What are biologics? How do they differ from traditional small-molecule therapies?
When you think of a drug, you probably think of a pill like Tylenol or Lipitor. You may not be as familiar with biologics, which are attracting a great deal of attention from policymakers and media. Biologics represent a different set of drugs, distinguished by their size, their informational and manufacturing complexity, and their therapeutic advantages. If you were to look at most drugs under a microsope, you would find that they are actually rather small relative to a typical biologic. Acetaminophen, which is the active ingredient in Tylenol, weighs 150 daltons (a dalton is a unit of atomic mass). Enbrel, on the other hand, which is a top-selling biologic indicated for several autoimmune diseases, weighs 150,000 daltons. To put that thousand-fold difference in visual terms, if Tylenol weighed as much as your mountain bike, then Enbrel would weigh as much as an unfueled 12-passenger private jet. Hence you will often hear people in the pharmaceutical industry refer to “small molecule”
