Haegarda prophylaxis reduces HAE attacks, improves quality of life
Real-world study included 36 adults who'd used on-demand therapy for a year
Long-term preventive treatment with Haegarda reduced the number and severity of attacks and the use of rescue medications in people with hereditary angioedema (HAE), while improving their quality of life, a recent study has found.
“These real-world findings indicate that long-term prophylaxis with [Haegarda] markedly improves important factors that contribute to the goal of achieving total disease control and normalization of patients’ lives,” the researchers wrote in “Patient outcomes associated with subcutaneous C1INH prophylaxis for hereditary angioedema: a retrospective analysis,” which was published in Allergy, Asthma & Clinical Immunology.
HAE is a form of angioedema that features recurrent swelling attacks that affect the deeper layers of the skin. Attacks may also occur in the mucosal linings of the respiratory and digestive tracts.
The disease is commonly caused by mutations that lower the production and/or function of the C1 esterase inhibitor (C1-INH) protein, causing levels of the signaling molecule bradykinin to rise. Bradykinin promotes blood vessel widening, allowing fluid to flow from the bloodstream into surrounding tissues, causing swelling.
Preventing swelling attacks is a cornerstone of HAE management and disease control. This is usually achieved by resorting to long-term prophylaxis, or preventive treatment, with medications that restore C1-INH levels, such as Haegarda, which provides patients with a version of C1-INH via a subcutaneous (under-the-skin) injection.
Effects of Haegarda preventive treatment
However, “real-world data on subcutaneous C1INH … usage and patient-level impacts on [HAE]-related outcomes and quality of life … are both lacking and challenging to generate,” wrote researchers in the U.S. who conducted a real-world retrospective study of 36 adults with HAE on long-term prophylaxis with Haegarda after being on on-demand therapy for at least a year to treat HAE attacks.
The patients had a mean age of 47.9 and most were white (89%) and female (64%). Almost all had HAE type 1, meaning the mutations they harbored lowered C1-INH production. Most had a family history of HAE (81%).
The study featured both patient interviews and a review of their medical data, which encompassed the year before Haegarda’s prescription, the patients’ visits when the treatment was prescribed, and the year after it was started.
Most of the patients (75%) were given Haegarda about twice weekly at an initial dose of 60 international units per kilogram of body weight (IU/kg). Five were given it at 40 IU/kg (14%), and four were given different doses.
Data gathered from interviews indicated patients’ mean annualized attack frequency decreased by 80.2% from a mean of 38.9 attacks a year before treatment with Haegarda to 7.7 attacks after starting it. For 20 patients, the annualized attack rate after starting Haegarda was one or fewer attacks a year. Twelve reported no attacks.
Mean attack severity also fell significantly after treatment, from 2.3 to 0.9, based on a scale from 0 (none/mild attacks) to 4 (very severe attacks).
A supporting analysis of medical data confirmed the decrease in the mean number of attacks a year, which dropped from 35 before treatment to 4.7 after it started. Attack severity could not be analyzed in the medical records because there wasn’t enough patients with available data.
Based on interviews with 34 patients, the use of rescue on-demand medications to treat HAE attacks fell by 77.2% after the prophylaxis was started — from 25.4 uses per patient a year to 5.4.
These results “were of a similar magnitude to findings reported in the COMPACT phase 3 clinical study of [Haegarda],” the researchers said.
Patients reported a high burden of HAE in their quality of life, with 75% to 89% reporting negative impacts in multiple facets of life quality.
With Haegarda, they described improvements in several quality of life domains, including emotional functioning/mental health (67%), social life/relationships (58%), daily activities (44%), work or school (39%), and physical activities (22%).
Although the study didn’t assess adherence to treatment, the researchers assumed that it should be reasonable considering the reported positive outcomes. “These are all important factors contributing to the ultimate goal of achieving total disease control and normalization of patients’ lives,” they wrote.
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