The US Food and Drug Administration is starting to publish letters the agency sent to pharmaceutical companies when their drugs were rejected, detailing information that until now has mostly been hidden from investors and the public.

The U.S. Food and Drug Administration on Thursday published more than 200 of its so-called complete response letters to drugmakers, a significant move to increase transparency of the agency's work. The published letters were issued in response to marketing applications of certain drugs or therapies submitted to the FDA between 2020 and 2024.

The FDA has released an “initial batch“ of more than 200 complete response letters (CRLs) in efforts to boost transparency. | The FDA has released an "initial batch" of more than 200 complete response letters (CRLs) in efforts to boost transparency.