Hereditary angioedema attack trends among patients maintained on lanadelumab long-term prophylaxis.

Background: Longitudinal studies using real-world data are needed to assess the effectiveness of long-term prophylaxis (LTP) for hereditary angioedema (HAE) during successive years of treatment. Objective: This United States-based retrospective analysis assessed the longitudinal effectiveness of lanadelumab LTP on attack rate reduction year on year in lanadelumab-treated patients with HAE. Methods: Data were from the Consortium of Independent Immunology Clinic's HAE Patient Registry, a dataset managed by Trio Health. Patients who were treated with lanadelumab between August 2018 and December 2023 and who remained on treatment for at least 6 months were included. Data were collected during routine clinic visits, with the time between clinic visits defined as "follow-up intervals" for outcome assessment. Given data were ascertained from real-world clinical practices, visits did not occur at uniform fixed intervals. Patients were followed for up to 4 visits after lanadelumab initiation. Results: The analysis included 141 patients with HAE due to C1 inhibitor deficiency or dysfunction. The mean ± SD duration on lanadelumab was over 3.5 years (1305 days ± 567). Mean length of follow-up intervals 1 to 4 were 376, 267, 286, and 283 days, respectively. Lanadelumab discontinuation rates were low (range 1.3%-3.1%) across the 4 intervals. The mean ± SD monthly attack rates ranged from 0.21 ± 0.43 (interval 1) to 0.16 ± 0.38 (interval 4) ( Conclusions: Patients on lanadelumab for at least 6 months had low discontinuation rates. Attack rates were low, and the proportion of attack-free patients increased across intervals, indicating attack-free status was achievable in the later years on treatment.