Treatment Effect and Safety of Icatibant in Pediatric Patients with Hereditary Angioedema.

BACKGROUND

Clinical manifestations of hereditary angioedema with C1 inhibitor deficiency (C1-INH-HAE) usually begin in childhood, often intensifying during puberty. Currently there are insufficient efficacy/safety data for HAE therapies in children and adolescents due to the small number of pediatric patients enrolled in studies.

OBJECTIVE

The objective of this phase 3 study was to evaluate the efficacy/safety of a single subcutaneous dose of icatibant (0.4 mg/kg; maximum 30 mg) in pediatric patients with C1-INH-HAE.

METHODS

Patients aged 2 years to younger than 18 years were categorized as prepubertal (children) and pubertal/postpubertal (adolescents). The primary end point was time to onset of symptom relief-earliest time posttreatment to 20% or more improvement in composite symptom score.

RESULTS

Thirty-two patients received icatibant (safety population: 11 children with attack, 10 adolescents without attack, and 11 adolescents with attack). The efficacy population consisted of 11 children and 11 adolescents with edematous attacks. Most attacks in the efficacy population (16 [72.7%]) were cutaneous, 5 (22.7%) were abdominal, and 1 (4.5%) was both cutaneous and abdominal; none was laryngeal. Overall, the median time to onset of symptom relief was 1.0 hour, the same for children and adolescents. Thirty-two treatment-emergent adverse events (all mild or moderate) occurred in 9 (28.1%) patients. Gastrointestinal symptoms were most common (9 events in 3 [9.4%] patients). Injection-site reactions affected most (90.6%) patients (particularly erythema and swelling), but almost all resolved by 6 hours postdose. Icatibant demonstrated a monophasic plasma concentration-time profile. Time to peak concentration was approximately 0.5 hours postdose.

CONCLUSIONS

Symptom relief was rapid, and a single icatibant injection in pediatric patients with C1-INH-HAE was well tolerated (ClinicalTrials.gov identifier, NCT01386658).