POSICOR: 143 Sudden Deaths Did Not Stop Approval
With study results kept secret, nation got another blood-pressure drug.
Senior FDA officials with the power to approve new
drugs were warned in advance about the dangers of Posicor, a pill for high blood pressure
and symptomatic chest pain.
MUTED WARNING Taking Posicor with certain other drugs posed a danger for heart rhythm disturbances. |
The clinical studies of Posicor "cast a shadow of
potential risk for serious arrhythmias," FDA medical team leader Dr. Shaw T. Chen
wrote on Dec. 18, 1996. The data in hand also showed Posicor would interact with certain
other drugs, posing potentially severe risk.
A 70-year-old man suffered "sudden death" in one
study of Posicor's effect on chest pain. The senior FDA officials also were told of sudden
deaths in 142 other patients who took either Posicor or a placebo in an ongoing study
focused on congestive heart failure. However, details from the 2,400-patient study
remained sealed because the manufacturer opposed breaking the experiment's confidentiality
until it was finished.
This left the FDA officials a choice: Wait a year or more,
or approve Posicor without knowing the details.
"I sure don't feel good about what I've seen,"
said Dr. Lemuel A. Moye, a member of the FDA's Cardiovascular and Renal Drugs Advisory
Committee that met on Feb. 28, 1997. Moye, a physician and biostatistician at the
University of Texas, suggested it would be prudent to delay judgment until the study's
results were unsealed. "I'm afraid that we are rushing into this."
According to a transcript of the meeting, Moye voiced
concern about Posicor's effect on heart rhythm and its potential to interact with other
compounds. "Patients will be taking this in fairly uncontrolled situations in
combinations of drugs which have ramifications yet unknown," he said.
Another committee member, Dr. Robert Califf, professor of
medicine at Duke University, said: "If this [drug] was really something that was
dramatically different, better than anything else in the way of relieving symptoms, then I
would look at it differently. But given the fact there are a lot of other effective
therapies out there, why not be safe with the public?"
Indeed, scores of other drugs for treating high blood
pressure were already on the market, and Posicor was not proved to offer lifesaving
benefit.
The drug's manufacturer, New Jersey-based Hoffman-La Roche
Inc., saw no need to delay.
"There is no signal that there is arrhythmic or
potentially arrhythmic risk with the drug," said Roche's Dr. Isaac Kobrin, terming
the sudden deaths of four patients in another study "a chance finding."
The committee voted, 5 to 3, to recommend approval of
Posicor, with Califf and Moye in the minority.
After presiding over the five-hour discussion, the committee
chairman, Dr. Barry M. Massie of San Francisco, abstained from voting amid a financial
conflict: Massie was a co-investigator in Roche's ongoing study of Posicor. After that
meeting, Roche hired him as a speaker for the drug, Massie acknowledges.
On June 20, 1997, the FDA approved Posicor.
Four days later, a Roche news release quoted Massie to
buttress the company's claim that "the incidence of side effects was low" during
clinical studies of Posicor.
Asked about this sequence of events, Massie said, "You
do wonder how the world would perceive it. I'm glad I didn't vote, let's put it that
way."
Doctors were cautioned in speck-sized type--beginning on the
278th line of the drug's label and again on the 365th about prescribing Posicor in
combination with various medications, including allergy pills, tranquilizers, a sleeping
pill and the heartburn drug Propulsid.
Authorities in Sweden in mid-1997 saw sufficient danger to
keep Posicor off the market. But the U.S. approval spurred high hopes for Roche. Analysts
at one brokerage firm, Salomon Smith Barney, projected sales of $2.9 billion within four
years.
Six months after approving Posicor, the FDA advised doctors
of the pill's "life-threatening" danger. The agency announced that it had
"received reports of dangerously lowered heart rates in about 20 patients."
Roche agreed to a label change--advising that Posicor should not be taken in combination
with cholesterol-lowering drugs. This brought to 26 the number of drugs that doctors were
warned not to prescribe with Posicor.
On June 8, 1998, Roche announced Posicor's withdrawal,
citing "evolving information concerning the potential for drug interactions" and
"preliminary results" from the ongoing heart failure study that had drawn the
attention of the advisory committee.
The study, Roche said, showed that the patients gained
"no overall" benefit from Posicor.
According to those familiar with the matter, the study also
found that the patients given Posicor died at a rate about 10% greater than those who took
a comparator. "It definitely did not look good," recalled Fenichel, who was then
the cardiac drug division's deputy director.
Apart from the clinical research, records filed with the FDA
show that doctors and others reported Posicor as a suspect in the deaths of 100 patients.
"Posicor should not have been approved," Moye
said. "Therefore, any death that was attributable to Posicor was an unnecessary
death."
The FDA's Woodcock and Lumpkin wrote in their May 1999
medical journal article that the problems that sunk Posicor also were
"unexpected." Asked recently about this, Woodcock retreated slightly; she said
that serious adverse reactions resulting from Posicor's interaction with one drug
"perhaps could have been anticipated."
Overall, she said, the agency had hoped for better
compliance with advice in the label to avoid the concomitant use of Posicor and the 26
other drugs it interacted with.
A spokesman for Roche, Martin Hirsch, declined to answer
questions but said the company "demonstrated sound and responsible judgment in the
way [it] developed, launched and marketed and withdrew Posicor. And we have cooperated
with the FDA throughout."