Effect of time to treatment on response to C1 esterase inhibitor concentrate for hereditary angioedema attacks.

BACKGROUND: C1 esterase inhibitor (C1-INH) concentrate is well established as effective therapy for hereditary angioedema (HAE). It is thought that treatment of an acute HAE attack with C1-INH as early as possible improves efficacy, but there are limited data from prospective studies supporting this recommendation. OBJECTIVE: To assess the effect of time to treatment (<6 vs ≥6 hours after start of an attack) with 20 U/kg of C1-INH concentrate on efficacy. METHODS: A post hoc analysis of time to treatment after start of an attack was performed for 2 studies with C1-INH concentrate: International Multicenter Prospective Angioedema C1-INH Trial (IMPACT) 1 (randomized, placebo-controlled) and IMPACT 2 (open-label, uncontrolled extension). Because of differences in study design, the data sets were analyzed separately. IMPACT 1 data were analyzed using Cox regression with hazard ratios (HRs). For IMPACT 2 data, linear regression was applied to evaluate whether earlier treatment leads to faster recovery. Descriptive statistics for treatment response were calculated for both studies. RESULTS: In IMPACT 1, treatment with C1-INH within less than 6 hours after start of an attack resulted in considerably shorter times to onset of symptom relief (HR, 3.36) and complete resolution (HR, 4.30) vs placebo. The benefit of C1-INH compared with placebo was reduced when administered after 6 or more hours (HRs, 1.18 for times to onset of symptom relief and 1.61 for complete resolution). Analysis of IMPACT 2 data indicated slower complete resolution of symptoms with later start of treatment. CONCLUSION: Early treatment with C1-INH (<6 hours) provides a better treatment response than late treatment (≥6 hours), supporting the international recommendation to treat HAE attacks as early as possible. TRIAL REGISTRATION: ClinicalTrials.gov Identifiers: NCT00168103 and NCT00292981.

Treatment response after repeated administration of C1 esterase inhibitor for successive acute hereditary angioedema attacks.

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).

Prospective study of C1 esterase inhibitor in the treatment of successive acute abdominal and facial hereditary angioedema attacks.

BACKGROUND: hereditary angioedema (HAE) is a rare disorder characterized by a quantitative or functional deficiency of C1 esterase inhibitor (C1-INH), resulting in periodic attacks of acute edema at various body locations. The symptoms of these painful attacks can be treated effectively with C1-INH concentrate. OBJECTIVE: to document the efficacy and safety of a weight-based dose of C1-INH concentrate in the treatment of successive HAE attacks at abdominal and facial locations. METHODS: acute facial and abdominal attacks were each treated with C1-INH concentrate using a single intravenous dose of 20 U/kg body weight. Efficacy end points included patient-reported time to onset of symptom relief and time to complete resolution of all symptoms. Safety was assessed by monitoring adverse events and assaying for markers of viral infection. RESULTS: we treated 663 abdominal attacks in 50 patients and 43 facial attacks in 16 patients (a total of 706 attacks in 53 patients). The median time to onset of relief for all attacks was 19.8 minutes, with a median time to complete resolution of 11.0 hours. The median time to onset of relief was 19.8 minutes for abdominal attacks and 28.2 minutes for facial attacks, indicating efficacy for both types of attack. No treatment-related serious adverse events occurred, and C1-INH concentrate was well tolerated. No human immunodeficiency virus, hepatitis virus, or parvovirus B19 infections arose during the study. CONCLUSION: the C1-INH concentrate dose of 20 U/kg provides rapid, effective, and safe treatment for successive HAE attacks at abdominal and facial locations.

Hereditary angioedema: Validation of the end point time to onset of relief by correlation with symptom intensity.

Time to onset of symptom relief in hereditary angioedema (HAE) is a common primary end point in clinical studies but it has never been validated by correlation with the course of HAE symptoms. This study was designed as a retrospective validation of the primary end point for a placebo-controlled phase II/III study in patients with HAE. Ninety-eight abdominal attacks were treated with 10 or 20 U/kg of a highly purified C1 esterase inhibitor (C1-INH) concentrate or placebo. The primary end point was the time to onset of symptom relief, as determined by the patients. Patients assessed the intensity of the symptoms of pain, nausea, vomiting, cramps, and diarrhea over time. By Spearman rank correlation, the primary end point was compared with the time to first reduction of (1) any symptom intensity, (2) the sum of symptom intensity scores, and (3) the intensity of the last symptom present at baseline. The C1-INH, 20 U/kg, and placebo groups were compared by one-sided two-sample Wilcoxon tests. The time to first reduction in intensity of the last symptom present at baseline had the highest correlation with the primary end point (r = 0.77). The time to onset of symptom relief and the time to the first reduction in intensity of the last symptom were significantly shorter for the C1-INH, 20 U/kg, group compared with placebo (p = 0.009 and p = 0.0036, respectively). The association with the intensity of single symptoms confirmed that the time to onset of symptom relief is an appropriate end point for assessing the efficacy of C1-INH therapy.

Prospective study of rapid relief provided by C1 esterase inhibitor in emergency treatment of acute laryngeal attacks in hereditary angioedema.

INTRODUCTION: Hereditary angioedema (HAE) is a rare disorder characterized by C1 esterase inhibitor (C1-INH) deficiency, resulting in periodic attacks of acute edema that can be life-threatening if they occur in the laryngeal region. We assessed the efficacy of C1-INH concentrate in the emergency treatment of rarely occurring acute laryngeal HAE attacks in a prospective, open-label clinical study. METHODS: Acute laryngeal attacks were each treated with C1-INH concentrate (Berinert) at a single dose of 20 U/kg body weight. Efficacy endpoints included time to onset of symptom relief and time to complete resolution of all symptoms, each based on the patient's assessment. RESULTS: All 39 laryngeal attacks in 16 patients were treated successfully. The median time to onset of symptom relief was 15 min. The median time to complete resolution of all symptoms was 8.25 h. No treatment-related serious adverse events occurred, and the treatment was well tolerated. The administration of C1-INH concentrate was not associated with any viral infections. CONCLUSION: C1-INH concentrate is an effective and safe emergency treatment for providing reliable and rapid relief from the potentially life-threatening symptoms of laryngeal HAE attacks.

Efficacy of human C1 esterase inhibitor concentrate compared with placebo in acute hereditary angioedema attacks.

BACKGROUND: Hereditary angioedema caused by C1 esterase inhibitor deficiency is a rare disorder. OBJECTIVE: To compare the efficacy of pasteurized C1 esterase inhibitor concentrate (Berinert, CSL Behring) at intravenous doses of 10 or 20 U/kg body weight with placebo in the treatment of single, acute abdominal or facial attacks in patients with hereditary angioedema. METHODS: This was a randomized, double-blind, placebo-controlled study in 125 patients with type I or II hereditary angioedema. The primary outcome was time from start of treatment to onset of symptom relief. Secondary outcomes were time to complete resolution, proportion of patients with worsened intensity of angioedema symptoms between 2 and 4hours after treatment, and number of vomiting episodes within 4 hours. RESULTS: Median time to onset of relief was significantly shorter with C1 esterase inhibitor concentrate at a dose of 20 U/kg than with placebo (0.5 vs 1.5 hours; P = .0025), whereas with 10 U/kg, the time to onset of relief was only slightly shorter than with placebo (1.2 vs 1.5 hours; P = .2731). Compared with placebo, the reduction in time to onset of relief was greatest for severe attacks (0.5 vs 13.5 hours). The secondary outcomes consistently supported the efficacy of the 20 U/kg dose. C1 esterase inhibitor concentrate was safe and well tolerated. No seroconversions were observed for HIV, hepatitis virus, or human B19 virus. CONCLUSION: C1 esterase inhibitor concentrate given intravenously at a dose of 20 U/kg is an effective and safe treatment for acute abdominal and facial attacks in patients with hereditary angioedema, with a rapid onset of relief.

Pharmacoeconomic evaluation of immunoglobulin treatment in patients with antibody deficiencies from the perspective of the German statutory health insurance.

Primary antibody deficiencies are the most common forms of primary immunodeficiencies. Substitution therapy with polyvalent immunoglobulins has been established as the standard therapy for antibody deficiencies for several decades. Until now mainly intravenous immunoglobulins (IVIG) have been used in Germany, and the majority of patients receive treatment in hospital outpatient clinics. In recent years subcutaneous administration of immunoglobulins (SCIG) has been developed which is administered as home self-infusion. Studies indicate no significant differences in immunoglobulin substitution therapy between SCIG and IVIG concerning outcome. We carried out a cost-minimization analysis to compare the two treatment alternatives in Germany. Under base case assumptions the treatment with SCIG is cost saving from the perspective of the German statutory health insurance. The main cost drivers are IVIG and SCIG; the incremental cost of SCIG compared to IVIG is most sensitive to changes in the immunoglobulin price and changes in the body weight of the patient.

The effect of weight on the efficacy and safety of C1 esterase inhibitor concentrate for the treatment of acute hereditary angioedema.

BACKGROUND: Despite the worldwide obesity epidemic, there have been very few studies investigating the influence of body weight on treatment dosing and outcomes in patients with hereditary angioedema (HAE). OBJECTIVE: The purpose of this analysis was to determine whether the standard weight-based dosing recommendation of C1 esterase inhibitor (C1-INH) concentrate (20 IU/kg) is adequate in HAE patients with a high body mass index (BMI). METHODS: Data from patients treated for HAE attacks with 20 IU/kg of C1-INH concentrate were retrospectively analyzed from the open-label IMPACT2 study (International Multicenter Prospective Angioedema C1-INH Trial). Patients were categorized according to BMI as being normal body weight, overweight, or obese. Efficacy end points were time to onset of symptom relief and time to complete resolution of symptoms. The safety profile was evaluated according to adverse events occurring within 7 to 9 days of treatment. RESULTS: Of 57 patients, 24 (42%) were of normal body weight, 20 (35%) were overweight, and 13 (23%) were obese. Median (95% CI) time to onset of symptom relief was 0.37 hour (0.29-0.57) in normal-weight patients, 0.48 hour (0.39-0.53) in overweight patients, and 0.58 hour (0.41-0.94) in obese patients. Median time (95% CI) to complete resolution of symptoms was 15.2 hours (9.3-23.2) in normal-weight patients, 22.6 hours (11.3-44.6) in overweight patients, and 11.0 hours (5.6-23.6) in obese patients (differences not significant). There were no relevant differences in the incidence of adverse events in normal-weight patients (54%), overweight patients (30%), and obese patients (54%). CONCLUSIONS: Treatment of HAE attacks with weight-based doses of C1-INH concentrate provided reliable treatment response, regardless of body weight, in these patients with HAE.

High-dose antithrombin III in the treatment of severe sepsis in patients with a high risk of death: efficacy and safety.

OBJECTIVE: To explore if patients with severe sepsis and with a predicted high risk of death (according to the Simplified Acute Physiology Score II) might have a treatment benefit from high-dose antithrombin III. DESIGN: Subgroup analysis of a randomized, placebo-controlled, double-blind, prospective phase III study. SETTING: Unifactorial and multifactorial reanalysis of prospectively defined populations from the KyberSept trial. PATIENTS: We studied 1,008 patients (43.6% of the overall intention-to-treat population, n = 2,314) with a predicted mortality rate of 30-60% at study entry as defined by the Simplified Acute Physiology Score II. INTERVENTIONS: Patients were randomized in a 1:1 fashion to receive either high-dose antithrombin III (30,000 IU intravenously over the period of 4 days) or placebo. MEASUREMENTS AND MAIN RESULTS: In a Kaplan-Meier analysis of patients with a predicted mortality of 30-60%, the survival time when followed up for 90 days after admission was increased in the high-dose antithrombin III group compared with placebo (p = .04). If heparin was avoided during the 4-day treatment phase with high-dose antithrombin III (n = 140) or placebo (n = 162), the treatment effect appeared to be even more pronounced: 28-day mortality rate, 35.7% vs. 44.4% (risk ratio, 0.804; 95% confidence interval, 0.607-1.064); 56-day mortality rate, 39.9% vs. 52.2% (risk ratio, 0.764; 95% confidence interval, 0.593-0.984); 90-day mortality rate, 42.8% vs. 55.1% (risk ratio, 0.776; 95% confidence interval, 0.614-0.986). Like in the overall population, the percentage with any bleeding was increased in patients receiving high-dose antithrombin III compared with placebo. Survival rates were in favor of high-dose antithrombin III in patients both with and without bleeding complications. CONCLUSIONS: Treatment with high-dose antithrombin III may increase survival time up to 90 days in patients with severe sepsis and high risk of death. This benefit may even be stronger when concomitant heparin is avoided.

Quality of life effects of antithrombin III in sepsis survivors: results from the KyberSept trial [ISRCTN22931023].

INTRODUCTION: Treatment of sepsis is aimed at increasing both the duration and quality of survival. A long-term focus on quality of life (QoL) in clinical trial evaluations of sepsis care should be a priority. METHOD: QoL data were used to evaluate the effects of intravenous antithrombin III treatment for severe sepsis measured for up to 90 days during the follow-up phase of the KyberSept phase III clinical trial. A visual analog scale and a Karnofsky scale were used to measure physical, psychologic, and social QoL at regular intervals. Changes from baseline between placebo and antithrombin III groups were assessed using Wilcoxon statistical tests, with additional analyses by severity of illness and admitting diagnosis. RESULTS: Among all sepsis survivors in the trial, there was a significant advantage on some attributes of QoL in the antithrombin III subgroup of patients who did not receive heparin as compared with the corresponding placebo group. DISCUSSION: The present study represents the first attempt to evaluate patient QoL over a relatively long period in a large, randomized, placebo-controlled sepsis trial. Over a 90-day period, survivors of severe sepsis receiving antithrombin III experienced significant improvements as compared with placebo on several attributes of QoL. In conclusion, the present study demonstrated that clinical improvements over an extended time period with antithrombin III were complemented by improvements in QoL, particularly in social and psychologic functioning, in many patients.