How Frances Oldham Kelsey kept thalidomide off the US market

In our previous blog post, we took a look at the approval process drugs have to go through in order to receive marketing authorization in the European Union. The European Medicines Agency (EMA) issues a recommendation based on the data from clinical trials and the European Commission ultimately decides whether a drug gets marketing authorization or not. In the USA, it’s the Food and Drug Administration (FDA) that reviews the data and makes a decision regarding marketing authorization.

Today, the authorization process in the EU is overall considered to be more stringent than in the USA, but several decades ago a now infamous drug did not get marketing authorization in the USA thanks to Canadian-American pharmacologist and physician Frances Oldham Kelsey (1914-2015). The drug we are talking about is thalidomide, also known under the brand names Softenon, Contergan, Thalomid, Talidex, Talizer, Distaval and Neurosedyn.

Frances Oldham Kelsey was hired by the FDA in 1960 and one of the first applications for drug approval she received was for thalidomide, a drug that was supposed to help relieve morning sickness in pregnant women. Though it had already been approved in Canada, Australia and more than 20 countries in Europe and Africa, Kelsey withheld approval due to lack of data from clinical trials. The company behind thalidomide (Richardson-Merrell) had actually gone as far as to provide false information. When thalidomide was tested in rats, the company had discovered birth defects but decided to not report this finding. Instead, they claimed that the drug did not cross the placental barrier and was safe for pregnant women.

By the end of 1961, however, it turned out Kelsey was right to withhold approval when the use of thalidomide by pregnant women in Europe was linked to birth defects in their babies. At that point, more than 10,000 children in 46 countries had been born with deformities. The severity and location of the deformities depended on the day(s) on which the mother used thalidomide during her pregnancy.

Kelsey’s persistence to keep thalidomide off the US market and the public outcry after the story about the deformed babies in Europe broke, quickly led to stricter drug regulations in the US. Pharmaceutical companies had to prove efficacy of new drugs to be marketed and had to disclose all side effects that were observed in clinical trials. Kelsey herself was awarded the President’s Award for Distinguished Federal Civilian Service by President John F. Kennedy in August 1962.