In its landmark lawsuit against GlaxoSmithKline, the New York State Attorney General accused the pharmaceutical giant of consumer fraud for not publishing negative findings about its antidepressant, Paxil, in essence, for not giving doctors and consumers the full story about its blockbuster drug.
Now comes a new study showing that the practice of selectively publishing only positive results and suppressing negative findings is an industry-wide habit. In a study published last week in PLoS Medicine, researchers at the University of California San Francisco discovered that only three-quarters of the randomized drug trials submitted for New Drug Applications (NDAs) between 2001 and 2002 were eventually published. Even more worrisome, trials with favorable outcomes were nearly five times more likely to be published than those with negative outcomes.
Furthermore, the researchers found evidence that primary outcomes were changed between the time the results were submitted to the FDA as NDAs and the time the studies were published. And when that happened, the results were invariably altered to favor the test drug, the researchers found.
These findings demonstrate that “the information that is readily available in the scientific literature to health care professionals is incomplete and potentially biased,” the UCSF researchers conclude.
In an accompanying editorial, a scientist for the Mayo Clinic who previously worked with the World Health Organization’s International Clinical Trials Registry Platform, agreed that the “trial literature is biased” and declared that the “the time has come to tackle the challenge of making key trial documents public.”
Fortunately, drug companies are now required by law to post the results of all their clinical trials, negative as well as positive, on a publicly available website. And the fact that the leading medical journals now require pretrial registration — i.e. researchers must post their trial protocols on a public website — should help cut down on the tendency to change primary outcome measures to favor drug results.
However, drug company-sponsored researchers still don’t have to publish the results of all randomized drug trials in medical journals. And since that is where doctors and consumers get most of their information, the full story about the safety and effectiveness of new drugs remains untold.