Inhalable insulin

Inhalable insulin was available from September 2006 to October 2007 in the United States as a new method of delivering insulin, a drug used in the treatment of diabetes, to the body. After the withdrawal of the only inhalable formulation, all currently available insulin formulations are administered by subcutaneous or intravenous injection. cite news |author=Justin Gillis |title=Inhaled Form of Insulin Is Approved |url=http://pqasb.pqarchiver.com/washingtonpost/access/977402861.html?dids=977402861:977402861&FMT=ABS&FMTS=ABS:FT&fmac=&date=Jan+28%2C+2006&author=Justin+Gillis&desc=Inhaled+Form+of+Insulin+Is+Approved |date=January 28, 2006 | publisher=The Washington Post |accessdate=2007-10-21]

The first such product to be marketed was Exubera, a powdered form of recombinant human insulin, delivered through an inhaler into the lungs where it is absorbed. cite web | title=FDA Approves First Ever Inhaled Insulin Combination Product for Treatment of Diabetes | url=http://www.fda.gov/bbs/topics/news/2006/NEW01304.html | work=News | date=January 27, 2006 | publisher=FDA] [cite web |title=Exubera |url=http://www.nektar.com/wt/page/how_it_works_2 |date= |publisher=Nektar |accessdate=] cite web |title=How Exubera works |url=http://www.exubera.com/content/how_works.jsp |date= |publisher=Pfizer |accessdate=2007-10-21] Once it has been absorbed, it begins working within the body over the next few hours. Diabetics still need to take a longer acting basal insulin by injection. cite news | title=Diabetes inhaler rejected for NHS - Insulin that can be inhaled rather than injected has been rejected by NHS advisers on grounds of cost | url=http://news.bbc.co.uk/1/hi/health/4919802.stm | date=19 April 2006 | publisher=BBC News - cost of £1,100 per person per year.]

A systematic review concluded that inhaled insulin "appears to be as effective, but no better than injected short-acting insulin. The additional cost is so much more that it is unlikely to be cost-effective." cite journal |author=Black C, Cummins E, Royle P, Philip S, Waugh N |title=The clinical effectiveness and cost-effectiveness of inhaled insulin in diabetes mellitus: a systematic review and economic evaluation |journal=Health technology assessment (Winchester, England) |volume=11 |issue=33 |pages=1–126 |year=2007 |pmid=17767897 |doi=] In October 2007, Pfizer announced that it would be discontinuing the production and sale of Exubera due to poor sales. cite news|author=John Simons|title=How the Exubera debacle hurts Pfizer |url=http://money.cnn.com/2007/10/19/magazines/fortune/simons_pfizer_erbitux.fortune/index.htm?postversion=2007101916 |date=19 October 2007 |publisher=CNNMoney |accessdate=2007-10-21] Several other companies are developing inhaled forms of the drug to reduce the need for daily injections among diabetics.

History

Insulin was introduced by Banting and Best in 1921 as an injectable agent. German researchers first introduced the idea of inhalable insulin in 1924. Years of failure followed until scientists realized they might be able to use new technologies to turn insulin into a concentrated powder with particles sized for inhalation.

This technology was developed so that the inhaled insulin can effectively reach the lung capillaries where it is absorbed. [cite web| title=Inhalational Insulin Therapy |url=http://insulin-news.com/inhalable-insulin.asp |year=2005 |publisher=Insulin News.com |accessdate=2007-10-22] Nektar Therapeutics of San Carlos, California developed this technology that paved the way for pharmaceutical companies to begin testing and formulating inhalable insulin. Once concrete methods were developed, human tests began in the late 1990s. In January 2006, the FDA approved the use of Exubera which is a form of inhalable insulin developed by Pfizer. cite web | title=FDA Approves First Ever Inhaled Insulin Combination Product for Treatment of Diabetes | url=http://www.fda.gov/bbs/topics/news/2006/NEW01304.html | work=News | date=January 27, 2006 | publisher=FDA]

Approval and competing drug development

"Exubera" is the brand name of first formulation of inhalable insulin to receive the US Food and Drug Administration (FDA) approval. cite web | title=FDA Approves First Ever Inhaled Insulin Combination Product for Treatment of Diabetes | url=http://www.fda.gov/bbs/topics/news/2006/NEW01304.html | work=News | date=January 27, 2006 | publisher=FDA] It is manufactured by Pfizer in collaboration with Nektar Therapeutics and is licensed for use by both type 1 and type 2 diabetics. However in the UK its use in under the National Health Service "should not be recommended because it could not be proven to be more clinically or cost effective than existing treatments", cite news | title=Diabetes inhaler rejected for NHS - Insulin that can be inhaled rather than injected has been rejected by NHS advisers on grounds of cost | url=http://news.bbc.co.uk/1/hi/health/4919802.stm | date=19 April 2006 | publisher=BBC News - cost of £1,100 per person per year.] except under special circumstances. [cite web |title=Diabetes (type 1 and 2), Inhaled Insulin - Final Appraisal Determination | url=http://www.nice.org.uk/download.aspx?o=372014&template=download.aspx | format=PDF | date=12 October 2006 | publisher=National Institute for Health and Clinical Excellence | accessdate=2006-11-21] In April 2006, the UK's National Institute for Health and Clinical Excellence issued a preliminary statement advising against the use of inhalable insulin on the grounds that the benefits of avoiding injections did not justify the higher cost of the new product. At that time, NICE recommended use of the new drug only in clinical trials. [cite web |title=Diabetes (type 1 and 2), Inhaled Insulin - Appraisal consultation document |url=http://www.nice.org.uk/page.aspx?o=305465 |month=April | year=2006 |publisher=National Institute for Health and Clinical Excellence |accessdate=2007-10-22]

Concerns have been expressed by the Institute for Safe Medication Practices about a serious risk of dosing errors when prescribing Exubera. [cite journal | author=Institute for Safe Medication Practices | title=Insulin dosed in mg? A set up for errors! | journal=Medication Safety Alert | month=July | year=2006 | url=http://www.ismp.org/Newsletters/ambulatory/archives/200607_1.asp] Insulin is traditionally prescribed in international units, but Exubera is prescribed in milligrams. 1 mg of Exubera is equivalent to 3 units of insulin, however, the increment is not linear: 3 mg of Exubera is equivalent to 8 units of insulin and not 9 units as might be expected, and the prescriber is strongly advised to refer to the manufacturer's conversion table before prescribing. Furthermore, because of retention of blister contents, three consecutive doses of 1mg blisters of Exubera results in a higher dose of insulin than a single 3mg blister of Exubera, further complicating prescribing calculations.

Exubera is considered a short or rapid acting insulin. In clinical studies, Exubera reached peak concentration levels faster than some insulins administered by injection.Thus, this form of insulin would begin working within the body faster than insulin that is injected. Type 1 and 2 diabetics will still need an injection of longer acting insulin to maintain a basal level for a 24 hour period.

As of October 18, 2007, Pfizer has announced that it will no longer manufacture or market Exubera. According to Chairman and CEO Jeffrey Kindler this is because Exubera "failed to gain acceptance among patients and physicians." cite news|author=John Simons|title=How the Exubera debacle hurts Pfizer |url=http://money.cnn.com/2007/10/19/magazines/fortune/simons_pfizer_erbitux.fortune/index.htm?postversion=2007101916 |date=19 October 2007 |publisher=CNNMoney |accessdate=2007-10-21]

At the time of Exubera's discontinuation, several other companies were pursuing inhaled insulin including Alkermes working with Eli Lilly and Company, [cite news |title=Alkermes Inc. AIR Inhaled Insulin System Human insulin inhalation powder Began Phase III trial to evaluate effectiveness in improving glucose control vs. injected premeal insulin in 400 patients 4/06 Type II diabetes |url=http://www.bioworld.com/servlet/com.accumedia.web.Dispatcher?forceid=413&next=bioWorldPhaseIII_searchDetails&search=1&htsid=0&htmax=1 |date=January 1, 2007 |publisher=Bioworld Today |accessdate=2007-10-22]
MannKind Corporation, [cite web |title=Technosphere Insulin - How it works | url=http://www.mannkindcorp.com/how-technosphere-work.aspx |year=2007 |publisher=MannKind Corp| accessdate=2007-10-22] , [ [http://www.nytimes.com/2007/11/16/business/16mannkind.html?ex=1352955600&en=d236cde029038835&ei=5088 Betting an Estate on Inhaled Insulin - New York Times ] ] and [http://www.aradigm.com Aradigm] working with Novo Nordisk. However, by March 2008, all of these products had been discontinued except for MannKind’s Technosphere Insulin (TI). [Lilly/Alkermes—RIP, AIR Insulin, Close Concerns, Inc. Company Watch, Diabetes Close Up #78, www.diabetescloseup.com, ]

Lung cancer concerns

On April 9, 2008, Pfizer announced in its "Dear Dr." letter that Exubera may have been associated with lung cancer: of the 4,740 patients who used Exubera in clinical trials, six have developed lung cancer as of April 2008, compared to only one of the 4,292 patients in the placebo group. The association was not statistically significant, and Pfizer maintained in its letter that "Exubera remains a safe and effective medication."

In a letter 18 June 2008, Pfizer informed UK doctors of the above mentioned six cases, noting that they all had a prior history of cigarette smoking and that they were planning to investigate further the "observed imbalance in diagnosed lung cases" with an international observational trial. Pfizer's letter also stated that Nektar had stopped searching for a new marketing partner and therefore Pfizer would withdraw its Marketing Authorisation around September 2008.

Pfizer patent infringement lawsuit

Novo Nordisk, a Danish diabetes pharmaceutical company, filed suit against Pfizer on August 1, 2006, claiming patent infringement. [cite news | author=Tom Neilson | title=Novo Nordisk sues Pfizer over Exubera patents | url=http://www.pharmaceutical-business-review.com/article_news.asp?guid=0BFEFD7E-2373-4ED8-B7FD-2513D2E7EAAB | date=4 August 2006 | publisher=Pharmaceurtical Business Review | accessdate=2006-11-21] [cite web | title=Novo-Nordisk A/S v. Pfizer, Inc. Exubera Patent Lawsuit | url=http://www.exubera-risks.com/druglitigation/novopfizer80106patentcmp.html | date=August 1, 2006 | accessdate=2006-11-21] [http://www.exubera-risks.com/druglitigation/novopfizer80106patentcmp.html The lawsuit] seeks both compensatory damages and injunctive relief. Novo sought a preliminary injunction preventing the release of Pfizer's planned September 2006 launch of the diabetes drug. A federal judge, however, delayed any decision on Novo Nordisk's request for injunctive relief until at least December 4, 2006 when a court hearing is scheduled in the case. [cite news | author=Peter Loftus | title=Pfizer-Novo Nordisk patent hearing set for December | date=August 10, 2006 | publisher=MarketWatch, Dow Jones | accessdate=2006-11-21 | url=http://www.marketwatch.com/News/Story/Story.aspx?dist=newsfinder&siteid=google&guid=%7B593CCD8E%2DDE10%2D451B%2DB1CC%2DDC5B00F09F62%7D&link=&keyword=exubera] [http://www.exubera-risks.com//druglitigation/novopfizer82206answer.html Pfizer's answer] contends that Novo wants to deny diabetics access to Exubera, the only FDA approved inhaled insulin, and interfere with the company's pharmaceutical business. [cite web | title=Novo-Nordisk A/S v. Pfizer, Inc. Exubera Patent Lawsuit: Pfizer’s Answer | url=http://www.exubera-risks.com//druglitigation/novopfizer82206answer.html | date=August 22, 2006 | accessdate=2006-11-21]

On December 14, 2006 a federal [http://www.exubera-risks.com/druglitigation/novopfizer121406ord.html judge denied Novo Nordisk's request] for a preliminary injunction to halt sales of Pfizer's inhaled insulin. [cite news | author=Chad Bray | title=Judge denies motion to block sale of Pfizer's Exubera | date=December 14, 2006 | publisher=MarketWatch, Dow Jones | accessdate=2006-12-14 | url=http://www.marketwatch.com/News/Story/Story.aspx?dist=newsfinder&siteid=google&guid=%7B593CCD8E%2DDE10%2D451B%2DB1CC%2DDC5B00F09F62%7D&link=&keyword=exubera] The [http://www.exubera-risks.com/druglitigation/novopfizer80106patentcmp.html patent lawsuit] , however, has not been dismissed, and [http://www.exubera-risks.com//druglitigation/novopfizer82206answer.html Pfizer's legal defenses] are preserved. The pharmaceutical companies are still litigating in court over their respective inhaled insulin patent claims, a process that could take some time to resolve.

References

* [http://www.exubera-risks.com/ Exubera Risks] -- News and resources on reported and suspected risks of inhaled insulin therapy
* [http://www.myafresa.com/ Inhaled Insulin] -- Inhaled Insulin unbiased patient site.
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Footnotes