Effective long-term prophylaxis with lanadelumab in adolescents with hereditary angioedema: EMPOWER/ENABLE

Symptoms of hereditary angioedema (HAE) typically first present during childhood, but the frequency/severity of attacks often increases at puberty. Real-world data on long-term HAE prophylaxis in adolescents are limited. We report pooled data from adolescent patients enrolled in two Phase 4 studies (EMPOWER, ENABLE) evaluating the effectiveness/safety of lanadelumab (monoclonal antibody directed against plasma kallikrein) for the prevention of HAE attacks.

Adolescent patients (aged 12 to <18 years) with HAE-C1INH enrolled in EMPOWER and ENABLE received open-label lanadelumab 300 mg once every 2 weeks. Effectiveness outcomes were based on patient-reported assessments of on-treatment HAE attacks. Safety was assessed through the recording of treatment-emergent adverse events (TEAEs) and serious adverse events. This analysis categorized patients as "new" or "established" lanadelumab patients.

Thirteen new and seven established patients on lanadelumab were included. The observed monthly attack rate in new patients fell from 3.8 (mean) and 2.8 (median) during the pre-enrollment period to 0.65 (mean) and 0.21 (median) during the cumulative study period after lanadelumab initiation (84.2% and 92.9% reductions, respectively). In established patients, mean (SD) HAE attack rate (as treated) during the overall study period was 0.04 (0.03) attacks/month. Most HAE attacks were of mild/moderate severity. Nine new patients reported 42 TEAEs, mostly mild/moderate in severity, with 3 TEAEs reported as serious. Seven established patients reported 12 TEAEs (all mild/moderate and non-serious). No TEAEs were related to lanadelumab.

These data support lanadelumab's effectiveness/safety in adolescents with HAE, consistent with results from Phase 3 lanadelumab studies in mixed adult/adolescent populations.

NCT03845400 (EMPOWER) and NCT04130191 (ENABLE).