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 In a review of trial data on Tamiflu, and on
GlaxoSmithKline's flu drug Relenza, scientists from the respected
research network the Cochrane Review said that while the medicines
can shorten flu symptoms by around half a day, there is no good
evidence behind claims they cut hospital admissions or lessen
complications of the disease.
"There is no credible way these drugs could prevent a pandemic,"
said Carl Heneghan, one of the lead investigators of the review and
a professor of evidence-based medicine at Britain's Oxford
University.
The review's main findings were that the medicines had few if any
beneficial effects, but did have adverse side effects that were
previously dismissed or overlooked.
"Remember, the idea of a drug is that the benefits should exceed the
harms," Heneghan said. "So if you can't find any benefits, that
accentuates the harms."
Yet Roche, which has been under fire for several years over its
refusal to allow the Cochrane team unrestricted access to Tamiflu
data, rejected the findings, saying it "fundamentally disagrees with
the overall conclusions" of their study.
"We firmly stand by the quality and integrity of our data ... and
subsequent real-world evidence demonstrating that Tamiflu is an
effective medicine in the treatment and prevention of influenza," it
said in a statement.
Tamiflu sales hit almost $3 billion in 2009 — mostly due to its use
in the H1N1 flu pandemic — but they have since declined.
The drug, one of a class of medicines known as neuraminidase
inhibitors, is approved by regulators worldwide and is stockpiled in
preparation for a potential global flu outbreak. It is also on the
World Health Organization's "essential medicines" list.
The United States has spent more than $1.3 billion buying a
strategic reserve of antivirals including Tamiflu, while the British
government has spent almost 424 million pounds ($703 million) on a
stockpile of some 40 million Tamiflu doses.
"DOWN THE DRAIN"
Heneghan's team say their analysis is the first based on full data — from 20 trials of Tamiflu, known generically as oseltamivir, and 26
trials of Relenza, also known as zanamivir.
At a briefing in London about their findings, Heneghan said the
money spent on stockpiles "has been thrown down the drain" because,
until now, the full data had not been seen by regulators,
governments, doctors or patients.
"The original evidence presented to government agencies around the
world was incomplete," said Fiona Godlee, editor of the British
Medical Journal which has spearheaded a four-year campaign to force
Roche to reveal all its Tamiflu data.
"And when they (the Cochrane review team) eventually received the
full information on these drugs, the complete evidence gives a very
much less positive picture."
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But the European Medicines Agency (EMA) — which approved the drug
for sale in Europe — disputed the claim they had not seen all the
Tamiflu data.
Enrica Alteri, head of medicines evaluation, said EMA had seen
and reviewed all 20 studies referred to in the review, and this new
analysis did not raise any fresh concerns or alter the agency's
assessment that Tamiflu's benefits outweigh its risks.
Wendy Barclay, a flu expert at Imperial College London with no links
to the Cochrane Review or the drugs, said she still felt the
benefits were worthwhile, particularly in a pandemic.
"If another pandemic came tomorrow, and the government had no drug
with which to treat thousands of influenza infected patients, I
imagine there would be a public outcry," she said.
The Cochrane review found that compared with a placebo, or dummy
pill, Tamiflu led to a quicker alleviation of flu-like symptoms of
around half a day (down from 7 days to 6.3 days) in adults, but the
effect in children was more uncertain.
There was no evidence of a reduction in hospitalizations or in flu
complications like pneumonia, bronchitis, sinusitis or ear
infections in either adults or children, Heneghan's team said, and
Tamiflu also increased the risk of nausea and vomiting in adults by
around 4 percent and in children by 5 percent.
Godlee described the battle with Roche as a "really lengthy cat and
mouse, Alice in Wonderland, bizarre experience of trying to get data
on a drug which governments around the world were busy buying,
stockpiling and spending billions of dollars on".
"Why did no-one else demand this level of scrutiny before spending
such huge sums on one drug?" she said. "The whole story gives an
extraordinary picture of the entrenched flaws in the current system
of drug regulation and drug evaluation."
 ($1 = 0.6028 British
pounds)
(Additional reporting by Ben Hirschler; editing by Tom Pfeiffer)
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