Discovery of Chemotherapeutic Drugs

In 1909 Paul Ehrlich and his laboratory identified Compound 606, later named arsphenamine and marketed as Salvarsan, an arsenic based agent effective against the spirochete bacteria that cause syphilis. It was the first agent whose therapeutic effect had been predicted and pursued from theoretical chemical reasoning rather than found by accident, and Ehrlich described the goal of a drug that would strike a specific pathogen as a magic bullet. Salvarsan became the most widely used treatment for syphilis until penicillin replaced it in the 1940s, and the systematic search it represented gave the emerging field of chemotherapy its name.