FDA Approves C1 Esterase Inhibitor Label Expansion for Prevention of Pediatric HAE Attacks

This morning, June 21, 2018, Shire plc announced that the US Food and Drug Administration (FDA) approved a label expansion for C1 esterase inhibitor [human] (CINRYZE) as a preventative measure for pediatric angioedema attacks in children aged 6 years and older with hereditary angioedema (HAE).

C1 esterase inhibitor is a treatment that increases the plasma levels of C1-INH of HAE patients who, due to an underlying deficiency in C1-INH, are susceptible to swelling. By replacing the deficient protein, C1-INH addresses the underlying cause and helps regulate the production of bradykinin released during an attack.

HAE is a rare genetic disorder characterized by recurring, debilitating, and painful attacks of edema (swelling) in various parts of the body, including the abdomen, face, feet, genitals, hands, and throat. Attacks can also be potentially life-threatening due to the risk of asphyxiation.

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

Data from a dedicated phase 3 multicenter single-blind study (0624-301) that evaluated the use of C1 esterase inhibitor in 12 patients living with HAE aged 7 to 11 served as the basis for the approval.

Inclusion criteria for trial participation included 12 patients aged 7 to 11 with HAE who 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. For 12 weeks, patients were administered 500 U and 1000 U of C1 esterase inhibitor every 3-4 days. Monthly normalized number of attacks served as the primary efficacy endpoint.

Compared with other clinical studies of pediatric, adolescent, and adult patients with HAE, the overall safety and tolerability of C1 esterase inhibitor proved to be similar in nature.

Respectively, 71.1% and 84.5% composed the mean reduction in the normalized number of attacks for C1 esterase inhibitor 500 U and C1 esterase inhibitor 1,000 U. In addition, the severity of attacks and the use of acute treatment were diminished with both doses as compared with baseline.

“This news is exciting for the HAE community because those living with HAE who are as young as 6 have a new option to help prevent attacks,” stated Anthony Castaldo, president of the US Hereditary Angioedema Association, in a recent statement.

Previously, C1 esterase inhibitor was granted approval for the label expansion by European Commission (EC) for 3 new indications that included routine prevention of angioedema attacks in children ages 6 years and over with severe and recurrent attacks of HAE.