Results from clinical trials on drugs approved by the US Food and Drug Administration (FDA) are almost three times more likely to be made public than results from trials on drugs that are not brought to market, according to a new study in The BMJ.

Researchers from McGill University investigated a total of 177 clinical trials, 96 on drugs that had approved by the FDA and 81 on drugs whose development had stalled. Drug development had stalled if there had been no further trials on the drug since 2009.

The researchers looked at whether results of the clinical trials had been published in academic journals, reported as conference abstracts or posted on Of the trials in approved drugs, 75% were published in academic journals compared to 37% of the trials on stalled drugs. Also, results were not reported at all for 15% of the trials on approved drugs compared to 34% of the trials on stalled drugs.

Whilst previous research has found that most drugs never make it to market, the researchers from McGill argue that reporting those results is important not just to inform future research but to recognise the efforts of the patients in those trials:

This failure to take even the initial steps at redeeming burdens of over 20,000 patients in our cohort alone runs contrary to major codes of ethics, and is troubling in the context of drugs where trial participation is likely to have involved exposure to unsafe or ineffective drugs. Moreover, non-publication deprives research systems and caregivers of state of the art evidence.

The researchers conclude that “there is little evidence to support the ongoing practice of withholding evidence from stalled drug trajectories.” Under the current law in the USA, results only have to be reported for trials on drugs that receive FDA approval. The US Department of Health and Human Services is currently seeking comments on whether to require trials on unlicensed drugs to also report their results. Please respond to the consultation before 23rd March.