A biologic medicine is defined by European legislation as ‘a medicine that contains one or more active substances made by or derived from a biological
source’. Biological, or natural, sources include microorganisms, animal cells or human cells. Some biologic medicines mimic proteins made naturally in the human body. Examples include insulin, growth hormone and growth factors that control blood
cell production. Other biologic medicines are not copies of proteins occurring naturally in the human body, but are enhanced in the laboratory to improve bioavailability, specificity, and effectiveness.
The best-known examples of these are antibodies, which bind to the surface of cells in the body and are used extensively in the treatment of cancer.
Biologic medicines in the broadest sense include any substance made in the laboratory from a living organism. This broad definition includes vaccines, immunotherapies, biosimilars, gene therapy
and stem cell or tissue therapy. In this section, however, biologic medicines will refer to protein-based medicines, such as insulin, while the other
substances covered in the broad definition will be described separately in different sections.