Management of acute attacks of hereditary angioedema: potential role of icatibant

Case report: Hereditary angioedema in pregnancy

Hereditary angioedema (HAE) is a rare genetic condition associated with episodic swelling due to dysfunction of bradykinin regulation pathways. This is most frequently caused by low level and/or function of the C1-esterase inhibitor protein (C1INH) which is known as hereditary angioedema with C1 inhibitor deficiency (C1INH-HAE). Pregnancy and labour can precipitate an attack, but the majority of women have an uncomplicated, spontaneous vaginal delivery. Intravenous C1INH is the first-line therapy in pregnancy and breastfeeding. It should be given if any obstetric intervention is planned. Routine prophylactic administration for uncomplicated vaginal birth is not mandatory but may be appropriate if symptoms recur frequently during the third trimester. Pregnant women with C1INH-HAE should deliver in a hospital with C1INH replacement, fiberoptic intubation and front-of-neck access equipment readily available. A documented treatment plan should be developed within a multi-disciplinary team to pre-empt complications. We describe a case of C1INH-HAE diagnosed in pregnancy.

Evaluation of staging criteria for disposition and airway intervention in emergency department angioedema patients

AIM

Angioedema is a nonpitting edema that can lead to death secondary to airway obstruction. Previously, a staging system based on localization of the angioedema was proposed for risk stratification of likelihood of need for admission or airway intervention. This study aims to evaluate a staging system based on angioedema localization as a method of predicting need for admission or airway intervention.

METHODS

This was a retrospective chart review of angioedema cases that presented to an academic emergency department (ED) from August 1, 2006, to January 31, 2018. Data were collected on location of swelling, treatment setting, and medical and procedural interventions. Cases were categorized by modified Ishoo criteria, defined as follows: 1, lips, face, periorbital, extremities, total body/diffuse swelling; 2, soft palate, posterior pharynx; 3, tongue; 4, larynx. Predictive probability of disposition by stage was then compared.

RESULTS

A total of 320 patients were included in this study (median age, 44 years; 54.4% female). Stage 4 was more likely to require intensive care unit care without (probability 17%) and with (67%) airway intervention compared with stage 1 without (2.5%) and with (0.1%) airway intervention. Conversely, stage 1 was more likely to be treated in ED and discharged (85%) compared with stage 4 (0%). Stage 4 was also more likely to require airway intervention (67%) compared with other stages (1, 0.1%; 2, 8.6%; 3, 16%).

CONCLUSION

Higher-stage patients were more likely to require higher levels of care and airway intervention. Thus, the staging system appears to be a valid method of predicting risk among ED angioedema patients.

Activation of bradykinin B2 receptor induced the inflammatory responses of cytosolic phospholipase A2 after the early traumatic brain injury

Phospholipase A₂ is a known aggravator of inflammation and deteriorates neurological outcomes after traumatic brain injury (TBI), however the exact inflammatory mechanisms remain unknown. This study investigated the role of bradykinin and its receptor, which are known initial mediators within inflammation activation, as well as the mechanisms of the cytosolic phospholipase A₂ (cPLA₂)-related inflammatory responses after TBI. We found that cPLA₂ and bradykinin B2 receptor were upregulated after a TBI. Rats treated with the bradykinin B2 receptor inhibitor LF 16-0687 exhibited significantly less cPLA₂ expression and related inflammatory responses in the brain cortex after sustaining a controlled cortical impact (CCI) injury. Both the cPLA₂ inhibitor and the LF16-0687 improved CCI rat outcomes by decreasing neuron death and reducing brain edema. The following TBI model utilized both primary astrocytes and primary neurons in order to gain further understanding of the inflammation mechanisms of the B2 bradykinin receptor and the cPLA₂ in the central nervous system. There was a stronger reaction from the astrocytes as well as a protective effect of LF16-0687 after the stretch injury and bradykinin treatment. The protein kinase C pathway was thought to be involved in the B2 bradykinin receptor as well as the cPLA₂-related inflammatory responses. Rottlerin, a Protein Kinase C (PKC) δ inhibitor, decreased the activity of the cPLA₂ activity post-injury, and LF16-0687 suppressed both the PKC pathway and the cPLA₂ activity within the astrocytes. These results indicated that the bradykinin B2 receptor-mediated pathway is involved in the cPLA₂-related inflammatory response from the PKC pathway.

Angioedema in the emergency department: a practical guide to differential diagnosis and management

Background

Angioedema is a common presentation in the emergency department (ED). Airway angioedema can be fatal; therefore, prompt diagnosis and correct treatment are vital.

Objective of the review

Based on the findings of two expert panels attended by international experts in angioedema and emergency medicine, this review aims to provide practical guidance on the diagnosis, differentiation, and management of histamine- and bradykinin-mediated angioedema in the ED.

Review

The most common pathophysiology underlying angioedema is mediated by histamine; however, ED staff must be alert for the less common bradykinin-mediated forms of angioedema. Crucially, bradykinin-mediated angioedema does not respond to the same treatment as histamine-mediated angioedema. Bradykinin-mediated angioedema can result from many causes, including hereditary defects in C1 esterase inhibitor (C1-INH), side effects of angiotensin-converting enzyme inhibitors (ACEis), or acquired deficiency in C1-INH. The increased use of ACEis in recent decades has resulted in more frequent encounters with ACEi-induced angioedema in the ED; however, surveys have shown that many ED staff may not know how to recognize or manage bradykinin-mediated angioedema, and hospitals may not have specific medications or protocols in place.

Conclusion

ED physicians must be aware of the different pathophysiologic pathways that lead to angioedema in order to efficiently and effectively manage these potentially fatal conditions.

[Management of patients with bradykinin-mediated angioedema in oral and maxillofacial surgery]

Bradykinin-mediated angioedema (AE) is a rare disease characterized by recurrent cutaneous or mucosal angioedema. This hereditary or acquired disease is of rapid installation, non-pruritic, usually painless and can affect the face, lips, larynx, gastrointestinal tract or extremities. When the affected area involves the upper respiratory tract, laryngeal angioedema can lead to imminent death by asphyxia. This is the reason for the high mortality rate (30 %) in undiagnosed or improperly managed patients. High-risk situations in oral and maxillofacial surgery procedures should be identified preoperatively. Short-term prophylaxis must be carried-out prior to any procedure that may trigger an attack. A multi-site reference center (CREAK) has been created to help clinicians to manage this disease. This article reviews the pathophysiologic mechanisms, the clinical presentations, the possible treatments, the acute strategies for attacks and different prophylactic possibilities in oral and maxillofacial surgery.

Icatibant in the treatment of Angiotensin-converting enzyme inhibitor-induced angioedema

We describe the case of a 75-year-old woman who presented with massive tongue and lip swelling secondary to angiotensin-converting enzyme inhibitor-induced angioedema. An awake fibre-optic intubation was performed because of impending airway obstruction. As there was no improvement in symptoms after 72 hours, the selective bradykinin B2 receptor antagonist icatibant (Firazyr) was administered and the patient's trachea was successfully extubated 36 hours later. To our knowledge this is the first documented case of icatibant being used for the treatment of angiotensin-converting enzyme inhibitor-induced angioedema in the United Kingdom and represents a novel therapeutic option in its management.

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.

Gastrointestinal manifestations, diagnosis, and management of hereditary angioedema

Abdominal pain is one of the most common conditions in clinical practice and yet a challenging complaint to accurately diagnose due to the vast number of possible etiologies. When other health care providers cannot identify the cause of abdominal pain, gastroenterologists are often looked upon to help solve the diagnostic dilemma. Consequently, it is incumbent upon gastroenterologists to be well versed in the diagnosis and management of not only common but also rare causes of abdominal pain. One such uncommon but well-described cause of abdominal pain is angioedema of the intestinal tract due to hereditary angioedema. Acute onset, recurrent abdominal pain of varying severity is its most common presenting symptom, and misdiagnosis can not only lead to unnecessary surgical procedures but also death. The purpose of this review is to raise awareness among gastroenterologists about hereditary angioedema as a potential cause of recurrent, unexplained abdominal pain.

Repeat treatment with icatibant for multiple hereditary angioedema attacks: FAST-2 open-label study

BACKGROUND

The For Angioedema Subcutaneous Treatment (FAST)-2, a phase III, double-blind, randomized, multicenter, placebo-controlled study (ClinicalTrials.gov identifier: NCT00500656), established the efficacy and safety of single injections of icatibant, a bradykinin B₂ receptor antagonist, in the treatment of hereditary angioedema (HAE) attacks. Here, we evaluate the efficacy and safety of repeated treatment with icatibant in adult patients experiencing HAE attacks during the FAST-2 open-label extension (OLE) phase.

METHODS

Patients completing the controlled phase were eligible to participate in the OLE phase and receive open-label icatibant (30 mg subcutaneously) for the treatment of cutaneous, abdominal, and/or laryngeal HAE attack(s) severe enough to warrant treatment. Time to onset of symptom relief was calculated for each attack. Descriptive analyses (median, 95% CIs) were performed for all attacks; post hoc analyses were conducted in patients with at least five icatibant-treated attacks throughout the FAST-2 OLE phase. Safety was also monitored.

RESULTS

Fifty-four patients received icatibant for 374 attacks (176 cutaneous, 168 abdominal, and 30 laryngeal). For cutaneous and/or abdominal attacks (attacks 2-5), the median times to onset of symptom relief ranged between 2.0 and 2.5 h. For all laryngeal attacks, the median times to regression (start of improvement) of symptoms ranged between 0.3 and 4.0 h. Post hoc analyses showed that the overall median time to onset of symptom relief was 2.0 h. Overall, 89.8% of attacks resolved with a single icatibant injection. No drug-related serious adverse events were reported.

CONCLUSIONS

These findings have demonstrated the efficacy and safety of repeated icatibant treatment for HAE attacks.

Using a bradykinin blocker in ACE inhibitor-associated angioedema in the emergency department

We report two cases of ACE inhibitor-associated angioedema and critical airway compromise, where the use of a selective bradykinin 2 receptor blocker resulted in rapid symptom resolution and prevented intubation to protect the airway.

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.

Icatibant for the Treatment of Hereditary Angioedema

OBJECTIVE

To review the pharmacology, pharmacokinetics, clinical trials, and safety of icatibant, a recently approved bradykinin B2 receptor antagonist for treatment of acute attacks of hereditary angioedema (HAE).

DATA SOURCES

Articles indexed in MEDLINE (1948-June 2012), International Pharmaceutical Abstracts(1970-May 2012), and Cumulative Index to Nursing and Allied Health Literature (1981-June 2012) were identified using the search terms icatibant, bradykinin B2 receptor antagonist, and hereditary angioedema. Additional references were identified from the reference lists of the articles identified.

STUDY SELECTION AND DATA EXTRACTION

English-language articles were reviewed.

DATA SYNTHESIS

Icatibant was evaluated in 3 Phase 3 clinical trials and found to be a safe and effective option for treatment of acute HAE. Icatibant was compared to placebo in 2 clinical trials (FAST-1 and FAST-3) and to tranexamic acid in the FAST-2 trial. Patients receiving icatibant in FAST-1 did not experience a significant improvement in median time to clinically significant relief of the index symptom (p = 0.14), whereas patients receiving icatibant in FAST-3 experienced a significant improvement in median time to at least 50% reduction in symptom severity (p < 0.001). When icatibant was compared to tranexamic acid in FAST-2, the median time to clinically significant relief of the index symptom was shorter for patients receiving icatibant (p < 0.001). The most common adverse events associated with the administration of icatibant were injection-site reactions, which were mild to moderate and transient. These data suggest that icatibant is a safe and effective treatment for acute attacks of HAE. Although direct comparisons of recently approved alternatives for treatment of acute attacks are lacking, there are administration advantages of icatibant over other agents. Additionally, the cost of icatibant is comparable to that of the C1 esterase inhibitor Berinert and less expensive than ecallantide.

CONCLUSIONS

Available efficacy data support that icatibant should be considered a safe and effective treatment for acute attacks of HAE. Additionally, limited treatment options for this rare condition, ease of administration, and comparable cost profile support its consideration for formulary inclusion.

An evidence-based review of the potential role of icatibant in the treatment of acute attacks in hereditary angioedema type I and II

INTRODUCTION

Icatibant, a first-in-class B2 bradykinin receptor antagonist, appears to have a favorable efficacy and safety profile for the treatment of acute attacks of hereditary angioedema in adults.

AIMS

To update the evidence and provide an overview of the available data on icatibant.

EVIDENCE REVIEW

Peer reviewed articles published and listed in Medline Search and published updated guidelines for the treatment of acute attacks in hereditary angioedema type I and II in adults were reviewed. The validity and quality of evidence were evaluated.

PLACE IN THERAPY

Clinical evidence for the treatment of acute hereditary angioedema attacks with icatibant is strong. Approximately 10% of the patients require a second dose. No serious adverse reactions have been reported. The only significant side effects consistently registered by 90% of patients are transient local pain, swelling, and erythema at the local injection site.

CONCLUSION

Subcutaneously administered 30 mg icatibant has been shown to be a safe and efficacious treatment in clinical trials. It is the only specific treatment authorized for self-administration by the subcutaneous route offering increased patient independence.

Many faces of angioedema: focus on the diagnosis and management of abdominal manifestations of hereditary angioedema

Angioedema of the intestinal tract is an infrequent but well-described cause of abdominal pain that can occur because of inherited, acquired, allergic, or drug-induced causes. Hereditary angioedema (HAE) is a genetic disorder that causes recurrent attacks of severe edema of various body parts, including the intestinal tract. Moderate to severe abdominal pain occurs in 43-93% of such attacks due to intestinal edema. Laryngeal edema is a potentially life-threatening manifestation. Failure to recognize and diagnose HAE or other causes of intestinal angioedema can lead to years of delay in diagnosis, and in the case of HAE, often to unnecessary abdominal surgeries. Recognizing the typical history of recurrent attacks of abdominal pain, oropharyngeal/laryngeal angioedema or cutaneous angioedema, family history of similar symptoms, association of attacks with stress or menses, and exacerbation of attacks after administration of estrogens or angiotensin-converting enzyme inhibitors will increase diagnostic accuracy. Interdisciplinary treatment is often necessary after the diagnosis of HAE, first with acute management in the emergency room or the intensive care unit, followed by either drug prophylaxis against future attacks using a C1-esterase inhibitor concentrate or attenuated androgens and discontinuation of medications known to trigger attacks. Newer drugs approved for treatment of acute attacks may have future roles in the prevention of attacks if further studies support their efficacy. Gastroenterologists in particular should maintain a high index of suspicion for the possibility of HAE or other causes of intestinal angioedema in patients with a history of recurrent abdominal pain.

Evidence-based recommendations for the therapeutic management of angioedema owing to hereditary C1 inhibitor deficiency: consensus report of an International Working Group

Angioedema owing to hereditary deficiency of C1 inhibitor (HAE) is a rare, life-threatening, disabling disease. In the last 2 years, the results of well-designed and controlled trials with existing and new therapies for this condition have been published, and new treatments reached the market. Current guidelines for the treatment for HAE were released before the new trials and before the new treatments became available and were essentially based on observational studies and expert opinion. To provide evidence-based HAE treatment guidelines supported by the new studies, a conference was held in Gargnano del Garda, Italy, from September 26 to 29, 2010. The meeting hosted 58 experienced HAE expert physicians, representatives of pharmaceutical companies and representatives of HAE patients' associations. Here, we report the topics discussed during the meeting and evidence-based consensus about management approaches for HAE in adult/adolescent patients.

Therapeutic approaches in hereditary angioedema

Hereditary angioedema (HAE) is characterized by acute attacks of edema with multiple localizations, the laryngeal angioedema being the most potentially lethal. In HAE, C1-INH impairments cause episodic increase in kallikrein activity leading to attacks of angioedema. Several therapies have recently become available to treat or to prevent HAE attacks, and others are under evaluation for this indication. Plasma-derived C1-INH, bradykinin receptor antagonists (icatibant), kallikrein inhibitors (ecallantide), or recombinant C1-INH is authorized on the market for HAE attack therapy or prophylaxis. Some of these compounds can be used exclusively to treat HAE attacks, whereas others can also be used as prophylactic therapies. Such therapies, although not available worldwide, can improve disease outcome due to their different mechanisms of action.

Icatibant in hereditary angioedema: news and challenges

Hereditary angioedema (HAE) is a rare condition. Its prognosis depends on whether there is laryngeal involvement with a risk of asphyxia, which is present in 25% of such cases. Improved understanding of the pathophysiology of this disease has resulted in the development of targeted therapies including icatibant, which acts as an antagonist at bradykinin B2 receptors. This agent has been shown to be effective in the treatment of attacks of HAE in three Phase III randomized double-blind published studies. Efficacy data have been collected in all types of attack: cutaneous, abdominal and laryngeal. Safety data are also encouraging. Icatibant is administered subcutaneously, with the potential for patients to self-administer. In the future, this therapy may offer increased independence for HAE patients.

rhC1INH: a new drug for the treatment of attacks in hereditary angioedema caused by C1-inhibitor deficiency

Recombinant human C1 esterase inhibitor (rhC1INH) (Ruconest(®), Pharming) is a new drug developed for the relief of symptoms occurring in patients with angioedema due to C1-inhibitor deficiency. Pertinent results have already been published elsewhere; this article summarizes the progress made since then. Similar to the purified C1-inhibitor derived from human plasma, the therapeutic efficacy of rhC1INH results from its ability to block the actions of enzymes belonging to the overactivated bradykinin-forming pathway, at multiple locations. During clinical trials into the management of acute edema, a total of 190 subjects received recombinant C1-inhibitor by intravenous infusion on 714 occasions altogether. Dose-ranging efficacy studies established 50 U/kg as the recommended dose, and demonstrated the effectiveness of this agent in all localizations of hereditary angioedema attacks. Studies into the safety of rhC1INH based on 300 administrations to healthy subjects or hereditary angioedema patients followed-up for 90 days have not detected the formation of autoantibodies against rhC1INH or IgE antibodies directed against rabbit proteins, even after repeated administration on multiple occasions. These findings met favorable appraisal by the EMA, which granted European marketing authorization for rhC1INH. Pharming is expected to file a biological licence with the US FDA by the end of 2010 to obtain marketing approval in the USA. The launch of rhC1INH onto the pharmaceutical market may represent an important progress in the management of hereditary angioedema patients.