NEW YORK (Reuters) - A government-sponsored trial of Pfizer Inc.'s blockbuster
arthritis drug Celebrex
was halted after patients taking the medicine had
more than twice as many heart attacks as patients taking a
placebo, the
company said on Friday.
Shares of Pfizer, a component of the Dow Jones
industrial average, fell 17 percent in early trading following
news
of the long-term trial, sponsored
by the National Cancer Institute.
The heart-attack findings for Celebrex
come only 10 weeks following Merck & Co.'s
recall of its similar arthritis
drug, Vioxx, after a study found the
drug doubled the incidence of heart attack and stroke among patients
taking
it to prevent colon polyps that cause cancer. Both drugs are from a
class known as COX-2 inhibitors.
"
This does not bode well for COX-2 inhibitors in general," said Ira
Loss, an analyst at Washington Analysis.
" The sense had been that
Celebrex is somehow different from the others."
A Pfizer spokesman declined to say if the company was considering
pulling Celebrex off the market.
Pfizer said the trial involved patients
taking 400-milligram and 800-milligram
daily doses of Celebrex to prevent
adenomas, tumors that grow from
glandular tissue. The anti-inflammatory drug was being tested on the
theory that
inflammation is a cause of cancer.
Officials of the U.S. Food and Drug
Administration were not immediately available for comment.
Vioxx and
Celebrex both work by selectively blocking a protein called COX-2 that
has been linked to inflammation.
They were both launched
in 1999 and
quickly became top-selling drugs, helped by massive television and
print advertising.
Pfizer also said on Friday that Celebrex was not shown to increase
heart risk in a second long-term trial designed to see if
the drug
could prevent
colon polyps.
The New York-based drugmaker said National Cancer Institute
officials decided to halt the other Celebrex trial, to test its
ability
to prevent
adenomas,
after confirming "an approximately 2.5-fold increase in their
risk of experiencing a major fatal
or non-fatal cardiovascular event
compared
to those taking placebo."
"
They (the NCI) will continue to follow patients in the study," said
Pfizer spokesman Paul Fitzhenry, although patients will
no longer be
given Celebrex. "
We alerted the Food and Drug Administration last night about the findings," said
Fitzhenry.
He said he could not elaborate on those discussions.
Asked if Pfizer
was considering pulling Celebrex off the market in view of the findings,
Fitzhenry said, "We cannot comment
beyond our earlier
statement," which did not discuss the possibility of withdrawing
the drug.