The evolving treatment landscape for hereditary angioedema in Sweden.

INTRODUCTION: Hereditary angioedema (HAE) is a rare genetic disorder, characterized by unpredictable, potentially life-threatening edema attacks. Treatment options include on-demand treatment (ODT) and long-term prophylactic (LTP) therapy. This study describes the HAE treatment landscape in Sweden, focusing on the uptake of recently reimbursed modern LTP therapies and patterns of ODT dispensation as an indirect proxy for breakthrough attacks. METHODS: This nationwide, longitudinal, registry-based study utilized data from the National Prescribed Drug Register in Sweden describing all dispensed drugs with approved indications for HAE between January 2020-May 2025. RESULTS: During 2024, 245 patients received HAE-specific drugs, with one-third dispensing LTP. Among patients with ≥12 months on modern LTP (n=69) who had at least one ODT dispensation event during their most recent 12 months of treatment (n=46/59 for lanadelumab; n=8/9 for berotralstat), the mean number of ODT packages dispensed-in addition to emergency stock ODT-was 4.3 per patient on lanadelumab and 6.5 per patient on berotralstat. Overall, 22% (n=15/69) of patients receiving modern LTP did not dispense ODT medication during their most recent 12-months of treatment. In total, 22% of patients (n=24/108) with at least one lanadelumab or berotralstat dispensation stopped dispensing modern LTP and switched to alternative LTP or ODT-only treatment options. DISCUSSION: This study provides valuable insights into real-world dispensation patterns of HAE drugs in Sweden. Despite the availability of modern LTP therapies, there remains relatively high ODT dispensation events, suggesting ongoing unmet need and underscoring the importance of optimizing prophylactic strategies to achieve total disease control.