Current medical management of hereditary angioedema: results from a large survey of US physicians

Barriers and facilitators to the implementation of guidelines in rare diseases: a systematic review

BACKGROUND

Rare diseases present a challenge to guideline implementation due to a low prevalence in the general population and the unfamiliarity of healthcare professionals. Existing literature in more common diseases references barriers and facilitators to guideline implementation. This systematic review aims to identify these barriers and facilitators in rare diseases from existing literature.

METHODS

A multi-stage strategy included searching MEDLINE PubMed, EMBASE Ovid, Web of Science and Cochrane library from the earliest date available to April 2021, Orphanet journal hand-search, a pearl-growing strategy from a primary source and reference/citation search was performed. The Integrated Checklist of Determinants of Practice which comprises of twelve checklists and taxonomies, informed by 57 potential determinants was selected as a screening tool to identify determinants that warrant further in-depth investigation to inform design of future implementation strategies.

RESULTS

Forty-four studies were included, most of which were conducted in the United States (54.5%). There were 168 barriers across 36 determinants (37 studies) and 52 facilitators across 22 determinants (22 studies). Fifteen diseases were included across eight WHO ICD-11 disease categories. Together individual health professional factors and guideline factors formed the majority of the reported determinants (59.5% of barriers and 53.8% of facilitators). Overall, the three most reported individual barriers were the awareness/familiarity with the recommendation, domain knowledge and feasibility. The three most reported individual facilitators were awareness/familiarity with the recommendation, agreement with the recommendation and ability to readily access the guidelines. Resource barriers to implementation included technology costs, ancillary staff costs and more cost-effective alternatives. There was a paucity of studies reporting influential people, patient advocacy groups or opinion leaders, or organisational factors influencing implementation.

CONCLUSIONS

Key barriers and facilitators to the implementation of clinical practice guidelines in the setting of rare diseases were at the individual health professional and guideline level. Influential people and organisational factors were relatively under-reported and warrant exploration, as does increasing the ability to access the guidelines as a potential intervention.

Are pediatricians familiar with hereditary angioedema?

Background

Hereditary angioedema (HAE) is an autosomal dominant disease characterized by recurrent episodes of subcutaneous or mucosal edema caused by excess bradykinin. The aim of the present study was to assess the knowledge of pediatricians about hereditary angioedema.

Methods

An online survey with 12 HAE-related and 14 demographics-related questions was e-mailed to all pediatricians who were members of the Brazilian Society of Pediatrics (n = 17 145) once a week during the months of June and July 2021. The electronic questionnaire assessed clinical manifestations, diagnosis, and treatment of hereditary angioedema in children and adolescents.

Results

Four hundred and fifty-five pediatricians responded to the questionnaire (2.6%), of whom 55 (12.1%) were board certified in Allergy and Immunology (A/I), while 400 (87.9%) were not (N-A/I). Three hundred and sixty-eight (80.9%) were female, 289 (55.7%) were under 50 years of age, 286 (62.9%) graduated from Medical School more than 10 years previously, 83 (18.2%) held an MSc/PhD degree, and 253 (55.6%) were living in the Southeast Region of Brazil. The median number of correct answers to the questions related to HAE among A/I was 7 out of 12 (58.3%), with median ranging from 4.5 to 8 correct answers, while for N-A/I it was 3 (25%), with median ranging from 2.5 to 4 correct answers (p < 0.001).

Conclusion

Knowledge about HAE among Brazilian pediatricians, whether board certified in Allergy and Immunology or not, was unsatisfactory. HAE is a rare disease, largely unknown among physicians; therefore, increasing awareness may lead to improvement in diagnosis and treatment.

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).

Attenuated androgen discontinuation in patients with hereditary angioedema: a commented case series

Background

Hereditary angioedema (HAE) is characterized by potentially severe and life-threatening attacks of localized swelling. Prophylactic therapies are available, including attenuated androgens. Efficacy of attenuated androgens has not been assessed in large, randomized, placebo-controlled trials and can be associated with frequent, and sometimes severe, side effects. As better tolerated targeted therapies become available, attenuated androgen withdrawal is increasingly considered by physicians and their patients with HAE. Attenuated androgens withdrawal has not been systematically studied in HAE, although examination of other disorders indicates that attenuated androgen withdrawal may result in mood disturbances and flu-like symptoms. Standardized protocols for attenuated androgen discontinuation that continue to provide control of attacks while limiting potential attenuated androgen withdrawal symptoms are not established as the outcomes of different withdrawal strategies have not been compared. We aim to describe the challenges of attenuated androgen discontinuation in patients with HAE and how these may continue into the post-androgen period.

Case presentation

We present a retrospective case series of 10 patients with confirmed type I HAE who have discontinued prophylactic treatment with attenuated androgens. The most common reason for attenuated androgen discontinuation was side effects. Attenuated androgens were either immediately withdrawn, tapered and/or overlapped with another treatment. The major challenge of discontinuation was the management of an increased frequency and severity of HAE attacks in some patients.

Conclusions

Healthcare teams need to undertake careful planning and monitoring after attenuated androgens discontinuation, and modify treatment strategies if HAE control is destabilized with an increased number of attacks. Discontinuation of attenuated androgens is definitively an option in an evolving HAE treatment landscape, and outcomes can be favourable with additional patient support and education.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13223-021-00644-0.

Current medical management of hereditary angioedema: Follow-up survey of US physicians

BACKGROUND

Physician surveys on hereditary angioedema (HAE) management in 2010 and 2013 revealed important trends in HAE care.

OBJECTIVE

To evaluate current HAE management and the impact of new treatment options on physician practice patterns over time.

METHODS

During June and July 2019, 5382 physicians were contacted by means of postal mail to complete a 47-question survey; 177 responded (3%).

RESULTS

Across the 3 surveys, the home replaced the emergency department as the most typically reported setting for HAE attack treatment (54.3% vs 11.6% in 2010 and 32.5% in 2013; P < .001). Physicians reported C1 esterase inhibitor (C1-INH) as the most typically prescribed long-term prophylactic treatment (LTP) (60.0% vs 20.4% in 2010 and 56.7% in 2013; P < .001). Subcutaneous LTP medications were most typically prescribed over intravenous (C1-INH, 41.4%; subcutaneous lanadelumab, 21%; intravenous C1-INH, 18.6%). Danazol, the most frequently prescribed LTP treatment, dropped to 6.4% (55.8% in 2010 and 23.4% in 2013; P < .001). The strongest nonefficacy factor influencing clinician treatment choice changed over time, with cost and (or) insurance coverage increasing to 43.7% (from 24.4% in 2010 and 40.5% in 2013; P = .001), whereas the concern over adverse effects dropped to 16.2% (from 55.8% in 2010 and 29.5% in 2013; P < .001). Physician-reported patient satisfaction remains high, with only 1.5% of physicians indicating patients are not satisfied with treatment.

CONCLUSION

The US physician survey data reflect improvements in the HAE management in recent years. Therapeutic advances in HAE have led to reported higher rates of home treatment of HAE attacks, reduced concern for adverse treatment effects, and high levels of patient satisfaction.

US HAEA Medical Advisory Board 2020 Guidelines for the Management of Hereditary Angioedema

Scientific and clinical progress together with the development of effective novel therapeutic options has engendered multiple important changes in the diagnosis and management of hereditary angioedema (HAE). We now update and extend the 2013 United States Hereditary Angioedema Association Medical Advisory Board guidelines for the treatment and management of HAE. The guidelines are based on a comprehensive literature review with recommendations indicating both the strength of our recommendation and the quality of the underlying evidence. Guidelines are provided regarding the classification, diagnosis, on-demand treatment, prophylactic treatment, special considerations for women and children, development of a comprehensive management and monitoring plan, and assessment of burden of illness for both HAE due to C1 inhibitor deficiency and HAE with normal C1 inhibitor. Advances in HAE treatment now allow the development of management plans that can help many patients with HAE lead a normal life. Achieving this goal requires that physicians be familiar with the diagnostic and therapeutic transformations that have occurred in recent years.

Canadian physician survey on the medical management of hereditary angioedema

BACKGROUND

Hereditary angioedema (HAE) is a rare disease that has significant morbidity and may be potentially fatal because of airway obstruction.

OBJECTIVE

To determine practice patterns in physicians treating HAE.

METHODS

A survey was designed to determine HAE practice patterns among Canadian physicians. These physicians were identified by sending the survey to members of 3 physician organizations (Canadian Hereditary Angioedema Network, Canadian Society of Clinical Immunology and Allergy, and Canadian Hematology Society).

RESULTS

Thirty-six physicians responded to the survey. Thirty-four physicians were included in the analysis. Most referrals to HAE-treating physicians were from family and emergency department physicians. The most common sites of swelling reported by patients to physicians were facial, peripheral, and abdominal. A mean of 53.9% of patients with type 1 and 2 HAE and 53.4% of patients with HAE with normal C1 esterase inhibitor were undergoing long-term prophylaxis. A mean of 41.9%, 19.4%, and 93.5% of respondents had some patients taking danazol, tranexamic acid, and C1-esterase inhibitor, respectively. Most physicians believed that severity and frequency of attacks were the most important determinants in deciding when to use prophylaxis. A mean of 88.2% of physicians used C1-esterase inhibitor to treat acute attacks and 79.4% used icatibant. All respondents were aware of HAE guidelines.

CONCLUSION

Physicians are using guidelines to support their practice and using agents suggested by guidelines with confidence. C1 inhibitor is being used widely for prophylaxis and treatment of acute attacks along with icatibant. However, certain special patient populations may require additional focus in future guidelines.

Hereditary angioedema education in otolaryngology residencies: survey of program directors

BACKGROUND

The objective of this work was to assess resident education regarding contemporary management of hereditary angioedema using a web-based survey.

METHODS

An 11-item, multiple-choice, electronic questionnaire was sent to all 106 accredited otolaryngology training programs in November 2016. Questions focused on resident education, management principles, and formalized assessment.

RESULTS

A total of 34 program directors responded, representing 32% of otolaryngology residences. Ninety-seven percent believed otolaryngology residents should be knowledgeable in the management of hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE). Specifically, 38% and 26% of program directors felt their residents were comfortable and very comfortable in C1-INH-HAE management, respectively. Of those surveyed, 18% have educational simulation activities and a protocol in place for C1-INH-HAE management. Forty-seven percent of respondents felt their training program provided adequate education and exposure to C1-INH-HAE. Over the last 5 years, 45% felt residents were exposed to 1 to 5 cases of C1-INH-HAE. Sixty-seven percent of residents were trained in the management of C1-INH-HAE through in-person lectures. Seventy-one percent of programs had no formal assessment of resident competency in C1-INH-HAE management.

CONCLUSION

This study is the first to offer insight into C1-INH-HAE education and management principles in otolaryngology training programs. Surveyed program directors believe residents need a strong knowledge base in the management of C1-INH-HAE but less than half feel their trainees acquire the necessary exposure to this emergent disease process. Future research efforts in this area should aim to determine optimal educational activities as well as how to best incorporate this into otolaryngology residency curricula.

The Association Between Hospital Characteristics and Nonresponse in Organization Survey: An Analysis of the National Healthcare Establishment and Workforce Survey in Malaysia

In any survey where some of the invited participants fail to respond estimates may be biased. The literature on survey nonresponse is substantial, and the intellectual focus has typically been on the nonresponse of individuals. An important yet less scrutinized area in the analysis of nonresponse is in organizational surveys, particularly surveys of health-care organizations. This study used data from the 2010 National Healthcare Establishment and Workforce Survey in Malaysia to examine the relationship between a set of measurable hospital attributes and their probability of survey response and the relationship between this probability and the differences in survey estimates. We found that readily measurable hospital characteristics such as size and geographical location are useful predictors of survey response likelihood. Larger hospitals and hospitals located in less developed geographical regions responded more favorably than their counterparts. We have also illustrated that the resulting response pattern affected some key survey estimates. These findings have the potential to extend our understanding of nonresponse to organization surveys in the health-care sector, potentially allow for the prediction of nonresponse, and help researchers to identify profiles of "reluctant responders" before a survey commences, so that additional engagement strategies may be used.

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.

Using Fresh Frozen Plasma for Acute Airway Angioedema to Prevent Intubation in the Emergency Department: A Retrospective Cohort Study

Background. Angioedema (AE) is a common condition which can be complicated by laryngeal edema, having up to 40% mortality. Although sporadic case reports attest to the benefits of fresh frozen plasma (FFP) in treating severe acute bouts of AE, little evidence-based support for this practice is available at present. Study Objectives. To compare the frequency, duration of intubation, and length of intensive care unit (ICU) stay in patients with acute airway AE, with and without the use of FFP. Methods. A retrospective cohort study was conducted, investigating adults admitted to large community hospital ICU with a diagnosis of AE during the years of 2007–2012. Altogether, 128 charts were reviewed for demographics, comorbidities, hospital courses, and outcomes. A total of 20 patients received FFP (108 did not). Results. Demographics and comorbidities did not differ by treatment group. However, nontreated controls did worse in terms of intubation frequency (60% versus 35%; p = 0.05) and ICU stay (3.5 days versus 1.5 days; p < 0.001). Group outcomes were otherwise similar. Conclusion. In an emergency department setting, the use of FFP should be considered in managing acute airway nonhereditary AE (refractory to steroid, antihistamine, and epinephrine). Larger prospective, better controlled studies are needed to devise appropriate treatment guidelines.

Self-administered C1 esterase inhibitor concentrates for the management of hereditary angioedema: usability and patient acceptance

Hereditary angioedema (HAE) is a rare genetic disease characterized by episodic subcutaneous or submucosal swelling. The primary cause for the most common form of HAE is a deficiency in functional C1 esterase inhibitor (C1-INH). The swelling caused by HAE can be painful, disfiguring, and life-threatening. It reduces daily function and compromises the quality of life of affected individuals and their caregivers. Among different treatment strategies, replacement with C1-INH concentrates is employed for on-demand treatment of acute attacks and long-term prophylaxis. Three human plasma-derived C1-INH preparations are approved for HAE treatment in the US, the European Union, or both regions: Cinryze(®), Berinert(®), and Cetor(®); however, only Cinryze is approved for long-term prophylaxis. Postmarketing studies have shown that home therapy (self-administered or administered by a caregiver) is a convenient and safe option preferred by many HAE patients. In this review, we summarize the role of self-administered plasma-derived C1-INH concentrate therapy with Cinryze at home in the prophylaxis of HAE.

Clinical manifestations, diagnosis, and treatment of hereditary angioedema: survey data from 94 physicians in Japan

BACKGROUND

Hereditary angioedema (HAE) is a rare and potentially life-threatening condition that results from mutations in the C1 inhibitor (C1-INH). Awareness of HAE among physicians in Japan is increasing, but real-world data are lacking.

OBJECTIVE

To explore the clinical manifestations, diagnosis, quality of life (QOL), and treatment of Japanese patients with HAE.

METHODS

A 14-point survey was developed and sent to 387 physicians in Japan (March to May 2014) to gather clinical data on their HAE patients' family history, severity and frequency of attacks, QOL, and therapy use.

RESULTS

Data on 171 HAE patients were collected from 94 physicians (24.3% response rate). Of the patients, 76.6% had a family history of angioedema (AE), and 11.7% had experienced a death in the family due to an AE attack. HAE type I occurred in 99 patients (57.9%), HAE type II occurred in 9 patients (5.3%), HAE with normal C1-INH occurred in 3 patients (1.8%), and an additional 60 patients were unclassified. Mean time from initial symptoms to diagnosis was 13.8 years. Attacks that required airway management and abdominal surgery with uncertain diagnosis were observed in 9.5% and 2.9% of patients, respectively. In the past year, 21.0% of patients presented with more than 10 attacks, 21.1% were admitted to the hospital for more than 1 day, and 28.7% were absent from work or school. On-demand C1-INH concentrate and prophylactic tranexamic acid were used in approximately half of the patients (47.4% and 39.2%, respectively).

CONCLUSION

HAE is a severe condition characterized by recurrent AE attacks. In Japan, delayed patient diagnosis and limited use of HAE-specific therapies exacerbate the burden on HAE patients.

Perioperative management for patients with hereditary angioedema

Hereditary angioedema (HAE) is a rare autosomal dominant disease that results from mutations in the C1-esterase inhibitor (C1-INH) gene. HAE is characterized by recurrent episodes of angioedema of the skin (face, extremities, genitalia, trunk), the gastrointestinal tract, and respiratory tract. Symptoms experienced can be debilitating, may impact quality of life, and can be life threatening. Preventing attacks particularly for patients undergoing procedures is critical. Patients with HAE may now treat acute attacks or prevent attacks with medications that have recently become available in the United States; however, these same medications can be used for perioperative management for patients undergoing medical, surgical, and dental procedures. Periprocedural planning is important for patients to reduce the incidence of acute attacks. Education is critical and increasing awareness of short-term prophylaxis options will allow providers to develop an appropriate action plan for their patients. The goal of this review is to increase awareness for HAE treating physicians, surgeons, anesthesia, and emergency room physicians by examining the available treatment options, researching the literature, and summarizing available data for periprocedural management. The availability of treatment options has increased over the past few years, expanding options for physicians and patients living with HAE and improve safety during the perioperative period and at the time of other procedures.

Critical appraisal of androgen use in hereditary angioedema: a systematic review

OBJECTIVE

To provide an objective basis for evaluating the risk-benefit ratio of long-term androgen use in patients with hereditary angioedema (HAE).

DATA SOURCES

PubMed was searched with no time limitations using the keywords hereditary angioedema or angio-oedema combined with danazol, stanozolol, and androgen.

STUDY SELECTION

Qualifying articles were English-language reports of androgen use in patients with HAE, with relevant safety and/or efficacy information. Reports were categorized according to level of evidence (LOE).

RESULTS

The search process identified 153 citations, 63 of which contained relevant information; 2 additional publications were identified while other citations were being reviewed. Fifteen LOE 2 studies and multiple LOE 4 reports provided efficacy data, confirming a high level of prophylactic efficacy for androgen therapy in HAE, with occasional reports of poor prophylactic response. Common adverse events include weight gain, menstrual irregularities, virilization, headaches, myalgias or cramps, mood changes, and elevations in creatine phosphokinase level, liver function test results, and serum lipid level. The risk of adverse events is often correlated with dose and/or treatment duration. Rare cases of hepatic adenomas and hepatocellular carcinoma associated with long-term androgen use often had no preceding changes in liver function test results.

CONCLUSION

Androgen therapy may be effective for most patients with HAE; however, potential risks and adverse effects must be carefully considered and discussed with patients when considering options for long-term HAE prophylaxis.

Tranexamic acid as maintenance treatment for non-histaminergic angioedema: analysis of efficacy and safety in 37 patients

Angioedema (AE) is a clinical syndrome characterized by localised swelling lasting several hours. The swelling is often recurring and can be lethal if it is located in the laryngeal region. Much progress has been made recently in the treatment of acute episodes, but no consensus has been reached on maintenance treatment. We have performed a national retrospective observational study to assess the use of tranexamic acid (TA) as maintenance treatment for non-histaminergic AE [hereditary AE (HAE) or idiopathic non-histaminergic AE]. Records for 64 cases were collected from 1 October 2012 to 31 August 2013; 37 of these were included (12 HAE with C1-inhibitor deficiency, six with HAE with normal C1-inhibitor and 19 idiopathic non-histaminergic AE). When treated with TA over six months, the number of attacks was reduced by 75% in 17 patients, 10 patients showed a lower level of reduction and 10 had the same number of attacks. In no instances were symptoms increased. No thromboembolic events were observed, and the main side effects were digestive in nature. Thus, TA, which is well tolerated and inexpensive, appears to be an effective maintenance treatment for some patients with HAE or idiopathic non-histaminergic AE.

Angioedema deaths in the United States, 1979-2010

BACKGROUND

Hospital admission data indicate that the angioedema incidence has increased during the past several decades. Little is known about mortality trends.

OBJECTIVES

To count the number of deaths associated with angioedema in the United States, investigate correlations with age, sex, race, and other contributory causes, and analyze trends from 1979 to 2010.

METHODS

All US death certificates in which angioedema was listed as an underlying or contributing cause of death during 1979 to 2010 were analyzed. Age-adjusted mortality rates were analyzed by age, sex, and race. Other conditions designated as the underlying cause of death were investigated.

RESULTS

From 1979 to 2010, there were 5,758 deaths in which angioedema was listed as a contributing cause. The age-adjusted death rate for hereditary angioedema decreased from 0.28 (95% confidence interval [CI] 0.25-0.32) to 0.06 (95% CI 0.05-0.08) per million persons per year. Conversely, mortality for angioedema increased from 0.24 (95% CI 0.21-0.27) to 0.34 (95% CI 0.31-0.37) per million. Blacks constituted 55% of angioedema deaths that were associated with use of angiotensin-converting enzyme inhibitors. On death certificates that listed hereditary angioedema as the underlying cause of death, cancer (frequently lymphoma or leukemia) was the second most commonly listed cause.

CONCLUSION

Angioedema-associated deaths were very rare from 1979 to 2010. Hereditary angioedema deaths became even more so, whereas nonhereditary angioedema deaths increased. Risks associated with angiotensin-converting enzyme inhibitors were higher in blacks. Lack of specific coding for acquired angioedema most likely explains the observed association between cancer and hereditary angioedema. In the future, more granular coding systems may help distinguish hereditary from acquired angioedema.

Hereditary angioedema treatment options: the availability of new therapies

Hereditary angioedema (HAE) is a potentially life-threatening autosomal dominant disease characterized by recurrent episodes of oedema, commonly occurring in the skin, abdomen, and upper respiratory tract. After many years during which limited treatment options were available, a range of newer therapies with proven efficacy have been approved in Europe by the European Commission for the treatment of HAE attacks. However, due to differing legislation and financial restrictions, these treatment options are not available in all countries. Home therapy and self-administration of treatment are recommended in order to minimize the burden of disease upon the patient, with the ideal treatment option being effective, well-tolerated, and easy to prepare and administer. Recently, the Hereditary Angioedema International Working Group (HAWK) consensus recommended early, on-demand treatment for HAE. This article reviews the current treatment options available, and considers the need for treatment guidelines to recommend the appropriate therapy.

Hereditary angioedema therapies in the United States: movement toward an international treatment consensus

BACKGROUND

Hereditary angioedema (HAE) is a rare, potentially life-threatening autosomal dominant disease characterized by recurrent angioedema attacks that affect the skin, gastrointestinal tract, and airway, including the larynx. Pharmacologic developments in HAE treatment have culminated in the recent introduction of 4 new HAE-specific therapies in the United States.

OBJECTIVES

In light of these new therapeutic options, this commentary outlines historical US HAE therapy choices, discusses the potential effect of the 4 recently approved HAE treatments, and considers strategies for optimizing their use in line with international treatment recommendations.

DISCUSSION

Treatment options for HAE in the United States have been limited to attenuated androgens and antifibrinolytic agents for long-term prophylaxis and FFP and supportive therapy for the management of acute attacks. The 4 new therapies that have recently become available (ie, 2 plasma-derived C1 esterase inhibitor (C1-INH) concentrates, the kallikrein inhibitor ecallantide, and the bradykinin β(2)-antagonist icatibant) have provided an opportunity to change routine HAE treatment. In 2009, despite the availability of 2 of the new treatments (ie, the plasma-derived C1-INH concentrates), a large survey of US physicians suggested that wide variability still existed in the treatment of patients with HAE. Since this survey was undertaken, clinical experience with all 4 new treatments has increased significantly, and because 3 of these agents (ie, 2 plasma-derived C1-INH concentrates and icatibant) can be self-administered by trained patients, physicians can now provide individualized care that is proven effective and more aligned with international guidance.