Clinical trial results for FDA-approved drugs often remain hidden, new study finds

"A team of American researchers examined 62 products by 42 pharma companies that gained FDA approval in 2016 and 2017. Collectively, these drugs and biologics were approved based on 1,017 clinical trials involving more than 187,000 participants....

Around a quarter of these trials were subject to the FDA Amendments Act, a transparency law that requires drug makers to register applicable trials on a public registry within 21 days of their start date, and to make their results public on the registry within 30 days of initial FDA approval of a product.

The study team found that 55 of the 62 FDA approvals included at least one clinical trial that was subject to the transparency law. However, in the case of 13 products, these trials did not consistently meet legal registration or reporting requirements.

Large pharma companies were far more likely to comply with the law. For example, Merck Sharp & Dohme was legally responsible for registering and reporting 27 trials, and fully complied in every single case. However, several other major players – Gilead, Johnson & Johnson / Janssen, Novo Nordisk, Sanofi, and Shire – fell short of legal requirements.

Nonetheless, the study – which also covered companies’ data sharing policies – found that overall, there had been “sustained improvement” in pharma industry disclosure practices compared to previous years...."