Nearly half of HAE patients in UK on preventive treatment: Survey
Data on meds in real world may help improve care for swelling attacks
Nearly half of hereditary angioedema (HAE) patients in the U.K. are on long-term prophylactic treatment to prevent swelling attacks, with more than 80% keeping a supply of on-demand therapies at home to treat sudden flares.
That’s according to data from a new national survey that also provided information on the prevalence of the different types of HAE in the U.K, as well as on the varying treatment choices and services available to patients.
According to researchers, “this study provides information about how real-world practice compares to published management guidelines and identifies areas where care could be improved.”
“These data are useful for planning service provision and improving services for these patients,” the team wrote.
The survey findings were reported in the study, “A national survey of hereditary angioedema and acquired C1 inhibitor deficiency in the United Kingdom,” published in The Journal of Allergy and Clinical Immunology: In Practice.
Survey on treatment answered by HAE, AAE patients
Hereditary angioedema, known as HAE, is characterized by swelling episodes affecting the skin and the mucosal lining of the respiratory and digestive tracts. Tissue swelling is due to the leakage of fluid from the bloodstream, which is driven by high levels of a signaling molecule called bradykinin that normally regulates blood pressure and inflammation.
HAE types 1 and 2 are caused by mutations in the SERPING1 gene, which carries instructions for making the C1-inhibitor (C1-INH) protein. C1-INH blocks the activity of proteins that promote bradykinin production. In HAE type 1, mutations prevent C1-INH production, while in HAE type 2, a less effective form of the protein is produced.
Acquired angioedema (AAE) is another type of angioedema that causes symptoms similar to those of HAE. It occurs when C1-INH levels are too low due to a disruption of the normal function of the immune system or to an autoimmune reaction, in which the body produces antibodies targeting and destroying C1-INH.
HAE now is estimated to affect one in 50,000 people worldwide, whereas AAE is estimated to affect one in 100,000 to one in 500,000 individuals across the globe. However, “the last published data in the UK looking at epidemiology [distribution] and service provision in HAE are from 2013 and 2014,” the researchers wrote.
With the goal of obtaining more accurate data reflecting disease prevalence, treatments, and services available in the United Kingdom to HAE and AAE patients, the U.K. HAE network distributed a survey to all centers in the country following these patients.
In all, 37 centers, accounting for 90% of all facilities following HAE and AAE patients in the U.K., supplied patient data. From these, 33 (89%) provided data from a formal patient database.
A total of 1,152 patients with HAE type 1/2 were identified, as were 91 others with AAE.
Estimates indicated the minimum prevalence of HAE in the U.K. was of one case per 59,000 individuals, while that of AAE was of one case per 734,000 individuals.
Treatment for HAE and AAE can broadly be divided into on-demand treatment to treat acute swelling attacks and prophylactic treatment to prevent them.
Nearly 40% of HAE patients can not administer their own treatment
Most of the HAE patients identified (82%) kept a home supply of on-demand treatment for acute attacks, with 61% of them being able to self-administer the treatment if needed. These values were slightly lower for those with AAE, with 75% of patients maintaining a supply of acute treatment at home and 52% able to self-administer the therapy.
Overall, this “indicates that a significant percentage of patients with HAE and AAE-C1-INH (39% and 48% respectively) are not able to self-administer acute therapy, and this warrants further exploration,” the researchers wrote.
C1-INH products and icatibant (sold as Firazyr) were the most commonly used types of on-demand treatment, with both taken by approximately half of the patients.
Nearly half of those with HAE (45%) were on long-term prophylaxis, mostly with androgens — typically danazol, sold as Danocrine, and used by 55% of patients — or tranexamic acid, used by 18%. Among those with AAE, 40% reported they were on long-term prophylactic treatment, usually with androgens (47%) or tranexamic acid (47%).
Adults were more likely to be on prophylactic treatments than adolescents, who in turn were more likely to be on such therapy than were children younger than 12.
This data “provides a useful baseline prior to the availability of more modern, targeted agents becoming available in the UK, and is useful as a comparison for any future surveys,” the researchers wrote.
[The survey information] indicates that a significant percentage of patients with HAE and AAE-C1-INH (39% and 48% respectively) are not able to self-administer acute therapy, and this warrants further exploration.
In all responding centers, patients were followed by specialists in clinical immunology. Most centers were able to prescribe all approved medications, although older products were more uniformly available.
Each center also provided a summary of the available services for HAE patients. Overall, centers usually provided in-house training on therapy self-administration, and between 60% and 70% of them offered treatments through home delivery.
“This study provides more up-to-date data on demographics, treatments modalities and services available to patients with HAE and acquired C1 inhibitor deficiency in the UK,” the researchers wrote.
“It is hoped that this survey and other future efforts will help provide information and form the basis for decision making, to ultimately provide the best care for this group of patients,” the team concluded.
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