Healthcare utilization of patients with hereditary angioedema treated with lanadelumab and subcutaneous C1-inhibitor concentrate.

Background: New hereditary angioedema (HAE) treatments have become available in recent years for the treatment of HAE due to C1-inhibitor (C1-INH) deficiency, including two subcutaneous (SC) options: a monoclonal antibody (lanadelumab) and a plasma-derived C1-INH concentrate (SC-C1-INH). Limited real-world data on these therapies have been reported. Objective: The objective was to describe new users of lanadelumab and SC-C1-INH, including demographics, healthcare resource utilization (HCRU), costs, and treatment patterns before and after beginning treatment. Methods: This was a retrospective cohort study that used an administrative claims data base. Two mutually exclusive cohorts of adult (ages ≥18 years) new users of lanadelumab or SC-C1-INH with ≥180 days of continuous use were identified. HCRU, costs, and treatment patterns were assessed in the 180-day period before the index date (new treatment use) and up to 365 days after the index date. HCRU and costs were calculated as annualized rates. Results: Forty-seven patients who used lanadelumab and 38 patients who used SC-C1-INH were identified. The most frequently used on-demand HAE treatments at baseline were the same for both cohorts: bradykinin B₂ antagonists (48.9% of the patients on lanadelumab, 52.6% of the patients on SC-C1-INH) and C1-INHs (40.4% of the patients on lanadelumab, 57.9% of the patients on SC-C1-INH). More than 33% of the patients continued to fill on-demand medications after treatment initiation. Annualized angioedema-associated emergency department visits and hospitalizations decreased after initiation of treatment, from 1.8 to 0.6 for the patients on lanadelumab and from 1.3 to 0.5 for the patients on SC-C1-INH. Annualized total healthcare costs after treatment initiation in the database were $866,639 and $734,460 for the lanadelumab and SC-C1-INH cohorts, respectively. Pharmacy costs accounted for >95% of these total costs. Conclusion: Although HCRU decreased after the initiation of treatment, angioedema-associated emergency department visits and hospitalizations and on-demand treatment fills were not completely eliminated. This indicates ongoing disease and treatment burden despite use of modern HAE medicines.