Clinical
Studies Can Differ by Funding Source, Type of Study
Breast cancer treatment trials that are funded by
drug companies are more likely to show positive results than studies
sponsored by other sources, say researchers in the journal Cancer.
There are also major differences in trial design
when the pharmaceutical industry pays the costs, the researchers add.
"This doesn't have implications tomorrow for patients,
but it does have implications for the kind of questions we address
and the kind of answers that we have for future patients," says study
author Dr. Jeffrey Peppercorn, at the University of North Carolina
School of Medicine.
The drug industry now spends more money on research
and development than the National Institutes
of Health (NIH).
With collaborations between industry and academic
medical centers more common, some experts are raising questions about
the quality of research and potential conflicts of interest.
Previous research has shown that clinical trials
of medications funded by pharmaceutical companies and other for-profit
entities were more likely to report positive findings than similar
trials funded by nonprofit groups.
Only one of those studies looked at cancer trials,
however. Meanwhile, half of all pharmaceutical company-sponsored medications
currently in the pipeline are for cancer.
Breast cancer is the most common cancer affecting
American women, striking more than 200,000 women in the US, and more
than 1 million worldwide, each year.
Until now, no one had undertaken a systematic study
of pharmaceutical sponsorship of clinical research in breast cancer.
For this study, Dr. Peppercorn and his colleagues
reviewed 140 studies in 10 English-language journals that reported
breast cancer treatment results over the past decade.
Of the 140 studies, almost half (48 percent) reported
some form of drug company involvement. Drug company participation increased
over the period in question, from 44 percent in 1993 to 58 percent
in 2003.
Eighty-four percent of studies published in 2003
that reported drug company involvement were positive, vs. 54 percent
of studies with other funding sources.
Clinical trials with ties to industry were also
more likely to have a single-arm study design, meaning the medication's
effectiveness was not tested against a comparison group.
Of the 2003 studies, 66 percent were single-arm
studies while only 33 percent of studies funded in other ways used
this design.
Industry-sponsored trials were also more likely
to involve patients with advanced disease.
"We found significant differences in the types of
studies by pharmaceutical and non-pharmaceutical funders," notes Dr.
Peppercorn.
"Companies may be very good at drug development
but, as they play a larger and larger role in financing clinical research,
we need to think carefully about what other clinical questions need
to be addressed that drug companies may not be exploring," notes Dr.
Peppercorn.
One expert tried to put the finding into perspective.
"This doesn't surprise me because most of the new
drugs being discovered are being discovered by the pharmaceutical industry," says
Dr. Jay Brooks, at Ochsner Health System in Baton Rouge, La.
In contrast, "in
the 1980s, most of the new compounds were discovered by the National Institutes of
Health and they went to the pharmaceutical industry with interesting
compounds and had them develop products," explains Dr. Brooks.
Also, 20 years ago, many people did not feel cancer
was a disease they could actually affect so there were not as many
medications in the pipeline, says Dr. Brooks.
"The pharmaceutical industry knows more about the
drugs it's bringing to trial so when they design a trial, they have
a higher chance of a positive trial," says Dr. Brooks. "In terms of
a single-arm trial, if the trial demonstrates a dramatic improvement
in survival, do you really need to do a large study?"
For now, breast cancer patients need to keep the
dialogue open with their physicians.
"Systemic issues in cancer trials or other medical
trials will never be more important than patients discussing with their
own physician options available, including clinical trials," says Dr.
Peppercorn.
"For the individual patient, the specifics of a
particular clinical trial are more important than the funding," he
says.
Always consult your physician for more information.
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