Pharmaceutical companies are holding back information from the public on why their medicines have been rejected by the US Food and Drug Administration, a study published in the BMJ has found.

An analysis of 61 FDA complete response letters sent out between August 2008 and June 2013 has revealed that the information released by drugmakers on the reasons for refusal only fully matched the regulator’s actual issues in 14% of cases. 

The researchers also found that in 21% there was no concordance between the CRL and the company’s press release at all, while nearly a fifth (18%) of CRLs weren’t even reported on. And only 59% of pharmas reported the need for extra clinical trials if they had been requested by the CRL, while of seven CRLs reporting higher mortality rates in treated participants only one associated press release reported this fact.

The researchers conclude that there are substantial differences in content between confidential CRLs and the information issued by sponsors, and so press releases “are generally an incomplete source of reasons for FDA non-approval of applications”.

CRLs are currently confidential, but campaigners have long argued that the US regulator should fully disclose this information, as occurs across the pond in Europe. The potential benefits of this would include “better informing the development of new drugs, facilitating a richer public health discourse, and counteracting misconceptions regarding FDA’s reasons for denial of applications,” the researchers argue.