As we’ve mentioned before, the entire planet seems to be getting jittery over the avian flu virus. Now, Roche AG has agreed to meet with generic manufacturers Teva Pharmaceutical Industries Ltd., Barr Pharmaceuticals Inc., Mylan Laboratories Inc. and Ranbaxy Laboratories Ltd. to license its patent and increase production of its antiviral drug Tamiflu (oseltamivir) to prepare for a possible bird flu outbreak. While only sixty-seven people in Asia are known to have been killed by the H5N1 virus, there is a real fear it could mutate and spark a worldwide pandemic.

Perhaps to avoid a public relations nightmare as well as a showdown on compulsory licensing for its drug, Roche now says it will sublicense Tamiflu production to any company that can produce it in sufficient quantities – now that just about every country is trying to stockpile the drug. Forty countries have placed orders with Roche so far and the company has been under pressure to allow others to produce Tamiflu so demand can be met. Some countries, such as Argentina, have said they will produce their own version of Tamiflu.

All of this is complicated by the fact that there isn’t really an emergency yet, only the heightened apprehension of an impending crisis. Unfortunately, it will be difficult for generics to manufacture Tamiflu. Tamiflu, a neuraminidase inhibitor, is a complex drug and takes 12 months to produce. While Roche claims it’s filling current Tamiflu orders on schedule, there could be a run on the drug if any major outbreak suddenly spooks the world. If generics are not licensed until its urgent, it may be too late. This gets trickier given that Tamiflu has a shelf life of five years and there is no way of knowing when an outbreak may occur.

And now there is the shortage of the raw material for Tamiflu!
staranise.jpegStar anise, an unusual fruit grown in China with a pungent, licorice-like flavor, is the herb from which Tamiflu is made. It is grown in four provinces in China and “huge quantities” of its seeds are needed in order to be purified and the shikimic acid extracted at the start of a 10-stage manufacturing process which takes a year.

More commonly used in Chinese cooking and for flavoring liqueurs such as anisette and Pernod, Star Anise (Illicium verum, an evergreen tree of the Magnoliaceae family) is similar to Anise but not the same. Only star anise grown in the four provinces of China is suitable for manufacture into Tamiflu and 90 per cent of the harvest is already used by Roche.

While Roche has developed a synthetic source of acidinic acid, made from the bacterium E. coli, star anise remains the chief source. Once shikimic acid is extracted from the seeds of star anise it is converted to epoxide in a process requiring three chemical steps carried out at low temperature on seven separate sites.

We need to keep in mind that Tamiflu is not a cure for the flu but it can lessen symptoms if taken shortly after they first appear. Whileinternet firms are cashing in on the panic buying of $10-a-tablet anti-viral drug as a defense against bird flu, researchers warned last week that they have seen signs the avian flu virus is becoming resistant to the drug. UK Professor Hugh Pennington warned people risked being “ripped off” by buying a drug they did not need noting that “The risk of them getting bird flu is low. Tamiflu is not [a] wonder drug. It was given to some people in Asia and did not stop them dying.”

I guess fire and pestilence is next.

Update: One commenter below pointed out that, according to an article in Nature, a 14-year-old Vietnamese patient (probably the one referred to above), was treated, recovered and was discharged from the hospital on 14 March 2005.

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