LONG-TERM EFFICACY OF SUBCUTANEOUS C1 INHIBITOR IN PEDIATRIC PATIENTS WITH HEREDITARY ANGIOEDEMA

Abstract

Introduction Hereditary angioedema (HAE) due to C1-inhibitor (C1-INH) deficiency is characterized by symptom onset in childhood, with earlier onset associated with a more severe disease course. Subcutaneous (SC) C1-INH is indicated for routine prophylaxis to prevent HAE attacks in adolescents and adults. We analyzed the long-term efficacy of C1-INH (SC) in pediatric patients treated in an open-label extension (OLE) of the phase III COMPACT trial. Methods Patients (age ≥6 years with ≥4 attacks over 2 consecutive months) were treated with C1-INH (SC) twice weekly for up to 140 weeks (52 plus up to 88 additional weeks). Subgroup analyses by age (≤17 vs >17 years) were performed for the percentage of responders (≥50% reduction in attacks relative to pre-study period), percentage of patients with Results Ten patients were ≤17 years old (mean [range] age, 13.3 [8-16] years; 40% female; range of exposure, 51 to 133 weeks; mean BMI, 23.4 kg/m2). All (100%) were responders (vs 91% of patients >17 years) and had 17 years). The median number of HAE attacks per month was similar in patients ≤17 years and >17 years (0.11 vs 0.09). No pediatric patients discontinued treatment due to a related adverse event. Conclusions Data from pediatric patients treated with C1-INH (SC) for ≥1 year did not reveal any efficacy differences relative to adult patients. C1-INH (SC) is effective and well tolerated in children and adolescents with HAE.