In our last class, Dr. Cohen mentioned that some anti-IgE antibodies have been tested in people with food allergies, most interestingly in people with allergies to peanuts. Peanut allergies seem to be on the rise in children in recent years, and can substantially decrease the quality of life for a person (and the families of people) with such allergies. A study published by Leung et al., in 2003 examined the effects of a humanized IgG monoclonal antibody against IgE called TNX-901. This antibody prevents IgE from binding to the Fc receptor on mast cells.
A placebo-controlled, double blind food challenge established that four subcutaneous injections (450 mg) of TNX-901 every four weeks (for a total study time of 16 weeks) raised the allergen tolerance threshold from one-half peanut to nine peanuts in subjects. While this is not enough to allow a person with peanut allergies to begin eating peanuts regularly, it is probably sufficient to prevent a deadly reaction in case of accidental exposure – and provide some peace of mind for those that must vigilantly avoid peanut exposure.
Although the results of the initial study were very promising, a legal battle over infringement rights between the drug’s maker Tanox, Inc., and Novartis and Genentech has shelved the drug indefinitely. A similar anti-IgE drug, omalizumab, is approved to treat asthma and is sometimes used off-label for those with extreme food allergies (for more on the mechanisms of this drug see Holgate et al., 2005). However, drug trials approving its use in food allergies, and thus insurance coverage for those who need it for such reasons, remain a few years off. In the end, it seems a drug that was fast-tracked because of its promising initial results has been delayed by years because of legal issues.
Holgate ST et al. (2005). Anti-immunoglobulin E treatment with omalizumab in allergic diseases: an update on anti-inflammatory activity and clinical efficacy. Clin Exp Allergy. 35(4):408-16.
Leung DY et al. (2003). Effect of anti-IgE therapy in patients with peanut allergy. N Engl J Med. 348(11):986-93.
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9 comments:
A sad commentary on health insurance and big pharma in this country. That aside, any idea how long patients would have needed to take the TNX-901? i.e., weekly for the rest of their lives?
Too true. How often it is that philanthropic pursuits get tripped up by financial snafus. The deadlock that surrounds the drug places the cost at about $1000/month (wikipedia: TNX-901). Perhaps continued development would bring the costs down, but for now, the drug is shelved. At the current price, one wonders about the cost/benefit of treatment for an off-label (i.e., uninsured) usage.
A couple neighbors of mine spent last weekend in the hospital with their 2-year-old son who had a severe reaction to peanuts. The poor kid has a lifetime of avoiding peanuts (which seems to be in so many things!) unless some of these therapies can come through for him. I immediately thought of him when I read your article.
While putting TNX-901 in stasis seems horribly cruel, remember that for every 1 promising marketed drug roughly 50-200 are aborted at some point in development, and all that work needs to be paid for somehow. That being said, this particular case seems to be more a commentary on the state of our legal system, and less about corporate greed.
In reponse to barteld7630-
According to the article, patients received a dose of anti-IgE every four weeks. Once a month might be inconvenient, but not as bad as avoiding nuts constantly.
In response to fritzj7630 -
The case could be seen both ways, but it really does seem to be all about the money. For a background article (however biased) you can check out:
THE WALL STREET JOURNAL
"Silent Treatment
How Genentech, Novartis Stifled A Promising Drug"
By DAVID P. HAMILTON
April 5, 2005
http://www.ahrp.org/infomail/05/04/05.php
This is a complicated issue. TNX-901 is a monoclonal Ab against IgE, as is Xolair (omalizumab) which Genentech owns. So immediately it became the subject of a patent infringement battle, even if Tamox wanted to test it for a different use, peanut allergy. The companies finally agreed to work together to test omalizumab in peanut-sensitive volunteers. In 2006 they halted the study because 2 placebo controls (got no Ab, but were exposed as a test to peanuts) had severe anaphylaxis. Fearing costly lawsuits (note that Merck just agreed to pay $4.85 billion for Vioxx suits) they stopped the trial and are redesigning it to not include a peanut challenge.
And that ~5 billion in Merck lawsuits is only if everyone agrees to the settlement...Merck was winning 1 in 2 cases, so it decided to settle. If the settlement offer is refused by enough plaintiffs, then it will be tossed and Merck will litigate every one. Could end up costing Merck much more than 5 billion.
In response to rachubin7630-
Everything privately funded is about money, true: but it is the legal battling that eats up years as well.
I want to have my DNA taken to the far ends of the Milkyway. Someone should order small plastic vials from the manufacturer using the green Thomas industrial catolog at the public library, look up vials /plastic. Next have someone make a kids rubber helium party baloon that is 1 inch bigger when its inflated so it goes higher in the sky. Have it made with glow in the dark stuff that shines at night. It will take two rubber baloons tied together to carry up the plastic vial taped to one of the baloons. Proceed to get poke-em lancets from the drug store to prick your finger. Now Space-Aliens flying in invisible craft in Earths skies could retrieve a drop of your blood when you release the baloons over the desert or nature park. Go ahead and dab a drop of blood onto the surface of the baloon instead if you want, then only one baloon is needed. Your baloon might be recognized by the Aliens up there. Or you might find the whole idea a bad thing. Should people who believe there is Aliens visiting our solor system send out a spacecraft way past Pluto that has a supply of fruit tree, vegetable and berry seeds so the Extra-terrestial star travellers can take it home?
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