After nearly a year of waiting, the Cochrane Collaboration has issued its much-anticipated report on the flu medications oseltamivir (Tamiflu) and zanamivir (Relenza). The result is unambiguous. The medications have little benefit when it comes to preventing one person from passing the flu onto another person or in preventing complications from the flu, such as pneumonia or hospitalization. But arriving at this result was not easy or straightforward.
Tamiflu is an anti-viral medication designed to block infected cells from releasing more virus particles into your body. The initial reports were promising. In a 2003 meta-analysis, Tamiflu was found to improve influenza symptoms, decrease hospitalizations and complications from influenza. When bird flu and swine flu appeared in 2005 and 2009 respectively, the fear that a global flu pandemic was coming prompted the World Health Organization to recommend stockpiling anti-viral drugs. As a result, countries around the world spent an approximate 7 billion dollars to create stockpiles of Tamiflu.
The money appeared to be well spent. However, in 2009 the UK National Health Service commissioned the Cochrane Collaboration (an international network of researchers) to review and update the evidence on the use of this class of medications. Initially, no one involved believed that the 2009 systematic review would yield any new insights. They were wrong.
The Cochrane researchers found that the 2003 study relied mostly on unpublished data supplied by Roche, the pharmaceutical company that makes Tamiflu. After multiple attempts to get access to the data, researchers ran their analysis with the data they had available. They found no evidence to support claims that Tamiflu prevented the spread of or complications from influenza.
The publication of their report in the British Medical Journal at the end of 2009 was coupled with a call for Roche to make all their data public. What followed was a back and forth media campaign of Byzantine claims, counter-claims and accusations. Those interested can follow it at www.bmj.com/tamiflu. By the end of 2012, the BMJ editor in chief went on record calling for the release of the data. A letter to the editor called for European governments to sue Roche to recoup the money they had spent on their stockpiles of Tamiflu. MPs in the UK were contemplating legislative action. In the end, it seemed that too much pressure was coming from too many sources. On April 2, 2013 Roche announced that it would hand over the data. And today, nearly a year later, we have the result of the newly released data. The benefit simply isn’t there. If you take Tamiflu, your flu symptoms will last 6.3 days rather than 7 days. That means on average you will get back on your feet a day earlier. But in terms of reducing hospitalizations, complications, or transmission during a pandemic (which is what we should care about) it has no benefit.
There are in fact two issues here. First is the issue of how and why governments spent billions of dollars of public money on a medication that apparently is not effective. Second, and in my opinion more importantly, is the issue of access to clinical data. I don’t want to minimize the importance of the mismanagement of public money, but the lack of access to clinical trial data has a more pernicious consequence than misspent funds. Suppressing information on the effectiveness of a medical therapy can lead to bad medical decisions and faulty public policy.
There are many who believe that a global flu pandemic is coming. Whether it will or not is impossible to say and most of my attempts to predict the future have proven to be woefully inadequate up to now. What I will say though is that the current strategy to deal with a potential pandemic has been based largely on stockpiling Tamiflu. If a global pandemic does come, we may find that all our built-up emergency preparedness measures will come down like a house of cards. If that happens we will be in serious trouble.
Christopher Labos MD CM FRCPC
Division of Epidemiology, Biostatistics and Occupational Health