The international WAO/EAACI guideline for the management of hereditary angioedema-The 2017 revision and update

The CC2D2B is a novel genetic modifier of the clinical phenotype in patients with hereditary angioedema due to C1 inhibitor deficiency

Hereditary angioedema due to C1 inhibitor deficiency (HAE-C1-INH) is a rare genetic disorder caused by pathogenic variants in the SERPING1 gene and characterised by swelling and a highly variable clinical phenotype. We aimed to identify novel modifying genetic factors predisposing to the clinical symptoms. We performed whole exome sequencing (WES) and comprehensive bioinformatic analysis in symptomatic and asymptomatic (three duos) family members with HAE-C1-INH. Selected variants identified using WES (present in all asymptomatic and absent in symptomatic patients) were determined using Sanger sequencing. We included 88 clinically well-characterised HAE-C1-INH patients from south-eastern Europe (nine asymptomatic) from 42 unrelated families. We identified 39 variants in 23 genes (ANKRD36C, ARGFX, CC2D2B, IL5RA, IRF2BP2, LGR6, MRPL45, MUC3A, NPIPA1, NRG1, OR5M1, OR5M3, OR5M10, OR8U3, PLCL1, PRSS3, PSKH2, PTPRA, RTP4, SEZ6, SLC25A5, VWA3A, and ZNF790). We selected variants in CC2D2B and PLCL1, which were analysed using Sanger sequencing in the entire group of HAE-C1-INH. We found significant differences in the frequencies of the CC2D2B c.190A>G (rs17383738) variant between symptomatic and asymptomatic patients, where heterozygotes were more common in asymptomatic HAE-C1-INH patients in comparison to symptomatic patients (55 % vs 23%; P = 0.049, OR = 4.24, 95% CI 1.07-14.69). Our study identified novel genetic factors that modify the clinical variability of HAE-C1-INH. We further demonstrated, in a large cohort, the importance of the CC2D2B gene as a disease-modifying factor. Based on linkage disequilibrium analysis, the CCNJ and ZNF518A genes might also be involved in the clinical variability of HAE-C1-INH.

Hereditary angioedema in cardiac surgery: Perioperative management considerations for a rare disease

INTRODUCTION

Hereditary Angioedema is a rare disease caused by C1 esterase inhibitor deficiency leading to diffuse and potentially life-threatening oedema formation. Preventing attacks is critical, particularly for patients undergoing cardiac surgery.

CASE REPORT

We report a case of a 71-years-old woman with a history of Hereditary Angioedema scheduled for open-heart surgery on Cardiopulmonary Bypass. Multidisciplinar teamwork and patient-targeted strategy were crucial to obtain a favorable outcome.

DISCUSSION

Cardiac surgery is a major stressor for Angioedema attacks because of Complement cascade and inflammatory response activation leading to potential life-threatening oedema formation. In literature only few cases of complex open heart surgery under Cardiopulmonary Bypass are described.

CONCLUSION

Continuous updating and multidisciplinarity are key elements to manage patients with Hereditary Angioedema in cardiac surgery in order to reduce morbidity and mortality.

Hereditary angioedema in Spain: medical care and patient journey

BACKGROUND

Hereditary angioedema due to C1 inhibitor deficiency (HAE-C1INH) is a genetic rare disease characterized by recurrent, transient and unpredictable episodes of cold, non-pruriginous oedema without associated urticaria. The characteristics of the disease have a considerable impact on the quality of life of patients. The aim of this study was to increase understanding of the patient journey of HAE in Spain.

METHODS

A multidisciplinary committee of 16 HAE experts (allergy, immunology, emergency department, hospital pharmacy and nursing) and 3 representatives of the Spanish Hereditary Angioedema Patient Association (AEDAF) who were patients or caregivers participated in the study. A review of the publications on HAE treatment was performed. Semi-structured interviews were performed to HAE experts, patients, or caregivers. Three meetings with the experts, patients and caregivers were held to share, discuss, and validate data obtained from literature and interviews and to build the model.

RESULTS

Throughout the project, the patient journey has been drawn up, dividing it into the stages of pre-diagnosis, diagnosis and treatment/follow-up. Some areas for improvement have been identified. Firstly, there is a need to enhance awareness and training on HAE among healthcare professionals, with a particular emphasis on primary care and emergency department personnel. Secondly, efforts should be made to minimize patient referral times to allergy/immunology specialists, ensuring timely access to appropriate care. Thirdly, it is crucial to encourage the study of the relatives of diagnosed patients to early identify potential cases. Fourthly, equitable access to self-administered treatments should be ensured, facilitated by systems that enable medication delivery at home and proper education and training for patients. Equitable access to long-term prophylactic treatment should also be prioritized for all patients in need. To standardize HAE management, the development of consensus guidelines that reduce variability in clinical practice is essential. Lastly, promoting research studies to enhance knowledge of the disease and align its treatment with new developments in the healthcare field should be encouraged.

CONCLUSIONS

The knowledge of the patient journey in HAE allowed us to identify improvement areas with the final aim to optimize the disease management.

A quantitative systems pharmacology model of plasma kallikrein-kinin system dysregulation in hereditary angioedema

Hereditary angioedema (HAE) due to C1-inhibitor deficiency is a rare, debilitating, genetic disorder characterized by recurrent, unpredictable, attacks of edema. The clinical symptoms of HAE arise from excess bradykinin generation due to dysregulation of the plasma kallikrein-kinin system (KKS). A quantitative systems pharmacology (QSP) model that mechanistically describes the KKS and its role in HAE pathophysiology was developed based on HAE attacks being triggered by autoactivation of factor XII (FXII) to activated FXII (FXIIa), resulting in kallikrein production from prekallikrein. A base pharmacodynamic model was constructed and parameterized from literature data and ex vivo assays measuring inhibition of kallikrein activity in plasma of HAE patients or healthy volunteers who received lanadelumab. HAE attacks were simulated using a virtual patient population, with attacks recorded when systemic bradykinin levels exceeded 20 pM. The model was validated by comparing the simulations to observations from lanadelumab and plasma-derived C1-inhibitor clinical trials. The model was then applied to analyze the impact of nonadherence to a daily oral preventive therapy; simulations showed a correlation between the number of missed doses per month and reduced drug effectiveness. The impact of reducing lanadelumab dosing frequency from 300 mg every 2 weeks (Q2W) to every 4 weeks (Q4W) was also examined and showed that while attack rates with Q4W dosing were substantially reduced, the extent of reduction was greater with Q2W dosing. Overall, the QSP model showed good agreement with clinical data and could be used for hypothesis testing and outcome predictions.

Delay in diagnosis is the most important proximate reason for mortality in hereditary angio-oedema: our experience at Chandigarh, India

BACKGROUND

Hereditary angio-oedema (HAE) is a rare autosomal dominant disorder characterized clinically by recurrent episodes of nonpruritic subcutaneous and/or submucosal oedema. Laryngeal oedema is the commonest cause of mortality in patients with HAE. Prior to the availability of first-line treatment options for the management of HAE, mortality was as high as 30%. Mortality has significantly declined in countries where first-line treatment options are available and patients can access these therapies. There is a paucity of literature on the outcomes of patients with HAE in developing countries where availability of and access to first-line treatment options are still a challenge.

OBJECTIVES

To report our experience on mortality in patients with HAE and to report factors associated with the death of these patients.

METHODS

We carried out a record review of all patients diagnosed with HAE between January 1996 and August 2022. Families with HAE who had reported the death of at least one family member/relative from laryngeal oedema were studied in detail.

RESULTS

Of the 65 families (170 patients) registered in the clinic, 16 families reported the death of at least one family member/relative from laryngeal oedema (total of 36 deaths). Of these 16 families, 14 reported that 1 or more family members had experienced at least 1 attack of laryngeal oedema. One patient died during follow-up when she was taking long-term prophylaxis with stanozolol and tranexamic acid, while the remaining 35 patients were not diagnosed with HAE at the time of their death. At the time of death of all 36 patients, at least 1 other family member had symptoms suggestive of HAE, but the diagnosis was not established for the family.

CONCLUSIONS

To our knowledge, this is the largest single-centre cohort of patients with HAE in India reporting mortality data and factors associated with death in these families. The delay in diagnosis is the most important reason for mortality.

Plasma-derived C1 esterase inhibitor pharmacokinetics and safety in patients with hereditary angioedema

Background

Over 40 years of use demonstrates that complement 1 esterase inhibitor (C1-INH) concentrate is effective and well tolerated for acute edema attacks and prophylaxis in patients with hereditary angioedema. OCTA-C1-INH is a new stable, virus-inactivated, nanofiltrated concentrate of C1-INH derived from human plasma.

Objective

We investigated the pharmacokinetics and safety profile of new C1-INH in people with hereditary angioedema during an attack-free period.

Methods

In this prospective, multicenter, open-label, single-arm study, adults with hereditary angioedema type I/II received a single intravenous dose of 20 IU/kg C1-INH. Blood samples were taken ≤30 minutes before infusion, and 0, 0.25, 1, 2, 6, 12, 24, 48, 72, 120, 144, and 168 hours after infusion. The primary end point was assessing the pharmacokinetic parameters of C1-INH measured by C1-INH activity. Safety end points were also examined.

Results

Twenty patients received a single dose of 20 IU/kg new C1-INH with a mean (standard deviation) total dose of 1457.3 (356.51) IU. Mean (standard deviation) area under the curve normalized by dose was 51.6 (17.9) h∙IU/mL/IU, maximum blood concentration was 1.14 (0.989) IU/mL, incremental recovery was 0.0466 (0.051) (IU∙kg)/(IU∙mL), half-life was 0.598 (0.716) hours, and time to maximum concentration was 0.598 (0.716) hours. No thromboembolic events were recorded. No treatment-emergent adverse events were rated as severe/serious.

Conclusion

PK parameters of new C1-INH were in line with those reported for other C1-INH concentrates. New C1-INH demonstrated a favorable safety profile in patients with C1-INH deficiency. Further studies are warranted to determine the effectiveness and longer-term safety of new C1-INH.

A Cross-Sectional Study of Quality of Life in Patients Enrolled in the Romanian Hereditary Angioedema Registry

BACKGROUND

Hereditary angioedema (HAE) is a rare potentially life-threatening genetic disorder characterized by recurrent episodes of angioedema without wheals that can affect any part of the body. The unpredictability of the attacks and the risk of passing the disease to the offspring result in significant physical and emotional burdens for patients, with a negative impact on quality of life. Data about the health-related quality of life in HAE patients from Romania are scarce. This study aimed to evaluate the disease-specific quality of life in patients with HAE from Romania and to determine associated factors.

METHODS

The study included adult patients with HAE enrolled in the Romanian HAE Registry. Disease-specific quality of life was measured using the Hereditary Angioedema Quality of Life questionnaire, a cross-culturally adapted, internationally validated structured survey.

RESULTS

The survey was completed by 94 patients (64.9% females; 35.1% males). The mean age of the participants was 44.9 years (SD 14.1). Most patients (88.3%) had type I HAE and were from urban areas (63.8%). The mean ages at symptom onset and diagnosis were 15.1 (SD 11.1) and 36.1 (SD 14.1) years, respectively. The mean diagnosis delay was 20.5 years (SD 14.2). In the evaluated period, all patients had at least one vial of on-demand treatment at home, and 10 were on long-term prophylaxis treatment. The general and dimensional quality of life scores were slightly above the median values of the reference scales. While the general score was not associated with sex or residence, a statistically significant, negative, weak correlation was detected with diagnostic delay.

CONCLUSION

The results suggest that despite the availability of on-demand treatment for all patients, there is a need for other diagnostic and therapeutic interventions to improve the management of the disease and the quality of life for HAE patients from Romania.

Clinical practice of hereditary angioedema in Belgium: opportunities for optimized care

INTRODUCTION

Hereditary angioedema (HAE) is a rare disorder characterized by unpredictable painful and potentially life-threatening swelling episodes. The international WAO/EAACI guideline on the diagnosis and management of HAE was recently updated and provides up-to-date guidance for the management of. In this paper, we assessed to what extent the Belgian clinical practice was aligned with the revised guideline, and whether there were opportunities to optimise Belgian clinical practice in HAE.

METHODS

We compared the updated international guideline for HAE with information we acquired on Belgian clinical practice, a Belgian patient registry and expert opinion analysis. The Belgian patient registry was developed with the involvement of eight Belgian reference centers for HAE patients. Eight Belgian experts, physicians in the participating centers, included patients in the patient registry and participated in the expert opinion analysis.

RESULTS

The main action points to further optimise the Belgian clinical practice of HAE are Work towards total disease control and normalize patients' life by considering the use of new and innovative long-term prophylactic treatment options; (2) inform C1-INH-HAE patients about new long-term prophylactic therapies; (3) assure the availability of on-demand therapy for all C1-INH-HAE patients; (4) implement a more universally used assessment including multiple aspects of the disease (e.g. quality of life assessment) in daily clinical practice; and (5) continue and expand an existing patient registry to assure continued data availability on C1-INH-HAE in Belgium.

CONCLUSIONS

In light of the updated WAO/EAACI guideline, five action points were identified and several other suggestions were made to optimise the Belgian clinical practice in C1-INH-HAE.

Pathophysiology of bradykinin and histamine mediated angioedema

Angioedema is characterized by swelling localized to the subcutaneous and submucosal tissues. This review provides an overview of angioedema, including the different types, triggers, and underlying pathophysiologic mechanisms. Hereditary and acquired angioedema are caused by dysregulation of the complement and kinin pathways. In contrast, drug-induced and allergic angioedema involve the activation of the immune system and release of vasoactive mediators. Recent advances in the understanding of the pathophysiology of angioedema have led to the development of targeted therapies, such as monoclonal antibodies, bradykinin receptor antagonists, and complement inhibitors, which promise to improve clinical outcomes in patients with this challenging condition. To accurately diagnose and manage angioedema, an understanding of this condition's complex and varied pathophysiology is both necessary and critical.

A Comprehensive Management Approach in Pediatric and Adolescent Patients With Hereditary Angioedema

Hereditary angioedema (HAE) is a rare autosomal-dominant disorder; most cases are characterized by low plasma levels of C1 esterase inhibitor (C1-INH). Clinical manifestations of HAE due to C1-INH deficiency include unpredictable, acute, recurrent episodes of nonpruritic swelling that can affect the face, trunk, limbs, and the respiratory, gastrointestinal, and genitourinary tracts. Attacks can be disfiguring, disabling, painful, and even life-threatening if laryngeal swelling occurs. Symptoms of HAE generally manifest in childhood. Effective medications are available and approved to treat HAE in children. However, evidence informing use of these medications in pediatric clinical practice is limited. Hereditary angioedema management plans are critical to optimize outcomes and should address on-demand treatment for acute attacks and plans to prevent potentially fatal laryngeal attacks. The plan should also comprise a holistic approach to address nonclinical aspects of HAE, including quality of life (QoL) and psychological issues. This article provides an overview of HAE management principles that health care providers can apply to treat pediatric patients to improve their QoL.

[Experiencia inicial de Lanadelumab en una paciente mexicana con angioedema hereditario tipo I]

Background

Hereditary angioedema type 1 (HAE1) is an autosomal dominant disorder, characterized by quantitative and qualitative deficiency of C1 inhibitor, excessive production of bradykinin and causing recurrent angioedema in varying degrees of severity that affects quality of life and life itself. from the patients. Lanadelumab is a human monoclonal antibody, a specific inhibitor of plasma kallikrein, approved for long-term prophylaxis of HAE1.

Case report

A 59-year-old female patient, diagnosed with HAE 1 since November 1987, without therapeutic response to danazol, fresh frozen plasma, or C1 inhibitor derived from intravenous plasma, requiring 3 to 9 monthly vials of icatibant acetate due to angioedema. laryngeal, cutaneous and visceral with highly altered quality of life indices. Lanadelumab 300 mg subcutaneously every 14 days was started. At the start of treatment, the AECT1 score was 1 point; AE-Qol2: 57 points, AAS3: 32 points, being followed up at 5, 10 and 12 months. After one year of treatment, the records showed an AECT1 of 19 points; AE-Qol2: 36 points and AAS3: 5 points. The requirement for icatibant acetate has been no more than 3 vials per month.

Conclusion

In accordance with the literature, lanadelumab offered a significant decrease in angioedema activity and a significantly positive impact on the pa- tient's quality of life, confirming that lanadelumab is an effective option for long-term HAE prophylaxis. .

The Disease Burden and Societal Costs of Hereditary Angioedema

BACKGROUND

According to the current treatment guidelines, the goals of treatment of patients with hereditary angioedema (HAE) are to achieve total control of the disease and to normalize patients' lives.

OBJECTIVE

This study aims to establish the entire burden of HAE comprising disease control, treatment satisfaction, reductions in quality of life, and societal costs.

METHODS

Adult patients with HAE under treatment at the Dutch national center of reference completed a cross-sectional survey in 2021. The survey consisted of different questionnaires: angioedema-specific questionnaires (4-week Angioedema Activity Score and Angioedema Control Test), quality of life questionnaires (Angioedema Quality of Life [AE-QoL] questionnaire and EQ-5D-5L), the Treatment Satisfaction Questionnaire for Medication (TSQM), and societal costs questionnaires (iMTA Medical Consumption Questionnaire and iMTA Productivity Cost Questionnaire).

RESULTS

The response rate was 78% (69 of 88). The entire sample had a mean Angioedema Activity Score of 16.61, and 36% of participants had poorly controlled disease as expressed by the Angioedema Control Test. The mean quality of life in the entire sample was 30.99 as expressed by the AE-QoL and 0.873 as expressed by the EQ-5D-5L utility value. Utilities dropped by 0.320 points during an angioedema attack. TSQM scores ranged from 66.67 to 75.00 across its 4 domains. On average, total costs per year incurred €22,764, predominantly existing of HAE-medication costs. Total costs showed substantial variation between patients.

CONCLUSIONS

This study describes the entire burden of HAE among Dutch patients comprising disease control, quality of life, treatment satisfaction, and societal costs. These results can inform cost-effectiveness analyses that can aid reimbursement decisions for HAE treatments.

Hereditary Angioedema

Hereditary angioedema (HAE) is a rare autosomal dominant genetic disorder that usual results from a decreased level of functional C1-INH and clinically manifests with intermittent attacks of swelling of the subcutaneous tissue or submucosal layers of the respiratory or gastrointestinal tracts. Laboratory studies and radiographic imaging have limited roles in evaluation of patients with acute attacks of HAE except when the diagnosis is uncertain and other processes must be ruled out. Treatment begins with assessment of the airway to determine the need for immediate intervention. Emergency physicians should understand the pathophysiology of HAE to help guide management decisions.

Current challenges and future opportunities in patient-focused management of hereditary angioedema: A narrative review

Patients with hereditary angioedema (HAE) experience a high burden of disease due to unpredictable, painful, disfiguring, and potentially life-threatening HAE attacks. Multiple HAE-specific medications for the on-demand treatment, short-term and long-term prophylaxis of HAE attacks have entered the market in recent years; however, the availability and access to these medications may vary between different countries. For this review, PubMed and EMBASE databases were searched for guidelines, consensus statements, and other publications on HAE management as well as publications on quality of life in patients with HAE. The current guidelines and recent literature on HAE management in specific countries are summarized with the aim to highlight the similarities and differences between guideline recommendations and the country-specific clinical practice. Improvement in quality of life, which is a key goal in HAE management, is also discussed and the country-specific trends are highlighted. Finally, the ways to achieve a more patient-centric approach to HAE management within the framework set by the clinical management guidelines are examined.

Et barn med hevelse rundt øyet

BACKGROUND

A young boy presented with acute ethmoiditis and recurrent periorbital swelling. The periorbital swelling was confirmed to be caused by a rare condition.

CASE PRESENTATION

Debut symptoms were acute rhinitis, unilateral periorbital swelling, fatigue, and swelling in the temple region, probably caused by an insect bite. Magnetic resonance imaging (MRI) of the sinuses showed bilateral ethmoiditis and unilateral periorbital cellulitis without subperiostal abscess formation, and antibiotics were prescribed. Because of recurrence of the periorbital swelling, an interdisciplinary team started an investigation for a differential diagnosis. The infestation of Hypoderma tarandi was confirmed by recent history of hiking in reindeer habitat, typical clinical presentation and detection of IgG hypodermin C antibodies.

INTERPRETATION

Human myiasis by Hypoderma tarandi is a rare condition in Norway. Typical clinical signs are unaffected general condition, migration of swelling in the forehead, recurrent unilateral periorbital swelling and normal CRP levels. Early-stage diagnosis and treatment will contribute to rapid symptom relief and prevent rare eye and intracranial complications. This case illustrates the importance of investigation for other conditions when the disease course is unexpected. The authors emphasise that knowledge about this disease is important in a variety of medical specialties.

Efficacy, pharmacokinetics, and safety of subcutaneous C1-esterase inhibitor as prophylaxis in Japanese patients with hereditary angioedema: Results of a Phase 3 study

BACKGROUND

Hereditary angioedema (HAE) is a rare and potentially life-threatening genetic disorder characterized by recurrent attacks of angioedema. HAE types I and II result from deficient or dysfunctional C1-esterase inhibitor (C1-INH). This Phase 3 study assessed the efficacy, pharmacokinetics (PK), and safety of subcutaneous (SC) C1-INH in Japanese patients with HAE.

METHODS

The prospective, open-label, multicenter, single-arm Phase 3 study recruited patients with HAE types I or II to an initial run-in period, followed by a 16-week treatment period where patients received 60 IU/kg C1-INH (SC) twice weekly. The two primary endpoints were the time-normalized number of HAE attacks per month and C1-INH functional activity at Week 16.

RESULTS

Nine patients entered the treatment period and completed the study. Treatment with C1-INH (SC) significantly reduced the mean monthly attack rate from 3.7 during the run-in period to 0.3 during treatment (exploratory p value of within-patient comparison = 0.004). After the last dose of C1-INH (SC) at Week 16, the mean trough concentration of C1-INH was 59.8%, and the mean area under the plasma concentration-time curve to the end of the dosing period and to the last sample were 5317.1 and 13,091.5 h•%, respectively. During the study, there were no deaths, serious adverse events, or adverse events leading to study discontinuation.

CONCLUSIONS

C1-INH (SC) (60 IU/kg twice weekly) was efficacious and well tolerated as a prophylaxis against HAE attacks in Japanese patients with HAE types I or II, which was supported by the increased and maintained C1-INH functional activity. EudraCT Number 2019-003921-99; JapicCTI-205273.

An investigational oral plasma kallikrein inhibitor for on-demand treatment of hereditary angioedema: a two-part, randomised, double-blind, placebo-controlled, crossover phase 2 trial

BACKGROUND

Guidelines recommend effective on-demand therapy for all individuals with hereditary angioedema. We aimed to assess the novel oral plasma kallikrein inhibitor, sebetralstat, which is in development, for on-demand treatment of hereditary angioedema attacks.

METHODS

In this two-part phase 2 trial, individuals with type 1 or 2 hereditary angioedema aged 18 years or older were recruited from 25 sites, consisting of specialty outpatient centres, across nine countries in Europe and the USA. Individuals were eligible if they had experienced at least three hereditary angioedema attacks in the past 93 days, were not on prophylactic therapy, and had access to and the ability to self-administer conventional attack treatment. In part 1 of the trial, participants were given a single 600 mg open-label oral dose of sebetralstat to assess safety, pharmacokinetics, and pharmacodynamics of the dose. Part 2 was a randomised, double-blind, placebo-controlled, two-sequence, two-period (2 × 2) crossover trial; participants were randomly assigned (1:1) to either sequence 1, in which they were given a single dose of 600 mg of sebetralstat to treat the first eligible attack and a second dose of placebo to treat the second eligible attack, or sequence 2, in which they were given placebo to treat the first eligible attack and then 600 mg of sebetralstat to treat the second eligible attack. Participants and investigators were masked to treatment assignment. The primary endpoint was time to use of conventional attack treatment within 12 h of study drug administration, which was assessed in all participants who were randomly assigned to treatment and who received study drug for two attacks during part 2 of the study. Safety was assessed in all participants who received at least one dose of study drug, starting in part 1. This study is registered with ClinicalTrials.gov, NCT04208412, and is completed.

FINDINGS

Between July 2, 2019, and Dec 8, 2020, 84 individuals were screened and 68 were enrolled in part 1 and received sebetralstat (mean age 38·3 years [SD 13·2], 37 [54%] were female, 31 [46%] were male, 68 [100%] were White). 42 (62%) of 68 participants completed pharmacokinetic assessments. Sebetralstat was rapidly absorbed, with a geometric mean plasma concentration of 501 ng/mL at 15 min. In a subset of participants (n=6), plasma samples obtained from 15 min to 4 h after study drug administration had near-complete protection from ex vivo stimulated generation of plasma kallikrein and cleavage of high-molecular-weight kininogen. In part 2, all 68 participants were randomly assigned to sequence 1 (n=34) or sequence 2 (n=34). 53 (78%) of 68 participants treated two attacks (25 [74%] in the sequence 1 group and 28 [82%] in the sequence 2 group). Time to use of conventional treatment within 12 h of study drug administration was significantly longer with sebetralstat versus placebo (at quartile 1: >12 h [95% CI 9·6 to >12] vs 8·0 h [3·8 to >12]; p=0·0010). There were no serious adverse events or adverse event-related discontinuations.

INTERPRETATION

Oral administration of sebetralstat was well tolerated and led to rapid suppression of plasma kallikrein activity, resulting in increased time to use of conventional attack treatment and faster symptom relief versus placebo. Based on these results, a phase 3 trial to evaluate the efficacy and safety of two dose levels of sebetralstat in adolescent and adult participants with hereditary angioedema has been initiated (NCT05259917).

FUNDING

KalVista Pharmaceuticals.

Immunogenicity and Safety of Anti-SARS-CoV-2 mRNA Vaccines in a Cohort of Patients with Hereditary Angioedema

Many factors may trigger hereditary angioedema (HAE) attacks. This study aims to gain insights into the benefits and potential risks of COVID-19 vaccination in HAE patients, focusing particularly on the possibility of triggering attacks. We enrolled 31 patients with HAE undergoing two doses of the SARS-CoV-2 mRNA Comirnaty-BioNTech/Pfizer vaccine. To evaluate the possible influence of the vaccine on disease control and attack frequency, we administered the angioedema control test (AECT) 4-week version before (T0), 21 days after the first dose (T1), and between 21 and 28 days after the second dose (T2). Despite 5 patients (16.1%) experiencing attacks within 72 h of the first dose administration, no significant variation in attack frequency was observed before and after vaccination [F(2,60) = 0.123; p = 0.799]. In addition, patients reported higher AECT scores at T1 and T2 compared to T0 [F(2,44) = 6.541; p < 0.05; post hoc p < 0.05)], indicating that the disease was rather more controlled after vaccinations than in the previous period. All patients showed a positive serological response to the vaccine without significant differences from healthy controls (U = 162; p = 0.062). These observations suggest that the vaccine administration is safe and effective in HAE patients.

Large Predominance of Off-Label Prescriptions of C1-Inhibitor Concentrates and Icatibant in a Real-Life Setting: A Retrospective Clinical Study

C1-inhibitor (C1INH) concentrates and the selective bradykinin B2 receptor antagonist icatibant are approved only for treating hereditary angioedema with C1INH deficiency. Yet, they are regularly prescribed off label in other types of bradykinin-mediated angioedema including angiotensin-converting enzyme inhibitor (ACEi)-related and undetermined angioedema. We conducted a retrospective chart review of inpatient prescriptions of C1INH concentrates and icatibant between 2016 and 2020 in the University Hospital of Angers. The first outcome was the proportion of prescriptions with explicit indication. Then, we determined the compliance of prescriptions with European Medicines Agency approvals and the French bradykinin-mediated angioedema reference center guidelines. Finally, we estimated the economic impact of inappropriate prescribing. The therapeutic indication was explicit in 90.4% of prescriptions (n = 66/73). Only 17.8% of prescriptions were for hereditary angioedema with C1INH deficiency, while 31.5% were for ACEi-related and 28.7% for undetermined angioedema. However, most off-label prescriptions were consistent with the French bradykinin-mediated angioedema reference center guidelines (73.3%). We estimated that 13% of drug expenditures were potentially excessive. The predominance of off-label prescriptions may be explained by the infrequency of hereditary angioedema and the absence of approved alternatives in other types of bradykinin-mediated angioedema. Most attacks were related to ACEis. Epinephrine was rarely prescribed as first-line therapy in attacks of unknown origin. Given the high prices of these drugs, we advocate the development of a readily available management algorithm of angioedema to reduce inappropriate prescriptions in our center. In addition, we think that the drug prescription circuit should be redesigned to ensure the traceability of prescribed vials in the dispensing areas.

Interplay between C1-inhibitor and group IIA secreted phospholipase A2 impairs their respective function

High levels of human group IIA secreted phospholipase A₂ (hGIIA) have been associated with various inflammatory disease conditions. We have recently shown that hGIIA activity and concentration are increased in the plasma of patients with hereditary angioedema due to C1-inhibitor deficiency (C1-INH-HAE) and negatively correlate with C1-INH plasma activity. In this study, we analyzed whether the presence of both hGIIA and C1-INH impairs their respective function on immune cells. hGIIA, but not recombinant and plasma-derived C1-INH, stimulates the production of IL-6, CXCL8, and TNF-α from peripheral blood mononuclear cells (PBMCs). PBMC activation mediated by hGIIA is blocked by RO032107A, a specific hGIIA inhibitor. Interestingly, C1-INH inhibits the hGIIA-induced production of IL-6, TNF-α, and CXCL8, while it does not affect hGIIA enzymatic activity. On the other hand, hGIIA reduces the capacity of C1-INH at inhibiting C1-esterase activity. Spectroscopic and molecular docking studies suggest a possible interaction between hGIIA and C1-INH but further experiments are needed to confirm this hypothesis. Together, these results provide evidence for a new interplay between hGIIA and C1-INH, which may be important in the pathophysiology of hereditary angioedema.

Therapeutic monoclonal antibodies with a focus on hereditary angioedema

Monoclonal antibodies (mAbs) have been shown to be effective and generally safe across a continually expanding list of therapeutic areas. We describe the advantages and limitations of mAbs as a therapeutic option compared with small molecules. Specifically, we discuss a novel mAb in the treatment of hereditary angioedema (HAE), a rare and potentially life-threatening condition characterized by recurrent unpredictable swelling attacks. HAE is mediated by dysregulation of plasma kallikrein activity leading to overproduction of bradykinin. Current prophylactic treatment for HAE includes androgens or replacement of the endogenous plasma kallikrein inhibitor, C1 inhibitor. However, there remains an unmet need for an effective, less burdensome treatment option. Lanadelumab is a fully human mAb targeting plasma kallikrein. Results from clinical trials, including a pivotal Phase 3 study and its ensuing open-label extension study, demonstrated that lanadelumab is associated with few treatment-related adverse events and reduced the rate of HAE attacks. This novel treatment option has the potential to significantly improve the lives of patients with HAE.

"Super" SERPINs-A stabilizing force against fibrinolysis in thromboinflammatory conditions

The superfamily of serine protease inhibitors (SERPINs) are a class of inhibitors that utilise a dynamic conformational change to trap and inhibit their target enzymes. Their powerful nature lends itself well to regulation of complex physiological enzymatic cascades, such as the haemostatic, inflammatory and complement pathways. The SERPINs α2-antiplasmin, plasminogen-activator inhibitor-1, plasminogen-activator inhibitor-2, protease nexin-1, and C1-inhibitor play crucial inhibitory roles in regulation of the fibrinolytic system and inflammation. Elevated levels of these SERPINs are associated with increased risk of thrombotic complications, obesity, type 2 diabetes, and hypertension. Conversely, deficiencies of these SERPINs have been linked to hyperfibrinolysis with bleeding and angioedema. In recent years SERPINs have been implicated in the modulation of the immune response and various thromboinflammatory conditions, such as sepsis and COVID-19. Here, we highlight the current understanding of the physiological role of SERPINs in haemostasis and inflammatory disease progression, with emphasis on the fibrinolytic pathway, and how this becomes dysregulated during disease. Finally, we consider the role of these SERPINs as potential biomarkers of disease progression and therapeutic targets for thromboinflammatory diseases.

Consider Hereditary Angioedema in the Differential Diagnosis for Unexplained Recurring Abdominal Pain

Health care providers are likely to encounter patients with recurrent unexplained abdominal pain. Because hereditary angioedema (HAE) is a rare disease, it may not be part of the differential diagnosis, especially for patients who do not have concurrent skin swelling in addition to abdominal symptoms. Abdominal pain is very common in patients with HAE, occurring in up to 93% of patients, with recurrent abdominal pain reported in up to 80% of patients. In 49% of HAE attacks with abdominal symptoms, isolated abdominal pain was the only symptom. Other abdominal symptoms that commonly present in patients with HAE include distension, cramping, nausea, vomiting, and diarrhea. The average time from onset of symptoms to diagnosis is 6 to 23 years. Under-recognition of HAE in patients presenting with predominant gastrointestinal symptoms is a key factor contributing to the delay in diagnosis, increasing the likelihood of unnecessary or exploratory surgeries or procedures and the potential risk of related complications. HAE should be considered in the differential diagnosis for patients with unexplained abdominal pain, nausea, vomiting, and/or diarrhea who have complete resolution of symptoms between episodes. As highly effective targeted therapies for HAE exist, recognition and diagnosis of HAE in patients presenting with isolated abdominal pain may significantly improve morbidity and mortality for these individuals.

Effectiveness and safety of lanadelumab in ethnic and racial minority subgroups of patients with hereditary angioedema: results from phase 3 studies

Background

The COVID-19 pandemic has highlighted disparities in healthcare, particularly in the United States, even though disparities have existed since the organization of the modern healthcare system. Recruitment of patients from racial and ethnic minority groups is often minimal in phase 3 clinical trials, and is further exacerbated in the case of trials for rare diseases such as hereditary angioedema (HAE). This can lead to a gap in the understanding of minority patients’ experiences with these diseases and their response to potential treatment options.

Methods

We reviewed data from phase 3 double-blind (HELP) and open-label extension (HELP OLE) trials of lanadelumab, a monoclonal antibody developed for long-term prophylaxis against attacks of HAE. Efficacy (attack rate reduction) and safety (adverse events) results from White patients were compared descriptively to those from Hispanic/Latino patients, Black/African Americans, and other minority Americans.

Results

Not surprisingly, few minorities were recruited across both studies: 9.5% Black, 2.4% Asian, and 7.1% Hispanic/Latino versus 88.1% White and 91.7% non-Hispanic/non-Latino received lanadelumab in HELP, and 4.7% Black, 0.9% Asian, 0.9% other, and 6.1% Hispanic/Latino versus 93.4% White and 93.4% non-Hispanic/non-Latino were enrolled in HELP OLE. Although these studies were conducted in the United States, Canada, Europe, and Jordan, all minorities were from the United States. Despite the number of minority patients being far less than expected for the population, there was no evidence that either efficacy or adverse event profiles differed between ethnic or racial groups.

Conclusions

The HELP and HELP OLE studies described herein recruited far fewer minorities than would be ideal to represent these populations. However, evidence suggests that the effectiveness and tolerance of lanadelumab are similar between the groups. Nonetheless, the disparity in recruitment into research for minorities has significant room for improvement.

Trial registration NCT02586805, registered 26 October 2015, https://clinicaltrials.gov/ct2/show/record/NCT02586805. NCT02741596, registered 18 April 2016, https://clinicaltrials.gov/ct2/show/NCT02741596.

Long-term prophylaxis in hereditary angioedema management: Current practices in France and unmet needs

Background: Hereditary angioedema (HAE) is characterized by unpredictable and potentially life-threatening attacks of cutaneous and submucosal swelling. Over the past decade, new agents, based on a better understanding of the underlying biologic mechanisms of HAE, have changed the face of long-term prophylaxis (LTP). Objective: The objective was to describe current practices and unmet needs with regard to LTP for HAE in expert centers in France. Methods: The study was conducted in France in 2020. Based on their experience with patients with HAE who had visited their center at least once in the past 3 years, physicians from 25 centers who are expert in the management of HAE were requested to fill in a questionnaire that encapsulated their active patient list, criteria for prescribing LTP, and medications used. They were asked about potential unmet needs with currently available therapies. They were asked to express their expectations with regard to the future of HAE management. Results: Analysis was restricted to 20 centers that had an active patient file and agreed to participate. There were 714 patients with C1 inhibitor (C1-INH) deficiency, of whom 423 (59.2%) were treated with LTP. Altered quality of life triggered the decision to start LTP, as did the frequency and severity of attacks. Ongoing LTP included androgens (28.4%), progestins (25.8%), lanadelumab (25.3%), tranexamic acid (14.2%), intravenous C1-INHs (5.6%), and recombinant C1-INH (0.7%). Twenty-nine percent of the patents with LTP were considered to still have unmet needs. Physicians' concerns varied among therapies: poor tolerability for androgens and progestins, a lack of efficacy for tranexamic acid and progestins, dosage form, and high costs for C1-INHs and lanadelumab. Physicians' expectations encompassed more-efficacious and better-tolerated medications, easier treatment administration for the sake of improved quality of life of patients, and less-expensive therapies. Conclusion: Despite the recent enrichment of the therapeutic armamentarium for LTP, physicians still expressed unmet needs with currently available therapies.

Pregnancy in women with Hereditary Angioedema due to C1-inhibitor deficiency: Results from the ITACA cohort study on outcome of mothers and children with in utero exposure to plasma-derived C1-inhibitor

Background

In women with Hereditary Angioedema (HAE) due to C1-inhibitor (C1INH) deficiency (C1INH-HAE), pregnancy counseling and treatment can be challenging. Despite the evidence of the immediate favorable outcome and safety of plasma-derived (pd)C1INH concentrate, there are no data regarding any difference among women who underwent or not pdC1INH during pregnancy or on children with in utero exposure to pdC1INH. The present interview study aimed at analyzing outcome of C1INH-HAE mothers and children according to pdC1INH-exposure during pregnancies.

Methods

C1INH-HAE women who experienced at least 1 pregnancy were included from seven centers of the Italian Network for Hereditary and Acquired Angioedema (ITACA). The interview study retrospectively analyzed pregnancies who underwent (group 1) or not (group 2) pdC1INH. The overall goals of the study included immediate and long-term outcomes, in terms of outcomes in the time interval between pregnancy and survey.

Results

A total of 168 pregnancies from 87 included women were analyzed. At term delivery (>37 gestation-week, GW) has been registered in 73.8% of cases, while spontaneous abortion (SA) occurred in 14.2% of cases with a mean GW 7 ± 2. The group 1 including pdC1INH-treated pregnancies comprised a third of the cohort (51/168, time interval 1.5 ± 10.4 yrs), while the group 2 represented 69.6% (117/168, time interval 32.8 ± 14 yrs). The same prevalence of SA occurred when comparing group 1 (11.7%) with group 2 (15.4%) with a similar GW at SA. The group 1 was older at the pregnancy time and younger at the interview than the group 2 (P < 0.01 for both); moreover, the group 1 showed a higher prevalence of cesarean delivery (P < 0.0001). The overall prevalence of obstetrical syndromes was similar between two groups: however, gestational diabetes was described only in pdC1INH-untreated pregnancies. In utero pdC1INH-exposed children (n = 45) did not show differences compared with unexposed ones (n = 99) in neonatal short-term outcomes.

Conclusion

Through appropriate management and counseling, most of C1INH-HAE women undergo successful pregnancy and delivery. For pregnant C1INH-HAE women being treated with pdC1INH, our findings are reassuring and might lead to an improvement of both the knowledge about treatments and the experience of HAE itself.

Annular urticarial lesions

Annular urticarial configurations are often associated with acute and chronic urticaria. Such lesions may be short-lived, migratory, transient, pruritic, and resolving with no residual evidence, making the diagnosis of urticaria an obvious one. Annular urticarial lesions can be the presenting signs of various cutaneous and systemic diseases. The differentiation of urticarial lesions may be made by considering the duration of an individual lesion longer than 24 hours, with burning and pain sensation in the lesions or lack of pruritus; skin marks such as postinflammatory pigmentation or purpura after resolution of the lesions; associated scaling or vehiculation in the lesions; systemic symptoms such as arthralgia, fever or fatigue; and several abnormal laboratory findings. The main differential diagnoses of annular urticarial lesions include urticarial vasculitis, autoinflammatory syndromes, hypersensitivity reactions, and connective tissue diseases.

Shared decision-making in the management of hereditary angioedema: An analysis of patient and physician perspectives

Background: Hereditary angioedema (HAE) is a rare genetic disorder characterized by recurrent, localized episodes of edema. Current treatment guidelines highlight the importance of shared decision-making (SDM) during implementation of HAE management plans. Objective: To determine what constitutes a successful SDM approach in HAE management. Method: Qualitative telephone interviews, which lasted ∼1 hour, were conducted with four HAE physicians and four patients from the APeX-S trial. The physicians were asked to describe the structure and/or content of typical HAE prophylaxis consultations and factors to consider when selecting medications for long-term treatment. Insights from these interviews were used to develop an SDM process diagram. The patients were interviewed to assess how closely the diagram fit their perspectives on the HAE consultation and their involvement in decisions that concerned their care. Interview transcripts were assessed by the interviewer to determine the degree of SDM involvement in each consultation by using qualitative criteria from the literature. Results: Two physicians followed a high-SDM format, and one physician used a "blended" approach. The fourth physician followed a standard (low SDM) format. A successful SDM approach was found to require pre-visit planning, a commitment on behalf of the physician to use SDM methods to learn more about the patient, and empowerment of the patient to reflect on and vocalize his or her preferences and/or needs. Patients engaged in SDM were more likely to proactively request a treatment switch. Conclusion: The adoption of validated HAE-specific treatment decision aids, as well as measures to change the mindsets of patients and physicians, may facilitate successful implementation of SDM in HAE.Clinical Trial Registration: The APeX-S trial was registered with clinicaltrials.gov (NCT03472040).

The Icatibant Outcome Survey: 10 years of experience with icatibant for patients with hereditary angioedema

In patients with hereditary angioedema (HAE), bradykinin causes swelling episodes by activating bradykinin B₂ receptors. Icatibant, a selective bradykinin B₂ receptor antagonist, is approved for on-demand treatment of HAE attacks. The Icatibant Outcome Survey (IOS; NCT01034969) is an ongoing observational registry initiated in 2009 to monitor effectiveness/safety of icatibant in routine clinical practice. As of March 2019, 549 patients with HAE type 1 or 2 from the IOS registry had been treated, for 5995 total attacks. This article reviews data published from IOS over time which have demonstrated that effectiveness of icatibant in a real-world setting is comparable to efficacy in clinical trials; one dose is effective for the majority of attacks; early treatment (facilitated by self-administration) leads to faster resolution and shorter attack duration; effectiveness/safety of icatibant has been shown across a broad range of patient subgroups, including children/adolescents and patients with HAE with normal C1 inhibitor levels; and tolerability has been demonstrated in patients aged ≥65 years. Additionally, this review highlights how IOS data have provided valuable insights into patients' diagnostic journeys and treatment behaviors across individual countries. Such findings have helped to inform clinical strategies and guidelines to optimize HAE management and limit disease burden. This research was sponsored by Takeda Development Center Americas, Inc. Takeda Development Center Americas, Inc., provided funding to Excel Medical Affairs for support in writing and editing this manuscript.

Using an extended treatment regimen of lanadelumab in the prophylaxis of hereditary angioedema: a single-centre experience

Aim

To explore and compare the efficacy of standard (300 mg every 2 weeks) and extended (300 mg every 4 weeks) dosing regimens of lanadelumab for long-term prophylaxis of hereditary angioedema (HAE).

Methods

We conducted a retrospective chart review of all patients with HAE on lanadelumab, which identified a total of 9 patients: 5 females and 4 males. The median age of patients was 31 years (IQR 20.7). The mean number of attacks per month before starting lanadelumab was 5.9 (SD 6.3). Patients were started on 300 mg of lanadelumab subcutaneously, every 2 weeks (standard group, n = 5) or every 4 weeks (extended group, n = 4).

Results

We observed a statistically significant improvement in the number of angioedema attacks per month in all 9 patients (p = 0.007). Five out of 9 patients (56%) achieved complete remission from attacks after starting lanadelumab. The effect of lanadelumab on number of angioedema attacks was significant in both groups; extended group (p = 0.03) and standard group (p = 0.01).

Conclusion

Lanadelumab is a safe and effective agent for long-term prophylaxis of HAE. An extended dosing regimen was equally effective as prophylaxis compared to a standard regimen. Further studies are needed to compare the 2 regimens in a larger patient group.

Absorption, metabolism, and excretion of [14C]-sebetralstat (KVD900) following a single oral dose in healthy male participants

Sebetralstat is an investigational oral plasma kallikrein inhibitor for the on-demand treatment of hereditary angioedema. Six healthy male participants received one dose of 600 mg (540 µCi) [¹⁴C]-sebetralstat. Plasma concentrations of sebetralstat and levels of total radioactivity in plasma, urine, and faeces were determined. Metabolite profiles of radioactivity were generated, and major metabolites structurally characterised.Radioactivity was rapidly absorbed and was excreted with a mean of 95.8% (63.4% faeces; 32.4% urine) recovered by 216 h. Sebetralstat was the major drug-related component in urine and faeces, although metabolism predominated overall (main metabolites: M19 (des-[methoxy-fluoro-methylpyridine]-sebetralstat), M10 (N-des-pyridone-sebetralstat-carboxylic acid), M3 (pyridine O-desmethyl-sebetralstat), and M34 (pyridine dioxy-dihydro-sebetralstat)). Sebetralstat was the main radiolabelled component in plasma (mean of 64.1% of the total radioactivity AUC_0-24), followed by relatively low proportions of metabolites: M19 (7.10%), M3 (4.01%), and M10 (4.00%). Although M19 was >10% of the plasma radioactivity AUC_0-24, in one participant it comprised a mean of <10% of AUC_0-24. Plasma levels of M19 were measured at the NOAEL dose in a rat toxicology study, where higher exposure was observed vs. that in humans.Given these findings and the lack of pharmacological activity of M19, it was concluded that there was no unique or disproportionate circulating metabolite in humans.

Characteristics of Patients Who Underwent a Diagnostic Test for Hereditary Angioedema Admitted Due to Angioedema

OBJECTIVE

Hereditary angioedema (HAE) is clinically characterized by recurrent attacks of angioedema. This study evaluated the clinical findings and examination results of patients admitted due to angioedema who then underwent a diagnostic test for HAE. The study aimed to assess the contribution of laboratory findings to the diagnostic process and to determine clinicians' level of awareness regarding the differential diagnosis of angioedema and the appropriate laboratory tests.

METHODS

Pediatric patients suspected to have HAE based on the presence of angioedema and screened for C1 esterase inhibitor levels and/or function were included in the study.

RESULTS

A total of 136 patients were evaluated for a preliminary diagnosis of HAE in the presence of angioedema. Angioedema was accompanied by urticaria in 65 patients (47.7%) and itching in 24 patients (17.6%). Patients were evaluated using laboratory tests, C4 levels were studied in 124 patients (91.1%) and were found to be within normal reference limits. C1 esterase inhibitor levels were studied in all patients and were found to be within normal limits. C1 esterase inhibitor function was also studied in 101 patients (74.2%) and was found to be within normal limits.

DISCUSSION

It was concluded that clinicians keep HAE in mind when encountering angioedema, but that increasing their knowledge of clinical findings that assist in differential diagnosis among angioedema types would be useful. The study authors would like to emphasize that this topic should be included in the specialty training curriculum to raise the awareness of clinicians, especially pediatricians, about clinical HAE findings and the algorithmic approach to the differential diagnosis of angioedema.

Orphan Drug Use in Patients With Rare Diseases: A Population-Based Cohort Study

Background: Orphan drugs are used for the diagnosis, prevention and treatment of rare diseases that, in the European Union, are defined as disorders affecting no more than 5 persons in 10,000. So far, a total of around 800 orphan medicinal products have been approved by the European Medicines Agency, however the utilization profile of orphan drugs has yet to be explored. This study aimed at assessing the utilization profile of orphan drugs authorized for marketing by the Italian Medicines Agency using population-based data.

Methods: A total of 21 orphan drugs used in outpatient settings, approved in the European Union before or during the 2008–2018 period and involving 15 rare diseases, were included in the study. The monitored population included patients with one of the conditions surveilled by the population-based Tuscany Registry of Rare Diseases and diagnosed between 2000–2018. A multi-database approach was applied, by linking data from the registry with information collected in drug prescriptions databases. The prevalence and intensity of use were estimated for the selected orphan drugs and other non-orphan medications, used to treat the same rare disease and for which a change in the prevalence of use was hypothesized after authorization of the orphan drug.

Results: For some diseases (acquired aplastic anemia, tuberous sclerosis complex, most metabolic diseases) a low prevalence of orphan drugs use was observed (range between 1.1–12.5%). Conversely, orphan drugs were frequently used in hemophilia B, Wilson disease and idiopathic pulmonary fibrosis (maximum of 78.3, 47.6 and 41.8%, respectively). For hemophilia B and Leber’s hereditary optic neuropathy, there are currently no other medications used in clinical practice in addition to orphan drugs. Six orphan drugs were used for the treatment of pulmonary arterial hypertension, appearing the elective therapy for this disease, albeit with different utilization profiles (range of prevalence 1.7–55.6%).

Conclusion: To the best of our knowledge, this is the first study investigating the utilization profile of orphan drugs prescribed in a defined geographical area, and providing relevant information to monitor over time potential changes in the prevalence of these medications as well as in the health care decision making.

Icatibant use in Brazilian patients with hereditary angioedema (HAE) type 1 or 2 and HAE with normal C1-INH levels: findings from the Icatibant Outcome Survey Registry Study

Background

Hereditary angioedema can be caused by C1-Inhibitor (C1-INH) deficiency and/or dysfunction (HAE-1/2) or can occur in patients with normal C1-INH (HAE nC1-INH).

Methods

The Icatibant Outcome Survey (IOS; NCT01034969) registry monitors the safety and effectiveness of icatibant for treating acute angioedema.

Objective

Present findings from Brazilian patients with HAE-1/2 and HAE nC1-INH participating in IOS.

Results

42 patients were enrolled (HAE-1/2, n = 26; HAE nC1-INH, n = 16). Median age at symptom onset was significantly lower with HAE-1/2 vs. HAE nC1-INH (10.0 vs. 16.5y, respectively; p = 0.0105), whereas median age at diagnosis (31.1 vs. 40.9y; p = 0.1276) and the median time between symptom onset and diagnosis (15.0 vs. 23.8y; p = 0.6680) were numerically lower vs. HAE nC1-INH, respectively. One icatibant dose was used for > 95% of HAE attacks. Median (range) time-to-event outcomes were shorter for patients with HAE nC1-INH vs. HAE-1/2, including time to first administration (0.5 [0–96.0] vs. 1.0 [0–94.0]h, respectively), time from first administration to complete resolution (1.0 [0–88.0] vs. 5.5 [0–96.0]h, respectively), and total attack duration (7.0 [0.3–99.0] vs. 18.5 [0.1–100.0]h, respectively). Mean (SD) time from attack onset to resolution was significantly shorter for patients with HAE nC1-INH vs. HAE-1/2 (9.8 [18.7] vs. 19.6 [24.0]h, respectively; p = 0.0174). 83 adverse events (AEs) in 42 patients were reported; most were mild (66.3%) or moderate (13.3%) and non-serious (75.9%). The most common icatibant-related AE was injection site erythema (HAE-1/2, 34.6%; HAE nC1-INH, 18.8%).

Study limitations

This was an observational study without a treatment comparator and that relied on patient recall.

Conclusions

Findings demonstrate effectiveness and tolerability of icatibant in Brazilian HAE patients.

Long-term prophylaxis with lanadelumab for HAE: authorization for temporary use in France

Background

Hereditary angioedema (HAE) is associated with a heavy burden of illness.

Objective

To evaluate use of lanadelumab in a French Authorization for Temporary Use (ATU) program.

Methods

ATU requests were made between October 12, 2018, and March 13, 2019; patients were followed through September 23, 2019. At entry, patients received lanadelumab 300 mg every 2 weeks. HAE attack characteristics were evaluated at day (D) 0 and months (M) 3 and 6. Patients completed the Angioedema Quality of Life (AE-QoL) questionnaire at initiation and monthly and the Angioedema Activity Score questionnaire daily in 28 day cycles (AAS28).

Results

In total, 77 patients received ≥ 1 lanadelumab dose; 69 had ≥ 1 quarterly follow-up visit (analyzed population). Mean (standard deviation [SD]) lanadelumab exposure was 240.4 (53.7) days. Lanadelumab dose was modified in 12 patients (mostly to every 4 weeks). For the analyzed population, compared with attacks/month (mean [SD]) within 6 months before ATU (2.68 [2.54]), fewer attacks occurred between initiation and first visit (0.16 [0.42]; P < 0.001) or last visit (0.16 [0.42]; P < 0.001); D15 and last visit (0.15 [0.41]); and D70 and last visit (0.17 [0.70]). AE-QoL total and domain scores were significantly higher at initiation versus M3 and M6; 55% and 65% of patients, respectively, achieved a minimal clinically important difference from D0 to M3 and D0 to M6. Proportion of patients with AAS28 of 0 was higher during M3 (90%) and M6 (83%) than initiation (59%). The most frequently reported adverse events included headache (7.3%) and injection site pain (6.3%).

Conclusions

Lanadelumab reduced attack rates, improved quality of life, and was generally well tolerated.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13223-022-00664-4.

Overview of SERPING1 Variations Identified in Hungarian Patients With Hereditary Angioedema

Background

Hereditary angioedema (HAE) due to C1-inhibitor (C1-INH) deficiency (C1-INH-HAE) is a rare autosomal dominant disorder, characterized by recurrent, unpredictable edematous symptoms involving subcutaneous, and/or submucosal tissue. C1-INH-HAE may be caused by more than 700 different mutations in the gene encoding C1-INH (SERPING1) that may lead to decreased protein synthesis or to functional deficiency.

Methods

Concentrations of C1-INH, C4, C1q, and anti-C1-INH antibodies, as well as functional C1-INH activity were determined in subjects suffering from edematous symptoms and admitted to the Hungarian Angioedema Center of Reference and Excellence. In those patients, who were diagnosed with C1-INH-HAE based on the complement measurements, SERPING1 was screened by bidirectional sequencing following PCR amplification and multiplex ligation-dependent probe amplification. For detecting large deletions, long-range PCRs covering the entire SERPING1 gene by targeting 2–7 kb long regions were applied.

Results

Altogether 197 individuals with C1-INH deficiency belonging to 68 families were identified. By applying Sanger sequencing or copy number determination of SERPING1 exons, 48 different mutations were detected in 66/68 families: 5 large and 15 small insertions/deletions/delins, 16 missense, 6 nonsense, and 6 intronic splice site mutations. Two novel variations (p.Tyr199Ser [c.596A>C] and the duplication of exon 7) were shown to cosegregate with deficient C1-inhibitor level and activity, while two other variations were detected in single patients (c.797_800delinsCTTGGAGCTCAAGAACTTGGAGCT and c.812dup). A series of long PCRs was applied in the remaining 2 families without an identified mutation and a new, 2606 bp long deletion including the last 91 bp of exon 6 (c.939_1029+2515del) was identified in all affected members of one pedigree. In the remaining one family, a deep intronic SERPING1 variation (c.1029+384A>G) was detected by a targeted next-generation sequencing panel as reported previously.

Conclusions

Sequencing and copy number determination of SERPING1 exons uncover most pathogenic variants in C1-INH-HAE patients, and further methods are worth to be applied in cases with unrevealed genetic background. Since knowledge of the genetic background may support the establishment of the correct and early diagnosis of C1-INH-HAE, identification of causative mutations and reporting data supporting the interpretation on the pathogenicity of these variants is of utmost importance.

Prophylactic use of an anti-activated factor XII monoclonal antibody, garadacimab, for patients with C1-esterase inhibitor-deficient hereditary angioedema: a randomised, double-blind, placebo-controlled, phase 2 trial

BACKGROUND

Hereditary angioedema is associated with dysregulation of the kallikrein-kinin system. Factor XII (FXII) is a key initiator of the kallikrein-kinin system, which produces bradykinin, a central mediator of angioedema. Garadacimab (CSL Behring) is a first-in-class, fully human, immunoglobulin G4 monoclonal antibody targeting activated FXII, intended to prevent attacks in patients with C1-esterase inhibitor-deficient hereditary angioedema (HAE-C1-INH). We aimed to investigate garadacimab as a treatment every 4 weeks for patients with HAE-C1-INH.

METHODS

In this double-blind, placebo-controlled, phase 2 study, patients with HAE-C1-INH were recruited from 12 research centres in Canada, Germany, Israel, and the USA. Eligible patients were aged 18-65 years and must have had at least four attacks of any severity over a consecutive 2-month period during the 3 months before screening or initiation of previous hereditary angioedema prophylaxis. After a run-in period of 4-8 weeks, patients were randomly assigned (1:1:1:1), using an interactive response technology via block randomisation (block sizes of 1-4), to either placebo or 75 mg, 200 mg, or 600 mg garadacimab. Patients were given an initial intravenous loading dose, and then, on day 6 and every 4 weeks for 12 weeks, they were given a subcutaneous dose of their allocated treatment. The primary endpoint was the number of monthly attacks in the intention-to-treat population (defined as all patients who underwent screening, provided consent, and were assigned to treatment) during the 12-week subcutaneous administration period assessed in the 200 mg and 600 mg garadacimab groups versus placebo. Safety was assessed in all patients who received at least one dose or partial dose of study treatment. This study is registered with ClinicalTrials.gov, NCT03712228.

FINDINGS

Between Oct 29, 2018, and Aug 28, 2019, 54 patients were screened, of whom 32 were randomly assigned to either placebo (n=8) or 75 mg (n=9), 200 mg (n=8), or 600 mg (n=7) garadacimab. The median age was 39·5 years (28·0-52·5) and 18 (56%) of 32 patients were female and 14 (34%) were male. The median number of monthly attacks during the 12-week subcutaneous treatment period was 4·6 (IQR 3·1-5·0) with placebo, 0·0 (0·0-0·4) with 75 mg garadacimab, 0·0 (0·0-0·0) with 200 mg garadacimab, and 0·3 (0·0-0·7) with 600 mg garadacimab. Compared with placebo, the rate of attacks was significantly reduced with garadacimab at 200 mg (reduced by 100% [95% CI 98-101]; p=0·0002) and 600 mg (reduced by 93% [54-110]; p=0·0003). No serious adverse events, deaths, or adverse events of special interest (anaphylaxis, thromboembolic events, and bleeding events) were observed.

INTERPRETATION

Garadacimab 200 mg and 600 mg every 4 weeks significantly reduced the number of monthly attacks versus placebo and was well tolerated during the study. Garadacimab is an efficacious, subcutaneous prophylaxis in patients with HAE-C1-INH and warrants phase 3 evaluation.

FUNDING

CSL Behring.

Psychometric study of the SF-36v2 in hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE)

BACKGROUND

The generic 36-item Short-Form Health Survey (SF-36v2) has been used to assess health related quality of life in adult patients with hereditary angioedema due to C1-inhibitor deficiency (C1-INH-HAE) even though it has not yet been validated for use in this specific disease.

OBJECTIVE

This study aims to validate the SF-36v2 for use in adult patients with C1-INH-HAE.

RESULTS

There was a very low item non-response rate (1-3.4%), with a high ceiling effect in 25/35 items and a low floor effect in 3/35 items. A moderate ceiling effect was observed in 5/8 dimensions of the SF-36v2, whereas no floor effect was noticed in any of the dimensions. Internal consistency was good to excellent with Cronbach's alpha coefficient ranging between 0.82 and 0.93 for the different dimensions. Construct validity was good: seven out of the 8 hypotheses defined on clinical criteria were confirmed, discriminant validity assessment showed significant differences among patients with different C1-INH-HAE severity, convergent validity showed a good correlation among the physical and mental component summaries of the SF-36v2 and the HAE-QoL total score (0.45 and 0.64 respectively, P < 0.001). Test-retest reliability was high with intraclass correlation coefficient varying from 0.758 to 0.962. The minimal clinically important difference was calculated by distribution methods and small differences in the domain scores and in the component summaries scores were shown to be meaningful.  CONCLUSIONS: The psychometric properties of the SF-36v2 show it can be a useful tool to assess HRQoL in adult patients with C1-INH-HAE, although with some content validity limitation.

METHODS

The psychometric properties of the SF-36v2 were evaluated in an international setting based on responses from 290 adult C1-INH-HAE patients in 11 countries.

Identification of novel biomarkers to distinguish bradykinin-mediated angioedema from mast cell-/histamine-mediated angioedema

BACKGROUND

The pathophysiology of the underlying paroxysmal permeability disturbances in angioedema (AE) is not well understood.

METHODS

To identify clinical and laboratory parameters specific for a certain AE subtype, 40 AE patients were prospectively enrolled: 15 hereditary (HAE), 13 ACE-inhibitor induced (ACE-AE), and 12 mast cell-mediated without wheals in chronic spontaneous urticaria (CSU-AE). Ten healthy subjects served as controls. Serum levels of markers indicating activation of the ficolin-lectin pathway, of endothelial cells, or those indicating impairment of vascular integrity or inflammation were assessed by enzyme-linked immunosorbent assay.

RESULTS

New routine clinical diagnostic criteria could not be identified, not even for distinguishing bradykinin-mediated (BK-) AE (ie, HAE and ACE-AE) from mast cell-/histamine-mediated CSU-AE. However, FAP-α and tPA were significantly increased in all AE compared to controls. In HAE, FAP- α, tPA, uPAR, pentraxin-3, Tie-2, sE-selectin, and VE-cadherin were significantly increased compared to controls. In HAE compared to CSU-AE and ACE-AE, sE-Selectin, Tie-2, and VE-Cadherin were significantly increased, whereas for Ang-2 the difference was significant compared to CSU-AE only. Tie-2 correlated strongly negatively with C4, C1-INH activity, and C1-INH function.

CONCLUSIONS

This study is the first to compare HAE, ACE-AE, and CSU-AE. Although significance is limited by small sample size, Tie-2 was identified as a new promising biomarker candidate for HAE. FAP- α and tPA might serve as a marker for AE in general, whereas sE-selectin and Ang-2 were increased in BK-AE only. Our results add information to the role of endothelial dysfunction and serine proteases in different AE subtypes.

The international WAO/EAACI guideline for the management of hereditary angioedema – The 2021 revision and update

Hereditary Angioedema (HAE) is a rare and disabling disease for which early diagnosis and effective therapy are critical. This revision and update of the global WAO/EAACI guideline on the diagnosis and management of HAE provides up-to-date guidance for the management of HAE. For this update and revision of the guideline, an international panel of experts reviewed the existing evidence, developed 28 recommendations, and established consensus by an online DELPHI process. The goal of these recommendations and guideline is to help physicians and their patients in making rational decisions in the management of HAE with deficient C1-inhibitor (type 1) and HAE with dysfunctional C1-inhibitor (type 2), by providing guidance on common and important clinical issues, such as: 1) How should HAE be diagnosed? 2) When should HAE patients receive prophylactic on top of on-demand treatment and what treatments should be used? 3) What are the goals of treatment? 4) Should HAE management be different for special HAE patient groups such as children or pregnant/breast feeding women? 5) How should HAE patients monitor their disease activity, impact, and control? It is also the intention of this guideline to help establish global standards for the management of HAE and to encourage and facilitate the use of recommended diagnostics and therapies for all patients.

Initial characteristics and follow-up of patients with a diagnosis of angiotensin-converting enzyme inhibitor induced angioedema

Background: A differential diagnosis between angiotensin-converting enzyme inhibitor (ACEi) angioedema (AE) and histaminergic AE (hAE) might be challenging. Follow-up data may help discriminate these conditions but are scarcely reported. Objective: To report on the follow-up of patients with suspected ACEi-AE and to describe the baseline characteristics of AE attacks in patients with a diagnosis of ACEi-AE after follow-up. Methods: Sixty-four patients with suspected ACEi-AE (i.e., with exposure to ACEi before the first attack, no urticaria associated, and normal C1-inhibitor levels) and at least one follow-up visit were included. Data were retrospectively collected at baseline and during the follow-up. Results: After the follow-up, the diagnosis of ACEi-AE was probable in only 30 patients. The remaining patients were reclassified as having probable hAE (21 patients) or undetermined-mechanism AE (13 patients). Patients with ACEi-AE were mostly men (61%), with a median age of 64 years (interquartile range [IQR] ±17 years), with a highly variable delay from ACEi introduction (median: 23 months; interquartile range: 103 months). Attacks preferentially involved lips (50%), tongue (47%), and throat (30%). Interestingly, patients with probable ACEi-AE after a follow-up also frequently presented with a history of allergy and atopic conditions (20%), attacks with preferential evening onset (25%), and spontaneous resolution in < 24 hours (26%), which are usually considered as suggestive of hAE. ACEi-AE attacks responded to icatibant in 79% of the patients. Conclusion: Patients with probable ACEi-AE were mostly men with facial involvement. A third of the patients with an initial suspected diagnosis of ACEi-AE had a final diagnosis of probable hAE. Although a follow-up of all patients should be a standard of care, it is critical to the correct diagnosis in the case of suspected bradykinin-associated AE, which may actually be due to histamine.

Time Trade-Off Utilities for Hereditary Angioedema Health and Caregiver States

BACKGROUND

Hereditary angioedema (HAE) is an inherited chronic rare disease characterised by recurrent swelling attacks that are associated with significant physical and psychological burden. There is limited understanding of the effect of attack location on this burden and of caregiver burden.

OBJECTIVE

Our objective was to capture the relative burden of HAE health and caregiver states, including different attack locations, through a time trade-off (TTO) analysis involving participants from the general public.

METHODS

Qualitative interviews were undertaken to inform vignette development for the TTO study, including vignettes for abdominal, facial, hand and laryngeal attack health states, and an attack-free and caregiver state. Members of the general public in England rated vignettes in TTO interviews, which included a visual analogue scale (VAS) component. For the development of the health state vignettes, qualitative interviews with 15 patients, 5 caregivers and 1 clinical expert were performed. TTO analysis was based on vignette valuation completed by 100 members of the general public.

RESULTS

The TTO values were as follows: attack-free, 0.783 (standard deviation [SD] 0.316); hand: 0.582 (SD 0.380); facial: 0.483 (SD 0.448); abdominal: 0.345 (SD 0.458); and laryngeal: 0.128 (SD 0.529). The caregiver rating was 0.762 (SD 0.303). V' scores were similar and consistent with TTO values.

CONCLUSION

TTO utility values demonstrate that HAE places a significant burden on patients, which is influenced by attack location, and on caregivers. These utility weights can provide important information on quality of life for future economic evaluations of treatments.

How satisfactory is on-demand icatibant from the patients' perspective in real life?

Background: Patients' satisfaction is important for the success of the management of chronic diseases. Objective: Our aim was to evaluate the satisfaction level of the patients with hereditary angioedema (HAE) for icatibant treatment. Methods: Patients with HAE C1 esterase inhibitor (C1-INH) were evaluated by using a questionnaire that included details of their icatibant-treated attacks. Patients' demographic and clinical features were collected from their medical records and personal attack diaries. The visual analog scale was used for determining the attack severity. Results: Of the total 161 patients with HAE C1-INH, 91% had HAE type I and were included in the study. Patients reported a median (interquartile range [IQR]) attacks of 2 (0.5-3) per month and 16 (4.5-36) attacks per year. The median (IQR) frequency of attacks treated with icatibant was 6 (0-20) per year. The mean ± standard deviation (SD) duration of treatment with icatibant was 3 ± 2.3 years. The self-administration rate was 91.3%. The mean ± SD time to administration and time to onset of symptom resolution were 1.6 ± 1.1 hours and 1.7 ± 1.3 hours, respectively. There was a correlation between the time to administration and time to onset of symptom resolution (r = 0.566; p < 0.0001). A total of 125 patients (77%) reported that they were very satisfied or satisfied with icatibant. No correlation was observed between the satisfaction level and the attack sites; however, the patients with more severe attacks were more satisfied with icatibant (p < 0.0001). A total of 52 patients reported 74 mild local reactions. Systemic reactions were not observed. Conclusion: The current real-life study showed that icatibant was safe and effective. Moreover, the patients' satisfaction level with icatibant was high. We believe that the availability of icatibant should be encouraged during HAE attacks because it enables patients to be more involved in their disease management.

Specific Targeting of Plasma Kallikrein for Treatment of Hereditary Angioedema: A Revolutionary Decade

Hereditary angioedema (HAE) is a rare, chronic, genetic disease that presents with nonpruritic angioedema of the face, extremities, airway (can be life-threatening), genitourinary system, and abdomen. These symptoms can significantly impair daily activities. Hereditary angioedema is classified into HAE owing to a deficiency of functional C1INH (HAE-C1INH) or HAE with normal C1INH (HAE-nl-C1INH). Both type I and II HAE-C1INH result from inherited or spontaneous mutations in the SERPING1 gene, which encodes for C1INH. These mutations result in C1INH dysfunction, leading to uncontrolled plasma kallikrein activity with excessive bradykinin production. Bradykinin receptor activation leads to vasodilation, increased vascular permeability, and smooth muscle contractions, resulting in submucosal angioedema through fluid extravasation. Hereditary angioedema nl-C1INH is caused by either a known or unknown genetic mutation. The underlying mechanism of HAE-nl-C1INH is less well understood but is thought to be related to bradykinin signaling. Plasma kallikrein inhibitors have been developed to inhibit the kallikrein-kinin pathway to prevent (prophylactic) and treat on-demand (acute) HAE attacks. Several of these medications are delivered through subcutaneous or intravenous injection, although new and emerging therapies include oral formulations. This article provides a historical review and describes the evolving landscape of available kallikrein inhibitors to treat HAE-C1INH.