The Food and Drug Administration (FDA) has expanded the indication for Haegarda® (C1 esterase inhibitor [human]; CSL Behring) to include routine prophylaxis to prevent hereditary angioedema (HAE) attacks in patients 6 years of age and older. Previously, the treatment was indicated for patients 12 years of age and older.

Haegarda is a human plasma-derived, purified, pasteurized, lyophilized concentrate of C1 esterase inhibitor (C1-INH) that is prepared from large pools of human plasma from US donors. The subcutaneous formulation allows for self-injection at home by the patient or caregiver after receiving proper training. Haegarda works by replacing deficient or dysfunctional natural C1-INH, restoring functional levels above >40% of normal levels. 

The expanded approval was based on data from the pivotal phase 3 COMPACT study and the COMPACT open-label extension (OLE) study that assessed the efficacy and safety of Haegarda in patients with symptomatic HAE type I or II. The randomized, double-blind, placebo-controlled COMPACT study included 6 patients 17 years of age or younger. Findings from the study showed that patients treated with Haegarda had a reduction in the number of HAE attacks by a median of 95% relative to placebo. Moreover, the use of rescue medication was reduced by a median of greater than 99% compared with placebo.

The COMPACT OLE study included a total of 126 patients aged 6 years and older, of which 9 patients were 17 years of age or younger. Results showed that all 9 patients had a 50% or greater reduction in the number of HAE attacks per month compared with the pre-study period, with a median of 97% reduction in the median number of attacks per month. All patients had less than 1 attack during a 4-week period, 4 patients had less than 1 attack throughout a year, and 1 patient was attack free.

In addition to the expanded pediatric indication, the prescribing information has been updated to include data from 4 patients who became pregnant during the COMPACT OLE study and received treatment until pregnancy was identified. Patients ranging in age from 19 to 32 years received Haegarda for 4 to 8 weeks during the first trimester. There were no reported complications during delivery and all women delivered healthy babies.

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Haegarda is available as a lyophilized powder in single-dose vials containing 2000 or 3000 IU.

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  1. US Food and Drug Administration approves Haegarda® (C1 esterase inhibitor subcutaneous [human]) for prevention of hereditary angioedema (HAE) attacks in pediatric patients. Accessed September 29, 2020. 
  2. Haegarda [package insert]. Kankakee, IL: CSL Behring LLC; 2020.