Effect of lanadelumab on attack frequency and QoL in Japanese patients with hereditary angioedema: Report of five cases.

Lanadelumab, a recombinant human anti-kallikrein monoclonal antibody, is recommended as the first-line option for long-term prophylaxis (LTP) in hereditary angioedema (HAE). However, the efficacy of lanadelumab and its effects on the quality of life (QoL) in Japanese HAE patients using real-world data have not been reported. Herein, we report the outcomes of five HAE patients who were treated with lanadelumab at two Japanese institutions. We retrospectively collected data on attack frequency and on-demand treatment frequency using an angioedema quality of life (AE-QoL) questionnaire. Our data corresponded to five Japanese HAE patients who started lanadelumab treatment: four with HAE due to C1-inhibitor deficiency (HAE-1) and one with HAE with a normal C1-inhibitor (HAE-nC1-INH). Two HAE-1 patients showed a reduction in both attacks and number of on-demand treatments. The other HAE-1 patients had an increase in the number of on-demand treatments, although there was no apparent reduction in attacks. The HAE-nC1-INH patient showed a slight increase in both attacks and number of on-demand treatments. Only one HAE-1 patient discontinued treatment after 1 month owing to side effects, including dizziness and headache. All four who continued treatment showed improved AE-QoL total and domain scores. Therefore, in this study, using real-world data, we demonstrated that lanadelumab reduced attack frequency and improved QoL in Japanese HAE patients.