Firazyr Lowers Attack Duration, But Increases Healthcare Costs in Angioedema Patients

Patients with hereditary angioedema caused by deficiencies in the complement C1-inhibitor protein experience symptomatic relief and remission with the use of on-demand treatments, according to an Italian study.

Firazyr (icatibant), an agonist of the bradykinin receptor, led to reduced attack durations compared to plasma derived C1-inhibitor treatments. But the treatment also was more expensive, significantly increasing healthcare costs.

This study, “Costs and effects of on-demand treatment of hereditary angioedema in Italy: a prospective cohort study of 167 patients,” was published in the journal BMJ Open.

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. So, timely treatment can help manage the condition and improve the patient’s quality of life.

To date, little is known about symptom reoccurrences, the impact and influence of treatment on swelling episodes, and the costs associated with on-demand interventions.

The Italian researchers evaluated the effectiveness and costs of two on-demand treatments — Firazyr and plasma-derived C1-inhibitors like Berinert and Cinryze — in patients with hereditary angioedema.

The study included a total of 167 patients, with a mean age of 43 years. Participants were recruited from the Milan angioedema center and studied through the course of a year. Patient information on angioedema attacks, medications, usefulness of treatments, and visits to the hospitals were evaluated.

A significant proportion of patients (79.6%) experienced angioedema attacks during the one-year follow-up. Overall, 1,508 attacks were reported, amounting to a mean of 11 attacks per person per year.

However, researchers reported that only 78.9% of the attacks received any treatment. In total, 704 attacks were treated with plasma-derived C1-inhibitors, 486 received Firazyr, and 318 were left untreated.

The median time an attack lasted after its onset was significantly shorter if a patient received treatment. Indeed, while untreated patients had a median attack duration of 47 hours, the attacks only lasted seven and 10 hours for those taking Firazyr or plasma derived C1-inhibitors, respectively.

Researchers attribute the faster remission rates with Firazyr to the dose variability seen in patients taking plasma-derived C1-inhibitors.

Despite being more effective than plasma-derived C1-inhibitors, Firazyr also was 54% more expensive, the team reported. The average cost per attack was €1,183 (about $1,350), amounting to €11 912 (about  $13,592) per year per patient.

“The results presented in this study may be used to populate future economic evaluations to inform decision-making on both prophylactic [preventive] and [on-demand treatments],” the researchers wrote.

“Further research is needed to understand the role played by treatment behaviors and specifically suboptimal dosing of [plasma-derived C1-inhibitors],” they added.