jueves, 19 de junio de 2014
La "sombra" de Tamiflu es alargada y...de_Roche de dudas sobre la investigación farmacéutica.(I)
Today we found out that Tamiflu doesn't work so well after all. Roche, the drug company behind it, withheld vital information on its clinical trials for half a decade, but the Cochrane Collaboration, a global not-for-profit organisation of 14,000 academics, finally obtained all the information. Putting the evidence together, it has found that Tamiflu has little or no impact on complications of flu infection, such as pneumonia.
That is a scandal because the UK government spent £0.5bn stockpiling this drug in the hope that it would help prevent serious side-effects from flu infection. But the bigger scandal is that Roche broke no law by withholding vital information on how well its drug works. In fact, the methods and results of clinical trials on the drugs we use today are still routinely and legally being withheld from doctors, researchers and patients. It is simple bad luck for Roche that Tamiflu became, arbitrarily, the poster child for the missing-data story.
And it is a great poster child. The battle over Tamiflu perfectly illustrates the need for full transparency around clinical trials, the importance of access to obscure documentation, and the failure of the regulatory system. Crucially, it is also an illustration of how science, at its best, is built on transparency and openness to criticism, because the saga of the Cochrane Tamiflu review began with a simple online comment.
In 2009, there was widespread concern about a new flu pandemic, and billions were being spent stockpiling Tamiflu around the world. Because of this, the UK and Australian governments specifically asked the Cochrane Collaboration to update its earlier reviews on the drug. Cochrane reviews are the gold-standard in medicine: they summarise all the data on a given treatment, and they are in a constant review cycle, because evidence changes over time as new trials are published. This should have been a pretty everyday piece of work: the previous review, in 2008, had found some evidence that Tamiflu does, indeed, reduce the rate of complications such as pneumonia. But then a Japanese paediatrician called Keiji Hayashi left a comment that would trigger a revolution in our understanding of how evidence-based medicine should work. This wasn't in a publication, or even a letter: it was a simple online comment, posted informally underneath the Tamiflu review on the Cochrane website, almost like a blog comment.(Más en español)
El doctor David Tovey, Editor en Jefe de la Cochrane ha dicho: “Ahora tenemos la revisión más robusta sobre los ´inhibidores de la neuraminidasa´. Inicialmente pensado para reducir las hospitalizaciones y las complicaciones graves de la gripe, el informe pone de relieve que el Tamiflu no ha demostrado estos efectos y que tiene problemas que no fueron informados plenamente en las publicaciones originales. Esto demuestra la importancia de asegurar que los datos de los ensayos son transparentes y accesibles “.
Y no solo en Europa se publican "denuncias"...
Consequences of human studies with unpublished results: what can be done?
Data from clinical trials with widely prescribed drugs have not been published. Pregabalin, gabapentin, paroxetine, oseltamivir, zanamivir are only some examples of drugs in which Phase III trials remain unpublished several years after study completion. Unpublished clinical trials could result in negative consequences in the economy of healthcare systems and mislead therapeutic decisions in clinical practice. Oseltamivir (Tamiflu ®) is only one example in which unpublished data resulted in unfortunate decisions by policy makers around the world. Oseltamivir was approved for the treatment of influenza by the European Medications Agency (EMEA), the Food and Drug Administration (FDA), and the National Institute for the Surveillance of Medicines and Foods (INVIMA) in Colombia. Tamiflu was also recommended by The World Health Organization (WHO) and stockpiling of this drug was encouraged by the Centers for Disease Control and Prevention (CDC). During 2009 the Ministry of Social Protection from Colombia acquired more than 1 million doses of oseltamivir at a total price of $34,000 million colombian pesos (approximately $16 millions USD). Most doses of oseltamivir were never used and passed their expiration date. Agencies through the world did not review the full Tamiflu dataset before the publishing statements supporting recommendations encouraging their use, purchase, and stockpiling of this drug. To the present day, results for the majority of Roche's Phase III intervention trials for oseltamivir remains unpublished over one decade after their completion date. (Más)