- D1.347 - Lanadelumab in Children with Hereditary Angioedema Aged 2 to

Lanadelumab received approval by the European Medicines Agency for the prevention of attacks of hereditary angioedema (HAE) in children aged 2 to <12 years in 2023, based on the phase 3 SPRING Study. In Europe, the lanadelumab starting dose in children aged 2 to <12 years is 150mg every 4 weeks (Q4W) in children weighing 10 to <20kg, 150mg every 2 weeks (Q2W) in children weighing 20 to <40kg, and 300mg Q2W in children weighing ≥40kg. Pharmacovigilance reports indicate that there have been >250 patient-years of clinical experience with lanadelumab 150mg since approval, mostly in the US. However, there are little-to-no real-world data published on the use of long-term prophylaxis including lanadelumab in the <12-year age group. Given the challenges of conducting studies of specific patient subgroups within rare diseases, a feasibility assessment was conducted to identify sites for participation in a chart review study of real-world lanadelumab treatment in paediatric patients with HAE.

We conducted a two-stage approach to identify sites for participation in the retrospective TAHORA study. Sites conducted an initial feasibility questionnaire to assess site-level patient characteristics and sample sizes, how often pediatric patients were seen outside of an attack, and what tracking systems were routinely used by patients/carers to document attacks. Sites selected post-feasibility then completed a pre-study assessment (PSA) to confirm their suitability for inclusion in the study.

A total of 26 sites from Argentina, France, Germany, Israel, Serbia and the UK conducted an initial feasibility questionnaire. Most indicated having 1 or 2 (max 4) patients aged 2 to <12 years who were receiving lanadelumab, with a paper-based format the most common method used by patients/caregivers to track attacks. Of the 26 sites, 25 completed the PSA. All 25 sites were selected for participation in the TAHORA study. PSAs confirmed the validity of the study inclusion/exclusion criteria, the primary objective of describing the real-world effectiveness of lanadelumab in paediatric patients with HAE and secondary objectives of describing lanadelumab safety, patient demographic and clinical characteristics, treatment patterns, and healthcare resource utilisation.

Feasibility assessments are critical in optimizing site selection of multicentre retrospective chart reviews such as TAHORA and in understanding potential limitations of data collection.