When popular painkiller drug Vioxx was pulled from the market after
being found to double cardiovascular risks, Pfizer, maker of the
rival arthritis medicine Celebrex, took a brave step. In fact, Pfizer
was so confident in their drug that they ran a 4,000-patient study
to see if Celebrex could prevent heart attacks.
What a mistake. For in a meeting, 32 U.S. Food and Drug Administration
(FDA) advisors unanimously voted that Celebrex actually increases
the risk of heart attack and stroke--prompting Pfizer to change
their tune. Now, instead of attempting to prove a heart benefit,
a new plan of action has surfaced: To compare the most commonly
used dose of Celebrex to another anti-inflammatory pill in hopes
to prove it poses no greater risk for the heart than similar drugs.
To find the answer to this question a trial will be conducted, involving
at least 20,000 patients at high risk for heart attacks.
A Likely Comparison
During a prior FDA panel meeting, FDA advisors recommend that Celebrex
be branded with a black box warning, the FDA's harshest label. However,
some suggest the warning could be removed if the trial shows Celebrex
does not cause more increased cardiovascular risks than other drugs
do.
One cardiologist on the panel suggested weighing Celebrex against
naproxen--the active ingredient in Bayer's Aleve--as it is a likely
comparator. A comparator must be the medicine least likely to cause
heart problems among rival treatments. While naproxen has been considered
a likely choice, no final decision has been made. Other comparator
candidates include:
- Ibuprofen (the active ingredient in Advil and Motrin)
- Diclofenac (marketed as Cataflam)
Further, in light of Celebrex's questioned credibility, it has
been estimated that Celebrex sales will drop 47 percent in 2005,
to $1.75 billion; Bextra, a related drug, sales could possibly drop
about $400 million.
Forbes.com
February 23, 2005
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