This is a single-arm, open-label study designed to evaluate the PK and safety of berotralstat weight-based treatment for the prevention of hereditary angioedema attacks in pediatric participants 2 to < 12 years of age. This study will consist of two treatment periods: a 12-week standard-of-care (SOC) treatment period followed by an open-label berotralstat treatment period lasting up to 144 weeks.~Participants will be enrolled into 4 dose cohorts; participant weight will be used to determine assignment to each cohort with the higher weight cohorts (Cohorts 1 and 2) enrolling first and in parallel. Safety assessments and PK modelling from all available PK data will then be used to confirm the weight bands for sequentially enrolling Cohorts 3 and 4.The effectiveness of berotralstat in this population will be summarized using descriptive statistical methods.
The purpose of this study is to evaluate the pharmacokinetics (PK) and safety of berotralstat to determine the appropriate weight-based dose for pediatric participants 2 to < 12 years old for prophylactic treatment to prevent attacks of hereditary angioedema (HAE).