TUESDAY, April 22, 2003 (HealthDayNews) -- A study of a different drug treatment for high blood pressure was cut tantalizingly short after showing it might be better for some patients than existing treatments.
And the reason for halting the trial had nothing to do with medicine, the researchers say, but rather a merger involving the company that sponsored the study.
"The results were going in their favor," says Dr. Henry R. Black, chairman of the department of medicine at Rush-St. Luke's-Presbyterian Medical Center in Chicago and lead author of a report on the study in the April 23/30 issue of the Journal of the American Medical Association.
The study "was stopped short, as far as we know, for business reasons that had a lot to do with the merger," Black says. "There are new people in charge."
The idea of the study was to see if a slow-release form of verapamil, a calcium channel blocker drug that has been around for a long time, could do better than either a beta blocker or a diuretic -- the two other standard high blood pressure medications -- in preventing heart attacks and strokes. The study enrolled 16,602 people at 661 centers in 15 countries. It was supposed to run for at least five years but was ended after three years, in 2000.
The ongoing results of the study were known only to a monitoring board of specialists not connected with the research, a standard procedure in such trials to avoid physician bias.
"Had they known the results, they would not have stopped the trial," Black says of the sponsoring company. "We were within a few events of showing with statistical significance that the verapamil treatment was better."
Blood pressure reduction was just about the same in patients given the three different drugs. The incidence of heart attacks was reduced by 18 percent in patients getting verapamil. That decrease was offset by a 15 percent increase in strokes, but the benefit of the drug was approaching statistical significance, Black says.
The merger that stopped the study came in April 2000 when G.D. Searle, sponsor of the trial, was acquired by another pharmaceutical company, Pharmacia.
But Pharmacia no longer exists. It was acquired last week by Pfizer Inc. of New York City. Pfizer spokespeople did not respond to a request for comment.
Stopping the trial was "incredibly stupid as well as unethical," says Dr. Drummond Rennie, professor of medicine at the University of California, San Francisco, a deputy editor of the journal and co-author of an accompanying editorial.
"Running a trial like this is a major obligation, not only to physicians but also to patients," Rennie says. "If you take on an obligation like this, you can't just blow it off. Any company that buys another has to fulfill that obligation."
The most important consideration is that stopping the trial was unethical, Rennie says. "Then, ironically, it turned out to be stupid as well," he says, since it might have increased sales of the drug.
Physicians will think twice about signing up for such a demanding, long-term trial unless they have written assurance that the sponsoring company will not default on its obligation, Rennie says.
The net result is that high blood pressure treatment is pretty much where it had been, Black says.
In his practice, Black generally starts treatment with a diuretic, "always planning a second drug." The choice between a beta blocker and a calcium channel blocker can depend on other problems a patient may have.
"If they have asthma, I would not use a beta blocker," he says. "Or if they have constipation, I would not use verapamil."
The important thing is to have high blood pressure diagnosed and treatment started, Black says.
More information
To learn more about high blood pressure and its treatment, visit the National Institutes of Health or the American Heart Association.
