worth it? there is little evidence that the flu drug Tamiflu reduces complications or hospitalizations health, a new study contends.
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BMJ released the latest volley in a battle over one of the most controversial drugs of the 21st century: the compound oseltamivir anti-influenza, better known as Tamiflu. A working group of the Cochrane Collaboration, an international network of scientists that conducts systematic reviews of the medical literature, conducted the most exhaustive meta-analysis yet of drug effectiveness and its conclusions are, again, pretty overwhelming.
Tamiflu can relieve symptoms of the flu earlier than they would otherwise, the authors say, but there is no evidence that it can prevent serious flu complications, or keep people out of hospital. The group questions the wisdom of buying massive stocks of drugs to prepare for an influenza pandemic, as many countries have done.
The review comes after a long fight to get stretched all available data from trials of Tamiflu from Roche, the company that produces the drug. The Cochrane group, with the active support of BMJ , eventually won that showdown, and thereby makes Tamiflu the poster child for a wider campaign successfully to ensure access to clinical trial data. (The European Medicines Agency has already said he will make the information it receives from pharmaceutical companies available to the public, and several companies, including Roche and GlaxoSmithKline, have pledged to become much more transparent.)
There is little disagreement that Tamiflu, which entered the market in 1999, is active against influenza virus at least a little. Studies have fairly consistently shown that it can shorten the duration of symptoms, which usually last about a week, up to 1 day. But the current debate is whether Tamiflu can also prevent serious complications and hospitalizations. (The data has never been strong enough to justify conclusions about whether it prevents death.)
The Acute Respiratory Infections Cochrane Group, led by Tom Jefferson, an independent researcher in Rome published its first review the effectiveness of Tamiflu in 06, on the basis of published documents. In it, they confirmed the then conventional wisdom that Tamiflu could reduce the complications of influenza and the risk of hospitalization in adults. But in 09, the group received a letter from a Japanese pediatrician, Keiji Hayashi, who questions the data.
To the surprise of the group, eight of the 10 studies reviewed in a 03 co-written meta-analysis by scientists and favorable Roche Tamiflu was never published. Roche initially refused to hand over the data. "I do not like being made a fool," Jefferson said in a story in the current issue of BMJ by science journalist Julia Belluz. "I trusted the literature. I trusted people who were doctors and researchers. I trusted the archive. I trusted Roche."
In an updated review released in December 09, the group concluded that without these private data, there was no evidence that Tamiflu prevented complications or hospitalizations. The results have changed the public's opinion about Tamiflu, and led to buyer's remorse in some of the countries stored drugs.
The letter Hayashi also marked the beginning of the quest for the Cochrane group Roche complete data. The company promised to send the so-called mass-clinical study reports documents containing patient data underlying the conclusions in the newspapers-that scientists in 09, but it was not until last year that all data sets actually happened. Cochrane says Roche Group has been evasive answers; the company says the delay was due to logistical problems, legal issues and privacy, and a lack of communication with scientists Cochrane
Now that the group has chewed the bitter numbers, the conclusions are not very different :. Patients get better a little earlier with Tamiflu, but there is not enough evidence to say they are at low risk of complications and hospitalization. Moreover, the authors write, side effects such as nausea and vomiting are more common than was known before. "We believe these results provide reason to question the storage of oseltamivir, its inclusion in the [World Health Organization] essential drug list and its use in clinical practice as an anti-influenza drug," the group written. (In a separate document, the group found such disappointing results for another drug against influenza, zanamivir, also known as Relenza, which sold far less than Tamiflu.)
Many scientists flu disagreed with the previous analysis of the Cochrane group and challenge the new results as well. Shorten the duration of symptoms, for one, is not useless, writes Wendy Barclay, chair of influenza virology at Imperial College London, in a statement released by the Science Media Centre (SMC) in London. "While one day does not look like much, a disease that lasts only six days, it is. In the community it gets people to work and to school," she wrote.
But perhaps more importantly, some researchers oppose the group's conclusions about the usefulness of Tamiflu in the event of an influenza pandemic. During the most recent pandemic, in 09 and 2010, scientists do not conduct randomized clinical trials of Tamiflu, the gold standard in medicine, and the Cochrane group did not consider the so-called observational studies. But a review of these studies during the pandemic, published last year by Jonathan Nguyen-Van-Tam of City Hospital Nottingham, U.K., showed that Tamiflu reduced the risk of serious complications. "We now know that antivirals have saved lives during a pandemic and we risk losing one of the few weapons we have because of too much negative publicity," said Peter Openshaw, director of the Center for respiratory infections Imperial College London, in a statement to the SMC.
Dissatisfied with the work of the Cochrane Collaboration, another group of scientists has already said he will repeat the work independently. the group multiparty for advice on science, which has an unrestricted grant from Roche, said it will take the observation data into account. virologist Albert Osterhaus of the Erasmus MC in Rotterdam, Netherlands, which launched the initiative last year, says its results will be announced at a meeting of flu in Riga in September.
one way to settle matters once and for all would be to put in place new clinical trials oseltamivir. The question is who finance them. There is little incentive for Roche to do so; patents on the drug will expire in most countries in 2016, paving the way for generic competitors to produce the compound Financial Times journalist Andrew Jack wrote in a story as published in BMJ this week.
This may mark the end of an incredibly successful run for Roche. Since the drug was launched in 1999, Tamiflu generated more than $ 18 billion in sales, Jack wrote. About half of this was for stocks pandemic, the vast majority of them have never been used and will soon expire; the US government alone spent $ 1.3 billion on its Tamiflu cache.
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