Box 1 | Market for hereditary angioedema

Analysing the market for drugs for hereditary angioedema is Uma Yasothan, IMS Health, London, UK.

It is estimated that 1 in 50,000 people are affected by hereditary angioedema (HAE), a rare genetic disease for which treatment of acute attacks and prophylaxis, long and short term, is needed². There are no approved treatments yet in the United States for this orphan disorder, although in Europe, plasma-derived C1 esterase inhibitor (C1INH) infusions have been used for many years. In 2007, worldwide sales of purified C1INH were US$1.5 million¹³, with the class showing a 3.5% growth over the previous year.

Icatibant (Firazyr; Jerini), a subcutaneous bradykinin B₂ receptor antagonist, received European approval in July 2008 for the treatment of acute attacks of HAE (with C1INH deficiency) and is anticipated to be available in the market in the third quarter of 2008. Icatibant received a non-approvable letter from the US FDA for this indication in April 2008, and the regulatory situation surrounding potential US approval is not clear at present. Bearing in mind that the drug would launch into the acute HAE market, with a potential for self-administration, analyst estimates for peak sales of icatibant range from $213 million by 2014 globally¹⁴ to $100 million¹⁵ for Europe alone.

In August 2008, UK-based Shire acquired Jerini, which could provide the marketing boost needed for an orphan drug such as icatibant. Icatibant is also in clinical trials for drug-induced angioedema, capillary leak syndromes and other inflammatory disorders, which if all approved could significantly expand its market potential. However, possible competitors for icatibant are also in late-stage development, including Pharming's recombinant C1INH, and a kallikrein inhibitor, ecallantide (Dyax), which is also administered subcutaneously.