Few New FDA-Approved Drug Indications Are Backed Up By High-Quality Clinical Trials: Study

The findings of new research raises questions about the quality of clinical trials used to support the safety and effectiveness of new drugs approved by federal regulators, indicating that few of the uses are later backed up by high-quality studies. 

Yale researchers found that post-approval studies, which are conducted after the FDA has already approved a drug for sale, can have varying degrees of quality.

Post-approval studies are often required by the FDA to provide further proof that the drug does what the manufacturer claims it does and does so safely, since many medications are initially approved based only on one industry-sponsored trial.

The report was published last week in the medical journal The BMJ, looking at prospective controlled clinical studies for all drugs that were published after the FDA initially approved them between 2005 and 2012. All of the drugs included in the study were approved on the basis of a single pivotal clinical trial.

In June 2015, The BMJ also published an analysis that warned about numerous discrepancies in data submitted to the FDA by medical device manufacturers seeking premarket approval for heart devices. Those discrepancies often included the number of participants varying in the actual study from the number reported to the FDA, substantially different results from similar FDA studies, and many of which were never peer reviewed.

According to the findings of this latest study, there were 117 new drugs for approved by the FDA for 123 indications based on one trial during that time period. There were no postapproval studies linked to 43 of the 123 indications, and the median total number of postapproval studies conducted for the rest of the indications was just one.

Researchers found a wide range in the number of patients included in the postapproval studies, and only about 18% of those approved indications were backed up with one or more randomized, controlled, double blind studies that showed the drug had superior efficacy to other treatments.

“These findings have important implications for clinical care. Both doctors and patients have high expectations for the safety and efficacy of a drug approved by the FDA,” the researchers stated. “But less than one third of new drug indications approved by the FDA on the basis of a single pivotal trial had at least one postapproval trial showing superior efficacy; even fewer used clinical outcomes.”

The study noted that the FDA has been pushing for reforms that would allow the agency to approve drugs based on smaller, shorter clinical trials, as well as observational studies and evidence gleaned from registries. The FDA has also proposed switching to reports from consumers to determine postmarket efficacy and safety. The researchers said these types of changes should be approached with caution.