Long-term prevention of hereditary angioedema attacks with lanadelumab in adolescents.

BACKGROUND: Lanadelumab was well-tolerated and effective in preventing hereditary angioedema (HAE) attacks in the phase 3, double-blind, placebo-controlled HELP Study and subsequent open-label extension study, HELP OLE (NCT02741596). OBJECTIVE: To evaluate outcomes from HELP OLE for adolescent patients aged 12 to 17 years. METHODS: HELP OLE comprised patients who completed the HELP Study (rollovers) and new eligible (lanadelumab-naive) patients. Rollovers received a single dose of lanadelumab 300 mg at the last HELP Study visit (day 0). Treatment was then paused until patients experienced their first investigator-confirmed HAE attack, following which lanadelumab 300 mg was administered every 2 weeks (Q2W) for up to 33 months (4 weeks/month). Lanadelumab-naive patients received lanadelumab 300 mg Q2W from day 0. Patient-reported outcomes included Angioedema Quality of Life Questionnaire (AE-QoL). Safety was monitored throughout the study. RESULTS: The subgroup analysis included 21 patients (8 rollovers, 13 lanadelumab-naive patients); 95.2% completed ≥ 30 months on study. Mean (SD) monthly attack rates decreased from 1.58 (1.0) at baseline to 0.11 (0.2) during treatment (mean 94.7% reduction). Eight (38.1%) patients were attack-free during treatment and, on average, 99.1% of days were attack-free (mean 27.7 days/month). Patients reported a mean (SD) AE-QoL total score of 27.5 (17.5) at baseline vs 7.5 (13.2) at end of study. Twelve (57.1%) patients reported treatment-related treatment-emergent adverse events; however, there were no treatment-related serious adverse events. CONCLUSION: Lanadelumab provided long-term efficacy in preventing HAE attacks, was associated with clinically meaningful improvements in health-related quality of life and high levels of treatment satisfaction, and was well-tolerated in adolescent patients.

Physician- and patient-reported outcomes by hereditary angioedema type: Data from a real-world study.

Background: Hereditary angioedema (HAE) is a rare genetic condition characterized by painful and often debilitating swelling attacks. Little is known about the differences in outcomes between patients with HAE types I or II (type I: HAE caused by C1 esterase inhibitor deficiency; type II: HAE caused by C1 esterase inhibitor dysfunction), with decreased or dysfunctional C1 esterase inhibitor (C1-INH), and those with normal C1-INH (nC1-INH-HAE). Objective: To compare physician- and patient-reported real-world outcomes in patients with HAE types I/II versus patients with nC1-INH-HAE. Methods: Data were drawn from the Adelphi HAE Disease Specific ProgrammeTM a real-world, cross-sectional survey of HAE-treating physicians and their patients in the United States conducted between July and November 2021. Physicians reported patient disease activity and severity, and recent attack history. Patient-reported outcomes were collected. Bivariate tests used were either the Student's t-test, the Fisher exact test, or Mann-Whitney U test. Results: Physicians (N = 67) provided data on 368 patients (92.4% HAE types I/II and 7.6% nC1-INH-HAE). Physicians reported that a higher proportion of patients with nC1-INH-HAE had moderate or high disease activity and moderate or severe disease severity both at diagnosis and at data collection versus those with HAE types I/II. Patients with nC1-INH-HAE versus patients with HAE types I/II experienced increased attack severity (34.6% versus 4.4%) and hospitalization rate during the most recent attack (39.3% versus 6.6%), and reported lower health status and quality of life, via the European Quality of Life 5 Dimension 5 Level (US tariff) and Angioedema Quality of Life, respectively. On average, 25% of the patients with nC1-INH-HAE reported absenteeism and work or activity impairment due to HAE compared with 2.7% of patients with HAE types I/II. Both patient groups reported improvements in disease activity and severity from diagnosis to the time of data collection. Conclusion: These real-world findings suggest that patients with nC1-INH-HAE have increased disease activity and severity, and experience greater impairment to their quality of life, work, and daily functioning than patients with HAE types I/II. Powered statistical analyses are required to confirm these findings.

A quantitative systems pharmacology model of plasma kallikrein-kinin system dysregulation in hereditary angioedema.

Hereditary angioedema (HAE) due to C1-inhibitor deficiency is a rare, debilitating, genetic disorder characterized by recurrent, unpredictable, attacks of edema. The clinical symptoms of HAE arise from excess bradykinin generation due to dysregulation of the plasma kallikrein-kinin system (KKS). A quantitative systems pharmacology (QSP) model that mechanistically describes the KKS and its role in HAE pathophysiology was developed based on HAE attacks being triggered by autoactivation of factor XII (FXII) to activated FXII (FXIIa), resulting in kallikrein production from prekallikrein. A base pharmacodynamic model was constructed and parameterized from literature data and ex vivo assays measuring inhibition of kallikrein activity in plasma of HAE patients or healthy volunteers who received lanadelumab. HAE attacks were simulated using a virtual patient population, with attacks recorded when systemic bradykinin levels exceeded 20 pM. The model was validated by comparing the simulations to observations from lanadelumab and plasma-derived C1-inhibitor clinical trials. The model was then applied to analyze the impact of nonadherence to a daily oral preventive therapy; simulations showed a correlation between the number of missed doses per month and reduced drug effectiveness. The impact of reducing lanadelumab dosing frequency from 300 mg every 2 weeks (Q2W) to every 4 weeks (Q4W) was also examined and showed that while attack rates with Q4W dosing were substantially reduced, the extent of reduction was greater with Q2W dosing. Overall, the QSP model showed good agreement with clinical data and could be used for hypothesis testing and outcome predictions.