Safety and efficacy of icatibant self-administration for acute hereditary angioedema

Hereditary angioedema with normal C1 esterase inhibitor: Current paradigms and clinical dilemmas

Background: A diagnosis of hereditary angioedema (HAE) with normal C1 esterase inhibitor (HAE-nl-C1-INH) can be challenging and pharmacologic management is not well defined. Objective: The objective was to discuss practical considerations in the clinical management of HAE-nl-C1-INH by using illustrative clinical vignettes to highlight and/or address select challenges. Methods: This was a narrative review. Results: Symptoms of HAE-nl-C1-INH overlap with HAE types I and II; the heterogeneity of presentation and symptom burden are diagnostic challenges. A patient history, with particular attention to whether urticaria or other symptoms of mast cell mediator release are present, is important because such symptoms would strongly suggest a mast cell-mediated pathway. A family history of angioedema is informative but a lack thereof does not rule out diagnosis. Expected laboratory findings would be normal for C4, C1-INH level and function, and Complement 1q; a genetic mutational analysis may be helpful, but current assays do not include all known mutations; most cases are categorized as unknown. To align with guideline-directed treatment approaches, the following stepwise approach is suggested for suspected HAE-nl-C1-INH: (1) thoroughly investigate the possibility of response to histaminergic and/or mast cell-targeting treatments; (2) if patients with normal C4, C1-INH level and/or function fail adequate trials with histamine/mast cell-directed therapy or have a mutation that suggests bradykinin pathway involvement, follow HAE type I and II treatment guidelines. Response to medications approved for HAE types I/II provides compelling support for a high clinical suspicion of HAE-nl-C1-INH. De-labeling an HAE-nl-C1-INH diagnosis may be appropriate if the initial diagnosis was made without adequate evaluation or if new information and/or testing indicates that the patient does not actually have HAE. Conclusion: Key unmet needs in HAE-nl-C1-INH include lack of confirmatory biomarker(s) for diagnosis and lack of prospective controlled clinical studies of pharmacologic products in this patient population.

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.

Clinical profile and treatment outcomes in patients with hereditary angioedema with normal C1 esterase inhibitor

Background

Hereditary angioedema (HAE) is often caused by low serum levels or functional deficiency in C1 inhibitor (C1-INH); however, in some cases, C1-INH serum level and function are measured as normal (HAE-nl-C1INH). Management of HAE-nl-C1INH is similar to management of HAE with C1-INH deficiency, including on-demand therapy for angioedema attacks and, potentially, prophylaxis. Recombinant human C1 esterase inhibitor (rhC1-INH) is indicated for treatment of acute HAE attacks. This study assessed the clinical profile and treatment outcomes in an HAE-nl-C1INH population with a history of rhC1-INH treatment.

Methods

Medical records containing patient-reported outcomes from ten US treatment centers were analyzed retrospectively for medical history, angioedema attack characteristics, attack treatments, and clinical outcomes.

Results

Twenty-three patients were included, with wide US geographic representation. Most patients (87.0%) were female; median age was 36.0 years (range, 19–67 years). Of 20 patients with available data, 4 had their first angioedema attack during childhood (aged <12 years), 3 during adolescence (aged 12–17 years), and 13 during adulthood (aged 18–29 years, n = 7; aged ≥30 years, n = 6). Median age at HAE-nl-C1INH diagnosis was 31.5 years (range, 9–59 years). Previous failed treatments included high-dose antihistamines (n = 20) and corticosteroids (n = 20). Use of US Food and Drug Administration (FDA)–approved HAE therapy positively impacted patient-reported assessments of angioedema attacks. Most patients were taking rhC1-INH or lanadelumab as prophylaxis and icatibant or rhC1-INH for acute management. Most patients reported improved disease control with these therapies, including reductions in angioedema attack frequency and severity. Although most patients were receiving prophylactic therapy, availability of treatment for breakthrough attacks was important.

Conclusion

Findings from this retrospective study support use of FDA-approved HAE medications for prophylaxis and acute treatment of HAE attacks in patients with HAE-nl-C1INH. Individualized HAE treatment regimens were needed to optimize therapeutic outcomes.

Icatibant promotes patients' behavior modification associated with emergency room visits during an acute attack of hereditary angioedema

Hereditary angioedema due to C1-inhibitor (C1-INH) deficiency (HAE-C1-INH) induces an acute attack of angioedema. In 2018, icatibant available for self-possession and subcutaneous self-administration was licensed for on-demand treatment in addition to intravenous C1-INH administration in Japan. We retrospectively evaluated the percentage of attacks in critical parts at emergency room (ER) visits and the time until visiting ER for C1-INH administration before and after the initial prescription of icatibant. The percentage of attacks in critical parts at ER visits before the prescription was 69.2%, but that was 80.0% when patients visited ER for additional C1-INH administration after the self-administration of icatibant. The time from the onset of an acute attack to visiting ER for the additional treatment after the self-administration of icatibant significantly increased from 6.2 h to 19.2 h (p < 0.001). Icatibant, therefore, promoted the patients' behavior modification associated with ER visits for C1-INH administration during an acute attack of HAE-C1-INH.

Safety and Outcomes Associated with the Pharmacological Inhibition of the Kinin-Kallikrein System in Severe COVID-19

Background: Coronavirus disease 19 (COVID-19) can develop into a severe respiratory syndrome that results in up to 40% mortality. Acute lung inflammatory edema is a major pathological finding in autopsies explaining O₂ diffusion failure and hypoxemia. Only dexamethasone has been shown to reduce mortality in severe cases, further supporting a role for inflammation in disease severity. SARS-CoV-2 enters cells employing angiotensin-converting enzyme 2 (ACE2) as a receptor, which is highly expressed in lung alveolar cells. ACE2 is one of the components of the cellular machinery that inactivates the potent inflammatory agent bradykinin, and SARS-CoV-2 infection could interfere with the catalytic activity of ACE2, leading to the accumulation of bradykinin. Methods: In this case control study, we tested two pharmacological inhibitors of the kinin–kallikrein system that are currently approved for the treatment of hereditary angioedema, icatibant, and inhibitor of C1 esterase/kallikrein, in a group of 30 patients with severe COVID-19. Results: Neither icatibant nor inhibitor of C1 esterase/kallikrein resulted in changes in time to clinical improvement. However, both compounds were safe and promoted the significant improvement of lung computed tomography scores and increased blood eosinophils, which are indicators of disease recovery. Conclusions: In this small cohort, we found evidence for safety and a beneficial role of pharmacological inhibition of the kinin–kallikrein system in two markers that indicate improved disease recovery.

A case of hereditary angioedema due to C1-inhibitor deficiency with recurrent abdominal pain diagnosed 40 years after the occurrence of the initial symptom

Hereditary angioedema due to C1-inhibitor deficiency (HAE-C1-INH) is a rare disease, which induces an acute attack of angioedema mediated by bradykinin. HAE-C1-INH can cause serious abdominal pain when severe edema develops in the gastrointestinal tract. However, because it takes a long time, 13.8 years on average in Japan, from the occurrence of the initial symptom to the diagnosis due to low awareness of the disease, undiagnosed HAE-C1-INH patients sometimes undergo unnecessary surgical procedures for severe abdominal pain. We herein present a 56-year-old patient with HAE-C1-INH, who underwent numerous abdominal operations. He frequently needed hospitalization with the administration of opioid due to severe abdominal pain. However, after he was accurately diagnosed with HAE-C1-INH at 55 years of age, he could start self-administration for an acute attack with icatibant, a selective bradykinin B2 receptor antagonist. Consequently, he did not need hospitalizing for ten months after the beginning of the treatment. A series of an accurate diagnosis and appropriate treatment for HAE-C1-INH improved his quality of life. Thus, HAE-C1-INH should be considered, when we meet patients with unidentified recurrent abdominal pain. This case highlights significance of an early diagnosis and appropriate treatment for HAE-C1-INH.

Pathophysiology of Hereditary Angioedema (HAE) Beyond the SERPING1 Gene

Hereditary Angioedema (HAE) is an autosomal dominant disorder characterized clinically by recurrent episodes of swelling involving subcutaneous tissues, gastrointestinal tract, and oro-pharyngeal area. Gene mutations are the most common genetic cause of HAE and observed in more than 90% of patients. More than 700 mutation variants have been described so far. Patients with angioedema who have no mutations in the gene for C1-INH and normal levels and activity of this inhibitor are labelled: normal C1 inhibitor HAE. These include genetic mutations in factor 12 gene, plasminogen gene, angiopoietin gene, kininogen 1, and myoferlin genes. The clinical manifestations of patients with these mutations are similar to with patients with C1-INH gene mutations. However, a later age of onset, oro-pharyngeal involvement, and higher female preponderance have been reported in these rare subtypes of hereditary angioedema. With the advent and increased accessibility of whole-exome sequencing, it is expected that new genetic defects and novel pathophysiological pathways will be identified in families with HAE of unknown cause or normal C1-INH angioedema. This review covers some of the recent advances in the field of HAE. The review focuses on pathophysiology of HAE beyond the well-known C1-INH deficiency phenotypes, including various biomarkers that can serve the diagnosis and management of these rare disorders.

Management of hereditary angioedema in Japan: Focus on icatibant for the treatment of acute attacks

Hereditary angioedema (HAE) is characterized by unpredictable, recurring and painful swelling episodes that can be disabling or even life-threatening. Awareness of HAE has progressively grown worldwide, and options for treatment of acute attacks and prevention of future attacks continue to expand; however, unmet needs in diagnosis and treatment remain. In Japan, recognition of HAE within the medical community remains low, and numerous obstacles complicate diagnosis and access to treatment. Importance of timely treatment of HAE attacks with on-demand therapies is continually demonstrated; recommended agents per the WAO/EAACI treatment guidelines published in 2018 include C1 inhibitor (C1-INH) concentrate, ecallantide, and icatibant. In Japan, multiple factors contribute to delayed HAE treatment (potentially leading to life-threatening consequences), including difficulties in finding facilities at which C1-INH agents are readily available. Recognition of challenges faced in Japan can help promote efforts to address current needs and expand access to effective therapies. Icatibant, a potent, selective bradykinin B₂ receptor antagonist, has demonstrated inhibition of various bradykinin-induced biological effects in preclinical studies and has shown efficacy in treating attacks in various clinical settings (e.g. clinical trials, real-world studies), and HAE patient populations (e.g. with C1-INH deficiency, normal C1-INH). Icatibant was approved in Japan for the treatment of HAE attacks in September 2018; its addition to the HAE treatment armamentarium contributes to improved patient care. In Japan, disease awareness and education campaigns are warranted to further advance the management of HAE patients in light of the unmet needs and the emerging availability of modern diagnostic approaches and therapies.

[Diagnosis and treatment of hereditary angioedema with normal C1-inhibitor level]

Hereditary angioedema (HAE) with normal C1-inhibitor level is a rare potentially life-threatening disorder with autosomal dominant inheritance which was first described in 2000. Its clinical presentation is similar to HAE with C1-deficiency. The review is summarized data about its prevalence, mechanisms, genetics and diagnostic criteria. Different subtypes and treatment options (on demand, short term and long-term prophylaxis) are discussed. We describe family clinical cases of 2 female patients with normal C1-inhibitor and plasminogen gene mutation. Their features were late diagnosis (in 10 and 25 years after the onset of symptoms), family history (similar genetic mutation in 3 female members of the same family, including 1-asymtomatic) and combination of face, tongue, larynx and abdominal angioedema in patient and her sibling.

Review of icatibant use in the Winnipeg Regional Health Authority

BACKGROUND

This is a retrospective review of the Winnipeg Regional Health Authority's (WRHA) angioedema patients who were dispensed icatibant in hospital. Icatibant is a bradykinin B2 receptor antagonist indicated for Hereditary Angioedema (HAE) types I and II and is used off-label for HAE with normal C1INH (HAE-nC1INH) and ACE-inhibitor induced angioedema (ACEIIAE). The WRHA's use of icatibant is regulated by the Allergist on call. We characterized icatibant's use and the timeline from patient presentation, compared the real-world experience with the FAST-3 trial and hypothesized the factors which may affect response to icatibant.

METHODS

Background data were collected on patients. Angioedema attack-related data included administered medications, performed investigations and the timeline to endpoints such as onset of symptom relief. Data was analyzed in R with the package "survival." Time-to-event data was analyzed using the Peto-Peto Prentice method or Mann-Whitney U-test. Data was also compared with published clinical trial data using the Sign Test. Fisher's Exact Test was used to produce descriptive statistics.

RESULTS

Overall, 21 patients accounted for 23 angioedema attacks treated with icatibant. Approximately half the patients had a diagnosis of HAE-nC1IHN and half of ACEIIAE. Of those presenting with angioedema, 65% were first treated with conventional medication. Patients without a prior angioedema diagnosis were evaluated only 40-50% of the time for C4 levels or C1INH function or level. The median time from patients' arrival to the emergency department until the Allergy consultant's response was 1.77 h. Patients with HAE-nC1IHN had median times to onset of symptom relief and final clinical outcome (1.13 h, p = 0.34; 3.50 h, p = 0.11) similar to those reported in FAST-3 for HAE I/II. Patients with ACEIIAE had longer median times to onset of symptom relief (4.86 h, p = 0.01) than predicted.

CONCLUSIONS

HAE-nC1INH may be an appropriate indication for treatment with icatibant. Conversely, the results of this study do not support the use of icatibant for the treatment of ACEIIAE, concordant with a growing body of literature. Patients should be stratified into groups of more- or less-likely icatibant-responders through history and laboratory investigations in order to prevent potential delays.

Orthognathic Surgery in Hereditary Angioedema With Normal C1 Inhibitor: A Clinical Response to Concentrated C1 Inhibitor Against Angioedema Attack

Hereditary angioedema (HAE) is a rare autosomal dominant disorder characterized by episodes of localized swelling, often of life-threatening severity. HAE due to C1 inhibitor (C1-INH) deficiency is common and is divided into types 1 and 2, but HAE with normal C1-INH is exceedingly rare. Herein, we describe the case of a patient with HAE with normal C1-INH undergoing orthognathic surgery. A 24-year-old woman came to our hospital with a diagnosed jaw deformity and commenced preoperative orthodontic treatment before scheduled orthognathic surgery. During the preoperative period, she experienced mild hoarseness. The hoarseness worsened, and computed tomography revealed mild laryngeal edema. Serum C1-INH, C3, C4, and CH50 levels were normal. Her younger sister had reportedly experienced a similar episode of lip edema previously. These findings supported a diagnosis of HAE with normal C1-INH. She underwent orthognathic surgery in close consultation with a hematologist and anesthesiologist at the age of 33 years. The surgery was completed without complications. She reported throat tightness 4 days after surgery, although her facial swelling was consistent with the procedure performed and was not remarkable. Concentrated C1-INH was administered, and the throat tightness slowly resolved within approximately 1 hour. Twenty-five days after surgery, she was discharged with reduced facial swelling. In the present case, orthognathic surgery was performed successfully in a patient with the exceedingly rare condition of HAE with normal C1-INH, in close consultation with a hematologist and an anesthesiologist. Postoperative throat tightness was successfully treated via the administration of concentrated C1-INH. Concentrated C1-INH administration can be considered in patients with HAE and normal C1-INH who experience angioedemic attack, keeping in mind that it may be slow to take effect.

Wolf in the sheep's clothing: intestinal angioedema mimicking infectious colitis

Hereditary angioedema (HAE) is a relatively rare clinical entity that can potentially cause life-threatening airway or intestinal oedema, patients with the latter usually presents with symptoms of gastroenteritis like vomiting, diarrhoea and abdominal pain. Here, we present a unique case of a less recognised type of HAE that is type III in a patient who presented with signs and symptoms consistent with infectious colitis. She previously had similar episodes and was managed multiple times with antibiotics, with no satisfactory response. There, she underwent extensive diagnostic evaluation. On the basis of findings of further investigations on the current visit, she was eventually diagnosed with intestinal angioedema. To the best of our knowledge, the present paper represents the third reported case of type III HAE-induced intestinal angioedema. Additionally, we undertake a literature review of HAE.

Subcutaneous Icatibant for the Treatment of Hereditary Angioedema Attacks: Comparison of Home Self-Administration with Administration at a Medical Facility

BACKGROUND

Hereditary angioedema (HAE) is a life-threatening disorder characterized by recurrent angioedema. Icatibant, a subcutaneous bradykinin-B2-receptor antagonist, is an effective on-demand therapy. Data outside the United States suggest that self-administration is tolerated and patient-preferred compared with administration by health care professionals at medical facilities (HCP-administration).

OBJECTIVE

A prospective, multicenter study was conducted in the United States to compare icatibant self-administration and HCP-administration.

METHODS

Subjects 18 years or older with type I or II HAE were recruited. The first 2 HAE attacks after enrollment were treated at medical facilities. Subjects were instructed by a health care professional on self-administration during icatibant treatment for the second HAE attack. Icatibant was self-administered for all subsequent attacks. For each treated HAE attack, efficacy, safety, and tolerability data were recorded.

RESULTS

Nineteen patients with HAE received icatibant for 79 distinct HAE attacks. Mean attack duration was significantly shorter with self-administration (n = 50; 547 ± 510 minutes) than with HCP-administration (n = 29; 968 ± 717 minutes; P = .006). Mean time to treatment was significantly shorter with self-administration (143 ± 226 minutes) than with HCP-administration (361 ± 503 minutes; P < .0001). Shorter times to treatment were associated with shorter time from treatment to symptom resolution (r = 0.35; P = .02). Improvements in visual analog scale score and patient symptom score from pretreatment to 4 hours postinjection were comparable between self-administration and HCP-administration. There were no serious adverse events or discontinuations due to adverse events with self-administration or HCP-administration.

CONCLUSIONS

Icatibant self-administration shortened attack duration and time to treatment, with no difference in safety or local tolerability compared with HCP-administration. These findings support icatibant as an effective on-demand option for home-based treatment.

Hereditary angioedema with normal C1 inhibitor in a French cohort: Clinical characteristics and response to treatment with icatibant

Introduction

The clinical characteristics and icatibant‐treatment outcomes of patients with hereditary angioedema with normal C1 inhibitor (HAE‐nC1 INH) are limited.

Methods

We retrospectively analyzed data from French HAE patients enrolled in the Icatibant Outcome Survey registry (from July 2009 to September 2013) to compare disease characteristics and the effectiveness and safety of acute icatibant‐treated angioedema attacks in patients with HAE‐nC1 INH, HAE with C1 INH deficiency (type I), or dysfunction (type II).

Results

One center in Grenoble contributed 22 patients with HAE‐nC1 INH and a family history of HAE while 15 centers across France contributed 153 patients with HAE type I and seven patients with HAE type II. Patients with HAE‐nC1 INH compared to HAE type I, respectively, were more likely to be female (88.1% vs. 63.4%), older at median age of disease onset (21 years vs. 15 years), and have a greater rate of abdominal (80% vs. 61%) and laryngeal (23% vs. 14%) attacks. Icatibant was effective in both groups though the median time to resolution of attack was significantly longer in the HAE‐nC1 INH group (20.0 h, 37 attacks) versus the HAE type I group (14.0 h, 67 attacks). Icatibant was self‐administered for 96.1% of attacks in patients with HAE‐nC1 INH and 75.8% in patients with HAE type I. No serious adverse side effects related to icatibant were reported.

Conclusions

These data help further define the disease characteristics of HAE‐nC1 INH in the French population and extend the limited data reporting the safe and effective use of icatibant in acute treatment of angioedema in French patients diagnosed with HAE‐nC1 INH.

Expert perspectives on hereditary angioedema: Key areas for advancements in care across the patient journey

BACKGROUND

Published literature documents the substantial burden of hereditary angioedema (HAE) with C1 inhibitor deficiency on the quality of life and work productivity of patients. However, despite advances in the field and the availability of guidelines to advise health care providers (HCP) on the diagnosis and management of HAE, there are still many challenges to overcome. For example, delayed diagnosis and misdiagnosis are common, and treatment practices vary worldwide.

OBJECTIVE

An international expert panel was convened to consider opportunities for improvements that would benefit patients with HAE.

METHODS

Based on professional and personal experiences, the experts developed schematics to describe the journey of patients through the following stages: (1) onset of symptoms and initial evaluation; (2) referral/diagnosis; and (3) management of HAE. More importantly, the panel identified key areas in which it was possible to optimize the support provided to patients and HCPs along this journey.

RESULTS

Overall, this approach highlighted the need for wider dissemination of algorithms and scientific data to more effectively educate HCPs from multiple disciplines and the need for more research to inform appropriate treatment decisions. Furthermore, HAE awareness campaigns, accurate online information, and referral to patient advocacy groups were all considered helpful approaches to support patients.

CONCLUSION

More detailed and widespread information on the diagnosis and management of HAE is needed and may lead to advancements in care throughout the journey of the patient with HAE.

Efficacy of on-demand treatment in reducing morbidity in patients with hereditary angioedema due to C1 inhibitor deficiency

BACKGROUND

Angioedema due to hereditary deficiency of C1 inhibitor causes temporarily disability. Guidelines recommend early on-demand treatment of attacks to reduce morbidity. In this prospective observational study, we evaluated the efficacy of on-demand approach.

METHODS

From January 2009 to August 2014, data on attacks and treatments were collected from 227 patients from our centre in Milan.

RESULTS

A total of 4244 attacks were reported; 50% were treated with approved therapies (pdC1-INH or icatibant), 15% were with tranexamic acid, and 35% were not treated. Attack locations were peripheral cutaneous (46%), abdominal (34%), multiple (12%), facial (5%) and laryngeal (3%). Attack severities were moderate (48%), mild (28%) and severe (24%). Median attack duration (data available for 2393 attacks) with approved therapies was 10 h, significantly shorter than without treatment (45 h) or with tranexamic acid (38 h). Most of the treatments were self-administered: 93% with icatibant and 59% with pd-C1-INH. Median attack duration with icatibant was 8 and 11.5 h with pd-C1 INH. Median time from onset of symptoms to drug administration was 1 h with icatibant and 2 h with pd-C1INH and median time from drug administration to complete resolution was 5.5 and 8 h, respectively. Second treatment was required in 12.7% of icatibant-treated attacks and in 1.9% of pdC1-INH-treated attacks.

CONCLUSION

This study provides evidence that on-demand treatment is effective in reducing disease-related morbidity. The use of on-demand treatment in Italy has increased up to 50% of attacks in the last years, reflecting a better adherence to international guidelines.

Presentation, diagnosis and treatment of angioedema without wheals: a retrospective analysis of a cohort of 1058 patients

BACKGROUND

The first classification of angioedema without wheals was recently reported and comprises different forms of the disease distinguished by aetiology, mediator of oedema and inheritance.

METHODS

In total, 1725 consecutive patients with angioedema without wheals were examined at our centre between 1993 and 2012. We excluded from the analysis 667 patients because of incomplete data or because angioedema was related to a specific factor.

RESULTS

According to the new classification of angioedema, the 1058 patients included in this analysis were diagnosed with hereditary (HAE; n = 377) or acquired angioedema (AAE; n = 681). The former group included HAE with C1-inhibitor (C1-INH) deficiency (C1-INH-HAE; n = 353) and HAE with normal C1-INH levels (n = 24), of which six had a factor XII mutation (FXII-HAE) and 18 had disease of unknown origin (U-HAE). The AAE group included disease with C1-INH deficiency (C1-INH-AAE; n = 49), AAE related to angiotensin-converting enzyme inhibitor treatment (n = 183), idiopathic histaminergic (IH-AAE; n = 379) and idiopathic nonhistaminergic angioedema (InH-AAE; n = 70). We compared hereditary and AAE with uncertain aetiopathogenesis: the FXII-HAE and U-HAE groups pooled (FXII/U-HAE) versus InH-AAE. The median age at onset of FXII/U-HAE and InH-AAE was 26 and 38 years, respectively. In addition, 56% of patients with FXII/U-HAE and 81% of those with InH-AAE reported more than five attacks per year (median duration of 48 h). The location of angioedema in patients with FXII/U-HAE versus those with InH-AAE was the following: face, 70% versus 86%; tongue, oral cavity or larynx, 55% versus 68%; limbs, 70% versus 56%; and gastrointestinal mucosa, 50% versus 20%. Prophylaxis with tranexamic acid was effective in all six patients with U-HAE and in 37 of 38 with InH-AAE who were started on this treatment.

CONCLUSION

Our findings in this cohort of patients with angioedema provide new information on the clinical characteristics, diagnosis and treatment of this disease.

Paediatric hereditary angioedema: a survey of UK service provision and patient experience

Hereditary angioedema (HAE) is a rare disease characterized by episodes of potentially life-threatening angioedema. For affected children in the United Kingdom, there are relatively few data regarding disease prevalence, service organization and the humanistic burden of the disease. To improve knowledge in these areas, we surveyed major providers of care for children with HAE. A questionnaire was sent to major paediatric centres to determine patient numbers, symptoms, diagnostic difficulties, management and available services. In addition, all patients at a single centre were given a questionnaire to determine the experiences of children and their families. Sixteen of 28 centres responded, caring for a total of 111 UK children. Seven children had experienced life-threatening crises. One-third of patients were on long-term prophylactic medication, including C1 inhibitor prophylaxis in four children. Eight centres reported patients who were initially misdiagnosed. Broad differences in management were noted, particularly regarding indications for long-term prophylaxis and treatment monitoring. We also noted substantial variation in the organization of services between centres, including the number of consultants contributing to patient care, the availability of specialist nurses, the availability of home therapy training and the provision of patient information. Ten of 12 patient/carer questionnaires were returned, identifying three common themes: the need to access specialist knowledge, the importance of home therapy and concerns around the direct effect of angioedema on their life. To our knowledge, this study represents the first dedicated survey of paediatric HAE services in the United Kingdom and provides useful information to inform the optimization of services.

Canadian hereditary angioedema guideline

Hereditary angioedema (HAE) is a disease which is associated with random and often unpredictable attacks of painful swelling typically affecting the extremities, bowel mucosa, genitals, face and upper airway. Attacks are associated with significant functional impairment, decreased Health Related Quality of Life, and mortality in the case of laryngeal attacks. Caring for patients with HAE can be challenging due to the complexity of this disease. The care of patients with HAE in Canada is neither optimal nor uniform across the country. It lags behind other countries where there are more organized models for HAE management, and where additional therapeutic options are licensed and available for use. The objective of this guideline is to provide graded recommendations for the management of patients in Canada with HAE. This includes the treatment of attacks, short-term prophylaxis, long-term prophylaxis, and recommendations for self-administration, individualized therapy, quality of life, and comprehensive care. It is anticipated that by providing this guideline to caregivers, policy makers, patients and their advocates, that there will be an improved understanding of the current recommendations regarding management of HAE and the factors that need to be considered when choosing therapies and treatment plans for individual patients. The primary target users of this guideline are healthcare providers who are managing patients with HAE. Other healthcare providers who may use this guideline are emergency physicians, gastroenterologists, dentists and otolaryngologists, who will encounter patients with HAE and need to be aware of this condition. Hospital administrators, insurers and policy makers may also find this guideline helpful.

Icatibant, an inhibitor of bradykinin receptor 2, for hereditary angioedema attacks: prospective experimental single-cohort study

CONTEXT AND OBJECTIVE

Hereditary angioedema (HAE) with C1 inhibitor deficiency manifests as recurrent episodes of edema involving the skin, upper respiratory tract and gastrointestinal tract. It can be lethal due to asphyxia. The aim here was to evaluate the response to therapy for these attacks using icatibant, an inhibitor of the bradykinin receptor, which was recently introduced into Brazil.

DESIGN AND SETTING

Prospective experimental single-cohort study on the efficacy and safety of icatibant for HAE patients.

METHODS

Patients with a confirmed HAE diagnosis were enrolled according to symptoms and regardless of the time since onset of the attack. Icatibant was administered in accordance with the protocol that has been approved in Brazil. Symptom severity was assessed continuously and adverse events were monitored.

RESULTS

24 attacks in 20 HAE patients were treated (female/male 19:1; 19-55 years; median 29 years of age). The symptoms were: subcutaneous edema (22/24); abdominal pain (15/24) and upper airway obstruction (10/24). The time taken until onset of relief was: 5-10 minutes (5/24; 20.8%); 10-20 (5/24; 20.8%); 20-30 (8/24; 33.4%); 30-60 (5/24; 20.8%); and 2 hours (1/24; 4.3%). The time taken for complete resolution of symptoms ranged from 4.3 to 33.4 hours. Adverse effects were only reported at injection sites. Mild to moderate erythema and/or feelings of burning were reported by 15/24 patients, itching by 3 and no adverse effects in 6.

CONCLUSION

HAE type I patients who received icatibant responded promptly; most achieved improved symptom severity within 30 minutes. Local adverse events occurred in 75% of the patients.

Open-label, multicenter study of self-administered icatibant for attacks of hereditary angioedema

BACKGROUND

Historically, treatment for hereditary angioedema (HAE) attacks has been administered by healthcare professionals (HCPs). Patient self-administration could reduce delays between symptom onset and treatment, and attack burden. The primary objective was to assess the safety of self-administered icatibant in patients with HAE type I or II. Secondary objectives included patient convenience and clinical efficacy of self-administration.

METHODS

In this phase IIIb, open-label, multicenter study, adult patients were trained to self-administer a single 30-mg icatibant subcutaneous injection to treat their next attack. Icatibant-naïve patients were treated by an HCP prior to self-administration. Evaluations included adverse event (AE) reporting, a validated questionnaire for convenience, and visual analog scale for efficacy.

RESULTS

A total of 151 patients were enrolled; 104 had an attack requiring treatment during the study, and 97 patients (19 naïve) were included in the self-administration cohort. Recurrence or worsening of HAE symptoms (22 of 97) was the most commonly reported AE; rescue medications including icatibant (N = 3) and C1-inhibitor concentrate (N = 6) were used in 13 cases. Overall, 89 of 97 patients used a single injection of icatibant. No serious AEs or hospitalizations were reported. Most patients (91.7%) found self-administration preferable to administration in the clinic. The median time to symptom relief (3.8 h) was comparable with results from controlled trials of icatibant.

CONCLUSIONS

With appropriate training, patients were successfully able to recognize HAE attacks and decide when to self-administer icatibant. This, coupled with the patient-reported high degree of satisfaction, convenience and ease of use supports the adoption of icatibant self-administration in clinical practice.

Guidance for diagnosis and treatment of acute angioedema in the emergency department: consensus statement by a panel of Italian experts

Angioedema attacks, characterized by the transient swelling of the skin and mucosae, are a frequent cause of visits to the emergency department. Swellings of the oral cavity, tongue, or larynx can result in life-threatening airway obstruction, while abdominal attacks can cause severe pain and often lead to unnecessary surgery. The underlying pathophysiologic process resulting in increased vascular permeability and plasma extravasation is mediated by vasoactive molecules, most commonly histamine and bradykinin. Based on the mediator involved, distinct angioedema forms can be recognized, calling for distinct therapeutic approaches. Prompt recognition is challenging for the emergency physician. The low awareness among physicians of the existence of rare forms of angioedema with different aetiologies and pathogenesis, considerably adds to the problem. Also poorly appreciated by emergency personnel may be the recently introduced bradykinin-targeted treatments. The main objective of this consensus statement is to provide guidance for the management of acute angioedema in the emergency department, from presentation to discharge or hospital admission, with a focus on identifying patients in whom new treatments may prevent invasive intervention.

Diagnosis and Treatment of Bradykinin-Mediated Angioedema: Outcomes from an Angioedema Expert Consensus Meeting

Several types of angioedema exist beyond hereditary angioedema (HAE) types I/II; however, the diagnostic and treatment needs of these conditions are not well understood. Noticeably, there are no licensed treatments available for other forms of angioedema beyond HAE types I/II, and similarly they are unresponsive to conventional antihistamine/glucocorticoid treatment. A group of angioedema experts met in Budapest in May 2013 to discuss such issues, presenting their experience, reviewing available literature and identifying unmet diagnostic and treatment needs in three different angioedema types: HAE with normal C1-inhibitor (C1-INH; previously referred to as type III HAE); nonallergic angiotensin-converting enzyme inhibitor (ACEI)-induced angioedema (ACEI-AAE), and acquired angioedema due to C1-INH deficiency (C1-INH-AAE). The group identified unmet diagnostic and treatment needs in HAE-nC1-INH, C1-INH-AAE and ACEI-AAE, explored remedies and made recommendations on how to diagnose and treat these forms of angioedema. The group discussed the difficulties associated with using diagnostic markers, such as the level and function of C1-INH, C1q and C4 to reliably diagnose the angioedema type, and considered the use of genetic testing to identify mutations in <i>FXII</i> or <i>XPNPEP2 </i>that have been associated with HAE-nC1-INH and ACEI-AAE, respectively. Due to the lack of approved treatments for HAE-nC1-INH, ACEI-AAE and C1-INH-AAE, the group presented several case studies in which therapies approved for treatment of HAE types I/II, such as icatibant, ecallantide and pasteurized, nanofiltered C1-INH, were successful. It was uniformly agreed that further studies are needed to improve the diagnosis and treatment of angioedema other than HAE types I/II. i 2014 S. Karger AG, Basel

Hereditary angioedema with normal C1 inhibitor

Until recently it was assumed that hereditary angioedema was a disease that results exclusively from a genetic deficiency of the C1 inhibitor. In 2000, families with hereditary angioedema, normal C1 inhibitor activity, and protein in plasma were described. Since then, numerous patients and families with that condition have been reported. Most of the patients were women. In many of the affected women, oral contraceptives, hormone replacement therapy containing estrogens, and pregnancies triggered the clinical symptoms. In some families mutations in the coagulation factor XII (Hageman factor) gene were detected.

In pursuit of excellence: an integrated care pathway for C1 inhibitor deficiency

There are estimated to be approximately 1500 people in the United Kingdom with C1 inhibitor (C1INH) deficiency. At BartsHealth National Health Service (NHS) Trust we manage 133 patients with this condition and we believe that this represents one of the largest cohorts in the United Kingdom. C1INH deficiency may be hereditary or acquired. It is characterized by unpredictable episodic swellings, which may affect any part of the body, but are potentially fatal if they involve the larynx and cause significant morbidity if they involve the viscera. The last few years have seen a revolution in the treatment options that are available for C1 inhibitor deficiency. However, this occurs at a time when there are increased spending restraints in the NHS and the commissioning structure is being overhauled. Integrated care pathways (ICP) are a tool for disseminating best practice, for facilitating clinical audit, enabling multi-disciplinary working and for reducing health-care costs. Here we present an ICP for managing C1 inhibitor deficiency.

Current status of implementation of self-administration training in various regions of Europe, Canada and the USA in the management of hereditary angioedema

Results from a 16-question survey about self-administration of hereditary angioedema (HAE) therapy, administered in Europe, Canada and the USA, were used to guide discussion at an international HAE expert meeting. The aim was to capture information about current practice in self-administered HAE therapy in these countries, including self-administration training, the key benefits of switching to self-administration, the barriers to self-administration and trends in self-administration. Overall, switching to self-administration therapy is looked upon favourably from both patient and clinician perspectives by virtue of the potential improvement in quality of life arising from optimisation of therapy and early intervention. The recent changes to product licences allowing self-administration provide additional options for the management of HAE.

Review of recent guidelines and consensus statements on hereditary angioedema therapy with focus on self-administration

Consensus meetings and the resulting recommendations shape treatment choices in rare diseases such as hereditary angioedema (HAE) because they combine the experience of prescribing physicians and the patients who are receiving therapy. Self-administration of HAE therapy was recognised as a potential treatment option in the first consensus publication in 2003. Recent studies have confirmed that self-administration of therapy resolves attacks quickly, safely and minimises burden of disease; however, the discovery of inconsistent treatment approaches is a concern and warrants investigation into the barriers that prevent adherence with current recommendations.

Current management options for hereditary angioedema

The aim of treatment of hereditary angioedema (HAE) due to C1 esterase inhibitor deficiency (HAE-C1-INH) is either treating acute attacks or preventing attacks by using prophylactic treatment. For treating acute attacks, plasma-derived C1 inhibitor (C1-INH) concentrates, a bradykinin B2 receptor antagonist, and a recombinant human C1-INH are available in Europe. In the United States, a plasma-derived C1-INH concentrate, a bradykinin B2 receptor antagonist, and a plasma kallikrein inhibitor have been approved. Fresh frozen plasma is also available for treating acute attacks. Short-term prophylactic treatment focuses on C1-INH and attenuated androgens. Long-term prophylactic treatments include attenuated androgens such as danazol, stanozolol, and oxandrolone, antifibrinolytics, and a plasma-derived C1-INH concentrate. Plasma-derived C1-INH and a bradykinin B2 receptor antagonist are permitted for self-administration and home therapy. The number of management options has increased considerably within the last few years, thus helping to diminish the burden of HAE.

Social costs of icatibant self-administration vs. health professional-administration in the treatment of hereditary angioedema in Spain

BACKGROUND

Icatibant is the only subcutaneous treatment for acute Type I and Type II hereditary angioedema with C1-esterase inhibitor deficiency (HAE-C1-INH) licensed for self-administration in Europe.

AIM

To compare the economic impact of two icatibant administration strategies: health professional-administration only (strategy 1) versus including the patient self-administration option (strategy 2).

METHODS

Economic evaluation model based on the building of a decision tree. Both strategies are assumed to have equivalent effectiveness. The payer (Spanish National Health System) and the social perspectives were considered. All relevant cost-generating factors were taken into account. The time horizon was one year. Sources of information included scientific evidence, official data and experts' opinion. A deterministic sensitivity analysis was carried out to quantify the underlying uncertainty in the model.

RESULTS

From the social perspective, which considers both direct (health care costs) and indirect costs (productivity losses), strategy 2 would result into average savings of €121.30 per acute attack compared to strategy 1. For Spain, this would achieve in an annual savings of €551,371. The reduction in direct costs accounts for 74% of the savings and lower indirect costs account for the remaining 26%. Savings per acute attack may range from €79.50 to €169.80; accordingly, the annual savings in Spain may vary between €90,319 and €2,315,360.

CONCLUSION

Costs related to the management of acute HAE attacks with C1 inhibitor deficiency may be substantially reduced through interventions targeting home treatment by training patients to self-administer icatibant.

Analysis of hereditary angioedema attacks requiring a second dose of ecallantide

BACKGROUND

Effective treatment of acute attacks is critical in managing hereditary angioedema (HAE). Ecallantide, a plasma kallikrein inhibitor, is approved for the treatment of HAE attacks. Occasionally, a second dose is needed when treating attacks of HAE.

OBJECTIVE

To evaluate the characteristics of HAE attacks requiring a second dose (dose B) of ecallantide.

METHODS

Data from all ecallantide clinical trials (EDEMA2, EDEMA4, and DX-88/19) that allowed an open-label dose B were included in this analysis. Patient and attack characteristics potentially predictive of dose B after ecallantide were analyzed by logistic regression. A multivariate model was built using a backward selection process, incorporating variables from the univariate model with P < .20 and removing factors with the highest P value until only significant (P < .05) factors remained.

RESULTS

The analysis included 732 ecallantide-treated HAE attacks in 179 patients. Dose B was required in 88 attacks (12.0%), most (80.5%) for incomplete response. By attack location, 31 of 325 abdominal attacks (9.5%), 17 of 158 laryngeal attacks (10.8%), and 40 of 242 peripheral attacks (16.5%) required dose B. On the basis of the univariate analysis, baseline severity (odds ratio = 1.33, P = .15) and peripheral attack (odds ratio = 1.80, P = .01) were identified as potential predictive factors; abdominal attacks had an inverse correlation (odds ratio = 0.64, P = .055). However, the multivariate analysis identified only peripheral attacks as statistically significantly correlated (P < .05) with dose B requirement.

CONCLUSION

A single, 30-mg dose of ecallantide was effective for most HAE attacks (88.0%). Patients with peripheral attacks of HAE were more likely to require a second dose of ecallantide after 4 hours.

TRIAL REGISTRATION

clinicaltrials.gov Identifiers: not applicable for EDEMA2 (trial was conducted before registration requirements were implemented), NCT00457015 for EDEMA4, and NCT00456508 for DX-88/19.

Assessment of rebound and relapse following ecallantide treatment for acute attacks of hereditary angioedema

BACKGROUND

Hereditary angioedema (HAE) is a rare genetic disease characterized by unpredictable and recurring attacks of angioedema. This study assessed potential attack rebound and relapse following treatment with ecallantide, a plasma kallikrein inhibitor approved for HAE attack treatment.

METHODS

Results were integrated from 2 double-blind, placebo-controlled studies of ecallantide treatment for HAE: EDEMA3-DB and EDEMA4. Symptoms were assessed by treatment outcome score (TOS), mean symptom complex severity (MSCS) score, and global response. Patients with improvement at 4 h post-dosing in all three measures followed by any sign of worsening at 24 h were considered to show potential rebound if worsening was beyond baseline or potential relapse if not beyond baseline. Likeliness of rebound or relapse was determined by the number of measures showing worsening and the magnitude of worsening. Patients receiving placebo who met the criteria for rebound/relapse were evaluated for descriptive comparison only.

RESULTS

Significantly more ecallantide-treated patients (42 of 70) compared to placebo (26 of 71) showed improvement in three measures at 4 h and were thus eligible for rebound/relapse (P = 0.006). Of the nine ecallantide-treated patients with signs of worsening at 24 h, none were likely rebound, one was assessed as possible rebound, one as likely relapse, and two as possible relapse. No patient with potential rebound/relapse experienced new symptoms after dosing. Medical intervention was required in one ecallantide-treated patient.

CONCLUSION

Ecallantide was efficacious for treating acute HAE attacks. Relapse was observed in a small proportion of patients, and there was little evidence of rebound.