D1.407 - Real-world patient characterization, prior long-term prophylactic prescribing patterns, and treatment outcomes for adults on berotralstat with hereditary angioedema in Japan

Hereditary angioedema (HAE) is a rare swelling disorder that can be treated with long-term prophylactic (LTP) medications reduce the frequency, duration, and severity of angioedema attacks. Berotralstat was the first targeted LTP for HAE approved in 2021 by the Ministry of Health, Labour and Welfare in Japan. This analysis aimed at describing patient characteristics, prior treatments, and treatment outcomes for patients with HAE receiving berotralstat as an LTP, including reasons for switching treatment to berotralstat, in Japan.

Data from the Adelphi HAE Wave II DSP, a real-world cross-sectional survey of physicians who manage HAE in Japan, were used. Data were collected between January 2023 – January 2024 for adults (≥18 years) who had received berotralstat for at least 12 months. Physicians used patients’ medical chart information alongside clinical judgement to report patient demographics, reasons for selecting berotralstat, and the effectiveness of berotralstat.

3 physicians were represented in the survey, accounting for 15 adult patients receiving berotralstat. The mean (SD) age of patients was 44.7 (13.9) years, with males accounting for 53.3% of the study sample. HAE Type I patients composed 66.7% of the population, while 26.7% of the sample were Type II and 6.7% were classified as unknown. Prior to initiating berotralstat, 53% of patients had no prior LTP use. Among patients with a prior LTP (n=7), 85.7% received tranexamic acid before switching to berotralstat. All physicians reported an overall lack of efficacy as the reason for discontinuation of the prior LTP, with 85.7% reporting that the prior LTP was not effective at reducing attack frequency and 28.6% reporting an ineffective reduction of attack severity. The top reasons cited for initiating berotralstat, irrespective of prior LTP use, were perceived efficacy in reducing the frequency of attacks (100.0%), the route of administration (60.0%), and efficacy in reducing the duration of attacks (60.0%). 86.7% of patients represented in the sample were reported by the physicians as being satisfied or completely satisfied with the overall efficacy of berotralstat.

Berotralstat was selected by physicians in Japan as an LTP for HAE primarily for its efficacy in reducing the frequency of HAE attacks. Upon initiating berotralstat, physicians reported high satisfaction with its efficacy in reducing the frequency and duration of attacks for their patients.