Clinical Experience with Berotralstat in Patients with Hereditary Angioedema with Normal C1-Esterase Inhibitor: A Commented Case Series

Hereditary angioedema (HAE) is a rare genetic disorder characterized by potentially life-threatening episodes of swelling. Most HAE cases are caused by deficient (type I) or dysfunctional (type II) C1-esterase inhibitor (C1-INH) protein. However, some patients present with a subtype of HAE that is associated with normal plasma levels of functional C1-INH protein and complement component 4 (HAE-nC1INH). Treatment of HAE-nC1INH is driven by clinical experience as robust clinical trial data to inform treatment decisions are lacking in this population. This retrospective case series assessed clinical features and treatment outcomes in 15 patients with HAE-nC1INH who initiated long-term prophylaxis with oral berotralstat 150 mg once daily as part of their disease management pathway. Most patients were female (93%), with a median age of 49 years. All patients experienced abdominal swelling attacks. On average, patients tried a mean of 4 different treatments for their HAE, including berotralstat. Although most patients associated prophylactic and on-demand medications that target the bradykinin pathway with improvements in the frequency and/or severity of attacks, treatment outcomes varied considerably between patients, highlighting the importance of a personalized approach to disease management. In this case series, berotralstat was an effective prophylactic treatment option in most patients with HAE-nC1INH. Further studies are required to demonstrate the potential efficacy, safety, and impact on quality of life of currently approved HAE therapies in patients with HAE-nC1INH.

Berotralstat in hereditary angioedema due to C1 inhibitor deficiency: first real-world evidence from a Canadian center

Background

Hereditary angioedema due to C1 inhibitor deficiency is a rare genetic condition that causes recurrent swelling with consequent functional impairment and decreased quality of life. Long-term prophylaxis (LTP) to prevent angioedema episodes is a key component of disease management. Berotralstat, an oral, once-daily plasma kallikrein inhibitor, was approved for LTP by Health Canada in 2022.

Methods

We conducted a retrospective, real-world study investigating the effectiveness and adverse effects of berotralstat. Data on angioedema frequency, disease control, and adverse events were tabulated. Patient satisfaction with treatment was scored on a 5-point Likert scale, with 1 representing very unsatisfied and 5 representing very satisfied with therapy.

Results

From June, 2022 and May, 2023, 8 patients with HAE type 1 or type 2 received berotralstat. Effectiveness data were available for 7 patients who continued the drug for at least 3 months, 4 of whom switched to berotralstat from plasma-derived C1 inhibitor LTP. In these 7 patients, the average number of attacks per month decreased from 3.3 to 1.6 (p<0.05), representing a ~52% reduction in attack frequency. Median angioedema control test score numerically improved from 8 to 13 (p=0.0781). Of the 8 patients who received berotralstat, 3 reported no adverse effects and 5 experienced gastrointestinal side effects, which were mild and transient in 3 and led to discontinuation in 1. Average treatment satisfaction was between satisfied and very satisfied at 4.3.

Conclusion

Berotralstat is an effective agent for long-term prophylaxis in HAE. Most patients experienced no adverse effects or mild, transient gastrointestinal symptoms.

Uncovering the true burden of hereditary angioedema due to C1-inhibitor deficiency: A focus on the Asia-Pacific region

Hereditary angioedema (HAE) due to C1-inhibitor deficiency or dysfunction is a rare genetic disorder that causes recurrent episodes of swelling in various parts of the body. Treatment goals of HAE aim to "normalize" life for all patients; however, lack of diagnostic facilities and limited access to effective treatment options in developing nations cause delays in diagnosis and place a significant burden on patients. In this review, we aim to highlight the burden of disease caused by C1-inhibitor HAE across the Asia-Pacific region, considering its epidemiology, morbidity and mortality, and socioeconomic and psychological impact. We also review the availability of guideline-recommended diagnostic facilities and treatments, and how patients are currently managed. Data were collected from published literature and HAE experts in the region, who provided information regarding diagnosis and management in their countries. Current practice was reviewed against international guidelines, as well as local guidelines/consensus used in Australia, Japan, and China. Suggestions are provided for improving the time to diagnosis in the region, increasing access to guideline-recommended treatments, and providing support to reduce the burden on patients and caregivers. There is an urgent need to improve HAE services and provide access to life-saving treatment in developing countries, and efforts should be made to increase awareness of guideline recommendations in high-income economies that do not currently provide long-term prophylactic treatments.

Network meta-analysis for indirect comparison of lanadelumab and berotralstat for the treatment of hereditary angioedema

Aim: With no head-to-head studies comparing the effectiveness of lanadelumab and berotralstat for prevention of hereditary angioedema (HAE) attacks, this network meta-analysis (NMA) aimed to indirectly compare the effectiveness of these treatments. Materials & methods: The NMA, using the published data from Phase III trials, was performed using a frequentist weighted regression-based approach following Rücker et al. Efficacy outcomes of interest were HAE attack rate per 28 days and ≥90% reduction in monthly HAE attacks. Results & conclusion: In this NMA, lanadelumab 300 mg administered every 2 weeks or every 4 weeks was associated with statistically significantly higher effectiveness versus berotralstat 150 mg once daily (q.d.) or 110 mg q.d. for both efficacy outcomes assessed.

A review of berotralstat for the treatment of hereditary angioedema

INTRODUCTION

Hereditary angioedema due to C1-inhibitor deficiency (C1-INH-HAE) imposes a significant disease burden on patients and their families. Unpredictable episodes of angioedema, which can lead to life-threatening conditions, have a significant impact on the quality of life of the patient. The fundamental aim of the treatment of C1-INH-HAE is to ensure that patients can lead a normal life. The most effective way to do this is to prevent the onset of angioedema attacks.

AREAS COVERED

This review gives a brief overview of the safety and efficacy of the oral kallikrein inhibitor berotralstat in C1-INH-HAE disease. It provides a comprehensive synopsis of the results of the first clinical trials with a targeted oral kallikrein inhibitor (APeX-1 [NCT02870972]; ZENITH-1 [NCT03240133]; APeX-2 [NCT03485911]; APeX-S [NCT03472040]; APeX-J [NCT03873116]), reviewing evidence on the efficacy and safety of the drug, and placing berotralstat on the spectrum of long-term prophylactic therapeutic options.

EXPERT OPINION

The availability of the first targeted oral prophylactic drug, the kallikrein inhibitor berotralstat, in 2021, is a milestone in the treatment of patients with hereditary angioedema.

Patient and caregiver perspectives on transitioning to oral prophylaxis in the emerging hereditary angioedema treatment landscape

This report describes the successful transition of two familial patients with HAE from injectable to oral prophylaxis without tapering prior therapy or employing a complex transition protocol.

Orladeyo (Berotralstat): A Novel Oral Therapy for the Prevention of Hereditary Angioedema

OBJECTIVE

The purpose of this article is to review the available trials that led to the Food and Drug Administration (FDA) approval of berotralstat, an oral kallikrein inhibitor, for the prevention of hereditary angioedema (HAE) attacks.

DATA SOURCES

PubMed and ClincalTrials.gov were searched using key term berotralstat to identify phase III clinical trials related to the FDA approval of berotralstat from April 2018 to May 2021.

STUDY SELECTION AND DATA EXTRACTION

Trials selected were those that influenced the FDA approval of berotralstat or provided novel information regarding the safety and efficacy of this therapy in the treatment of HAE.

DATA SYNTHESIS

Both APeX-2 and ApeX-J found clinically significant benefit with berotralstat 150 mg daily for reduction in HAE attacks when compared with placebo (1.31 vs 2.35, P < 0.001, and 1.11 vs 2.18, P < 0.001, attacks in the APeX-2 and APeX-J trials, respectively). APeX-2 also showed a statistically significant benefit for berotralstat 110 mg daily (1.65 vs 2.35 attacks [1.65 attacks, P = 0.024]).

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

An advantage berotralstat has over the other approved therapies is that it is administered orally, which may garner patient preference because of ease of administration. Berotralstat has also shown a potential benefit in reducing the need for standard-of-care treatment for HAE attacks, which has not been studied with alternative agents.

CONCLUSIONS

Berotralstat 150 mg daily has been proven safe and effective in clinical studies and appears to be a viable oral alternative to parenteral medications currently used in HAE prophylaxis.

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.