Roche stands accused of withholding key trial data relating to its antiviral Tamiflu, raising questions about its safety and effectiveness.

__A report by the Cochrane Collaboration claims that Roche has refused to provide full access to all its data which leaves questions about how well Tamiflu (oseltamivir) works unresolved. Specifically, the Cochrane researchers set out to test Roche’s claim that Tamiflu prevented complications and reduced the number of people needing hospital treatment.

However, they insist their investigation was hampered by Roche’s refusal to provide all of its trial data for analysis. They obtained some clinical study reports from the European Medicines Agency but found inconsistencies with published reports and possible under-reporting of side effects.

Meantime, the BMJ has initiated an investigation, published to coincide with the report, which it says also raises serious concerns about access to drug data, the use of ghost writers in drug trials and the whole approval process.__ The BMJ, noting that Roche has admitted that some of the published papers had been ghost-written, also says its probe reveals how "different regulators took different approaches to the data submitted to them, leading to conflicting messages about its effectiveness".__

The journal states that the EMA released a proportion of the clinical study reports relating to the Tamiflu trials to Cochrane, but admitted that it did not ask for the remainder from Roche, although it was legally entitled to do so. The EMA has since told the BMJ that it plans to start publishing reports for all drugs submitted for approval in the next few years.

The Cochrane researchers believe that Tamiflu appears to affect antibody production and this is important because influenza vaccination relies on an antibody response to be effective. This is a claim that Roche refutes, but when asked by the BMJ, the Swiss major "refused to explain how the drug works". __

As such, the Cochrane group says that “until more is known about the mode of action of neuraminidase inhibitors, health professionals, patients and other decision makers need to reflect on the findings of this review before making any decision about the use of the drug". The researchers also argue that Tamiflu’s ability to prevent the spread of influenza has not been demonstrated in trials.

__Fiona Godlee, BMJ editor-in-chief said she hopes the EMA will indeed keep its aforementioned promise about publishing reports, "but we are still a long way away from having a full trial history for all drugs in clinical use. Public safety and the proper use of public money demands that we should stop at nothing less than this."__

The BMJ also claims that the US Food and Drug Administration chose not to review the largest ever trial of Tamiflu when considering the drug for approval. It states that “Tamiflu has not been shown to prevent such complications [serious bacterial infections].”

__However, the US Centers for Disease Control and Prevention continue to cite key published trials of Tamiflu, the BMJ states, claiming a reduced risk of influenza complications, even after Roche admitted that some of these trials have been ghost written.__

Dr Godlee continued by saying that "the discrepancies between the conclusions reached by different regulators around the world highlights the absurd situation we find ourselves in". She argued that "in a globalised world, regulators should cooperate and pool their limited resources. Otherwise, we will continue to waste money and risk people's health on drugs that don't work."

The latest probe follows just over two years after an expert review published by the BMJ said there is no clearevidence thatTamiflu prevents complications like pneumonia in healthypeople. __ __That study, which updated a 2006 review published in The CochraneLibrary, acknowledged that Tamiflu (and other neuraminidase inhibitors)have a modest effect in reducing flu symptoms and infectivity inotherwise healthy adults by about one day.

Roche refutes claims

__Roche responded by saying it provided the Cochrane group with “3,200 pages of very detailed information, enabling their questions to be answered" and that it had made full study data available to regulatory authorities. The company added that “numerous clinical trials and real-life medical experience show Tamiflu is effective in reducing the severity and duration of influenza symptoms as well as specified secondary complications".

The Basel-headquartered group went on to say that “analyses by health authorities and independent research groups show that, during the 2009 H1NI pandemic, Tamiflu saved lives and reduced hospitalisation". Roche ended by stressing it "stands behind the robustness and integrity of our data supporting the efficacy and safety of Tamiflu".