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By Kate Kelland, Health and Science Correspondent
LONDON, April 10 (Reuters) - Researchers who have fought foryears to get full data on Roche's flu medicine Tamiflusaid on Thursday that governments who stockpile it are wastingbillions of dollars on a drug whose effectiveness is in doubt.
In a review of trial data on Tamiflu, and onGlaxoSmithKline's flu drug Relenza, scientists from therespected research network the Cochrane Review said that whilethe medicines can shorten flu symptoms by around half a day,there is no good evidence behind claims they cut hospitaladmissions or lessen complications of the disease.
"There is no credible way these drugs could prevent apandemic," said Carl Heneghan, one of the lead investigators ofthe review and a professor of evidence-based medicine atBritain's Oxford University.
The review's main findings were that the medicines had fewif any beneficial effects, but did have adverse side effectsthat were previously dismissed or overlooked.
"Remember, the idea of a drug is that the benefits shouldexceed the harms," Heneghan said. "So if you can't find anybenefits, that accentuates the harms."
Yet Roche, which has been under fire for several years overits refusal to allow the Cochrane team unrestricted access toTamiflu data, rejected the findings, saying it "fundamentallydisagrees with the overall conclusions" of their study.
"We firmly stand by the quality and integrity of our data... and subsequent real-world evidence demonstrating thatTamiflu is an effective medicine in the treatment and preventionof influenza," it said in a statement.
Tamiflu sales hit almost $3 billion in 2009 - mostly due toits use in the H1N1 flu pandemic - but they have since declined.
The drug, one of a class of medicines known as neuraminidaseinhibitors, is approved by regulators worldwide and isstockpiled in preparation for a potential global flu outbreak.It is also on the World Health Organization's "essentialmedicines" list.
The United States has spent more than $1.3 billion buying astrategic reserve of antivirals including Tamiflu, while theBritish government has spent almost 424 million pounds ($703million) on a stockpile of some 40 million Tamiflu doses.
"DOWN THE DRAIN"
Heneghan's team say their analysis is the first based onfull data - from 20 trials of Tamiflu, known generically asoseltamivir, and 26 trials of Relenza, also known as zanamivir.
At a briefing in London about their findings, Heneghan saidthe money spent on stockpiles "has been thrown down the drain"because, until now, the full data had not been seen byregulators, governments, doctors or patients.
"The original evidence presented to government agenciesaround the world was incomplete," said Fiona Godlee, editor ofthe British Medical Journal which has spearheaded a four-yearcampaign to force Roche to reveal all its Tamiflu data.
"And when they (the Cochrane review team) eventuallyreceived the full information on these drugs, the completeevidence gives a very much less positive picture."
But the European Medicines Agency (EMA) - which approved thedrug for sale in Europe - disputed the claim they had not seenall the Tamiflu data.
Enrica Alteri, head of medicines evaluation, said EMA hadseen and reviewed all 20 studies referred to in the review, andthis new analysis did not raise any fresh concerns or alter theagency's assessment that Tamiflu's benefits outweigh its risks.
Wendy Barclay, a flu expert at Imperial College London withno links to the Cochrane Review or the drugs, said she stillfelt the benefits were worthwhile, particularly in a pandemic.
"If another pandemic came tomorrow, and the government hadno drug with which to treat thousands of influenza infectedpatients, I imagine there would be a public outcry," she said.
The Cochrane review found that compared with a placebo, ordummy pill, Tamiflu led to a quicker alleviation of flu-likesymptoms of around half a day (down from 7 days to 6.3 days) inadults, but the effect in children was more uncertain.
There was no evidence of a reduction in hospitalisations orin flu complications like pneumonia, bronchitis, sinusitis orear infections in either adults or children, Heneghan's teamsaid, and Tamiflu also increased the risk of nausea and vomitingin adults by around 4 percent and in children by 5 percent.
Godlee described the battle with Roche as a "really lengthycat and mouse, Alice in Wonderland, bizarre experience of tryingto get data on a drug which governments around the world werebusy buying, stockpiling and spending billions of dollars on".
"Why did no-one else demand this level of scrutiny beforespending such huge sums on one drug?" she said. "The whole storygives an extraordinary picture of the entrenched flaws in thecurrent system of drug regulation and drug evaluation." ($1 = 0.6028 British Pounds) (Additional reporting by Ben Hirschler; editing by TomPfeiffer)
