More than half of clinical trials don't see the light of day, even five years after the subject drug hits the market, according to a new study. Researchers looked at 90 drugs approved by FDA between 1998 and 2000, tracing all 909 trials submitted to support approval. Only 43 percent of those studies made it into the scientific literature, leaving 56 percent in filing cabinets and desk drawers.
It's true that 76 percent of pivotal trials did see publication, usually within three years of approval. But that still leaves 24 percent out of the public eye. And leaving data unpublished amounts to "scientific misconduct," the University of California, San Francisco authors said in their new article in PLoS.
The research team also found evidence of cherry-picking; a big Phase II or III study showing that the new drug outperforms an older med was more likely to be published than a trial that found the new no better than the old. Combined with the missing, unpublished trials, this selective reporting could cause doctors to unnecessarily favor newer, more expensive drugs.
The question is whether the FDA Amendments Act passed last fall--which will require all trials to be registered and all results posted--will affect the publication record. For that we'll have to wait and see.