Biases in Animal Studies May Differ From Those In Clinical Trials, UCSF Study Finds

By Jeffrey Norris | UCSF.edu | January 24, 2014

A new analysis of animal studies on cholesterol-lowering statins by UC San Francisco researchers found that non-industry studies had results that favored the drugs even more than studies funded by industry.

The analysis of 63 animal studies of statins, led by Lisa Bero, PhD, UCSF professor clinical pharmacy, was published online January 21, 2014, in the scientific journal PLoS Biology.
 
In previous studies, Bero determined that drug-company-sponsored clinical trials were associated with publication of outcomes that favor the sponsor. Bero’s work has been cited as part of policy reform efforts that have led many journal publishers, agencies and institutions to require researchers to disclose funding sources and possible conflicts of interest when presenting their research.
 
The impetus for the current study, Bero said, was to explore whether or not industry-funded animal studies also would be likely to yield more positive outcomes for the companies’ drug candidates.
 
But in their analysis the researchers found the opposite: Results of animal studies that had industry sponsorship were less likely to measure a benefit for statins in slowing or preventing arterial disease. Of the studies that disclosed funding, 9 of 19 industry-sponsored studies had results that favored statins, in comparison to 18 out of 28 studies that favored statins among studies not funded by industry.
 
The explanation may be, said Bero, that "the interests of the pharmaceutical industry might be best served by underestimating efficacy prior to clinical trials, and overestimating efficacy in clinical trials. By underestimating efficacy in preclinical studies, the pharmaceutical industry could reduce the money spent on clinical trials that did not lead to marketable products."
 
"Because demonstrating drug efficacy in human studies is linked to drug company profits, drug companies may have more incentive to publish favorable efficacy findings of human drug studies than animal studies."
 
However, the reason for the opposite findings obtained in analyzing animal and human studies merits additional investigation, Bero said. Selective reporting of study outcomes might play a role, she suggested.
 
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