Effect Measure

The current pandemic with swine H1N1 remains sensitive to the oral neuriminidase inhibitor, oseltamivir (Tamiflu), an antivial. How long that will last isn’t clear, and neither drug in this category (Tamiflu or zanamivir/Relenza) is very effective, although they appear to work to some extent against sensitive influenza virus. But Tamiflu can be expensive and the cost adds up when we are talking of tens or hundreds of millions of doses. Part of the cost is that the drug company that makes Tamiflu, Roche, is in business to make money and isn’t readily giving up its licensing rights to allow others to make the drug and supply it more cheaply. But another part of the problem is that oseltamivir is not easy to make and requires expensive feed materials.

Or does it? More than 3 years ago we noted that a faster and cheaper way to make oseltamivir had been developed and put into the public domain. But nothing seems to have become of it. We wonder why.

“A shorter road to Tamiflu synthesis”

Comments

#1 Jeff
August 21, 2009

A new study by Oxford researchers suggests Tamiflu and Relenza are not appropiate for young children.
#2 revere
August 21, 2009

Jeff: Controversial issue. Like everything it is a balance. The “study” you refer to is not at all definitive or even very informative, as I recall (am away and don’t have access). It could still be true, but you have to read the original, not news reports of it.
#3 Jeff
August 21, 2009

The article mentioned above contains a link to the original BMJ study:

http://www.bmj.com/cgi/content/full/339/aug10_1/b3172
#4 phytosleuth
August 21, 2009

The wheels of pharmaceuticals move slowly?

A Short and Practical Synthesis of Oseltamivir Phosphate (Tamiflu) from (−)-Shikimic Acid.

Publish May, 2009

http://pubs.acs.org/doi/abs/10.1021/jo900218k
#5 phytosleuth
August 21, 2009

And another synthetic recipe:

An alternative synthesis of Tamiflu (R): a synthetic challenge and the identification of a ruthenium-catalyzed dihydroxylation route.
Yamatsugu K, Kanai M, Shibasaki M
TETRAHEDRON Volume: 65 Issue: 31 Pages: 6017-6024 Published: AUG 1 2009
#6 revere
August 21, 2009

Jeff: This is the study we took a careful look at here and is linked in the post.
#7 DLMCD
August 21, 2009

It was my understanding that WHO has granted approval for Indian drug company Cipla’s generic version of Tamiflu, called Antiflu, and has included it in WHO’s list of prequalified medicines. Cipla planned to make the generic Oseltamivir available for sale to less affluent countries at a fraction of the cost of Tamiflu. Do you know anything more about how this may be progressing?
#8 Valerie Brown
August 22, 2009

To change the subject, I saw a news item (Australian) about multiple dose vaccine vials for swine flu being a risk for spreading a number of bloodborne diseases, including HIV. http://www.theage.com.au/national/infectious-disease-risk-in-swine-flu-jabs-20090820-es2a.html

Is this true? Are multiple dose vials going to be used in the US?
#9 Harold
August 22, 2009

Now, I’m only a bit of a chemist instead of a chemical engineer, but it seems to me that 3 years could be rather too short to go from the lab bench all the way to full scale FDA blessed production.

For things like drugs that are manufactured with the “pot” method (the other method requires essentially one factory for each chemical reaction) I don’t know how much time is usually required for scaling up, but I do know it can be non-trivial. If Roche is pursuing this or other cheaper methods (which I gather is the case) but is running into problems there’s no particular reason they’d be publicizing a blow by blow account.

And never forget that this is a three stereocenter molecule, as you point it’s not easy to make. I remember a similar fuss back when a three or so stereocenter HIV protease inhibitor was developed.
#10 miso
August 22, 2009

Revere,
Let’s not forget funding health professionals and keeping such a positive spin on Tamiflu and it’s growing list of short comings for years hasn’t been cheap, and it isn’t getting any cheaper for Roche.
#11 Magpie
August 24, 2009

Jeff, strangely the reporting conflates Relenza and Tamiflu (note that the article only mentions Relenza at the start, and then goes on at length about the Tamiflu results, as if Relenza was in the same boat). While the results were similar (not much, but something, and likely life saving when used en mass in a serious outbreak), the more dangerous side effects (ie dehydration) was limited to the Tamiflu. Relenza has the benefits with fewer side effects.

Which makes me a bit baffled as to why Relenza isn’t more widely stockpiled compared with Tamiflu. Not baffled enough to buy into Miso’s conspiracies, but baffled nonetheless.

BTW: an important outcome from the release of stockpiled antivirals is “security theatre” (*), or something of a societal placebo. People are willing to take their kids home if the hospital gives them that magic drug they’ve heard of. The fact that it actually does something is important and may save lives, but IMO is secondary to the greater change in attitude and behavior we could hope for – though, again, all the more reason to go with the option with the fewer side effects.

(*We’re familiar with security theatre? It’s where a risk is disproportionately feared, such as the risk of being killed by terrorists (which is vanishingly small for most people in most areas). Security theatre is something visible, to show the punters you take it all seriously and make them feel more secure, even if the visible response is something that won’t really help (it’s the low-profile response that actually helps, but that doesn’t make most people feel better). Even if the improvement to risk is illusory, the assessment of risk was itself illusory. Helping people to feel secure – especially against a threat that really is smaller than they think – is worthwhile, IMO).
#12 miso
August 27, 2009

The irony that proves some health professionals parrot “accepted wisdom” without daring to think, for fear of loosing funding.

Experimental drug helps save critical swine flu victim

As the 20-year-old left intensive care last night following a marathon 38 days – including 31 on breathing machines – a team from Melbourne’s The Austin hospital were still coming to terms with how they had saved the chronic asthmatic.

After arriving at the hospital on July 10, Mr Luong’s lungs became so full of mucus they were almost solid, going from about 200g to more than 1kg and having no chance of passing oxygen into his blood.

Efforts to sustain him on traditional ventilators literally blew Mr Luong’s lungs apart – causing air to fill his chest cavity and place pressure on his heart as well as dangerous pockets of air under his skin.

As his condition worsened an examination of the student’s stomach revealed it had shut down, meaning the Tamiflu needed to fight off swine flu could not be digested.

With an intravenous drip the only way of getting medication into Mr Luong, the team decided to try a liquid form of flu drug Relenza – a highly experimental formula not registered anywhere in the world, which had to be flown in from the U.S. where it had been produced for clinical trials unrelated to swine flu.

A relieved Mr Luong was yesterday coming to terms with enormous effort made to save his life. “All I can remember is getting needles about 40 days ago,” he said.

“I have strong parents that love me and have prayed for me.”

In Adelaide yesterday, a Hove man, 37, suffering from swine flu with no underlying medical conditions died, becoming the 11th death in South Australia.”

Source:http://www.news.com.au/adelaidenow/story/0,22606,25950004-5006301,00.html