The results of head-to-head drug trials largely depend upon the pharmaceutical company which is funding the studies, according to an analysis carried out by researchers at the University of California, San Francisco.
The UCSF researchers examined 192 published results of trials carried out between 1999 and 2005, comparing one cholesterol-lowering statin drug to another, or to a non-statin drug, and found that if the reported results favoured the test drug, the trial was about 20 times more likely to be funded by the maker of the statin than by the comparison pharmaceutical firm. Even more striking, they claim, if the conclusions of the trial backed the test drug, the trial was about 35 times more likely to be funded by its maker of that drug rather than the comparison drug. The results of the new analysis are reported in the latest editions of PLoS Medicine.
"Many people are concerned about the growing proportion of drug trials funded by the drug's manufacturers," said study author Lisa Bero, professor of clinical pharmacy and health policy studies at the university. Results of trials affect what drugs are covered by medical plans, and what treatments physicians will prescribe, he noted, so “if drug trial outcomes are largely determined by who pays for the trial, we don't really know what the best drug is." Bero is senior author on the PLoS paper.
The UCSF researchers noted that a number of factors could explain why results favoured the drug's sponsor, such as sponsors opting not to report results that didn't favour their products, or drugmakers selectively funding trials that were likely to produce significant results. Additionally, "the lack of true clinical outcome measures in these direct head-to-head comparisons of drugs is disappointing because the studies don't give us the best information we need to choose one statin over another," argued Prof Bero, who added that “the lack of true clinical outcome measures in these direct head-to-head comparisons of drugs is disappointing because the studies don't give us the best information we need to choose one statin over another".
However, the industry is convinced by the UCSF researchers’ findings and Ken Johnson, senior vice president of Pharmaceutical Research and Manufacturers of America said that "the new study overlooks the crucial role of the Food and Drug Administration in reviewing and approving claims that are based on clinical trial results. Our industry is dependent upon well-designed clinical trials that will pass muster with the FDA".