TUESDAY, June 4 (HealthDay News) -- The drugs emerging from clinical trials in recent years seem less impressive than those developed in decades gone by, a new review finds.
Looking at more than 300 studies done since 1966, researchers found that drugs under development these days are less likely to solidly outperform placebos -- the sugar pills or other inert substances against which new drugs are tested.
From 1966 to 1990, the average study drug was about four times as likely to achieve a particular outcome than a placebo. But in trials done since 2001, drugs were only 36 percent more likely than placebos to show a desired effect, researchers reported in the June issue of the journal Health Affairs.
The reasons for the "worrisome decline" are not clear, said lead researcher Dr. Mark Olfson, a professor of clinical psychiatry at Columbia University in New York City.
But it's possible, he said, that "much of the low-hanging fruit has already been picked. In other words, many of the easiest-to-discover effective treatments may have already been found."
Another possibility, though, is that drugs from days of yore were not as impressive as they seemed at the time.
Trials done today generally have a more rigorous design, and they may be producing fewer "spuriously inflated findings" compared to older clinical trials, Olfson said.
A researcher not involved in the work said the findings are interesting, but "raise more questions than answers."
"The study is not designed to tell us the causes," said Ted Kaptchuk, an associate professor of medicine at Harvard Medical School, and director of the university's program in placebo studies.
"Are the new drugs in the pipeline just not as good?" Kaptchuk asked. It's not clear. In part, he said, that's because other research has found that people in clinical trials these days are more likely to respond t
All rights reserved