Industry-funded clinical trials of breast cancer medicines report more favorable results than research conducted independently, a new study reports.
Some 84 percent of company-supported drug studies published in 10 major medical journals in 2003 reported positive results about the breast cancer drugs they investigated, according to an analysis by Dr. Jeffrey Peppercorn, a cancer physician and researcher at University of North Carolina, Chapel Hill's School of Medicine, and colleagues at Harvard's Dana-Farber Cancer Institute.
Nonindustry-supported studies were far less likely to be upbeat, publishing favorable results just 54 percent of the time.
The analysis, published online this week in Cancer, the journal of the American Cancer Society, is the latest to raise questions about the role pharmaceutical companies play in funding and shaping research used to decide whether drugs are safe and effective.
Earlier analyses that looked at published studies of heart, psychiatric and other types of cancer drugs all have found that industry involvement tends to result in favorable research findings. What's not clear is whether industry support skews the research, said Peppercorn, the paper's lead author.
"Just because the results are positive, I don't think we can assume that the results are biased," he said.
But the connection between positive drug studies and industry funding has raised concerns in recent years as the industry's role has grown. Pharmaceutical company support of drug research surpassed government funding in the early 1990s and since then has taken on an increasingly dominant role.
A Harvard School of Public Health paper published in 2005 estimated that drug companies finance up to 70 percent of all clinical trials in the United States. Drug companies invested $15.5 billion in clinical trials last year, according to the Pharmaceutical Research and Manufacturers of America, or PhRMA, the industry's lobby and advocacy group.
"The pharmaceutical industry is not only a major player, it is the major player," Peppercorn said. "We need to pay attention to this because we need to know if important questions are not being asked."
Peppercorn's team looked at 140 breast cancer studies published in 1993, 1998 or 2003 in leading medical journals. Among all 140 published studies analyzed, researchers found that 78 percent of industry-sponsored studies reported favorable results, while just 66 percent of nonindustry studies were positive.
Peppercorn said there are many possible explanations for the discrepancy. For one, he said, drug companies may be less inclined to publish when studies are negative. Or it could be that pharmaceutical companies are "flat out better" at identifying medicines most likely to perform well in clinical trials, Peppercorn said.
A new national clinical trials registry, administered by the federal government, will track results from all registered trials, published or not.
The pharmaceutical industry favors the explanation that drug companies are savvier about clinical research.
"We know how to do clinical trials," said Alan Goldhammer, deputy vice president of regulatory affairs for PhRMA. "A lot of drugs that are not going to be successful are never brought into the clinic. Of course we're going to be more likely to publish favorable results."
Jerome Reichman, a professor at the Duke University law school and critic of the pharmaceutical industry's growing role in clinical trials, said he doesn't accept the industry explanation. He notes that pharmaceutical companies often justify high drug prices by saying they have to cover the costs of testing drugs that flop.
Reichman said having the drug companies behind clinical trials means there will be less good research comparing how well new products do against existing drugs.
"They will never ask the question, 'Is there another drug that will do just as good or better at a cheaper price?' - they have no incentive," said Reichman, who cowrote a recent paper that argues for public funding and oversight of clinical trials. It was published in the January issue of the journal Economist's Voice.
Peppercorn, who is a consultant to the drug company Merck and is on the speaker's bureau of the biotechnology drug maker Genentech, said it's important to remember that industry-supported clinical research has generally served patients well.
He noted that Herceptin, the only U.S.-approved treatment for a certain type of aggressive breast cancer, was developed primarily through research paid for by its manufacturer, Genentech. Glaxo- SmithKline, which is seeking U.S. Food and Drug Administration approval for Tykerb, an experimental drug that targets the same aggressive form of breast cancer, also has invested heavily in trials.