C1 Inhibitor Cinryze Approved by FDA for Prophylaxis Against Hereditary Angioedema Attacks

What is Hereditary Angioedema (HAE)?

Hereditary angioedema (HAE) is an autosomal dominant condition associated with episodic attacks of nonpitting edema. HAE affects about 6-10,000 individuals in the United States. Patients with HAE have low levels of C1 inhibitor (a serine protease inhibitor). Edema is caused by unregulated generation of bradykinin.


C1 protein, showing subunits C1r, C1s, and the C1q tails. Image source: Wikipedia.


Classical and alternative complement pathways. Image source: Wikipedia.

New therapies for hereditary angioedema (HAE)

In recent years, 5 pharmaceutical companies have developed drugs which stop acute attacks of HAE or can be used for prophylaxis.

There are 2 preparations of C1 inhibitor purified from plasma which have been used in Europe for decades (Cinryze and Berinert P). There is also a recombinant C1 inhibitor (not obtained from plasma). A kallikrein inhibitor (Ecallantide) and a bradykinin type 2 receptor antagonist (Icatibant) are in testing phases. It is likely that HAE treatment will change dramatically in near future.


New therapies for hereditary angioedema (HAE).

Cinryze C1-esterase inhibitor

In October 2008, the U.S. Food and Drug Administration licensed the first product (called Cinryze) in the United States intended to protect people with hereditary angioedema (HAE).

Cinryze, a C1-esterase inhibitor product derived from human plasma, should greatly enhance treatment options for those with hereditary angioedema and potentially save lives.

C1-esterase inhibitor is low or does not function properly in individuals with HAE. Cinryze was effective in preventing or decreasing the frequency of attacks in most but not all HAE patients.

Cinryze is a highly purified, pasteurized and nanofiltered human plasma-derived C1 inhibitor. C1 inhibitor therapy has been used for more than 30 years in Europe.

Cinryze is administered intravenously and can be used every 3-4 days for routine prevention of HAE attacks. It is manufactured by Lev Pharmaceuticals Inc. in New York through a contract agreement with a Dutch company.

References:
New therapies for hereditary angioedema (HAE)
FDA Licenses for Marketing New Therapy for Rare Genetic Disease. FDA News, 10/2008.
C1 Esterase Inhibitor (Human), Product Approval Information, FDA. Package insert (PDF, 162 KB).
Drug Name: Cinryze (C1 Inhibitor (Human). CenterWatch Newly Approved Drug Therapies.
New therapies for hereditary angioedema: Disease outlook changes dramatically. Frank et al. JACI, Volume 121, Issue 1, Pages 272-280 (January 2008).
Hereditary angioedema, Supplement of Annals of Allergy, Asthma and Immunology, 01/2008.
Angioedema Due to Angiotensin Converting Enzyme Inhibitors. Allergy Cases, 01/2008.
Audio: New Therapies on Horizon for Angioedema Attacks. AAAAI, 03/2008.

HAE: annual drug cost alone for prophylactic C1 esterase inhibitor is $450k - nearly $5 mln for every decade of life http://goo.gl/BCVtu