Long‐term prevention of hereditary angioedema attacks with lanadelumab: The HELP OLE Study

BACKGROUND: The aim was to evaluate long‐term effectiveness and safety of lanadelumab in patients ≥12 y old with hereditary angioedema (HAE) 1/2 (NCT02741596). METHODS: Rollover patients completing the HELP Study and continuing into HELP OLE received one lanadelumab 300 mg dose until first attack (dose‐and‐wait period), then 300 mg q2wks (regular dosing stage). Nonrollovers (newly enrolled) received lanadelumab 300 mg q2wks from day 0. Baseline attack rate for rollovers: ≥1 attack/4 weeks (based on run‐in period attack rate during HELP Study); for nonrollovers: historical attack rate ≥1 attack/12 weeks. The planned treatment period was 33 months. RESULTS: 212 patients participated (109 rollovers, 103 nonrollovers); 81.6% completed ≥30 months on study (mean [SD], 29.6 [8.2] months). Lanadelumab markedly reduced mean HAE attack rate (reduction vs baseline: 87.4% overall). Patients were attack free for a mean of 97.7% of days during treatment; 81.8% and 68.9% of patients were attack free for ≥6 and ≥12 months, respectively. Angioedema Quality‐of‐Life total and domain scores improved from day 0 to end of study. Treatment‐emergent adverse events (TEAEs) (excluding HAE attacks) were reported by 97.2% of patients; most commonly injection site pain (47.2%) and viral upper respiratory tract infection (42.0%). Treatment‐related TEAEs were reported by 54.7% of patients. Most injection site reactions resolved within 1 hour (70.2%) or 1 day (92.6%). Six (2.8%) patients discontinued due to TEAEs. No treatment‐related serious TEAEs or deaths were reported. Eleven treatment‐related TEAEs of special interest were reported by seven (3.3%) patients. CONCLUSION: Lanadelumab demonstrated sustained efficacy and acceptable tolerability with long‐term use in HAE patients.