(Reuters Health)—Drug companies are inconsistent about disclosing data related to clinical trials of new medicines, a new report says.
Researchers examined publicly available data on clinical trials for 15 new medicines from 10 companies that were cleared for sale by the U.S. Food and Drug Administration in 2012.
Two of the companies disclosed all trials and complied with legal disclosure requirements for medicines approved that year, according to the study published online Nov. 12 in BMJ Open.
But almost half of all the reviewed drugs had at least one undisclosed advanced drug trial involving human participants, the study found.
“Your physician prescribes your drugs based on prescription guidelines on the labels, and these are based on publicly available evidence,” says lead study author Jennifer Miller, an ethics researcher at New York University Langone Medical Center. “It is nearly impossible to have evidence-based medicine without all of the evidence.”
To assess transparency in clinical trials, Miller and colleagues reviewed publicly available information on drugs approved by the FDA that were sponsored by the 20 pharmaceutical companies with the highest market value.
The analysis included drugs for cancers of the breast, colon and rectum, skin, kidney and blood, as well as for HIV, tuberculosis, multiple sclerosis and rare genetic disorders. Researchers also looked at trials for a meningitis vaccine and an anti-clotting drug.
For all of the drugs combined, the researchers examined data on 318 trials involving almost 100,000 people.
Only 57% of the trials for each drug were typically registered properly, and only 20% of the final results were reported on ClinicalTrials.gov, a database maintained by the National Library of Medicine at the National Institutes of Health.
Just 56% of the results were published in academic journals and only 65% were published or had their results reported in some meaningful way, the analysis found.
Limitations of the study include its use of data from a single year, and its focus only on large pharmaceutical companies, the authors acknowledge. The research team is in the process of expanding their analysis to add more years and include smaller companies as well as drug development at academic centers, the authors note.
While the nuances of clinical trial reporting and publication may seem esoteric, the quality of public information has a big impact on patients, said Dr. Andrew Prayle, a researcher at the University of Nottingham in the U.K. who wasn’t involved in the study.