Breakthroughs in hereditary angioedema management: a systematic review of approved drugs and those under research

Etiology, Recent Advances, and Clinical Trials Data for the Treatment of Angioedema: A Review

Angioedema is a health issue that affects parts of the body like the upper pulmonary and gastric pathways and is identified by abrupt, nonpitting enlargement of the skin, mucous membranes, or both. The swelling usually lasts a few hours to 72 hours and may appear as non-puritic, subcutaneous, or submucosal organ edema. It is characterized by localized swelling brought on by the release of histamine. Itching is rare, and usual areas of appearance include the hands, feet, face, and genitalia, with periorbital swelling being the most often. The main objective of this review article is to study in brief the classifications, etiology, pathophysiology, and clinical trial data by describing the recent advancement in the treatment of angioedema. Various research articles obtained from different journals indexed under Scopus and SCI were used to prepare the review article and for illustrative work software such as Biorender and Microsoft Word was used. Histaminemediated angioedema, linked to allergic reactions, coexists with urticaria. Bradykinin-mediated angioedema, exemplified by hereditary angioedema and acquired forms, lacks urticaria. Idiopathic angioedema, with uncertain etiology. Imitated angioedema results from non-IgE-mediated reactions, often induced by medications. It is a complicated medical condition with a variety of causes and mechanisms. Over time, outcomes for patients have been greatly improved by a growing understanding of its etiology, pathophysiology, and available treatments. The field of medical treatment for this difficult problem is always changing, and this is partly due to clinical trials.

Advent of oral medications for the treatment of hereditary angioedema

BACKGROUND

Hereditary angioedema (HAE) is a rare genetic disorder characterized by unpredictable, debilitating episodes of submucosal and/or subcutaneous tissue swelling, which may be life-threatening depending on anatomic location. The two primary management strategies for HAE are ready access to effective on-demand treatment in all patients and the prevention of attacks (short-term prophylaxis [STP] and long-term prophylaxis [LTP]) in appropriate patients. All approved on-demand and most LTP medications require subcutaneous or intravenous administration. Injection-related challenges include trypanophobia (fear of needles), difficulty with self-administration, injection-site reactions (e.g., pain, erythema, bleeding, bruising), and anxiety-all contributing to poor compliance and administration delays. Oral HAE treatments may improve outcomes by reducing treatment barriers.

AIM

To review oral therapies, approved or in development, for on-demand treatment and/or prevention of HAE attacks.

MATERIALS AND METHODS

To provide a comprehensive review, data was obtained from publicly available resources through a targeted PubMed literature review and supplemented by information provided on company websites (search cutoff of May 31, 2024).

RESULTS

Berotralstat, an oral plasma kallikrein (PKa) inhibitor, is approved for LTP. Sebetralstat, another PKa inhibitor, is the investigational first oral on-demand HAE treatment to complete a phase 3 trial. Deucrictibant, an oral bradykinin B2 receptor antagonist, has completed phase 2 trials for on-demand therapy and LTP. Several other oral PKa inhibitors (ATN249, VE-4666, and VE-4062) are in early development for LTP.

CONCLUSION

Substantial advances have been made in the development of oral treatments for HAE. These treatments have the potential to improve and optimize clinical outcomes, satisfaction, and quality of life among patients with HAE.

Safety of medications for hereditary angioedema during pregnancy and lactation

INTRODUCTION

Hereditary Angioedema (HAE) attacks show an increased frequency and severity for pregnant and lactating females secondary to the hormonal changes. The diagnosis and management of HAE in pregnant and lactating females pose a challenge for physicians due to the rarity of the disease and the paucity of the data for specific management.

AREAS COVERED

In this manuscript, we discuss the diagnosis and special presentation of HAE types 1 and 2 in pregnant and lactating females, including acute management, short-term prophylaxis, long-term prophylaxis, and drugs that should be avoided. Relevant publications were found through key word search of papers indexed in both Google Scholar and PubMed on 1 July 2022.

EXPERT OPINION

Treatment of HAE in the past has been mainly provided by experts; however, with more medications and an increasing number of patients, knowledge of how to care for HAE patients during pregnancy and lactation is important to review. Despite approval of additional medications in many countries, plasma-derived C1-inhibitor remains the drug of first choice for treatment in this unique population. Additional research is needed to increase safe access to other therapy options. We hope that future clinical studies, registries, and databases will shed additional light on this subject.

Picomolar Sensitivity Analysis of Multiple Bradykinin-Related Peptides in the Blood Plasma of Patients With Hereditary Angioedema in Remission: A Pilot Study

Background

Hereditary angioedema (HAE) is a rare autosomal dominant disease; the most well understood forms concern the haplodeficiency of C1 esterase inhibitor (C1INH) and a gain of function mutation of factor XII (FXII). The acute forms of these conditions are mediated by an excessive bradykinin (BK) formation by plasma kallikrein.

Methods

A validated LC-MS/MS platform of picomolar sensitivity developed for the analysis of eleven bradykinin-related peptides was applied to the plasma of HAE-C1INH and HAE-FXII sampled during remission.

Results

In HAE-C1INH plasma, the concentrations of the relatively stable BK1−5 fragment (mean ± S.E.M.: 12.0 ± 4.2 pmol/L), of BK2−9 (0.7 ± 0.2 pmol/L) and of the sums of BK and its tested fragments (18.0 ± 6.4 pmol/L) are significantly greater than those recorded in the plasma of healthy volunteers (1.9 ± 0.6, 0.03 ± 0.03 and 4.3 ± 0.8 pmol/L, respectively), consistent with the previous evidence of permanent plasma kallikrein activity in this disease. Kinin levels in the plasma of HAE-FXII patients did not differ from controls, suggesting that triggering factors for contact system activation are not active during remission.

Conclusion

BK1−5, BK2−9 and the sum of BK and its fragments determined by the sensitive LC-MS/MS technique are proposed as potential biomarkers of HAE-C1INH in remission while this was not applicable to HAE-FXII patients.

The place of scales and questionnaires in assessing the disease’s severity and the long-term prophylaxis’s prescribing in patients with hereditary angioedema

Hereditary angioedema is a hereditary life-threatening disease characterized by recurrent angioedema of various strength and localization. To date, definite diseases severity criteria have not been developed. There are many different factors to consider not only the frequency of episodes, but also their duration, strength, influence on the patient's appearance, the severity of the pain syndrome. Disease related quality of life, the number of work disability days, and the patient's satisfaction with the prescribed treatment are important. In addition, there are no criteria for prescribing long-term prophylaxis, and no parameters for choosing a specific drug. The introduction of specific scales and questionnaires developed to assess such characteristics as disease activity, disease control, quality of life in patients with recurrent angioedema into clinical practice seems to be the best solution for both questions. The comprehensive understanding of the diseases severity in a particular patient can be carried out with the combined use of assessment tools.

Considerations for transition from subcutaneous to oral prophylaxis in the treatment of hereditary angioedema

BACKGROUND

Hereditary angioedema (HAE) is a rare genetic disorder characterized by unpredictable localized episodes of edema, which is frequently managed with long-term prophylactic medications. Until recently, long-term prophylaxis has predominantly required regular intravenous or subcutaneous administration, however the recent approval of berotralstat (Orladeyo™) offers an orally administered prophylactic which may be associated with a lower burden of treatment compared to injectable options for some patients.

CASE PRESENTATION

This report describes four participants in the APeX-S trial who transitioned from subcutaneously administered lanadelumab (Takhzyro®) to daily oral berotralstat for long-term HAE prophylaxis. Lanadelumab dosing continued after berotralstat commencement in all patients and was tapered before discontinuation in three of the four patients. No substantial increases in HAE attack rates were observed after the transition to berotralstat monotherapy. One patient experienced a treatment-related adverse event (dyspepsia), which was mild and self-resolving.

CONCLUSIONS

All four patients described in this case series successfully transitioned from lanadelumab to berotralstat monotherapy for long-term prophylaxis without significant complications and without the use of a complex transition protocol. The decision to transition to berotralstat monotherapy and how the transition should be achieved was discussed between patient and physician, ensuring that the comfort and perspectives of the patients were considered during the treatment transition. This report highlights the importance of individualization of HAE management plans to address both the disease and treatment burdens of HAE, and thus to provide the best possible quality of life for each patient.

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.

Assessment and management of disease burden and quality of life in patients with hereditary angioedema: a consensus report

BACKGROUND

Hereditary angioedema (HAE) is a rare disease characterized by unpredictable, potentially life-threatening attacks, resulting in significant physical and emotional burdens for patients and families. To optimize care for patients with HAE, an individualized management plan should be considered in partnership with the physician, requiring comprehensive assessment of the patient's frequency and severity of attacks, disease burden, and therapeutic control. Although several guidelines and consensus papers have been published concerning the diagnosis and treatment of HAE, there has been limited specific clinical guidance on the assessment of disease burden and quality of life (QoL) in this patient population. Practical guidance is critical in supporting effective long-term clinical management of HAE and improving patient outcomes. The objective of this review is to provide evidence-based guidelines for an individualized assessment of disease burden and QoL in patients with HAE.

METHODS

A consensus meeting was held on February 29, 2020, consisting of 9 HAE experts from the United States and Europe with extensive clinical experience in the treatment of HAE. Consensus statements were developed based on a preliminary literature review and discussions from the consensus meeting.

RESULTS

Final statements reflect the consensus of the expert panel and include the assessment of attack severity, evaluation of disease burden, and long-term clinical management of HAE caused by C1-esterase inhibitor deficiency. Patient-reported outcome measures for assessing HAE attack severity and frequency are available and valuable tools; however, attack frequency and severity are insufficient markers of disease severity unless they are evaluated in the broader context of the effect on an individual patient's QoL. QoL assessments should be individualized for each patient and minimally, they should address the interference of HAE with work, school, social, family, and physical activity, along with access to and burden of HAE treatment. Advances in HAE therapies offer the opportunity for comprehensive, individualized treatment plans, allowing patients to achieve minimal attack burden with reduced disease and treatment burden.

CONCLUSION

This consensus report builds on existing guidelines by expanding the assessment of disease burden and QoL measures for patients with HAE.

A Robust Bioassay of the Human Bradykinin B2 Receptor that Extends Molecular and Cellular Studies: The Isolated Umbilical Vein

Bradykinin (BK) has various physiological and pathological roles. Medicinal chemistry efforts targeted toward the widely expressed BK B₂ receptor (B₂R), a G-protein-coupled receptor, were primarily aimed at developing antagonists. The only B₂R antagonist in clinical use is the peptide icatibant, approved to abort attacks of hereditary angioedema. However, the anti-inflammatory applications of B₂R antagonists are potentially wider. Furthermore, the B₂R antagonists notoriously exhibit species-specific pharmacological profiles. Classical smooth muscle contractility assays are exploited over a time scale of several hours and support determining potency, competitiveness, residual agonist activity, specificity, and reversibility of pharmacological agents. The contractility assay based on the isolated human umbilical vein, expressing B₂R at physiological density, was introduced when investigating the first non-peptide B₂R antagonist (WIN 64338). Small ligand molecules characterized using the assay include the exquisitely potent competitive antagonist, Pharvaris Compound 3 or the partial agonist Fujisawa Compound 47a. The umbilical vein assay is also useful to verify pharmacologic properties of special peptide B₂R ligands, such as the carboxypeptidase-activated latent agonists and fluorescent probes. Furthermore, the proposed agonist effect of tissue kallikrein on the B₂R has been disproved using the vein. This assay stands in between cellular and molecular pharmacology and in vivo studies.

Clinical characteristics and burden of illness in patients with hereditary angioedema: findings from a multinational patient survey

Background

Hereditary angioedema (HAE) is a rare, debilitating, genetic disease characterized by unpredictable, recurrent, and potentially fatal swelling of the skin and mucous membranes. We conducted a noninterventional, cross-sectional, web-based survey of patients with a self-reported diagnosis of HAE type 1/2 in Australia, Austria, Canada, France, Germany, Spain, Switzerland, and the United Kingdom to gain a comprehensive real-world understanding of the characteristics of HAE and its burden from the perspective of the patient. The survey included questions on clinical and demographic characteristics, burden of disease, and treatment. Instruments used to measure patient-reported outcomes included the Angioedema Quality of Life questionnaire (AE-QoL), 12-Item Short-Form Health Survey (SF-12v2), Angioedema Control Test (AECT), Hospital Anxiety and Depression Scale (HADS), and Work Productivity and Impairment questionnaire (WPAI). Data were analyzed with descriptive statistics.

Results

A total of 242 patients (67.4% female; mean [range] age 43.8 [18–92] years) completed the survey. The mean (SD) age at first symptoms was 11.5 (8.9) years, while diagnosis occurred at 20.8 (13.2) years. Patients reported a mean (SD) of 12.5 (14.1) attacks in the past 6 months. The most recent attack occurred within the past month in 79.7% of patients; most were of moderate severity, 6.6% affected the larynx, 21.9% lasted ≥ 3 days, and 76.4% were treated with on-demand medication. Hospitalizations and emergency/urgent care visits were highest for patients with more attacks. At the time of the survey, 62.4% of patients were using long-term prophylaxis, including 34.4% using androgens. Moderate to severe anxiety and depression were reported in 38.0% and 17.4% of patients, respectively, as measured using the HADS. The severity of anxiety and depression was associated with poorer quality of life and productivity, measured using the AECT (mean overall score 8.00 [moderate perceived disease control]), AE-QoL, WPAI, and SF-12v2. Scores for AECT, AE-QoL, and WPAI were also worse with a higher number of attacks.

Conclusions

This survey study of a broad international sample of patients with HAE showed that despite the availability of on-demand treatment and long-term prophylaxis for the prevention of attacks, patients across a wide geographical area continue to have high disease activity, likely due to restrictions in the availability of medications or incorrect use. Subsequently, significant disease burden, including impaired quality of life and mental health and decreased productivity, was evident. Increased patient education and access to newer, more effective therapies are needed.

Sugar Matters: Improving In Vivo Clearance Rate of Highly Glycosylated Recombinant Plasma Proteins for Therapeutic Use

Correct glycosylation of proteins is essential for production of therapeutic proteins as glycosylation is important for protein solubility, stability, half-life and immunogenicity. The heavily glycosylated plasma protein C1-inhibitor (C1-INH) is used in treatment of hereditary angioedema attacks. In this study, we used C1-INH as a model protein to propose an approach to develop recombinant glycoproteins with the desired glycosylation. We produced fully functional recombinant C1-INH in Chinese hamster ovary (CHO) cells. In vivo we observed a biphasic clearance, indicating different glycosylation forms. N-glycan analysis with mass spectrometry indeed demonstrated heterogeneous glycosylation for recombinant C1-INH containing terminal galactose and terminal sialic acid. Using a Ricinus Communis Agglutinin I (RCA₁₂₀) column, we could reduce the relative abundance of terminal galactose and increase the relative abundance of terminal sialic acid. This resulted in a fully active protein with a similar in vivo clearance rate to plasmaderived C1-INH. In summary, we describe the development of a recombinant human glycoprotein using simple screening tools to obtain a product that is similar in function and in vivo clearance rate to its plasma-derived counterpart. The approach used here is of potential use in the development of other therapeutic recombinant human glycoproteins.

In Vitro Modeling of Bradykinin-Mediated Angioedema States

Kinins (peptides related to bradykinin, BK) are formed from circulating substrates, the kininogens, by the action of two proteases, the kallikreins. The only clinical application of a BK receptor ligand, the B₂ receptor antagonist icatibant, is the treatment of the rare hereditary angioedema (HAE) caused by the deficiency of C1-esterase inhibitor (C1-INH). Less common forms of HAE (genetic variants of factor XII, plasminogen, kininogen) are presumably mediated by increased BK formation. Acquired forms of BK-mediated angioedema, such as that associated with angiotensin-I converting enzyme (ACE) inhibition, are also known. Antibody-based analytical techniques are briefly reviewed, and support that kinins are extremely short-lived, prominently cleared by ACE. Despite evidence of continuous activation of the kallikrein–kinin system in HAE, patients are not symptomatic most of the time and their blood or plasma obtained during remission does not generate excessive immunoreactive BK (iBK), suggesting effective homeostatic mechanisms. HAE-C1-INH and HAE-FXII plasmas are both hyperresponsive to fibrinolysis activation. On another hand, we suggested a role for the alternate tissue kallikrein–kinin system in patients with a plasminogen mutation. The role of the BK B₁ receptor is still uncertain in angioedema states. iBK profiles under in vitro stimulation provide fresh insight into the physiopathology of angioedema.