A biologic medicine is a large molecule typically derived from living cells and used in the treatment, diagnosis or prevention of disease. Biologic medicines include therapeutic proteins, DNA vaccines, monoclonal antibodies and fusion proteins. Biologic medicines are often 200 to 1,000 times the size of a small molecule drug and are far more complex structurally. They are also highly sensitive, making them more difficult to characterize and produce. Due to both their size and sensitivity, biologic medicines are almost always injected into a patient’s body.
How are biologic medicines developed?
[wp_ad_camp_4]Biologic medicines are made in living organisms to produce proteins to treat various diseases, often by genetically modifying cell constructs or cell lines. DNA technology is often used to insert desirable genes or remove undesirable ones within a living cell or via a vector such as a virus, prompting a specific function – such as the production of a protein to treat disease. This relatively new advance in biotechnology has led to the development of many of today’s most important medicines, including monoclonal antibodies for cancer, human insulin for diabetes and the cloning of the naturally occurring protein, erythropoietin to stimulate the production of red blood cells in the treatment of chronic anemia.
The genetic code of a chosen protein, such as human insulin or an immune system antibody, is identified and replicated by combining different segments of DNA to build a functional DNA sequence. The DNA sequence is introduced into the host cell of a living organism, such as bacteria, yeast or mammal cells, altering the cell’s genetic makeup and coding it to produce the chosen protein. Genetically modified cell lines are carefully selected and cultured in large bioreactors before the biologic medicine is extracted through complex and lengthy purification processes.
Each step is intricate, sensitive and often specific to a particular medicine, requiring significant skill and expertise. Even minor alterations may lead to changes in cell behavior and differences in the structure, stability or other quality aspects of the end product. Any of these differences have the potential to affect the treatment’s safety, efficacy and shelf life, and to increase the risk of an unwanted immune response.
- Guildford-Blake, R. and Strickland, D.Guide to Biotechnology 2008. Biotechnology Industry Organization.[Online] 2008. [Cited: August 24, 2012.]
- Biologics and biosimilars | An overview. Amgen Inc. One Amgen Center Drive. Thousand Oaks, CA 91320-1799