Immunology Update: Biologics.

Biologics are substances made from a living organism or its products. These include genes, proteins (eg, antibodies, receptors, enzymes, inhibitors), recombinant proteins, and fusion proteins. Biologics often are produced using recombinant DNA technology. For example, monoclonal antibodies are produced by inserting human genes into immortalized cell cultures, which then produce the gene product (ie, an antibody) in large quantity. Another approach is to fuse genetic material from nonhuman sources (eg, mice) with human genetic material. The fused gene is inserted into a tissue culture that produces the gene product (ie, a chimeric monoclonal antibody). Biologics are used to manage many conditions, including malignant and nonmalignant conditions. They are widely used in the treatment of human epidermal growth factor receptor 2 ( ERBB2 [formerly HER2 or HER2/neu ])-positive breast cancer. They also are used in the treatment of leukemias, lymphomas, and colorectal and lung cancer. Biologics improve outcomes in autoimmune disorders, such as rheumatoid arthritis, ankylosing spondylitis, psoriasis, inflammatory bowel disease, and multiple sclerosis. Other uses include erythropoietin for renal failure-associated anemia and the new proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors for treatment of patients with persistently elevated low-density lipoprotein levels despite statin treatment who are at high risk of cardiovascular events.