Medical Literature - 2012

Vasekar M, Craig TJ. 2/2012 Current Allergy and Asthma Reports

Much has been written about hereditary angioedema (HAE) in recent literature; however, the prevalence of angiotensin-converting enzyme inhibitor-induced angioedema (ACEiIA) far exceeds that of HAE. Similarly, multiple therapies have been developed for HAE, yet no definitive therapy is available for ACEiIA. In this article, we discuss the mechanism, prevalence, pathophysiology, and management of ACEiIA, with focus on newer therapies recently approved for HAE and how they may be effective for ACEiIA.

Available from: link.springer.com/article/10.1007%2Fs11882-011-0238-z

Hsu D, Shaker M. 10/2012 Current Opinion in Pediatrics

PURPOSE OF REVIEW: To review and update the management and understanding of hereditary angioedema (HAE), while integrating insights into pediatric subtleties that exist in practice.

RECENT FINDINGS: Major advances have recently been made in HAE treatment. Ecallantide (a kallikrein inhibitor approved for use in the United States in December 2009) and icatibant (a selective bradykinin B2 receptor antagonist approved for use in the United States in August 2011) represent novel subcutaneous therapies for acute HAE exacerbations. Recombinant human C1 esterase inhibitor (C1INH) serves as a promising future alternative to current mainstay acute and prophylactic treatment with plasma-derived C1INH. Recent guidelines have outlined new algorithms for short-term and long-term prophylaxis against HAE exacerbations.

SUMMARY: The evolving standard of care for HAE management involves not only treatment of acute exacerbations but also individualized patient preference-sensitive short-term and long-term prophylaxis. Updated international consensus guidelines provide useful protocols, whereas recent clinical reviews have raised awareness of HAE. Further advances will likely focus on improving patient access to convenient acute and prophylactic treatment with C1INH.

Available from: journals.lww.com/co-pediatrics/pages/articleviewer.aspx?year=2012&issue=10000&article=00015&type=abstract (small fee)

Bernstein JA, Shea EP, Koester J, Iarrobino R, Pullman WE. 9/2012 Allergy

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. Copyright © 2012 John Wiley & Sons A/S.

Available from: onlinelibrary.wiley.com/doi/10.1111/j.1398-9995.2012.02864.x/full

Bewtra AK, Levy RJ, Jacobson KW, Wasserman RL, Machnig T, Craig TJ. 9/2012 Allergy and Asthma Proceedings

C1-inhibitor (INH) concentrate, which is recommended as first-line treatment for acute hereditary angioedema (HAE) attacks in many countries, was recently approved in the United States. We sought to solicit patients’ feedback about their health-related quality of life (HRQoL) while being treated with C1-INH concentrate for acute HAE attacks under real-world conditions, as well as the personal impact of the availability of C1-INH on lifestyle and mental health domains. Subjects enrolled in an open-label study of C1-INH at 20 U/kg for acute HAE attacks were invited to participate in a prospectively designed survey to solicit “real-time” patient responses that were collected via an interactive voice response service or online with a personal computer. Eighteen subjects submitted 60 quarterly HRQoL and treatment impact survey responses over 29 months. Seventeen of 18 patients responding reported mean short form 12 HRQoL scores that were within a normal range. More than one-half indicated that C1-INH availability made them feel somewhat or much better, and >80% reported having a better outlook on the future and feeling more secure about the danger of life-threatening attacks. These data confirm a high level of HRQoL and a positive impact in lifestyle and emotional domains among patients who were treated for acute attacks of HAE with C1-INH concentrate.

Available from: ingentaconnect.com/content/ocean/aap/2012/00000033/00000005/art00008

Blatman KH, Ditto AM. 5/2012 Allergy and Asthma Proceedings

Idiopathic anaphylaxis (IA) is defined as anaphylaxis without any identifiable precipitating agent or event. The clinical manifestations of IA are the same as allergen-associated (immunologic) anaphylaxis and include urticaria, angioedema, hypotension, tachycardia, wheezing, stridor, pruritus, nausea, vomiting, flushing, diarrhea, dysphagia, light-headedness, and loss of consciousness. Patients usually tend to have the same manifestations on repeated episodes. IA is a prednisone-responsive disease that is ultimately a diagnosis of exclusion. Approximately 40% of patients are atopic. Serum tryptase (or urine histamine or its metabolite) will be elevated acutely but if elevated in the absence of anaphylaxis, should suggest alternative diagnoses including indolent systemic mastocytosis. A focused history, examination, and follow-up will dictate whether a patient’s symptoms may be attributable to disorders that mimic anaphylaxis, such as indolent systemic mastocytosis, carcinoid syndrome, pheochromocytoma, hereditary angioedema acquired C1 esterase inhibitor deficiency, or panic attacks. The presence of urticaria may help limit the differential because they do not usually accompany any of the aforementioned disorders, except for indolent systemic mastocytosis. IA is classified according to the symptoms as well as the frequency of attacks. Patients who experience six or more episodes in a year or two or more episodes in 2 months are classified as IA-frequent (IA-F). Patients who experience fewer episodes are classified as IA-infrequent (IA-I). This distinction is important because IA-F patients initially will require prednisone as disease-modifying therapy whereas most IA-I patients will not. Patients with IA must carry and know when and how to self-administer epinephrine.

Bas M. 11/2012 Expert Review of Clinical Immunology

Bradykinin is the key mediator of symptoms of hereditary angioedema (HAE), a rare genetic disorder characterized by recurrent episodes of edema of the skin, mucosa and muscle. Icatibant, a bradykinin B(2) receptor antagonist, is an effective and generally well-tolerated treatment option for acute attacks of type I and II HAE. A Phase III randomized, double-blind, placebo-controlled study, FAST-3 (NCT00912093), was designed to further evaluate the efficacy and safety of icatibant in patients presenting with moderate to very severe cutaneous and/or abdominal or mild-to-moderate laryngeal symptoms. Severe laryngeal attacks were treated with open-label icatibant. The controlled phase of FAST-3, completed in October 2010 with results published in December 2011, demonstrated that compared with placebo, icatibant evoked clinically meaningful and statistically significant efficacy across multiple end points in the treatment of type I and II HAE attacks. In addition, icatibant was generally well tolerated and no drug-related serious adverse events were experienced.

Available from: tandfonline.com/doi/full/10.1586/eci.12.67

Kusuma A, Relan A, Knulst AC, Moldovan D, Zuraw B, Cicardi M, et al. 9/2012 The American Journal of Medicine

BACKGROUND: Episodes of acute subcutaneous angioedema affecting the extremities in patients with known hereditary angioedema are called peripheral attacks. These attacks are considered to be of limited clinical importance.

OBJECTIVE: To evaluate the impact of peripheral attacks in patients with hereditary angioedema and to assess the response to treatment with recombinant human C1-inhibitor (rhC1INH).

METHODS: Hereditary angioedema patients with a peripheral attack included in a clinical database of rhC1INH were analyzed. Visual analog scale (VAS) scoring was used to evaluate symptom severity and response to therapy. RESULTS: Sixty-five patients with a peripheral attack were identified. VAS scores for 64 patients were available. Twenty-nine (45%) patients reported a single peripheral location of the attack, the others multiple locations. Eight patients (13%) indicated moderate (VAS 20-50 mm) and 55 (86%) severe (VAS >50 mm) swelling, 17 (27%) had moderate and 35 (55%) severe pain, while 8 (13%) patients reported moderate and 51 (80%) severe dysfunction for the peripheral attack. Symptom VAS scores decreased over time more rapidly in patients treated with rhC1INH than in patients treated with placebo. Onset of relief was achieved in 95% of the rhC1INH-treated patients within 4 hours, whereas only 21% of saline-treated patients had relief in the same time period.

CONCLUSION: Peripheral attacks in hereditary angioedema patients often are located at multiple anatomical locations and frequently have associated pain and dysfunction, in addition to swelling, as dominant symptoms. The medical need for treatment of these attacks may be underestimated. Treatment with rhC1INH constitutes a therapeutic option for acute peripheral hereditary angioedema attacks. Copyright © 2012 Elsevier Inc. All rights reserved.

Available from: amjmed.com/article/S0002-9343%2812%2900122-2/fulltext

Bork K. 8/2012 Current Allergy and Asthma Reports

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.

Available from: link.springer.com/article/10.1007%2Fs11882-012-0273-4

Prior N, Remor E, Gomez-Traseira C, Lopez-Serrano C, Cabanas R, Contreras J, et al. /2012 Health and Quality of Life Outcomes

BACKGROUND: There is a need for a disease-specific instrument for assessing health-related quality of life in adults with hereditary angioedema due to C1 inhibitor deficiency, a rare, disabling and life-threatening disease. In this paper we report the protocol for the development and validation of a specific questionnaire, with details on the results of the process of item generation, domain selection, and the expert and patient rating phase.

METHODS/DESIGN: Semi-structured interviews were completed by 45 patients with hereditary angioedema and 8 experts from 8 regions in Spain. A qualitative content analysis of the responses was carried out. Issues raised by respondents were grouped into categories. Content analysis identified 240 different responses, which were grouped into 10 conceptual domains. Sixty- four items were generated. A total of 8 experts and 16 patients assessed the items for clarity, relevance to the disease, and correct dimension assignment. The preliminary version of the specific health-related quality of life questionnaire for hereditary angioedema (HAE-QoL v 1.1) contained 44 items grouped into 9 domains.

DISCUSSION: To the best of our knowledge, this is the first multi-centre research project that aims to develop a specific health-related quality of life questionnaire for adult patients with hereditary angioedema due to C1 inhibitor deficiency. A preliminary version of the specific HAE-QoL questionnaire was obtained. The qualitative analysis of interviews together with the expert and patient rating phase helped to ensure content validity. A pilot study will be performed to assess the psychometric properties of the questionnaire and to decide on the final version.

Available from: ncbi.nlm.nih.gov/pmc/articles/PMC3489868/

Longhurst HJ, Nzeako UC. 3/2012 British Journal of Hospital Medicine

Available from: magonlinelibrary.com/doi/full/10.12968/hmed.2012.73.3.148 (small fee)

Martello JL, Woytowish MR, Chambers H. 4/2012 American Journal of Health-System Pharmacy

PURPOSE: The pharmacology, pharmacokinetics, efficacy, safety, dosage, administration, adverse effects, and place in therapy of ecallantide, a kallikrein inhibitor for the treatment of hereditary angioedema (HAE), are reviewed.

SUMMARY: Ecallantide is the first member of the kallikrein inhibitor class approved for the treatment of acute attacks of HAE. Ecallantide works by binding to kallikrein, preventing the conversion of kininogen to bradykinin, which reduces vascular permeability, thus reducing the swelling associated with acute attacks of HAE. Ecallantide has been studied for the treatment of HAE in three Phase II studies and two Phase III studies. These studies were collectively known as the EDEMA (Evaluation of DX-88’s Effect in Mitigating Angioedema) studies. Phase III clinical trials found that ecallantide is superior to placebo in ameliorating patient symptoms associated with acute attacks of HAE at any anatomical site. Ecallantide has a favorable safety profile, with the most common adverse effects being gastrointestinal effects, headache, and injection site reactions. The most severe adverse effects of ecallantide are the risk of anaphylaxis and the possible development of antiecallantide antibodies. A risk evaluation and mitigation strategy program has been approved by the Food and Drug Administration to help ensure the safety and efficacy of ecallantide use. The recommended dose is 30 mg given as three separate subcutaneous injections.

CONCLUSION: Ecallantide is a novel agent approved for the treatment of acute attacks of HAE at any anatomical site. It is one of only three medications approved for this indication in the United States, presents a unique mechanism of action, and appears to be safe and effective when used for its labeled indication.

Available from: ajhp.org/content/69/8/651

MacGinnitie AJ, Campion M, Stolz LE, Pullman WE. 3/2012 Allergy and Asthma Proceedings

Hereditary angioedema (HAE) is characterized by episodic attacks of edema. HAE is caused by low levels of the protein C1 esterase inhibitor, which inhibits plasma kallikrein, the enzyme responsible for converting high-molecular-weight kininogen to bradykinin. Unregulated production of bradykinin leads to the characteristic clinical symptoms of swelling and pain. Ecallantide is a novel plasma kallikrein inhibitor effective for treatment of acute HAE attacks. This study was designed to analyze the efficacy of ecallantide for treating HAE attacks by attack location, attack severity, patient gender, and body mass index (BMI). An analysis of integrated data from two double-blind, placebo-controlled trials of ecallantide for treatment of acute HAE attacks was undertaken. For the purpose of analysis, symptoms were classified by anatomic location and, for each location, by the patient-assessed severity of the attack. Efficacy versus placebo was examined using two validated patient-reported outcomes: treatment outcome score and mean symptom complex severity score. One hundred forty-three attacks were analyzed (73 ecallantide and 70 placebo). Ecallantide was equally effective in both male and female subjects. Ecallantide had decreased efficacy for patients with BMI > 30 kg/m(2). Ecallantide showed efficacy for treatment of severe and moderate attacks, and was effective for abdominal, internal head and neck, external head and neck, and cutaneous locations. In summary, ecallantide is effective for treatment of acute HAE attacks of different symptom locations and severity; outcomes were similar for men and women. However, the standard dose was less effective for obese patients.

Available from: ingentaconnect.com/content/ocean/aap/2012/00000033/00000002/art00013

Moldovan D, Reshef A, Fabiani J, Kivity S, Toubi E, Shlesinger M, et al. 6/2012 Clinical and Experimental Allergy

BACKGROUND: Hereditary angioedema (HAE) owing to C1 inhibitor deficiency is an autosomal dominant disorder, characterized by recurrent, potentially life-threatening, localized attacks of tissue swelling. Current treatment involves the infusion of C1 inhibitor protein (C1-INH) isolated from human plasma.

OBJECTIVES: This open-label extension to a European, Israeli and Argentinean randomized study (NCT00262301) aimed to investigate the efficacy and safety of recombinant human C1 inhibitor (rhC1-INH) as a first-line treatment following an HAE attack, together with its effect on subsequent attacks.

METHODS: An HAE-specific visual analogue scale (VAS) 0-100 mm was used by patients to assess the severity of attack at four anatomical locations. Patients were treated with one, single-vial, fixed-dose of rhC1-INH (2100 U), followed by up to two further vials at the investigators discretion. The primary end-point was the time from first rhC1-INH injection to first onset of relief of symptoms (> 20 mm decrease on VAS). Response to treatment was defined as the onset of relief within 4 h.

RESULTS: A total of 57 patients were treated for 194 HAE attacks. Overall, sustained relief of symptoms was achieved in 87% of rhC1-INH-treated patients within 4 h of treatment, with 57% of attacks requiring only one vial of rhC1-INH. When categorized by successive attacks experienced by individual patients, the response rate to rhC1-INH treatment was 96%, 83%, 87%, 80% and 80% for attacks 1-5 respectively. Treatment with rhC1-INH was well tolerated, with no discontinuations owing to treatment-emergent adverse events and no adverse events relating to immunogenicity.

CONCLUSIONS AND CLINICAL RELEVANCE: Treatment with rhC1-INH provides fast-onset relief for an HAE attack, with a high rate of therapeutic response maintained throughout subsequent attacks. Copyright © 2012 Blackwell Publishing Ltd.

Available from: onlinelibrary.wiley.com/wol1/doi/10.1111/j.1365-2222.2012.03984.x/full

Caballero T. 12/2012 Journal of Clinical Immunology

Hereditary angioedema (HAE) is a rare disorder caused by a deficiency of C1 esterase inhibitor, characterized by recurrent, highly variable attacks of subcutaneous or submucosal edema that may affect multiple body sites. Clinical studies of acute HAE therapies have required the use of assessment tools to evaluate both pretreatment attack severity (baseline severity) and changes in symptom severity following treatment (treatment response). This article reviews the range of assessment tools used for efficacy determination of acute HAE therapies, based on a review of relevant clinical studies. Because the goal is relief of symptoms (rather than cure), patient-reported outcomes (PROs) form the basis of these tools. Tools used to evaluate baseline severity typically employ location-specific assessment of symptom severity, using either categorical descriptions (which may be converted into numerical variables) or a visual analog scale (VAS). Some studies define the initial or most symptomatic site as an “index” site for purposes of efficacy determination, while others (such as the Mean Symptom Complex Severity score used in clinical studies of ecallantide) use a composite score that reflects all sites. Assessment of treatment response typically employs the same tool(s) to evaluate baseline severity, and may be either time-based (e.g., time to achievement of minimal or no symptoms) or symptom-based (e.g., degree of symptom relief at predetermined time points). Although it is unlikely that therapies will be compared using identical assessment tools, prospective or retrospective validation ensures the adequacy and relevance of such tools, which should be taken into consideration when therapies are compared.

Available from: link.springer.com/article/10.1007%2Fs10875-012-9734-8

Cicardi M, Bork K, Caballero T, Craig T, Li HH, Longhurst H, et al. 2/2012 Allergy

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. Copyright © 2011 John Wiley & Sons A/S.

Available from: onlinelibrary.wiley.com/doi/10.1111/j.1398-9995.2011.02751.x/full

Tang R, Chen S, Zhang HY. 6/2012 Chinese Medical Sciences Journal

OBJECTIVE: To determine the safety and efficacy of fresh frozen plasma (FFP) infusion for the treatment of hereditary angioedema (HAE).

METHODS: The medical records of patients with HAE admitted to Peking Union Medical College Hospital who had received FFP infusion during 2004 and 2010 were reviewed and PubMed database from 1966 to the present were searched using the following hereditary angioedema and fresh frozen plasma. The patient’s age, sex, body location of HAE attacks, the dose of FFP infusion, time of beginning to improvement, time to complete remission, complication, C1 inhibitor activity, and outcome were analyzed.

RESULTS: A total of 13 enrolled patients (7 male and 6 female) received 16 times of FFP infusion, including 2 patients undergoing FFP infusion in Peking Union Medical College Hospital and 11 patients reported in the literature. The mean dosage of FFP infusion was 586-/+337 mL. Two cases suffered from worsening abdominal pain and one case experienced skin rash. Only 1 patient had no improvement in symptom owing to transfusion related reaction. There was a definite improvement in symptom 49-/+19 minutes after beginning FFP infusion. The remission time decreased from 61.7-/+27.0 hours to 3.3 (2.0, 12.0) hours after FFP infusion. FFP infusion was effective for both type I and type II HAE.

CONCLUSION: FFP seems to be safe and effective for acute attacks of HAE.

Cicardi M, Johnston DT. 5/2012 Acta Haematologica

Hereditary angioedema (HAE), a rare autosomal dominant disorder, was first described in the late 19th century. The disease remained poorly understood and without therapeutic options until the latter half of the 20th century. Advances in the understanding of immunologic and hematologic pathways have shed light on HAE, a disease characterized by painful and unpredictable recurrent attacks of nonpitting edema without urticaria. Recognition that a deficiency of complement component 1 (C1) esterase inhibitor leads to overproduction of vasoactive kinins that cause angioedema paved the way for the development of early treatments. Increased understanding of the role of bradykinin in hereditary and acquired forms of C1 esterase inhibitor deficiency has led to the development of more targeted treatments for this painful, debilitating and potentially life-threatening disease. Copyright © 2012 S. Karger AG, Basel.

Available from: karger.com/Article/FullText/336590

Wahn V, Aberer W, Eberl W, Fashauer M, Kuhne T, Kurnik K, et al. 9/2012 European Journal of Pediatrics

Hereditary angioedema due to C1 inhibitor (C1 esterase inhibitor) deficiency (types I and II HAE-C1-INH) is a rare disease that usually presents during childhood or adolescence with intermittent episodes of potentially life-threatening angioedema. Diagnosis as early as possible is important to avoid ineffective therapies and to properly treat swelling attacks. At a consensus meeting in June 2011, pediatricians and dermatologists from Germany, Austria, and Switzerland reviewed the currently available literature, including published international consensus recommendations for HAE therapy across all age groups. Published recommendations cannot be unconditionally adopted for pediatric patients in German-speaking countries given the current approval status of HAE drugs. This article provides an overview and discusses drugs available for HAE therapy, their approval status, and study results obtained in adult and pediatric patients. Recommendations for developing appropriate treatment strategies in the management of HAE in pediatric patients in German-speaking countries are provided.Conclusion Currently, plasma-derived C1 inhibitor concentrate is considered the best available option for the treatment of acute HAE-C1-INH attacks in pediatric patients in German-speaking countries, as well as for short-term and long-term prophylaxis.

Available from: ncbi.nlm.nih.gov/pmc/articles/PMC3419830/

Riedl M. 3/2012 Clinical Therapeutics

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 beta(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. Copyright A© 2012 Elsevier HS Journals, Inc. All rights reserved.

Available from: clinicaltherapeutics.com/article/S0149-2918%2812%2900081-1/abstract

Aberer W. 9/2012 Annals of Medicine

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.

Available from: tandfonline.com/doi/full/10.3109/07853890.2012.687833

Kreuz W, Rusicke E, Martinez-Saguer I, Aygoren-Pursun E, Heller C, Klingebiel T. 1/2012 Transfusion

BACKGROUND: C1-esterase inhibitor (C1-INH) replacement therapy is the treatment of choice for acute edema attacks in patients with hereditary angioedema (HAE).

STUDY DESIGN AND METHODS: Our retrospective, observational study assessed the efficacy and safety of home therapy with a human plasma-derived C1-INH concentrate (pC1-INH) in 20 pediatric patients with HAE who had previously been treated with physician-based therapy. While on home therapy, 15 patients received on-demand treatment and five received individual replacement treatment (IRT). RESULTS: The switch to home therapy did not involve a significant increase in the dose of pC1-INH administered, but there was a significant increase in dosing frequency. Although only two patients were affected, the frequency of laryngeal attacks appeared to decrease on home therapy. All attacks, including laryngeal edema, were treated successfully during home therapy with pC1-INH. The mean annual number of days hospitalized was reduced from 3.8 during physician-based therapy to 0.11 during home therapy. No side effects or injection site complications were reported. The median time from onset of attack to administration of pC1-INH was reduced from 67.5 minutes during physician-based therapy to 15 minutes after switching to home therapy. The corresponding median time to initial symptom relief for all types of attack was reduced from 60 to 40 minutes.

CONCLUSION: As in adults, home therapy with pC1-INH is effective and safe in the treatment of HAE attacks in pediatric patients; a larger, randomized study should ideally confirm our findings before this approach can be considered the standard of care for pediatric patients. Copyright © 2011 American Association of Blood Banks.

Available from: onlinelibrary.wiley.com/doi/10.1111/j.1537-2995.2011.03240.x/full

Zanichelli A, Bova M, Coerezza A, Petraroli A, Triggiani M, Cicardi M. 8/2012 Allergy

Icatibant, a bradykinin B2 receptor antagonist, is an established treatment for acute attacks of hereditary angioedema (HAE) with C1-inhibitor (C1-INH) deficiency. We describe our experience with icatibant in eight patients with angioedema because of acquired C1-INH deficiency (AAE). Forty-eight moderate-to-severe attacks were treated with subcutaneous icatibant 30 mg; two moderate attacks resolved without treatment. The median (range) duration of treated attacks (onset to complete resolution) was 9.33 (1.67-39.00) h; durations of the untreated attacks were 72 and 96 h. Symptom improvement following icatibant treatment occurred in 0.5 (0.25-2.10) h and complete resolution in 6.75 (0.50-30.75) h. A single icatibant injection achieved complete symptom resolution in 47 attacks; one facial attack required a second injection. One peripheral attack responded less quickly than other treated attacks. Five patients reported transient injection site reactions. Icatibant appeared to provide effective symptom relief and was generally well tolerated. Copyright © 2012 John Wiley & Sons A/S.

Available from: onlinelibrary.wiley.com/doi/10.1111/j.1398-9995.2012.02853.x/full

Hack CE, Mannesse M, Baboeram A, Oortwijn B, Relan A. 10/2012 Biodrugs

BACKGROUND AND OBJECTIVE: Recombinant human C1-inhibitor (rhC1INH) is used to treat acute angioedema attacks in hereditary angioedema (HAE) due to a genetic C1INH deficiency. Recombinant proteins in general may induce antibody responses and therefore evaluation of such responses in the target population is an essential step in the clinical development program of a recombinant protein. Here we report the assessment of the immunogenicity of rhC1INH in symptomatic HAE patients.

METHODS: Blood samples collected before and after administration of rhC1INH were tested for antibodies against plasma-derived (pd) or rhC1INH, or against host-related impurities (HRI). Above cut-off screening results were confirmed with displacement assays, and also tested for neutralizing anti-C1INH antibodies. Finally, the relation of antibodies to clinical efficacy and safety of rhC1INH was analyzed.

RESULTS: Data from 155 HAE patients who received 424 treatments with rhC1INH were analyzed. 1.5% of all pre-exposure tests and 1.3% of all post-exposure tests were above the cut-off level in the screening assay for anti-C1INH antibodies. Six patients (3.9%) had anti-rhC1INH antibodies positive in the confirmatory assay. In two patients, confirmed antibodies were pre-existing with no increase post-exposure; in three patients, the antibodies occurred on a single occasion post-exposure; and in one patient, on subsequent occasions post-exposure. Neutralizing anti-pdC1INH antibodies were not found. Anti-HRI antibodies in the screening assay occurred in <0.7% of the tests before exposure to rhC1INH, in <1.9% after first exposure and in <3.1% after repeat treatment with rhC1INH. Five patients had anti-HRI antibodies positive in the confirmatory assay. In one patient, the antibodies were pre-existing, whereas in three of the 155 rhC1INH-treated patients (1.9%), confirmed anti-HRI antibodies occurred at more time points. Antibody findings were not associated with altered efficacy of rhC1INH or adverse events.

CONCLUSION: These results indicate a reassuring immunosafety profile of rhC1INH as a treatment for acute HAE attacks.

Available from: link.springer.com/article/10.1007/BF03261888

Wood P. 5/2012 Medical Clinics of North America

The 2 most commonly encountered primary immunodeficiency syndromes in adult practice are antibody deficiency disorders and hereditary angioedema.Immunologic therapy for these disorders has significantly improved patient management. Therapy with immunoglobulin leads to improvement in overall quality of life. With increasing survival rates and decreasing levels of life-threatening infections in patients with primary antibody deficiencies, disease complications are more commonly encountered. Treatment of these complications with monoclonal antibody therapy seems promising and is likely to increase in the future. More recently,several additional agents have become available, including novel drugs targeted at different elements of the disease process. Copyright © 2012 Elsevier Inc. All rights reserved.

Available from: sciencedirect.com/science/article/pii/S0025712512000752 (small fee)

Lane CJ, Grant JA, Dougherty D 3rd. 1/2012 Postgraduate Medicine

Originally identified in 1882, hereditary angioedema (HAE) is a debilitating and potentially fatal disorder. Although a number of therapies have been identified, many are relatively ineffective or are associated with significant side effect concerns that limit their efficacy. Fortunately, the 2008 approval of plasma-derived C1 esterase inhibitor concentrate for disease prophylaxis provides clinicians with a novel and effective treatment unencumbered with severe side effect concerns for those with this debilitating disorder. However, despite advances in modern medicine, HAE remains a condition marked by a myriad of symptoms that mimic a range of other disorders, from allergic angioedema to acute abdomen, and accurate diagnosis remains a concern. Using articles from the medical literature from the late nineteenth and early twentieth centuries documenting families with HAE, we will review its history and pathophysiology as well as describe current trends in its diagnosis and treatment. Additionally, we will emphasize the humanistic impact of the disorder by describing the real-life experiences of a contemporary family who has documented their experience with HAE across 7 generations.

Available from: tandfonline.com/doi/abs/10.3810/pgm.2012.01.2527

Nzeako UC, Longhurst HJ. 4/2012 European Journal of Gastroenterology and Hepatology

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.

Available from: journals.lww.com/eurojgh/pages/articleviewer.aspx?year=2012&issue=04000&article=00001&type=abstract (small fee)

Keizer RJ, Budde IK, Sprengers PF, Levi M, Beijnen JH, Huitema AD. 2/2012 The Journal of Clinical Pharmacology

A novel formulation of C1 esterase inhibitor concentrate, a plasma product used in the treatment of hereditary angioedema (HAE), was studied in a clinical trial for similarity in pharmacokinetics (PK) compared with the reference product. Direct trial data were limited given the availability of patients, and therefore a modeling approach was used to study similarity. Type I error of the study was evaluated using simulations based on retrospective data. A population PK modeling analysis was performed on data from the trial. Analysis of variance was carried out on results of a noncompartmental PK analysis (NCA) of the clinical data. Simulations showed that type I error was inflated to 62% (P < .05) when bioequivalence criteria (confidence intervals within 80%-125%) were adhered to strictly. In the clinical trial, 13 HAE patients were evaluable. The population PK analysis showed no significant differences in PK parameters, whereas confidence intervals for all parameters were within 80% to 125%. The relative differences in area under the curve, incremental recovery, and mean residence time estimated using NCA were all close to 1. The novel formulation showed similar PK characteristics to the original formulation. The model-based approach showed that strict criteria for PK comparison could not be applied in this analysis. Copyright 2012 American College of Clinical Pharmacology.

Available from: onlinelibrary.wiley.com/doi/10.1177/0091270010394446/full

Riedl MA, Hurewitz DS, Levy R, Busse PJ, Fitts D, Kalfus I. 1/2012 Annals of Allergy, Asthma, and Immunology

BACKGROUND: Hereditary angioedema (HAE) is a rare disease caused by C1INH gene mutations, which leads to a deficiency or dysfunction of C1 inhibitor (C1 INH), resulting in recurrent episodes of severe and potentially life-threatening edema.

OBJECTIVE: To evaluate the efficacy and safety of repeat use of nanofiltered C1 esterase inhibitor (human) (C1 INH-nf) for the short-term treatment of HAE attacks. METHODS: In this open-label study, patients received C1 INH-nf, 1,000 U intravenously, for the treatment of HAE attacks. Efficacy end points included the proportion of attacks with unequivocal relief of the defining symptom within 1 and 4 hours after receiving study drug and time to beginning of relief of the defining symptom. Safety was monitored through adverse event reporting, vital signs measurements, and laboratory testing.

RESULTS: A total of 113 patients were enrolled in the study from September 21, 2006, through March 31, 2009, and received 885 doses of C1 INH-nf. A total of 609 HAE attacks were treated with C1 INH-nf, and the numbers of attacks achieving unequivocal relief of the defining symptom within 1 and 4 hours after the start of the first dose were 412 (68%) and 529 (87%), respectively. Of 101 patients treated for an attack during the study period, 80 achieved unequivocal relief of their first attack within 4 hours after study medication (response rate, 79%); median time to the beginning of unequivocal relief was 0.75 hour. C1 INH-nf was safe and well tolerated.

CONCLUSIONS: This open-label study demonstrates the efficacy and safety of C1 INH-nf for short-term treatment of HAE attacks.

TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00438815. Copyright © 2012 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Available from: annallergy.org/article/S1081-1206%2811%2900859-3/abstract

Groner A, Nowak T, Schafer W. 10/2012 Transfusion

BACKGROUND: Human plasma-derived products–such as C1 esterase inhibitor (C1-INH) concentrate, used to treat hereditary angioedema–carry with them the risk of transmitting blood-borne viruses and, theoretically, prion proteins. To minimize this risk, three complementary approaches are implemented: selection and testing of plasma donations for the absence of pathogenic blood-borne viruses, similarly testing and releasing the plasma pool for fractionation, and ensuring that the manufacturing process includes validated steps for pathogen inactivation and removal.

STUDY DESIGN AND METHODS: This article describes the selection of plasma for the production of C1-INH and the studies used to confirm the pathogen reduction capacity of the manufacturing process: three independent virus reduction steps–pasteurization, hydrophobic interaction chromatography (HIC), and virus filtration–and two prion reduction steps. Samples of product intermediates from the manufacturing steps were spiked with a panel of enveloped and nonenveloped viruses and two prion preparations and subjected to a valid scaled-down version of the respective manufacturing steps resulting in the quantification of the pathogen reduction factors.

RESULTS: Validation studies demonstrated overall virus reduction factors for all viruses of more than 15 log, considerably exceeding the potential amount of virus present in a plasma pool for fractionation. Prion proteins were also efficiently removed by the manufacturing process, as currently determined in evaluating the prion removal capacity of the ammonium sulfate precipitation and HIC steps.

CONCLUSION: The pathogen reduction capacity demonstrated here indicates that the manufacturing process of the C1-INH Berinert is highly effective for reducing enveloped and nonenveloped viruses and prion proteins. Copyright © 2012 American Association of Blood Banks.

Available from: onlinelibrary.wiley.com/doi/10.1111/j.1537-2995.2012.03590.x/full

Prematta MJ, Bewtra AK, Levy RJ, Wasserman RL, Jacobson KW, Machnig T, et al. 10/2012 Advances in Therapy

INTRODUCTION: Prodromal symptoms commonly precede hereditary angioedema (HAE) attacks. There is continuing interest in evaluating prodromes as treatment indicators, but a paucity of relevant data. This study was designed to prospectively identify prodomal characteristics in patients voluntarily reporting such information around the time of seeking treatment for an acute HAE attack.

METHODS: Twenty-eight patients with HAE were enrolled in this survey, which was conducted in the context of an open-label study of treatment of HAE attacks with plasma-derived C1-inhibitor concentrate. At the time of treatment, patients were encouraged to answer survey questions about prodromal symptoms preceding that particular HAE attack.

RESULTS: Twenty-one patients provided prodromal information for 253 treated HAE attacks. Seventy-one percent of patients (15/21) reported prodromes. Three patients accounted for approximately 80% of the attacks and 89% of the reported prodromal symptoms. Prodromes were experienced before 67.6% (171/253) of attacks, with a mean of 1.4 prodromes per attack. Fatigue was the most frequent prodrome (42% of attacks), followed by nausea (26%), and flu-like symptoms (22%). The median duration of a prodrome before an attack was 12 h (range, 0.33-24 h).

CONCLUSIONS: Despite many limitations in the study design, these findings confirm that prodromes are frequently associated with HAE attacks in many patients and occur sufficiently early to allow time for treatment initiation. The frequency of “false positive” prodromal symptoms remains undetermined, and the authors captured data only on attacks severe enough to warrant treatment. Additional well-designed prospective studies are clearly needed to continue investigating the potential clinical relevance of prodromes.

Available from: link.springer.com/article/10.1007%2Fs12325-012-0053-5

Grant JA, White MV, Li HH, Fitts D, Kalfus IN, Uknis ME, et al. 7/2012 Allergy and Asthma Proceedings

Patients with hereditary angioedema (HAE) may have attacks triggered by dental, medical, or surgical procedures. This analysis evaluated the efficacy and safety of preprocedural administration of nanofiltered C1 esterase inhibitor (C1 INH-nf; human) for the prevention of HAE attacks during and after dental, medical, or surgical procedures. Data were reviewed retrospectively from two acute treatment trials in which at least 1000 U of C1 INH-nf was administered i.v. within 24 hours before an emergency or noncosmetic medical, surgical, or dental procedure. Dosing data, HAE attacks reported within 72 hours, and adverse events (AEs) reported within 7 days after a preprocedural dose of C1 INH-nf were analyzed to assess efficacy and safety. Forty-one unique subjects (8 children and 33 adults) received C1 INH-nf for 91 procedures (40 in children and 51 in adults). The majority of procedures (56%) involved dental work and 44% involved a variety of surgical or medical procedures. A single 1000-U dose of C1 INH-nf was administered for 96% of procedures. An HAE attack did not occur within 72 hours after C1 INH-nf dosing for 98% (89/91) of procedures. Two HAE attacks were reported after the procedure, and both were treated with C1 INH-nf and achieved relief. None of the reported AEs were judged to be related to C1 INH-nf or were associated with an HAE attack. This analysis supports the efficacy and safety of preprocedural administration of C1 INH-nf for the prevention of HAE attacks.

Available from: ingentaconnect.com/content/ocean/aap/2012/00000033/00000004/art00008

Bernstein JA, Moellman JJ. 5/2012 Postgraduate Medicine

Hereditary angioedema (HAE) is a rare disorder generally caused by a deficit in the activity of C1-esterase inhibitor (C1-INH). Symptoms manifest as recurrent episodes of nonallergic, nonpruritic, and nonpitting edema. Attacks commonly occur on the extremities, trunk, genitalia, abdomen, or head and neck–the latter 2 locations are associated with the greatest morbidity and mortality. In the United States, there has been a considerable void in effective HAE treatments and emergency management guidelines. Clinical outcomes using agents such as fresh-frozen plasma, attenuated androgens (danazol), or plasmin inhibitors (aminocaproic acid) have not been ideal. Recent years have seen progress with US Food and Drug Administration (FDA) approval of several products for acute HAE treatment. Plasma concentrate of C1-INH has long been the treatment of choice in many parts of the world, and a pasteurized formula received FDA approval in October 2009 for treating attacks. Ecallantide, a plasma kallikrein inhibitor, and icatibant, a bradykinin receptor antagonist, were approved in December 2009 and August 2011, respectively, for treatment of acute attacks. A recombinant C1-INH product is in late development stages for treating acute attacks. These new treatments provide symptom relief within hours, dramatically shorten attack duration, and decrease mortality from airway compromise. For the first time, US physicians have rapid-acting and highly effective treatments for managing acute HAE attacks.

Stolz LE, Sheffer AL. 1/2012 Expert Review of Clinical Immunology

Hereditary angioedema (HAE) is a rare genetic disorder characterized by unpredictable, episodic, incapacitating attacks of well-demarcated angioedema in the absence of urticaria and pruritus. HAE is due to deficient or dysfunctional C1-esterase inhibitor activity, which results in unopposed activation of plasma kallikrein, resulting in increased levels of bradykinin. Ecallantide is a potent and specific plasma kallikrein inhibitor approved for the treatment of acute attacks of HAE affecting any anatomic site. In Phase III clinical trials, subcutaneously administered ecallantide demonstrated significant, rapid and durable symptom relief. Ecallantide was effective for all attack types, including potentially life-threatening laryngeal attacks. The main safety concern is potentially serious hypersensitivity reactions, including anaphylaxis. Ecallantide represents an important treatment option for the management of acute attacks of HAE.

Available from: tandfonline.com/doi/full/10.1586/eci.11.81

Relan A, Bakhtiari K, van Amersfoort ES, Meijers JC, Hack CE. 2/2012 Biodrugs

BACKGROUND: Recombinant human C1-inhibitor (rhC1INH; Ruconest) has been developed for treatment of acute angioedema attacks in patients with hereditary angioedema (HAE) due to heterozygous deficiency of C1INH. Previous reports suggest that administration of plasma-derived C1INH products may be associated with an increased risk for thromboembolic complications.

OBJECTIVES: Our aim is to evaluate the effects of rhC1INH on coagulation and fibrinolysis in symptomatic HAE patients.

METHODS: Levels of various coagulation and fibrinolytic parameters were determined in pre- and post-exposure plasma samples from HAE patients included in a randomized clinical trial. Patients were treated with either saline, or 50 or 100U/kg rhC1INH for an acute angioedema attack.

RESULTS: Prior to rhC1INH treatment, the majority of patients had low to normal activated partial thromboplastin times (aPTT) and increased levels of prothrombin fragment 1+2, thrombin-antithrombin complexes, D-dimers and plasmin-antiplasmin complexes, all of which indicate activation of both coagulation and fibrinolysis. Infusion of rhC1INH at doses up to 100U/kg did not affect these parameters except for a dose-dependent prolongation of aPTT, confirming that rhC1INH is an inhibitor of the contact system, and that F1+2 levels decreased.

CONCLUSION: Coagulation and fibrinolytic systems are activated in HAE patients suffering from an acute angioedema attack. Treatment with rhC1INH at 50 or 100U/kg had no effect on parameters reflecting activation of these systems except for a significant effect on aPTT, which likely reflects a pharmacodynamic effect of rhC1INH, and a reduction on plasma levels of the prothrombin activation fragment F1+2. We conclude that these results argue against a prothrombotic effect of treatment with this rhC1INH product in HAE patients.

Available from: link.springer.com/article/10.2165%2F11599490-000000000-00000

Plosker GL. 10/2012 Biodrugs

Conestat alfa is a recombinant human C1 inhibitor used in the treatment of angioedema attacks in patients with hereditary angioedema (HAE). Patients with type I or II HAE have a deficiency in functional C1 inhibitor, which is an important regulator of complement and contact system activation. The therapeutic efficacy of conestat alfa in the treatment of angioedema attacks in patients with HAE was evaluated in two similar randomized, double-blind, placebo-controlled trials conducted in North America and Europe. The randomized controlled phases of both studies were closed after interim analyses provided compelling evidence of statistically significant positive efficacy findings and showed no apparent adverse safety findings. Results of the pooled analysis of the two trials showed that conestat alfa provided significantly faster initial relief of symptoms than placebo. The median time to the beginning of relief of symptoms (primary endpoint) was 66 minutes with conestat alfa 100 units/kg, 122 minutes with conestat alfa 50 units/kg, and 495 minutes with placebo. Conestat alfa was also statistically superior to placebo for the secondary endpoint of median time to minimal symptoms, with values of 266, 247, and 1210 minutes for the respective treatment groups. On the basis of data from open-label extension studies and integrated analyses of clinical trial data, conestat alfa has demonstrated efficacy in the treatment of repeated HAE attacks and in patients with potentially life-threatening HAE attacks with involvement of the upper airways. Conestat alfa was generally well tolerated in clinical trials, with the most frequently reported adverse event being headache. In the two randomized controlled trials, headache and vertigo were the only adverse events deemed to be related to study treatment.

Available from: link.springer.com/article/10.1007/BF03261889

Boccon-Gibod I, Bouillet L. 6/2012 Clinical and Experimental Immunology

We evaluated the efficacy and safety of icatibant self-administration in 15 patients with hereditary angioedema (HAE) types I or III, for 55 acute attacks (mostly severe or very severe). Icatibant self-administration was generally effective: first symptom improvement occurred in 5 min-2 h (HAE type I; n = 17) and 8 min-1 h (HAE type III; n = 9) for abdominal attacks and 5-30 min (HAE type I; n = 4) and 10 min-12 h (HAE type III; n = 6) for laryngeal attacks. Complete symptom resolution occurred in 15 min-19 h (HAE type I; n = 8) and 15 min-48 h (HAE type III; n = 9) for abdominal attacks and 5-48 h (HAE type I; n = 3) and 8-48 h (HAE type III; n = 5) for laryngeal attacks. No patient required emergency hospitalization. The only adverse events were mild, spontaneously resolving injection site reactions. Patients reported that carrying icatibant with them gave them greater confidence in managing their condition.Copyright © 2012 The Authors. Clinical and Experimental Immunology © 2012 British Society for Immunology.

Available from: ncbi.nlm.nih.gov/pmc/articles/PMC3390482/

Tourangeau LM, Castaldo AJ, Davis DK, Koziol J, Christiansen SC, Zuraw BL. 3/2012 International Archives of Allergy and Immunology

BACKGROUND: C1 inhibitor (C1INH) has recently been approved in the USA for the treatment of acute attacks in hereditary angioedema (HAE) patients. The literature suggests that treatment with C1INH is most effective when administered early in an attack. Home infusion of C1INH allows for the earliest possible intervention since patients can initiate therapy at the first sign of symptoms.

METHODS: We performed an observational, prospective study on 39 subjects with HAE utilizing two groups of patients: one receiving on-demand C1INH replacement therapy in a medical facility and the other self-managing on-demand C1INH replacement therapy in the home setting under the supervision of a treating physician. All subjects completed online questionnaires weekly for 8 weeks.

RESULTS: There were statistically significant decreases in attack duration (p < 0.0001), pain medication use (p < 0.0001) and graded attack severity (p < 0.005) in the subjects who received C1INH in the home setting versus the clinic-based group. Attack frequency was similar between the groups. The home group experienced more frequent injection-related side effects; however, the clinic group noted more severe adverse events from C1INH.

CONCLUSION: Physician-supervised self-managed C1INH replacement therapy is a safe and effective treatment for patients with HAE with potential benefits in diminishing attack duration and attack severity. Copyright © 2011 S. Karger AG, Basel.

Available from: karger.com/Article/FullText/329635

Zuraw BL, Kalfus I. 9/2012 American Journal of Medicine

OBJECTIVE: Nanofiltered C1-inhibitor (C1INH-nf) is approved for prophylactic treatment of hereditary angioedema. This study assessed the efficacy and safety of C1INH-nf as prophylactic therapy in a large cohort of patients with hereditary angioedema.

METHODS: An open-label multicenter extension study was performed involving 146 subjects with hereditary angioedema who were treated with C1INH-nf for up to 2.6 years in centers throughout the United States. Subjects were to be treated with C1INH-nf 1000 units every 3 to 7 days. The primary efficacy variable was the number of attacks of angioedema experienced.

RESULTS: Subjects experienced a 93.7% reduction in attacks while taking prophylactic C1INH-nf (0.19 attacks per month; interquartile range, 0.00-0.64) compared with the historical rate of attacks. Some 87.7% reported an attack frequency of 1 or less attack per month during prophylactic C1INH-nf and 34.9% had no attacks during the study. Some 7.5% of subjects experienced relatively frequent attacks despite twice-weekly C1INH-nf. Although twice-weekly dosing was highly effective in most subjects, once-weekly dosing provided adequate control in a subgroup of subjects. No clinical characteristics predicted the response to prophylactic C1INH-nf, including historical attack frequency. C1INH-nf was well tolerated.

CONCLUSION: Prophylactic C1INH-nf is highly effective and safe, and provides durable prophylaxis in the majority of patients with hereditary angioedema. The recommended dose of C1INH-nf 1000 units twice weekly is supported by this open-label study. Individual patients may benefit from further dose adjustment on the basis of response to therapy and individual treatment goals. Copyright Published by Elsevier Inc.

Available from: amjmed.com/article/S0002-9343%2812%2900381-6/fulltext

Farkas H, Zotter Z, Csuka D, Szabo E, Nebenfuhrer Z, Temesszentandrasi G, et al. 12/2012 Allergy

BACKGROUND: Hereditary angioedema is a potentially life-threatening disorder, because edema occurring in the mucosa of the upper airways can lead to suffocation. The management of HAE consists of avoiding the triggering factors, prophylaxis, and the acute treatment of edematous episodes. Medical procedures can also provoke edematous attacks, and therefore, short-term prophylaxis (STP) is recommended before such interventions. Our aim was to evaluate the efficacy and safety of STP administered before medical procedures.

METHODS: We conducted a retrospective analysis before and a prospective survey after establishing the diagnosis in a group of 137 (60 males, 77 females; 20 pediatric and 117 adult) patients with HAE. Both were implemented using questionnaires, patient diaries and hospital charts focusing on medical interventions provoking edematous attack, and the medicinal products (C1-INH concentrate, tranexamic acid, and danazol) administered for STP.

RESULTS: Comparing surgical interventions performed without pre-event STP (in 39/89 patients before HAE was diagnosed), or after STP (in 3/55 cases after diagnosis), we found a significant (P < 0.0001, Fisher’s exact test) reduction in the number of edematous episodes. Evaluating the efficacy of the drugs administered for STP revealed that C1-INH concentrate (Berinert() , CSL Behring, Marburg, Germany) was significantly (P = 0.0096, Fisher’s exact test) superior to orally administered drugs in reducing the instances of postprocedural edema. None of the medicinal products caused adverse events potentially related to STP.

CONCLUSIONS: STP reduces the number of postprocedural edematous episodes. C1-INH concentrate is safe and effective for prophylaxis. When this agent is not available, danazol is a potential alternative for prophylaxis before elective medical interventions. Copyright © 2012 John Wiley & Sons A/S.

Available from: onlinelibrary.wiley.com/doi/10.1111/all.12032/full

Hack CE, Relan A, van Amersfoort ES, Cicardi M. 1/2012 Allergy

BACKGROUND: Hereditary angioedema (HAE) is a heterozygous deficiency of first component of complement-inhibitor (C1INH). Insufficient C1INH activity leads to uncontrolled activation of plasma cascade systems, which results in acute angioedema attacks in patients with HAE. Plasma-derived or recombinant C1INH products are approved for the treatment of such angioedema attacks. The target level of C1INH activity needed to achieve optimal efficacy, however, remains unknown. We determined the plasma level of C1INH associated with optimal clinical efficacy in the treatment of angioedema attacks.

METHODS: Efficacy and pharmacokinetic data were reviewed from recently published placebo-controlled randomized trials in the treatment of HAE with either plasma-derived or recombinant C1INH products, tested at various doses.

RESULTS: A dose-dependent effect was observed on time to the beginning of relief of symptoms, on time to resolution of symptoms, and on the response rate within 4 h. Optimal efficacy of C1INH therapy is achieved at doses >50 U/kg. This dose increases plasma C1INH activity in almost all patients to values >0.7 U/ml (70% of normal), the lower limit of the normal range. The differences in half-lives of the various C1INH products do not have an obvious effect on clinical efficacy.

CONCLUSION: A review of the efficacy and pharmacokinetic data from recently published controlled studies in the treatment of HAE attacks suggests that efficacy of C1INH therapy is optimal when C1INH activity levels are restored to the normal range. Copyright © 2011 John Wiley & Sons A/S.

Gandhi PK, Gentry WM, Bottorff MB. 10/2012 Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy

STUDY OBJECTIVE: To investigate reports of thrombotic events associated with the use of C1 esterase inhibitor products in patients with hereditary angioedema in the United States.

DESIGN: Retrospective data mining analysis.

SOURCE: The United States Food and Drug Administration (FDA) adverse event reporting system (AERS) database.

MEASUREMENTS AND MAIN RESULTS: Case reports of C1 esterase inhibitor products, thrombotic events, and C1 esterase inhibitor product-associated thrombotic events (i.e., combination cases) were extracted from the AERS database, using the time frames of each respective product’s FDA approval date through the second quarter of 2011. Bayesian statistical methodology within the neural network architecture was implemented to identify potential signals of a drug-associated adverse event. A potential signal is generated when the lower limit of the 95% 2-sided confidence interval of the information component, denoted by IC025 , is greater than zero. This suggests that the particular drug-associated adverse event was reported to the database more often than statistically expected from reports available in the database. Ten combination cases of thrombotic events associated with the use of one C1 esterase inhibitor product (Cinryze) were identified in patients with hereditary angioedema. A potential signal demonstrated by an IC025 value greater than zero (IC025 = 2.91) was generated for these combination cases.

CONCLUSION: The extracted cases from the AERS indicate continuing reports of thrombotic events associated with the use of one C1 esterase inhibitor product among patients with hereditary angioedema. The AERS is incapable of establishing a causal link and detecting the true frequency of an adverse event associated with a drug; however, potential signals of C1 esterase inhibitor product-associated thrombotic events among patients with hereditary angioedema were identified in the extracted combination cases. Copyright © 2012 Pharmacotherapy Publications, Inc.

Available from: onlinelibrary.wiley.com/doi/10.1002/j.1875-9114.2012.01126/full

McCormack PL. 3/2012 Drugs

Tranexamic acid, a synthetic derivative of the amino acid lysine, is an antifibrinolytic agent that acts by binding to plasminogen and blocking the interaction of plasmin(ogen) with fibrin, thereby preventing dissolution of the fibrin clot. Tranexamic acid (Transamin) is indicated in Japan for use in certain conditions with abnormal bleeding or bleeding tendencies in which local or systemic hyperfibrinolysis is considered to be involved. This article reviews the efficacy and tolerability of tranexamic acid in conditions amenable to antifibrinolytic therapy and briefly overviews the pharmacological properties of the drug. In large, randomized controlled trials, tranexamic acid generally significantly reduced perioperative blood loss compared with placebo in a variety of surgical procedures, including cardiac surgery with or without cardiopulmonary bypass, total hip and knee replacement and prostatectomy. In many instances, tranexamic acid also reduced transfusion requirements associated with surgery. It also reduced blood loss in gynaecological bleeding disorders, such as heavy menstrual bleeding, postpartum haemorrhage and bleeding irregularities caused by contraceptive implants. Tranexamic acid significantly reduced all-cause mortality and death due to bleeding in trauma patients with significant bleeding, particularly when administered early after injury. It was also effective in traumatic hyphaema, gastrointestinal bleeding and hereditary angioneurotic oedema. While it reduces rebleeding in subarachnoid haemorrhage, it may increase ischaemic complications. Pharmacoeconomic analyses predicted that tranexamic acid use in surgery and trauma would be very cost effective and potentially life saving. In direct comparisons with other marketed agents, tranexamic acid was at least as effective as epsilon-aminocaproic acid and more effective than desmopressin in surgical procedures. It was more effective than desmopressin, etamsylate, flurbiprofen, mefenamic acid and norethisterone, but less effective than the levonorgestrel-releasing intra-uterine device in heavy menstrual bleeding and was as effective as prednisolone in traumatic hyphaema. Tranexamic acid was generally well tolerated. Most adverse events in clinical trials were of mild or moderate severity; severe or serious events were rare. Therefore, while high-quality published evidence is limited for some approved indications, tranexamic acid is an effective and well tolerated antifibrinolytic agent.

Available from: link.springer.com/article/10.2165%2F11209070-000000000-00000

Hofstra JJ, Kleine Budde I, van Twuyver E, Choi G, Levi M, Leebeek FW, et al. 3/2012 Clinical Immunology

From 1997, plasma-derived C1-inhibitor concentrate (Cetor) has been available to HAE and AAE patients. Recently, a virus reducing 15 nm nanofiltration step has been introduced in the production process. A randomized, double-blind controlled cross-over study was performed to compare the pharmacokinetics (PK) of nanofiltered (C1-INH-NF) with conventional C1-inhibitor (C1-INH). Efficacy and safety were investigated in an open-label, on-demand and a prophylactic study. No differences in pharmacokinetic parameters between C1-INH and C1-INH-NF were found (13 non-symptomatic HAE patients). Both C1-inhibitor products equally increased plasma C4 levels. In the on-demand study, 14 acute angioedema attacks in 8 patients were analyzed. In the prophylactic study, 1 AAE and 5 HAE patients experienced in total 31 attacks during 748 observation days. In total 180,000 units of C1-INH-NF were administered. No product-related adverse events occurred, and no anti-C1-antibodies were induced. Nanofiltration in the production process of C1-inhibitor did not affect the pharmacokinetics, efficacy, and safety. Copyright A© 2011 Elsevier Inc. All rights reserved.

Available from: sciencedirect.com/science/article/pii/S1521661611003330 (small fee)

Craig TJ, Bewtra AK, Hurewitz D, Levy R, Janss G, Jacobson KW, et al. 7/2012 Allergy and Asthma Proceedings

Placebo-controlled studies established the efficacy of replacement therapy with C1 esterase inhibitor (C1-INH) concentrate for treating single acute hereditary angioedema (HAE) attacks, but only limited data from prospective studies are available on repeated treatment of successive HAE attacks. This study evaluates the association between repeated treatments with 20 U/kg of C1-INH concentrate (Berinert; CSL Behring, Marburg, Germany) for HAE attacks at any body location and treatment response. In a post hoc analysis of an open-label extension study (International Multicenter Prospective Angioedema C1-INH Trial [I.M.P.A.C.T.2]), the association between repeated treatment with C1-INH and times to onset of symptom relief and complete resolution of HAE symptoms was assessed in patients who were treated for at least 15 attacks by linear regression on the ordinal attack number. Eighteen patients received C1-INH concentrate for at least 15 HAE attacks over a mean duration of 34 months. Demographic and baseline characteristics of these patients were similar to those of all patients in the study. The distribution of body locations and the intensity of HAE attacks were similar for each of the first 15 attacks and subsequent attacks. The extent of previous use of C1-INH concentrate had no effect on the time to onset of symptom relief, the time to complete resolution of HAE symptoms, or the time between attacks treated with C1-INH concentrate; the median of individual linear regression coefficients was not statistically significantly different from 0. Treatment with 20 U/kg of C1-INH concentrate provided consistent treatment response in patients treated for multiple successive HAE attacks at any body location. (Clinicaltrials.gov identifier: NCT00292981).

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