Bayer knew that their new medicine, KL-730, which they would name
“Prontosil,” was effective against bacteria because of the unique marriage
between the azo dye and sulfanilamide. Except that it wasn’t. What the
Germans had never performed was an isolated test of sulfanilamide alone.
A group of French scientists at the Institut Pasteur in Paris repeated an
experiment with various sulfanilamides on a group of forty mice,
including a treatment group with sulfanilamide alone and no azo dye.
After a few days, the Parisian team evaluated the response among the
test animals. Almost all of the mice died who were treated with newer azo-
sulfanilamide combinations, but all of the mice lived who were treated
with Prontosil, Rubiazol, and sulfanilamide alone. The Bayer scientists
had assiduously labored to protect their patent rights over Prontosil, sure
that it represented a bonanza, but they had never considered that
sulfanilamide alone might be the subjugator. At about the same time that
the Institut Pasteur scientists made their discovery, the Bayer group was
unearthing the same sobering fact. While it was a tremendous moment for
mankind, it was a financial catastrophe for Bayer; the sulfanilamide
molecule had been discovered (and patented) in 1908 by Viennese chemist
Paul Gelmo, and was now in the public domain. The financial goldmine
had evaporated before their eyes.
Bayer did profit from sulfanilamide. They marketed it around the world
as Prontosil, even after realizing that sulfanilamide alone was the effective
agent, without the need for the azo dye. (It also explains why Prontosil was
only effective in vivo and not in vitro. In a test tube full of bacteria,
Prontosil posed no risk. Only animals have the enzyme that separates the
dye from sulfanilamide. If testing had only occurred in test tubes, and not
animals, Prontosil would have appeared as a failure, and it was this and
other drugs that educated the early pharmaceutical manufacturers that
“pro-drugs” were genuine. At times, pro-drugs are ideal—a pro-drug is
intentionally manufactured so it can survive digestion, turning into the
active metabolite once in the bloodstream.)
Prontosil and other forms of sulfanilamide hit the world market in
1935, immediately making an impact. “Virtually overnight, mortality from
childbed fever [Strep pyogenes] fell from 20 to 30% to 4.7%.”^9 Physicians
across the United States and Europe embraced the new drug, but the
American public became intimately acquainted with the new sulfa drug in
1936 when Franklin Delano Roosevelt Jr., while a student at Harvard