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AP Reuters: Tamiflu shelf life

Health officials have told governments they can keep Tamiflu for longer to help fight the swine flu pandemic. It means stockpiles of the drug that governments started to build up 5 years ago in response to the outbreak of bird flu will not need to be thrown away before winter in the Northern Hemisphere, when the pandemic is expected to spread. Some 220 million individual treatments of Tamiflu — each with 10 capsules to be taken over 5 days — have been sent to governments around the world since 2004 by the manufacturer, Swiss pharmaceuticals company Roche Holding AG, said spokeswoman Claudia Schmitt on Tuesday [18 Aug 2009]. It is unclear how many of the treatments remain in stockpiles and how many have been used to treat outbreaks of bird flu and, more recently, swine flu, Schmitt said.

Antivirals such as Tamiflu can shorten swine flu [influenza pandemic (H1N1) 2009 virus infection] by about a day if started within 2 days of the onset of the disease. GlaxoSmithKline’s Relenza is believed to be similarly effective. European Union members also have approved the extension of the shelf-life of Relenza, or zanamivir, from 5 years to 7 years.

Tamiflu packages state that the drug should be used within 5 years of manufacture. Health authorities in Europe, the United States, Canada, Hong Kong and Australia have approved extending that to 7 years for use against the pandemic strain of swine flu, said Schmitt. The extension does not apply to Tamiflu’s use against seasonal flu.

The decision may be in time to help some Asian countries that stockpiled the drug against the earlier outbreak of bird flu to avoid the expense of replacing it during the pandemic declared in June 2009. The World Health Organization accepts the decisions to approve the extension of the shelf life, and it is acceptable to apply the extension retroactively in this case, said WHO spokesman Gregory Hartl. "It is WHO’s view that shelf-life extensions are a matter for national regulatory authorities," Hartl said.

WHO estimates that up to 2 billion people could become infected with the disease [influenza pandemic (H1N1) 2009 virus infection] over the next 2 years, so it would be impossible at the current rate to provide doses of the drug to everyone infected. To help bridge the gap, Roche has licensed several other producers to make a generic version of the drug oseltamivir, which Roche markets as Tamiflu. In addition, Schmitt said, "we are scaling up production of Tamiflu so we will be able, if required, beginning next year to produce about 400 million treatments per year." She said Roche was still fulfilling the promise it announced in May 2009 to donate 5.65 million treatments of Tamiflu to WHO to help developing countries cope with the pandemic. That comes on top of an earlier donation of 5 million treatments.

[Byline: Alexander Higgins]

****** [2] Date: Tue 18 Aug 2009 Source: Reuters News [edited] <>

The World Health Organisation said on Tuesday [18 Aug 2009] it was up to national regulatory authorities to decide whether to extend the shelf life of the flu drug Tamiflu by 2 years, as recommended by Swiss drug maker Roche (ROG.VX). The United States, Canada, Australia, Hong Kong and the European Union’s drug watchdog have extended Tamiflu’s shelf life to 7 years from 5 after company data showed the active ingredient’s longer stability, a Roche spokeswoman said.

Tamiflu, known generically as oseltamivir, is the front line antiviral being used against the influenza pandemic (H1N1) 2009 virus, commonly known as swine flu, which is causing an influenza pandemic. Capsules kept in government stockpiles worldwide or currently on the market carry a 5-year expiry date. "It is WHO’s view that shelf-life extensions are a matter for national regulatory authorities," WHO spokesman Gregory Hartl said in a statement sent to journalists.

The WHO says most people infected with H1N1 have mild symptoms, and Tamiflu should be given only to flu sufferers at high risk, including pregnant women or those with complications such as pneumonia. The European Medicines Agency has said it is acceptable to apply the extension to current stocks of the drug during a flu pandemic, a decision followed last month [July 2009] by Switzerland.

"We are working with health authorities to also extend the shelf life in other markets because it makes sense," Roche spokeswoman Claudia Schmitt told Reuters. Roche was providing its stability data to governments to help them extend the shelf life of their stockpiles, she said. "Governments have had stockpiles since the bird flu time," she added, referring to the H5N1 avian flu strain which erupted in 2003 and also responds to treatment with the antiviral.

Since 2004, Roche has fulfilled government orders for 270 million Tamiflu treatment courses in 96 countries, Schmitt said. The drug manufacturer has donated about 10.65 million treatment courses to the WHO for distribution and use in the poorest countries. The 1st donation to the U.N. agency was made in 2004 and the 2nd in May [2009], as H1N1 spread more widely. "A large amount of the 2nd donation is newly produced. It is a product that will expire many years from now," she said.

The WHO spokesman said the agency did not have any new estimate of global production capacity for vaccines now being developed by drug companies. The WHO has previously estimated that drug companies could produce up to 94 million doses per week, but the amount will depend on factors including whether one dose or 2 are needed, and how much of the active agent will be needed per dose. In the United States, Novavax Inc (NVAX.O) reported on Tuesday [18 Aug 2009] that a new kind of flu vaccine worked against the H1N1 virus in ferrets, the closest animal to humans when it comes to being infected with influenza. Leading flu vaccine makers include Sanofi-Aventis (SASY.PA), GlaxoSmithKline (GSK.L), Novartis (NOVN.VX), Baxter (BAX.N), CSL (CSL.AX) and Solvay (SOLB.BR).

In Dar es Salaam, WHO Director-General Margaret Chan said work on producing a vaccine was proceeding now that manufacturers in developed and developing countries had received the seed virus from the WHO’s collaborating centres. "We expect vaccines, the 1st batch of which would be available in September, October [2009]," Chan told reporters.

[Byline: Stephanie Nebehay]

— Communicated by: ProMED-mail Rapporteur Mary Marshall

[The continued profligate use of Tamiflu in the treatment of mild infections may ultimately promote the expansion of Tamiflu-resistant virus, since resistance is conferred by mutation at a single site in the neuraminidase gene. Fortunately, there is no evidence so far to suggest that Tamiflu resistance is spreading widely, and it is likely that Tamiflu will remain effective until suitable vaccines become available. – Mod.CP]

— Gary Greenberg, MD MPH    Sysop / Moderator Occ-Env-Med-L MailList Univ. N. Carolina School Public Health Medical Director Urban Ministries of Wake County Open Door Clinic