Closing the
barn door after the horse is out: Cleveland Clinic To Lead
Large Study on Safety, Efficacy of COX-2 Inhibitors, OTC
Painkillers…a summary of links to stories around the country
Researchers at the
Cleveland Clinic will lead the first large-scale study
to compare the cardiovascular risks of COX-2 inhibitors and
older pain medications in patients with risk factors, clinic
officials announced on Tuesday, the
New York Times
reports.
Pfizer, which manufactures the COX-2 inhibitor Celebrex,
will fund the study. According to Steven Nissen, a
cardiologist at the Cleveland Clinic who will lead the
study, the study will include 20,000 arthritis patients who
have previously experienced a heart attack, stroke or
angina; underwent coronary bypass surgery or a stent
procedure; or have diabetes. Concerns about the
cardiovascular risks of COX-2 inhibitors have increased
recently, but researchers have not conducted a large-scale
study on high-risk patients to examine the issue, Nissen
said (Saul, New York
Times, 12/14).
Merck withdrew the COX-2 inhibitor Vioxx from the market
in September 2004 over concerns that the medication could
increase risk for cardiovascular events, and Pfizer in April
removed the COX-2 inhibitor Bextra from the market over
similar concerns. Celebrex is the only COX-2 inhibitor that
remains on the market in the U.S., and the label warns that
the medication could increase risk for cardiovascular
events. In addition,
FDA earlier this year warned that other non-steroidal
anti-inflammatory drugs, such as the over-the-counter pain
medications Advil and Aleve, also could increase risk for
cardiovascular problems.
Study Details
The double-blind study will include arthritis patients in
the U.S., Canada, Latin America, Europe and Australia
(Sternberg,
USA Today,
12/14). Researchers will randomly assign study participants
to take a daily dose of one of three pain medications -- 200
milligrams of Celebrex; 2,400 milligrams of ibuprofen, sold
under the brand-name Motrin; or 1,000 milligrams of
naproxen, sold under the brand-name Aleve -- for 24 months
(Henderson,
Boston Globe,
12/14). Study participants also will take low doses of
aspirin and other medications, such as statins, recommended
for individuals with heart diseases. In addition, study
participants will take Prilosec to help prevent stomach
bleeding and ulcers, which are possible side effects of
NSAIDs. Researchers will begin an 18-month enrollment period
for the study in 2006 and will track participants for an
average of two years. Researchers will collect and store
study data at Cleveland Clinic and will provide a copy of
the data to
NIH, with results expected after four years (Winslow,
Wall Street Journal,
12/14). Thomas Fleming, chair of the Department of
Biostatistics at the
University of Washington, will lead a committee that
will monitor the study with the authority to end the study
if safety concerns develop (USA
Today, 12/14). Members of the committee will
not accept compensation from companies that manufacture
medications used in the study.
Nissen Comments
Nissen said that Pfizer initiated the study, which could
cost as much as $100 million to conduct. He added that
Pfizer has agreed to provide researchers with "an
extraordinary degree of independence." He added, "The public
and the medical community are confused. The relative safety
of these three drugs is simply not known. We're going to
answer the question: are they the same or are they not" (Wall
Street Journal, 12/14). Nissen said, "All the
other trials that I'm aware of are really in quite low-risk
patients, and so they just aren't comparable" (New
York Times, 12/14). He added, "The idea here
is if you know what happens in the highest-risk individuals,
you will know how to use the drugs in people at lower risk.
We will have 10 times the statistical power of any trial
ever done of these drugs" (Marchione,
AP/Detroit News,
12/14).
Additional Comments
Pfizer spokesperson Mariann Caprino said that the company
could not comment on the cost of the study. She added,
"We're certainly very pleased that the Cleveland Clinic is
heading the study, and it is about to get under way, because
clearly this is an important question and a very important
patient population that the study is going to look at" (New
York Times, 12/14). Jason Napodano, an analyst
at
Zacks, said that the study would have only a small
impact on Celebrex sales until the release of results (Boston
Globe, 12/14). Celebrex sales have decreased
by 45% since last year to $1.26 billion in the first nine
months of this year (New
York Times, 12/14). "Vioxx took 18 months to
see a real statistical difference between Vioxx and
naproxen, and we know that Vioxx clearly is not as safe. But
Celebrex, I don't know," Napodano said, adding, "I think
Celebrex is safer than Vioxx, but how it will compare to
naproxen?" (Boston
Globe, 12/14). Alastair Wood, a professor of
medicine and pharmacology at
Vanderbilt University and chair of a former FDA advisory
committee on the safety of pain medications, said, "It may
be that at the end of this, one or the other drug will be
superior. That's exactly what we need to know" (New
York Times, 12/14).