Biologic drugs have revolutionized the treatment of an increasing array of medical conditions that have failed to respond adequately to traditional drugs. These include cancers, rheumatoid arthritis, and conditions affecting the skin, heart, and nervous system.
Now that we know more about the molecular basis of health and disease and have gained greater expertise in biotechnology, the development of biologic drugs has accelerated, complementing and, in some cases, replacing traditional drugs. These biologics can be identical to or can very closely resemble natural hormones, such as human insulin—the first biologic drug to appear in 1982—or growth hormone. Other biologics are monoclonal antibodies, stimulating or enhancing our body’s immune system to zero in and block selective substances in the body or attack specific cell types, such as tumors.
Unlike biologics, traditional drugs are generally small molecules produced by chemical reactions, with a specific chemical structure. The active ingredient in approved generic equivalents must be identical to the original traditional drug. Moreover, the generic must be bioequivalent—that is, it must act in the body in the same way and to the same extent as the reference drug, as well as being freely interchanged with it.
By contrast, biologics are large and complex molecules produced by approaches involving recombinant DNA technology. Unlike traditional drugs, the composition of biologics and the effects they produce may differ significantly based on how they are prepared, even when there are only subtle differences in their preparation. Moreover, the final product is too complex to be characterized by existing analytical methods to determine whether it is chemically identical to the original.
Because biologics are so expensive, the development and approval of far less costly generic biologics have been subject to long and heated debate. In the United States, legislation was enacted in 2010 that enables the FDA to grant expedited approval to biosimilars—biologics that closely resemble but are not necessarily identical to the original product—but draft guidelines have yet to be finalized. Since 2001, the European Medicines Agency has had procedures for biosimilar approval, with the requirement that they produce the same effects and can be interchanged with the original.
SEE ALSO Food and Drug Administration (1906), Human Insulin (1982), Growth Hormone (1985), Herceptin (1998), Enbrel, Remicide, and Humira (1998), Iressa and Erbitux (2003), Avastin (2004), Lucentis (2006).
The twenty-first century has witnessed a distinct shift in the source of new drugs from plants and chemicals to biologic drugs. Biologic drugs are virtually identical to natural substances produced in our bodies. By applying recombinant DNA technology, it has become possible to produce virtually unlimited supplies of these highly specific and potent drugs. Because these drugs alter the fundamental causes of medical disorders, they offer more than mere symptomatic relief.