Oral Plasma Kallikrein Inhibitor for Prophylaxis in Hereditary Angioedema.

BACKGROUND: Hereditary angioedema is a life-threatening illness caused by mutations in the gene encoding C1 inhibitor (also called C1 esterase inhibitor) that lead to overactivation of the kallikrein-bradykinin cascade. BCX7353 is a potent oral small-molecule inhibitor of plasma kallikrein with a pharmacokinetic and pharmacodynamic profile that may help prevent angioedema attacks. METHODS: In this international, three-part, dose-ranging, placebo-controlled trial, we evaluated four doses of BCX7353 (62.5 mg, 125 mg, 250 mg, and 350 mg once daily) for the prevention of angioedema attacks over a 28-day period. Patients with type I or II hereditary angioedema with a history of at least two angioedema attacks per month were randomly assigned to BCX7353 or placebo. The primary efficacy end point was the number of confirmed angioedema attacks. Key secondary end points included angioedema attacks according to anatomical location and quality of life. RESULTS: A total of 77 patients underwent randomization, 75 received BCX7353 or placebo, and 72 completed the trial. The rate of confirmed angioedema attacks was significantly lower among patients who received BCX7353 at daily doses of 125 mg or more than among those who received placebo, with a 73.8% difference at 125 mg (P<0.001). Significant benefits with respect to quality-of-life scores were observed in the 125-mg and 250-mg dose groups (P<0.05). Gastrointestinal adverse events, predominantly of grade 1, were the most commonly reported adverse events, particularly in the two highest BCX7353 dose groups. CONCLUSIONS: Once-daily oral administration of BCX7353 at a dose of 125 mg or more resulted in a significantly lower rate of attacks of hereditary angioedema than placebo. Mild gastrointestinal symptoms were the principal side effect. (Funded by BioCryst Pharmaceuticals; APeX-1 ClinicalTrials.gov number, NCT02870972 .).

Hereditary angioedema with F12 mutation: Clinical features and enzyme polymorphisms in 9 Southwestern Spanish families.

BACKGROUND: Information on F12 mutation hereditary angioedema (HAE) is still limited, but Spain is now recognized as having one of the highest concentrations of cases in Western Europe. OBJECTIVE: To describe unique features of HAE in Spanish carriers of the F12 mutation and investigate a potential role for angiotensin-converting enzyme (ACE) and aminopeptidase-P polymorphisms in disease expression. METHODS: This was a prospective observational cohort study of 35 individuals (80% females) from 9 unrelated families carrying the p.Thr309Lys mutation. We analyzed detailed medical records and complement activity (C4, C1q, C1 inhibitor) and screened for mutations in exon 9 of the F12 gene and 2 polymorphisms: XPNPEP2 c-2399A and the ACE insertion/deletion polymorphism. RESULTS: The p.Thr309Lys mutation was found in all individuals. Three of the 9 index patients had a clinically negative family history, and 72% of males and 29% of females were asymptomatic. Sixteen females (44% estrogen dependent, 56% estrogen sensitive) were clearly symptomatic. The most common locations of attacks were the abdomen (63%), face (25%), and peripheral structures (6%). Triggers other than hyperestrogenic states included stress and minor trauma or pressure. Short-term treatment with C1-inhibitor concentrate and icatibant and long-term prophylaxis with tranexamic acid were useful. The combination of the I allele and A allele was detected in 17% of patients. CONCLUSION: The polymorphisms analyzed were not a major determinant of disease expression in our population. We recommend searching for F12 mutations in women with edema attacks without associated wheals and with normal C1-inhibitor levels, particularly when they develop symptoms during hyperestrogenic states or are of Western European or African origin.

Development of a disease-specific quality of life questionnaire for adult patients with hereditary angioedema due to C1 inhibitor deficiency (HAE-QoL): Spanish multi-centre research project.

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.

A multicriteria decision analysis (MCDA) applied to three long-term prophylactic treatments for hereditary angioedema in Spain.

Introduction: Hereditary angioedema (HAE) is a rare genetic disease that impairs quality of life and could be life-threatening. The aim of this study was to apply a multicriteria decision analysis to assess the value of three long-term prophylactic (LTP) therapies for HAE in Spain. Methods: A multidisciplinary committee of 10 experts assessed the value of lanadelumab (subcutaneous use), C1-inhibitor (C1-INH; intravenous), and danazol (orally), using placebo as comparator. We followed the EVIDEM methodology that considers a set of 13 quantitative criteria. The overall estimated value of each intervention was obtained combining the weighting of each criterion with the scoring of each intervention in each criterion. We used two alternative weighting methods: hierarchical point allocation (HPA) and direct rating scale (DRS). A reevaluation of weightings and scores was performed. Results: Lanadelumab obtained higher mean scores than C1-INH and danazol in all criteria, except for the cost of the intervention and clinical practice guidelines. Under the HPA method, the estimated values were 0.51 (95% confidence interval [CI]: 0.44-0.58) for lanadelumab, 0.47 (95%CI: 0.41-0.53) for C1-INH, and 0.31 (95%CI: 0.24-0.39) for danazol. Similar results were obtained with the DRS method: 0.51 (95%CI: 0.42-0.60), 0.47 (95%CI: 0.40-0.54), and 0.27 (95%CI: 0.18-0.37), respectively. The comparative cost of the intervention was the only criterion that contributed negatively to the values of lanadelumab and C1-INH. For danazol, four criteria contributed negatively, mainly comparative safety. Conclusion: Lanadelumab was assessed as a high-value intervention, better than C1-INH and substantially better than danazol for LTP treatment of HAE.

Angioedema Due to Acquired Deficiency of C1-Inhibitor: A Cohort Study in Spain and a Comparison With Other Series.

BACKGROUND: Data on acquired angioedema due to C1-inhibitor deficiency (C1-INH-AAE) from 4 European countries (France, Italy, Germany, and Hungary) were recently published. OBJECTIVE: To report data from a group of 50 patients with acquired C1-INH deficiency from Spain, of whom 46 had angioedema, and compare them with other European series. METHODS: We performed a retrospective observational study of 46 patients with C1-INH-AAE and 4 asymptomatic patients. Clinical and biological characteristics and associated diseases were assessed and compared with other European series. RESULTS: Women accounted for 73.9% of cases. The prevalence of C1-INH-AAE related to hereditary forms was 1/10.1. Overall, 8.7% patients were aged <40 years. Diagnostic delay was 1.1 years. Angioedema mainly affected the face (91.3%), followed by the oropharynx (63%), extremities (50%), and abdomen (37%). Only 1 patient underwent orotracheal intubation. Erythema marginatum was present in 1 patient. A hematologic disorder was recorded in 50% of patients. Angioedema preceded all benign conditions, mostly monoclonal gammopathy of undetermined significance, but appeared very close to or after malignant hematologic diseases (median, 2.2 and 0.29 years). Autoimmune diseases were associated in 50% (autoimmune thyroiditis, 21.5%; systemic lupus erythematosus, 10.9%). Half of them coexisted with hematologic disorders. Anti-C1-INH antibodies were found in 67% of tested patients and were not related to the associated disease. Long-term prophylaxis was necessary in 52.2%, most of whom responded to tranexamic acid. CONCLUSIONS: This study emphasizes the possibility of C1-INH-AAE in patients younger than 40 and in autoimmune diseases other than systemic lupus erythematosus such as autoimmune thyroiditis.

Efficacy and safety of hizentra®, a new 20% immunoglobulin preparation for subcutaneous administration, in pediatric patients with primary immunodeficiency.

Subcutaneous IgG treatment for primary immunodeficiencies (PI) is particularly well suited for children because it does not require venous access and is mostly free of systemic adverse events (AEs). In a prospective, open-label, multicenter, single-arm, Phase III study, 18 children and five adolescents with PI were switched from previous intravenous (IVIG) or subcutaneous (SCIG) IgG treatment to receive dose-equivalent, weekly subcutaneous infusions of Hizentra(®) for 40 weeks. Mean IgG trough levels were maintained in patients previously on SCIG, or increased in those previously on IVIG, regardless of age. No serious bacterial infections were reported during the efficacy period of the study. The rates of non-serious infections were 4.77 (children) and 5.18 (adolescents) infections per patient per year. Related AEs were observed in seven children (38.9%) and two adolescents (40%). Three serious AEs and two AEs leading to discontinuation (all unrelated) were reported in children. Hizentra(®) is an effective and well-tolerated treatment for pediatric patients.

Deciphering the Genetics of Primary Angioedema with Normal Levels of C1 Inhibitor.

The genetic alteration underlying the great majority of primary angioedema with normal C1 inhibitor (nl-C1-INH-HAE) cases remains unknown. To search for variants associated with nl-C1-INH-HAE, we genotyped 133 unrelated nl-C1-INH-HAE patients using a custom next-generation sequencing platform targeting 55 genes possibly involved in angioedema pathogenesis. Patients already diagnosed with F12 alterations as well as those with histaminergic acquired angioedema were excluded. A variant pathogenicity curation strategy was followed, including a comparison of the results with those of genotyping 169 patients with hereditary angioedema due to C1-inhibitor deficiency (C1-INH-HAE), and only filtered-in variants were studied further. Among the examined nl-C1-INH-HAE patients, carriers of neither the ANGPT1 p.Ala119Ser nor the KNG1 p.Met379Lys variant were found, whereas the PLG p.Lys330Glu was detected in four (3%) unrelated probands (one homozygote). In total, 182 different variants were curated, 21 of which represented novel mutations. Although the frequency of variants per gene was comparable between nl-C1-INH-HAE and C1-INH-HAE, variants of the KNG1 and XPNPEP1 genes were detected only in nl-C1-INH-HAE patients (six and three, respectively). Twenty-seven filtered variants in 23 different genes were detected in nl-C1-INH-HAE more than once, whereas 69/133 nl-C1-INH-HAE patients had compound heterozygotes of filtered variants located in the same or different genes. Pedigree analysis was performed where feasible. Our results indicate the role that alterations in some genes, like KNG1, may play in disease pathogenesis, the complex trait that is possibly underlying in some cases, and the existence of hitherto unrecognized disease endotypes.