Drug Discovery in the Modern Age: How We Got Here and What Does It Mean?

The modern pharmaceutical industry can trace its roots back to the chemical and dye manufacturing industry of the late 19th century, developed for the burgeoning textile industry of the industrial revolution. Early microscopists utilized these various chemicals and dyes to stain and enhance the semitransparent features of cells, protists, and bacteria. It was noted early on that some of these dyes showed marked selectivity and some showed marked bactericidal activity. Paul Ehrlick was the first to translate these two observations into the development of a chemotherapeutic agent, a chemical substance with affinity for a specific target. In this case, it was the development of a series of trivalent arsenical drugs active against spirochete-induced syphilis, ultimately resulting in the development and manufacture of “Neosalnarsan” for the treatment of human syphilis. Ehrlick’s “magic bullet” concept and early championing of the concept of chemotherapy, along with his many other contributions in the field of immunology, led him to be awarded the Nobel Prize for Medicine and Physiology in 1908 and can arguably be cited as the start of the modern era of drug discovery and development. Ehrlich’s laboratory synthesized and tested 913 compounds in the trivalent arsenic series before they came up with a compound with sufficient efficacy and manufacturability and delivery characteristics (1). Since that time, the numbers and shear volumes involved in the discovery process have increased orders of magnitudes, to today’s corporate compound collections, which are measured in the millions.