Drug Patterns and Economic Costs Among Patients with Hereditary Angioedema

Area of Science:

• Real-world evidence in hematology and immunology.
• Health economics and outcomes research in rare diseases.

Background:

• Hereditary angioedema (HAE) management involves long-term prophylaxis (LTP) and on-demand treatment (ODT).
• Subcutaneous (SC) LTP options, including C1-esterase inhibitor (C1-INH-SC) and lanadelumab, are available for HAE.
• Understanding real-world treatment patterns and expenditures is crucial for optimizing HAE care.

Purpose of the Study:

• To evaluate real-world patterns of SC LTP use, ODT prescriptions, and associated treatment expenditures in HAE patients.
• To assess adherence and discontinuation rates for SC LTP in a US cohort.
• To quantify the economic burden of HAE management, including ODT and emergent care costs.

Main Methods:

• Retrospective cohort study utilizing a US healthcare claims database (February 2018 - June 2022).
• Included patients aged ≥12 years initiating SC LTP (C1-INH-SC or lanadelumab) for HAE.
• Evaluated LTP adherence (MPR), discontinuation, annualized ODT prescriptions, and annualized treatment expenditures (ODT, hospitalizations, ED visits).

Main Results:

• The study included 196 HAE patients (65 C1-INH-SC, 131 lanadelumab) with a mean age of 39 years; 69% were female.
• Mean follow-up was 19 months, with an LTP adherence of 73% and a discontinuation rate of 48%.
• Annualized ODT prescriptions averaged 3.8 per patient, with total mean annual treatment expenditures of $209,547, including over $200,000 for ODT, hospitalizations, and ED visits.

Conclusions:

• Real-world adherence to SC LTP for HAE is suboptimal, with nearly 50% of patients discontinuing treatment.
• Treatment-related expenditures remain high, averaging over $200,000 annually, driven primarily by ODT and emergent care costs.
• These findings underscore the need for improved strategies to enhance LTP adherence and reduce the overall economic burden in HAE management.