Long-term safety and effectiveness of berotralstat for hereditary angioedema: The open-label APeX-S study.

BACKGROUND: Berotralstat (BCX7353) is an oral, once-daily inhibitor of plasma kallikrein recently approved for prevention of angioedema attacks in adults and adolescents with hereditary angioedema (HAE). The objective of this report is to summarize results from an interim analysis of an ongoing long-term safety study of berotralstat in patients with HAE. METHODS: APeX-S is an ongoing, phase 2, open-label study conducted in 22 countries (ClinicalTrials.gov, NCT03472040). Eligible patients with a clinical diagnosis of HAE due to C1 inhibitor deficiency (HAE-C1-INH) were centrally allocated to receive berotralstat 150 or 110 mg once daily. The primary objective was to determine long-term safety and the secondary objective was to evaluate effectiveness. RESULTS: Enrolled patients (N = 227) received berotralstat 150 mg (n = 127) or 110 mg (n = 100) once daily. The median (range) duration of exposure was 342 (11-540) and 307 (14-429) days for the 150-mg and 110-mg groups, respectively. Treatment-emergent adverse events (TEAEs) occurred in 91% (n = 206) of patients. The most common TEAEs across treatment groups were upper respiratory tract infection (n = 91, 40%), abdominal pain (n = 57, 25%), headache (n = 40, 18%), and diarrhea (n = 31, 14%) and were mostly mild to moderate. Fifty percent (n = 113) of patients had at least one drug-related adverse event (AE; 150 mg, n = 57 [45%]; 110 mg, n = 56 [56%]), and discontinuations due to AEs occurred in 19 (8%) patients (150 mg, n = 13 [10%]; 110 mg, n = 6 [6%]). Three (1.3%) patients experienced a drug-related serious TEAE. Among patients who received berotralstat through 48 weeks (150 mg, n = 73; 110 mg, n = 30), median HAE attack rates were low in month 1 (150 mg, 1.0 attacks/month; 110 mg, 0.5 attacks/month) and remained low through 12 months (0 attacks/month in both dose groups). Mean HAE attack rates followed a similar trend, and no evidence for patient tolerance to berotralstat emerged. In both dose groups, angioedema quality of life scores showed clinically meaningful changes from baseline. CONCLUSIONS: In this analysis, both berotralstat doses, 150  and 110 mg once daily, were generally well tolerated. Effectiveness results support the durability and robustness of berotralstat as prophylactic therapy in patients with HAE. TRIAL REGISTRATION: The study is registered with ClinicalTrials.gov (NCT03472040).

Oral berotralstat for the prophylaxis of hereditary angioedema attacks in patients in Japan: A phase 3 randomized trial.

BACKGROUND: With no approved treatments in Japan for the prevention of hereditary angioedema (HAE) attacks, there is a significant unmet need for long-term prophylactic therapies for Japanese patients with HAE. Berotralstat (BCX7353) is an oral, once-daily, highly selective inhibitor of plasma kallikrein in development for prophylaxis of angioedema attacks in HAE patients. METHODS: APeX-J is a phase 3, randomized, double-blind, placebo-controlled, parallel-group, 3-part trial conducted in Japan (University Hospital Medical Information Network identifier, UMIN000034869; ClinicalTrials.gov identifier, NCT03873116). Patients with a clinical diagnosis of type 1 or 2 HAE underwent a prospective run-in period of 56 days to determine eligibility, allowing enrollment of those with ≥2 expert-confirmed angioedema attacks. Patients were randomly assigned (1:1:1) and stratified by baseline attack rate (≥2 vs. <2 expert-confirmed attacks/month between screening and randomization) to receive once-daily berotralstat 110 mg, berotralstat 150 mg, or placebo. The primary endpoint was the rate of expert-confirmed angioedema attacks during dosing in the 24-week treatment period. RESULTS: Nineteen patients were randomized to receive once-daily berotralstat 110 mg (n = 6), berotralstat 150 mg (n = 7), or placebo (n = 6). Treatment with berotralstat 150 mg significantly reduced HAE attacks relative to placebo (1.11 vs. 2.18 attacks/month, p = .003). The most frequently reported treatment-emergent adverse events (TEAEs) in berotralstat-treated patients (n = 13) were nasopharyngitis (n = 4, 31%), abdominal pain, cough, diarrhea, and pyrexia (n = 2 each, 15%). CONCLUSIONS: Orally administered, once-daily berotralstat 150 mg significantly reduced the frequency of HAE attacks and was safe and well tolerated, supporting its use as a prophylactic therapy in patients with type 1 or 2 HAE in Japan.

Oral once-daily berotralstat for the prevention of hereditary angioedema attacks: A randomized, double-blind, placebo-controlled phase 3 trial.

BACKGROUND: Berotralstat (BCX7353) is an oral, once-daily inhibitor of plasma kallikrein in development for the prophylaxis of hereditary angioedema (HAE) attacks. OBJECTIVE: Our aim was to determine the efficacy, safety, and tolerability of berotralstat in patients with HAE over a 24-week treatment period (the phase 3 APeX-2 trial). METHODS: APeX-2 was a double-blind, parallel-group study that randomized patients at 40 sites in 11 countries 1:1:1 to receive once-daily berotralstat in a dose of 110 mg or 150 mg or placebo (Clinicaltrials.gov identifier NCT03485911). Patients aged 12 years or older with HAE due to C1 inhibitor deficiency and at least 2 investigator-confirmed HAE attacks in the first 56 days of a prospective run-in period were eligible. The primary efficacy end point was the rate of investigator-confirmed HAE attacks during the 24-week treatment period. RESULTS: A total of 121 patients were randomized; 120 of them received at least 1 dose of the study drug (n = 41, 40, and 39 in the 110-mg dose of berotralstat, 150-mg of dose berotralstat, and placebo groups, respectively). Berotralstat demonstrated a significant reduction in attack rate at both 110 mg (1.65 attacks per month; P = .024) and 150 mg (1.31 attacks per month; P < .001) relative to placebo (2.35 attacks per month). The most frequent treatment-emergent adverse events that occurred more with berotralstat than with placebo were abdominal pain, vomiting, diarrhea, and back pain. No drug-related serious treatment-emergent adverse events occurred. CONCLUSION: Both the 110-mg and 150-mg doses of berotralstat reduced HAE attack rates compared with placebo and were safe and generally well tolerated. The most favorable benefit-to-risk profile was observed at a dose of 150 mg per day.