Thalidomide and the Making of an American Hero

 by Anna Danso-Amoako

Dr Kelsey receiving her award
from President Kennedy (1962)

Within stereochemistry, which is the study of the spatial arrangement and manipulation of atoms within molecules, some molecules can be described as chiral. These chiral molecules that have a carbon atom bonded to four different groups. If you were to observe the mirror image of the molecule you wouldn’t be able to superimpose the image onto the original much like how it’s impossible to match your right hand to your left. These stereoisomers can be described as enantiomers,the mirror images of each other.

Within the pharmaceutical industry chiral molecules are widely used with over 50% of drugs containing . Usually this poses no issues as one or both enantiomers provide useful properties but this isn’t always the case. One notable case of this was the drug Thalidomide. While the right hand enantiomer was a sedative effective at treating morning sickness and marketed as such, the left hand enantiomer caused birth defects. Pregnant women in many countries who took Thalidomide had children with severe birth defects. 

However, America managed to avoid a large number of cases of children born with birth defects due to the thorough evaluation by Dr Frances Kelsey, a medical reviewer from the Food and Drug Administration, FDA. Dr Kelsey was undoubtedly qualified in her judgement of drugs for the FDA having received degrees in Pharmacology and Medicine. In her early career with the FDA she observed work to understand the mortalities behind a drug marketed as the Elixir of Sulfanilamide which was designed to treat infections. Following a series of animal studies from her mentor, it was established that a solvent added to the drug to improve its marketability towards children contributed to both the deaths of the animals and the people who took the drug. The drug was artificially flavoured with raspberry flavouring by adding Diethylene glycol, or more commonly known as antifreeze.

As one of Dr Kelsey’s first cases to be reviewed was for Thalidomide from the drug manufacturer Richardson-Merrell. Dr Kelsey found the information the company provided to her lacked solid scientific evidence in its usage and effects but was rather largely based on testimonials of physicians. For this reason she denied their application. Despite mounting pressure put on Dr Kelsey from Merrell she insisted that the drug wouldn’t be safe as there was no evidence to suggest that it wouldn’t harm foetuses. A report was later published that found the drug caused peripheral neuritis, a type of nerve inflammation raised by Dr Kelsey’s concerns for the implications of the drug. At the time it was thought that drugs taken by a pregnant mother wouldn’t affect a foetus as it was believed it couldn’t be absorbed by the placenta. However research Dr Kelsey was involved in to understand the effects of Quinine, a drug for the treatment of malaria on pregnant rabbits proved otherwise and led her to question the implications of taking the drug. 

After six failed attempts at approval and with the discovery of fatal effects of the drug in Europe where it was already approved, Merrell withdrew their application. Dr Kelsey’s insistence that evidence for the drug be provided saved numerous American children from developing the birth defects associated with Thalidomide and for this she was honoured with the President’s Award for Distinguished Federal Civilian Service by President Kennedy. 

Dr Kelsey’s work for the FDA continued until she was 90 years but her impact on ensuring the safety of drugs through rigorous testing and approval processes is her legacy to the world.