such as monoclonal antibodies, have a highly complex molecular structure that is difficult to identify or characterize and they are manufactured using the most innovative technologies.

In biologics, monoclonal antibodies have relevance in the treatment of pathologies that affect a large number of people: cancer, lymphoma, rheumatoid arthritis, psoriasis, ulcerative colitis or Crohn’s disease.  5

Image 1. Differences between small molecule, biological molecule and monoclonal antibody

Biosimilars are medicines manufactured through biotechnology and which have demonstrated their equivalence in quality, efficacy and safety to the reference product.

One of the key differences between biosimilars and reference biologics is how clinical trials operate during the development process. With biologics, the goal of trials is to ascertain the clinical efficacy of the product. With biosimilars the goal is to demonstrate that the product is comparable to the reference biologic product in terms of its pharmacokinetics, pharmacodynamics, safety and immunogenicity. In other words, the goal is to demonstrate the scientific concept of comparability to show that minor differences between the two do not have a relevant impact on the final therapeutic result. 4

Image 2. Key differences between biosimilars and reference products


Image 3. Main differences between generic, biologic and biosimilar6


  1. BioSim. Guía de medicamentos biosimilares para médicos. 2017. ISBN: 978-84-697-2838-3. Available on:
  2. Biosimilars and their role in cancer treatment. Available on:
  3. Rodríguez de la Cuerda AL. Biosim. Biosimilares en España. Presentación XI Encuentro de Autoridades Competentes en Medicamentos de los Países Iberoamericanos (EAMI) “De la estrategia a la acción en los medicamentos”. 22nd June 2016. Varadero, Cuba. Available on: