Long-term prophylactic treatment and related real-world outcomes of patients with hereditary angioedema in Germany: A retrospective analysis of German claims and medical chart data.

Background: Hereditary angioedema (HAE) is a rare genetic disorder characterized by recurrent swelling episodes that are potentially life threating and substantially impair quality of life. This study aimed to generate real-world evidence on the utilization of long-term prophylaxis (LTP), residual disease burden, and economic outcomes among patients with HAE in Germany. Methods: This retrospective cohort study examined LTP patterns and associated real-world outcomes using 2 anonymized German statutory health insurance datasets (AOK PLUS and GWQ) and a medical chart review (MCR) from 1 specialized HAE center. Claims datasets included patients initiating LTP between 2019 and 2023. The MCR provided complementary clinical information and was used to assess the plausibility of prescription-based estimates for attack frequency. Outcomes included LTP treatment sequences, HAE attacks requiring on-demand treatment (ODT), healthcare resource utilization and direct cost. Results: Across the claims datasets, 77 patients initiated first-line LTP: 30 (39.0%) with intravenous C1 esterase inhibitors (C1INH IV), 24 (31.2%) with lanadelumab, 16 (20.8%) with subcutaneous C1INH, and 7 (9.1%) with berotralstat. During follow-up, 27 patients (35.1%) switched therapy, most commonly from C1INH IV to lanadelumab. Despite prophylaxis, 64% of patients experienced at least 1 HAE attack requiring ODT, while 36% remained attack-free during the first year after LTP start. Median time to first treated attack ranged from 114 to 132 days. Prescription-based attack estimates were generally consistent with physician-documented attack frequencies but tended to yield slightly higher attack rates. Annual healthcare costs were driven primarily by outpatient medications, averaging €233,190 and €206,392 per person-year in the AOK PLUS and GWQ cohorts, respectively. Conclusion: This study provides real-world evidence on LTP use in Germany and demonstrates that a substantial proportion of patients continues to experience treated attacks despite prophylaxis. These findings highlight the importance of ongoing monitoring, individualized treatment optimization, and continued access to ODT.