D3.324 - Hereditary Angioedema Attack Frequency and Severity According to Individuals Taking Berotralstat for Long-Term Prophylaxis

Reducing the frequency and severity of hereditary angioedema (HAE) attacks is an important goal of long-term prophylaxis (LTP), playing a key role in improving quality of life for individuals with HAE. Berotralstat is the only targeted oral LTP approved for the treatment of HAE. This study aimed to understand real-world experience with berotralstat.

An online discussion and survey were conducted among individuals with HAE in the United States in 2023, 2024, and 2025. Eligibility criteria were age ≥18 years, diagnosis of HAE, and current use of berotralstat for LTP at the time of study recruitment. Changes in attack frequency and severity after berotralstat initiation were stratified by prior LTP use and berotralstat treatment duration. Treatment satisfaction was also assessed and stratified by attack frequency and severity.

The mean age of the 181 individuals included over the 3-year period was 43.9 years, and 75% were female. Of the 95 participants naïve to LTP, 95% reported that their HAE attack frequency decreased since starting berotralstat. Among the n=86 who switched to berotralstat from another LTP, 65% reported that their attacks were less frequent compared with their prior LTP; 19% said they were more frequent, and 16% reported that the frequency remained unchanged. Most (75%) participants naïve to LTP, and 59% of those switching from a prior LTP reported less severe attacks. None of the individuals naïve to LTP, and only 7% who switched to berotralstat reported that their attacks were more severe. Most individuals on berotralstat <1 year (n=70) or ≥1 year (n=111) reported less frequent (78% and 82%, respectively) and less severe attacks (64% and 70%). Nearly all (99%) individuals were at least somewhat satisfied with berotralstat. Participants who experienced less frequent (n=146) and less severe attacks (n=121) were extremely satisfied with berotralstat (87% and 82%, respectively); satisfaction was also high for individuals with the same number of attacks (67%) and severity of attacks (83%). Satisfaction was lower for individuals who experienced more frequent/more severe attacks since starting berotralstat; of the 17 who experienced more frequent attacks, 1 was dissatisfied, and of the 6 who had more severe attacks, 1 was dissatisfied.

Most individuals with HAE had fewer and less severe attacks after starting berotralstat, regardless of their use of prior LTP or time on berotralstat. Most participants were highly satisfied with berotralstat.