OBJECTIVES: To evaluate hereditary angioedema (HAE) attacks before and after initiation of berotralstat, a targeted oral long-term prophylaxis, among HAE patients without C1-inhibitor deficiency using 30-day and 90-day baseline recall periods.

METHODS: This retrospective pre-post study used Optime Care Specialty Pharmacy Data, with data ranging from December 15, 2020 – January 8, 2024. Optime Care is the sole dispenser of berotralstat in the US and the database captures longitudinal patient-reported HAE attacks, measured before berotralstat initiation (30-day and 90-day baseline recall periods) and at each refill (~monthly). Eligible patients had HAE without C1-inhibitor deficiency—based on C1-inhibitor levels/function and C4 levels—with ≥1 attack self-assessment in baseline and follow-up, and ≥2 berotralstat dispensings. Follow-up spanned from first to last berotralstat dispensing and was segmented into 30-day and 90-day intervals (using 30-day and 90-day baseline recall periods, respectively). HAE attack rates per-patient-per-month (PPPM) in each follow-up interval were compared with baseline using mean differences, 95% confidence intervals (CIs), and p-values from generalized estimating equations linear regression models with robust standard errors.

RESULTS: Among 353 patients without C1-inhibitor deficiency initiating berotralstat, mean age was 48.1 and 78.5% were female. Mean PPPM attack rates during the 30-day and 90-day baseline periods were 5.54 and 4.75, respectively. Using 30-day intervals, mean attack rate reduction (95% CI) from baseline was -3.54 (-4.26, -2.83) at 12 months and -3.02 (-4.00, -2.04) at 18 months (both p<0.001). Using 90-day intervals, mean attack rate reduction (95% CI) from baseline was -2.48 (-3.10, -1.85) at 12 months and -2.18 (-2.92, -1.43) at 18 months (both p<0.001).

CONCLUSIONS: Berotralstat was associated with significant and sustained reductions in attack rates among HAE patients without C1-inhibitor deficiency in the US using either 30-day or 90-day baseline recall periods.