Patients in Germany treat acute hereditary angioedema attacks with Firazyr (icatibant) earlier and have fewer severe attacks than do patients in 11 other countries where Firazyr is also approved, a retrospective study shows.
The disparity is thought to arise from a easier access to Firazyr in Germany and a public healthcare system that provide 100% reimbursement, investigators said.
The study, “Management of patients with hereditary angioedema in Germany: comparison to other countries in the Icatibant Outcome Survey,” was published in the Journal of The European Academy of Dermatology and Venereology.
The most common type of hereditary angioedema (HAE) is the one resulting from a genetic defect in the C1 protein inhibitor (C1-INH). Loss of this protein causes rising levels of bradykinin, a vasodilator that triggers blood vessels to widen and become more permeable, leading to swelling. Timely treatment can help manage the condition and improve the patient’s quality of life.
Firazyr, an inhibitor of bradykinin marketed by Shire Pharmaceuticals, is approved for self-administration in HAE-C1-INH patients experiencing acute angioedema attacks, based on results of clinical trials that include a Phase 3b open-label study (NCT01919801).
An international registry study — called Icatibant Outcome Survey (IOS; NCT01034969) — opened in 2009 to monitor clinical outcomes of patients treated with Firazyr. It demonstrated that Firazyr works as well in a real-world setting as in clinical trials, leading to an early resolution of attacks.
A country-specific analysis of IOS also suggested that German patients treat their attacks earlier than those elsewhere. Researchers in Germany decided to compare the demographics and outcomes of German patients versus patients in other IOS countries.
This was the “first report, using real-world IOS data, detailing the experience in Germany with icatibant for the acute treatment of HAE in adults and subsequent comparison with other IOS countries,” the researchers wrote.
Using IOS data from July 2009 to January 2017, researchers gathered information on 160 attacks in 93 German patients, and 1,442 attacks in 592 patients from 11 other IOS countries –Austria, Brazil, Czech Republic, Denmark, France, Greece, Israel, Italy, Spain, Sweden, and the United Kingdom. (Firazyr is also approved in the U.S. to treat acute attacks of hereditary angioedema in adults.)
Analysis of demographic and baseline characteristics — sex, diagnosis, and location of attacks — showed no significant differences between the patients in Germany and elsewhere.
Still, the researchers reported, German patients were significantly less likely to report severe or very severe angioedema attacks compared to those in other countries.
No significant differences were seen in the number of Firazyr-treated attacks among patients, and, consistent with previous studies, most patients in this study self-administered treatment for an attacks, regardless of country.
There also was no significant difference in speed in which attacks were acknowledged among patients from different countries.
But investigators found that German patients treated their attacks with Firazyr significantly earlier than patients in other countries, with mean time from attack to onset of treatment being 1.3 hours in German patients and 4.2 hours in those elsewhere.
The time to complete symptom resolution (7.6 hours vs. 15.1 hours) and duration of attacks (8.9 hours vs. 19.3 hours) were also shorter in German patients compared to the other patients.
These findings “affirm German patient awareness and acceptance of physician recommendations … that promote treatment as early as possible,” along with a high patient confidence in managing their disease, the researchers wrote.
They also pointed to the high reimbursement level in Germany and easy access to Firazyr as possible explanations for early treatment in these patients. In the 11 other countries, “icatibant may be more difficult to obtain and doses perhaps retained for treatment of attacks that are deemed more severe,” the researchers concluded.
Two of the study’s seven researchers are employees of Shire at its Switzerland international office headquarters.