Trends in treatment in Swedish patients with hereditary angioedema
Published: December 14, 2022
Hereditary angioedema (HAE) is caused by low levels of, or defective function of, C1inhibitor (C1-INH), which leads to dysregulation of plasma kallikrein, an enzyme that generates bradykinin from high molecular weight kininogen. Activation of the bradykinin type B2 receptor results in typical manifestations of HAE with swellings in the face and limbs, gastrointestinal angioedema, and sometimes laryngeal edema. Considering the impact of the disease on a patient´s quality of life, there is a need for efficient long-term prophylaxis (LTP), as well as emergency medications for the treatment of HAE.
In a nationwide retrospective study recently published in The Journal of Allergy and Clinical Immunology: In Practice, Sundler Björkman and colleagues investigated rates and patterns of prescribed drugs for the LTP and emergency treatment of HAE, as well as drugs that may interfere with HAE disease control, in Sweden.
The study was based on a cohort of 239 individuals with HAE type 1 and 2. Data were collected from the Prescribed Drug Register from July 2005 to the end of 2019. The Prescribed Drug Register registers all prescriptions of pharmaceutical drugs both in primary and secondary care. Data on dispensed prescriptions were measured.
This study shows a usage of LTP in about 50% of HAE patients. The most striking findings were the high use of attenuated androgens, in approximately 10% of HAE patients, despite concerns regarding side effects. The use remained unchanged during the time-period investigated in this study. About 30% of patients use C1-INH as LTP, and there is an increasing use of C1-INH as LTP in certain patient subgroups. Tranexamic acid remains an important agent for LTP in HAE in Sweden, used by approximately 10% of patients, particularly in children and young adults. The usage of the emergency medication icatibant (B2 receptor antagonist) was introduced in 2010 in Sweden. By 2019 icatibant was collected by half of the patient population. A higher rate of dispensed prescriptions of icatibant was most notable among women aged 20 years or older with a decline after menopause, implying a higher HAE attack frequency in young women because of higher estrogen levels.
Currently the LTP of HAE is on the threshold of a paradigm shift. Both orally administered small-molecule compound inhibitors and subcutaneously administered monoclonal antibodies against plasma kallikrein were recently introduced. It will be important to follow how these novel pharmaceuticals will affect current treatment strategies and the need for emergency medications in HAE.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.