(Adds company comments, paragraphs 13-14)
By Julie Steenhuysen
CHICAGO Oct 13 A long-term analysis of people
who took the arthritis drug Vioxx confirms it doubles the risk
of strokes and heart attacks, researchers said on Monday, but
this risk goes away a year after people stop taking it.
And other drugs in the same class of painkillers known as
Cox-2 inhibitors may cause similar harm, they said.
"The good news is the data suggests that the risk doesn't
persist forever. The risk goes back toward normal after a year
of follow up," said Dr. Robert Bresalier of the M.D. Anderson
Cancer Center at the University of Texas, whose study appears
in the journal Lancet.
Safety data from this same study in 2004 set off alarms
that Vioxx increased the risks of heart attacks and stroke,
prompting drug maker Merck & Co Inc (MRK.N) to withdraw the
popular painkiller from the market.
Merck last year inked a $4.85 billion deal to settle
thousands of claims for heart attacks, strokes and deaths
allegedly caused by the drug. The original study, funded by
Merck, was meant to determine whether Vioxx could prevent
polyps that raise the risk of colon cancer.
A 2005 analysis by Bresalier and colleagues published in
the New England Journal of Medicine suggested that it took 18
months for the drug to increase the risk of heart attacks and
strokes, a time frame that played a prominent role in Merck's
legal defense of Vioxx.
The journal later posted a correction on its Web site,
saying the difference was not statistically significant. The
new analysis, done with independent statisticians, suggests the
risk occurs early and persists, Bresalier said.
"This data shows you can't precisely determine the timing
of the risk. It does appear to start relatively early," he said
in a telephone interview.
The study, dubbed Approve, looked at the effects of three
years of treatment with Vioxx, or rofecoxib, in 2,587
patients. Patients were checked for side effects while on the
drug and two weeks after they stopped.
It includes one-year follow-up data on patients who stopped
taking the drug because of heart side effects.
"In essence, the relative risk remained about the same,"
MERCK CALLS DATA LIMITED
People who took Vioxx in the study had about the double the
risk of having a heart attack or stroke than those who took a
dummy pill, he said.
Merck said that overall findings were consistent with the
original study, but noted not all patients were able to be
followed after they stopped taking the drug and the analysis
was not able to take into account other heart risks.
The company said in a statement it believes that the
research "using limited data from a prematurely terminated
study needs to be interpreted very cautiously and in the
context of the rest of the data from the extensive clinical
development program for Vioxx."
Bresalier said a number of studies since the initial safety
warning on Vioxx suggest other Cox-2 inhibitors, including
Pfizer Inc's (PFE.N) Celebrex, or celecoxib, and non-steroidal
anti-inflammatory drugs (NSAIDS) such as ibuprofen, also carry
a higher risk of heart trouble.
"I think the preponderance of data now does suggest this is
a class effect," he said.
Cox-2 drugs were designed to be safer replacements for
NSAIDS, including aspirin and naproxen, which can cause deadly
"There seems to be an increased risk for most if not all
non-steroidal anti-inflammatory drugs. That doesn't mean these
aren't good drugs. It's just there is some increased risk we
need to be aware of," he said.
Vioxx had generated sales of $2.5 billion a year before the
arthritis and chronic pain pill was withdrawn from U.S.
drugstores almost four years ago. Pfizer's Celebrex has
remained on the market.
(Editing by Will Dunham and Cynthia Osterman)