FDA Approves Label Expansion of C1 Esterase Inhibitor for Pediatric Hereditary Angioedema Patients

This is the first and only therapy indicated in the US to help prevent angioedema attacks in pediatric patients as young as 6 years old.

Shire announced that the US Food and Drug Administration (FDA) approved a label expansion for C1 esterase inhibitor (CINRYZE) in prevention of angioedema attacks in children aged 6 years and older with hereditary angioedema.

The approval was backed on data from a phase 3 multicenter single-blind study (0624-301) that evaluated the use of CINRYZE in 12 patients 7—11 years old with hereditary angioedema.

“Symptoms of hereditary angioedema often present in childhood with the average child experiencing their first hereditary angioedema attack around the age of 10,” Andreas Busch, PhD, executive vice president, head of research and development, Shire, said in a statement. “With the FDA label expansion of CINRYZE, children as young as 6 years old living with hereditary angioedema now have the first FDA approved treatment option available to help prevent attacks.”

The patients enrolled in the study were required to have an average of ≥1.0 angioedema attacks per month that were moderate, severe, or required acute treatment during the 12-week baseline observation period. Patients received 500 U and 1000 U of CINRYZE every 3—4 days for 12 weeks.

Primary efficacy endpoint of the trial was monthly-normalized number of attacks. Compared with the baseline period, the mean reduction in normalized number of attacks for patients taking 500 U and 1000 U was 71.1% and 84.5%, respectively. The doses lessened the severity of attacks and reduced the use of acute treatment compared to baseline.

The overall safety and tolerability of CINRYZE in similar in clinical studies of pediatric, adolescent and adult patients. Adverse effects included headache, nausea, pyrexia and infusion site erythema, however, none of the effects led to discontinuation of the study.

The active substance in CINRYZE raises plasma levels of C1-INH in patients with hereditary angioedema who are prone to swelling due to an underlying deficiency, in which case treatment addresses the underlying cause and replaces the deficient protein to regulate the production of bradykinin released during an attack.

CINRYZE has been approved in the US for routine prophylaxis against attacks in adolescents and adults living with hereditary angioedema since October 2008.