Roche Tamiflu’s Effectiveness Unproven Due to Hidden Data, Researchers Say

Roche Holding AG (ROG)’s Tamiflu antiviral treatment may not be as safe and effective as the Swiss drugmaker says, according to independent researchers who asked the company to publish data withheld from public review.

While Tamiflu helps flu sufferers feel better an average of 21 hours more quickly after initial symptoms, it didn’t reduce the number of people who went on to be hospitalized, researchers at the non-profit Cochrane Collaboration said today in a report. Though stockpiled to prevent the spread of flu, the drug hasn’t been proven effective for that purpose, the British Medical Journal said in an article published with the Cochrane report.

More information is needed to assess whether stockpiling Tamiflu is a good use of government funds, BMJ said. The drug generated 3.2 billion Swiss francs ($3.37 billion) in sales in 2009, the height of the H1N1 flu pandemic. Basel-based Roche said the medicine is safe and effective.

“It may be that shortening symptoms for 21 hours is a good value for money,” Deborah Cohen, BMJ’s investigations editor, said in a telephone interview. “I remain to be convinced. The bottom line is that people need to have access to all the data. They need to be able to do an independent review.”

The Cochrane report cited a “gap between evidence and policy,” saying the official pandemic-response plans in the U.S. and U.K. are based in part on research that hadn’t been published.

In December 2009, after Tamiflu had established itself as the mainstay of H1N1 treatment, Cochrane released its first report saying the drug’s effectiveness in treating flu complications couldn’t be proven because Roche wouldn’t supply data from eight studies.

Roche Response

Roche said it would post full clinical study reports -- thousands of pages of information, a deluge compared to the thousands of words in the clinical trial articles usually published in medical journals -- on a password-protected website for doctors and scientists to review.

Cochrane said it got 3,195 pages of study reports for 10 trials of Tamiflu, chemically known as oseltamivir.

Yet Roche only provided the first of four to five sections of each report, the Cochrane researchers said. The team turned to public information requests from regulators, getting 22,453 pages from the European Medicines Agency -- which included the second section of each report. Researchers are awaiting results from a request for the rest placed to the Food and Drug Administration last year.

The review remains incomplete. The researchers said they still can’t be sure whether Tamiflu actually reduces complications of flu.

Side Effects

Data in the published and unpublished versions of reports sometimes didn’t match, Cochrane said. One published trial listed no drug-related serious side effects, while the unpublished version listed three “possibly related to oseltamivir.”

Roche doesn’t believe there’s a discrepancy, Silvia Dobry, a spokeswoman, wrote in an e-mailed response to questions yesterday. The company reviewed a proposed protocol from Cochrane last year and believed it had already made available enough data to answer the researchers’ questions, Dobry wrote.

“Today it is standard practice for Roche to publish all its clinical trial data, but seven to 10 years ago (the time period Cochrane is looking at) this was not standard policy within industry or within Roche,” she wrote.

Little New

The company believed the published studies “reflected accurately the benefits of the drug, and that the additional studies provided little new information and would therefore be unlikely to be accepted for publication by most reputable journals,” Dobry wrote.

Tamiflu proved itself to be effective and safe during the 2009 H1N1 pandemic, she wrote. Roche rose 0.2 percent to 164.20 Swiss francs at 9:05 a.m. in Zurich.

The World Health Organization will keep Tamiflu on its list of essential drugs, Gregory Hartl, a spokesman for the Geneva- based agency, said in a telephone interview. The WHO doesn’t dispute the 21-hour figure, he said. However, the agency also looks at evidence collected on the ground during outbreaks, he said, instead of focusing on clinical trials.

“Cochrane is looking at apples, and we are looking at apples and oranges,” he said.

Cochrane’s research was funded by the U.K. National Institute for Health Research’s Health Technology Assessment program. The Cochrane Collaboration studies the effectiveness of health treatments.

To contact the reporter on this story: Naomi Kresge in London at nkresge@bloomberg.net

To contact the editor responsible for this story: Phil Serafino at pserafino@bloomberg.net

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