Roche’s Tamiflu Not Proven to Cut Flu Complications

Michelle Fay Cortez
December 9, 2009

The effectiveness of Roche Holding AG’s Tamiflu in treating flu complications in healthy adults can’t be determined because the Swiss drugmaker wouldn’t supply data from eight studies, an independent research group said.

The exclusion led the Cochrane Collaboration to reverse its previous finding that the pill warded off pneumonia and other deadly conditions linked to influenza. Tamiflu has been the mainstay of treatment for swine flu, which has killed almost 9,000 people since April, according to the World Health Organization. Roche said the drug is effective.

An analysis of 20 studies showed that Tamiflu, which is expected to generate 2.7 billion francs ($2.64 billion) in sales this year, eased and shortened symptoms if taken quickly. It found no clear evidence that the drug prevented lower respiratory tract infections or complications of influenza, according to the nonprofit research group in a review published in the British Medical Journal.

“We have multibillion-dollar public health policies in place that rely on evidence not available for independent analysis,” Tom Jefferson, the lead researcher from the Cochrane Collaboration in Rome, said in a telephone interview.

The report, an update of a 2005 analysis by Cochrane, excluded eight studies funded by Roche that haven’t been published and whose full data wasn’t given to the researchers. The exclusion reversed the group’s earlier finding that Tamiflu protects against complications.

Insufficient Evidence

“We now conclude there is insufficient evidence to describe the effects of Tamiflu on complications of influenza or the drug’s toxicity,” Jefferson said.

The group, which reviews medical evidence, excluded the eight studies, involving 2,500 patients, because it couldn’t get satisfactory access to the data involving the healthy adults in the study, he said.

Roche, based in Basel, Switzerland, defended the drug’s benefits and its research, saying confidentiality agreements with patients enrolled in the trials kept the company from giving the investigators unreserved access to the findings.

“We fully stand behind the robustness of the data and the integrity of that data, particularly the efficacy and safety of Tamiflu, the conduct of our studies and publication policies,” David Reddy, head of the company’s global pandemic task force, said on a conference call with reporters. “We believe this drug is playing a pivotal role in the management of the current pandemic.”

Roche Offer

Roche offered to give the full findings to the researchers if they signed a confidentially agreement, Reddy said. The researchers declined the offer, he said.

Two published trials show Tamiflu reduces complications in patients with seasonal influenza, while an observational study suggests it may lower death rates, Reddy said. Data emerging from the swine flu pandemic shows giving the drug within two days of symptoms appearing is the only effective way to help patients, he said.

The Cochrane report raises questions about how drugs are reviewed, approved and distributed, Fiona Godlee, the British journal’s editor in chief, wrote in an editorial. The studies originally used to establish the benefits of Tamiflu were written by Roche employees and paid consultants, under-reported serious side effects and failed to clearly identify all the authors, she wrote. In at least one case, a study was attributed to a researcher who disavowed any involvement to the journal, Godlee wrote.

‘Taken on Trust’

Governments relied on the studies to justify the widespread use of Tamiflu, known chemically as oseltamivir, she said. The reviewers were unable to find any independent studies of the drug in healthy adults, she said.

“This case exposes how much of the evidence on drug safety and effectiveness is taken on trust,” Godlee wrote. “Governments around the world have spent billions of pounds on a drug that the scientific community has found itself unable to judge.” She called for more independent research, greater access to raw data used to license and sell drugs and stricter regulations on the conduct, review and publication of medical research.

More than 8,768 people worldwide have died from swine flu since it was first identified in Mexico and the U.S. in April, according to the Geneva-based WHO. More than 68 million people have taken Tamiflu since it was approved a decade ago. Influenza kills as many as 500,000 people worldwide each year.

WHO Recommends

The WHO recommends giving Tamiflu to infected people with a high risk of developing complications, including pregnant women and people with underlying medical conditions. The researchers said there is little evidence now available to show that otherwise healthy people should be routinely given Tamiflu.

In the U.K., patients can get a Tamiflu prescription by calling a national hotline or filling out an online questionnaire about their symptoms.

“The evidence shows that if taken within 24 hours, Tamiflu reduces symptoms of influenza by about a day,” Jefferson said. “It may reduce transmission. But we could not verify the claims that Tamiflu reduces complications. Once you took out the eight unpublished studies, the data relating to healthy adults that weren’t published, what remained showed no effect.”

To contact the reporter on this story: Michelle Fay Cortez in London at


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