From the Summary: "A biological product, or biologic, is a preparation, such as a drug or a vaccine, that is made from living organisms. Compared with conventional chemical drugs, biologics are relatively large and complex molecules. They may be composed of proteins (and/or their constituent amino acids), carbohydrates (such as sugars), nucleic acids (such as DNA), or combinations of these substances. Biologics may also be cells or tissues used in transplantation. A biosimilar, sometimes referred to as a follow-on biologic, is a therapeutic drug that is highly similar but not structurally identical, to a brand-name biologic (i.e., the reference product). [...] The FDA [Food and Drug Administration] regulates both biologics and chemical drugs. Before a biologic or biosimilar may be marketed in the United States, it must be licensed (i.e., approved) by FDA. [...] The high costs of pharmaceuticals in general--and biologics in particular--has led to an increased interest in understanding the federal government's role in the development of costly new therapeutics. In the case of many biosimilars approved by FDA, the associated brand-name biologic was originally discovered by scientists at public-sector research institutions. These brand-name biologics--Remicade, Enbrel, Humira, Avastin--are among the top-selling drugs in the United States and worldwide."
CRS Report for Congress, R44620
Congressional Research Service: https://crsreports.congress.gov/