New doubts over Tamiflu
Updated on 08 December 2009
The claim was that Tamiflu could reduce the hospitalising of patients with swine flu by up to 60 per cent. But Channel 4 News can reveal that a key paper upon which this claim was based is being questioned. Email us your experiences of Tamiflu at firstname.lastname@example.org.
Scientists attempting to peer review the paper requested vital data, and did not get it. Tonight we report a key plank of the evidence for Tamiflu's effectiveness is being called into question.
As swine flu hit the UK, the anti-viral drug Tamiflu hit the headlines, becoming the de facto first line of defence against the epidemic.
It was lauded for reducing the length and duration of flu-like illnesses and, importantly, for reducing hospitalisations.
Governments around the world stockpiled supplies. In the UK alone the estimated bill for Tamiflu is approaching half a billion pounds.
Tonight Channel 4 News can reveal that serious scientific questions are being raised over the evidence base for Tamiflu.
Scientists we have spoken to say they have been unable to judge and properly test some of the claims made about the antiviral by its makers, Roche.
Claims about the drug's effectiveness in reducing hospitalisations have been a key factor in decisions by governments around the world to stockpile Tamiflu (oseltamivir). Manufacturer Roche estimates that sales of Tamiflu this year will reach £1.6bn.
Tamiflu's benefits are well-publicised. Advocates say it reduces the chance of flu being transmitted in the first place, and that once someone has become infected it shortens the duration of the illness. Today's review confirms these findings.
But the drug is also credited with reducing complications and hospitalisations in those who develop full-blown flu. In a recent interview Roche Pharmaceuticals CEO William Burns said: "What Tamiflu can do is actually reduce hospitalisations by more than 60 per cent, which is really important if we are in the midst of a major pandemic."
This is the claim now under scrutiny. The investigation by Channel 4 News and the British Medical Journal (BMJ) has discovered that an independent team of scientists has been unable to verify the scientific evidence-base to support it.
The review, commissioned in July by the NHS and published today at BMJ.com, was conducted by the Cochrane Collaboration - a worldwide group of scientists and researchers that reviews medical research. They are internationally recognised for their work.
Speaking on Channel 4 News, Dr Tom Jefferson, one of the Cochrane reviewers said: "This is not just any drug, this is a public health drug which is recommended by governments... and the World Health Organisation - and has been recommended for some years."
Much of the Cochrane team's work has looked at the leading piece of clinical research supporting claims that Tamiflu reduces hospitalisations. This research was authored by swiss scientist Professor Laurent Kaiser.
His research, based on 10 clinical trials set up by Roche found that Tamiflu reduced by 59 per cent the number of people with flu who ended up in hospital. Roche have repeatedly referred to Professor Kaiser's paper when talking about Tamiflu's ability to reduce hospitalisations.
The study released today acknowledges that Tamiflu has a modest effect in reducing symptoms and duration of illness in otherwise healthy adults by about one day, but says there is insufficient published data to independently confirm its effects on reducing complications leading to hospitalisations .
When the Cochrane reviewers approached Professor Kaiser for the original data in order to verify his conclusions, he said he didn't have it and referred them to Roche. However, following detailed communication with the company, Roche did not supply the Cochrane team with the complete data they had requested and they were unable to verify the paper's findings.
Because they were unable to independently verify this data, the Cochrane review disregarded Kaiser’s paper from their analysis of the scientific evidence base supporting Tamiflu’s effectiveness in reducing complications. This removes a key plank of evidence supporting a claim repeatedly made by Roche and governments like ours.
And without this study, the reviewers came to a stark conclusion. Dr Jefferson told Channel 4 News: "We didn't find any convincing evidence that Tamiflu affects complications such as as hospitalisations and chest infections."
Dr Fiona Godlee, editor-in-chief of the BMJ, says this leaves important questions about effectiveness unresolved.
She said: "I think we're now in a situation where the evidence base for Tamiflu is far from compelling. Really, government needs to get to grips with this and to understand the truth around the evidence, given that this is a drug on which vast sums of public money have been spent."
But Roche stand by the paper saying that the study reports on which the paper was based had been shared with regulatory authorities worldwide. A spokesman for Roche said: "I think the figure of around 60 per cent reduction in complications, that came from this - the analysis of that was robust".
Roche also put forward a number of observational studies which they say support the effectiveness of Tamiflu in reducing complications.
Channel 4 News and the BMJ asked Professor Nick Freemantle and Dr Melanie Calvert, from the University of Birmingham, to review these observational studies. They concluded: "Oseltamivir may reduce the risk of pneumonia in otherwise healthy people who contract flu. However, the absolute benefit is small, and side effects and safety should also be considered.
Professor Freemantle added: "There is very little evidence to support the widespread use of oseltamivir in the otherwise healthy population who are developing signs of influenza like illness."
Dr Fiona Godlee and Professor Mike Clarke, Director of the UK Cochrane Centre, say this updated review is important because it calls into question not only the effectiveness of Tamiflu but "the whole system by which drugs are evaluated, regulated and promoted".