Preventive Treatment of Hereditary Angioedema: A Review of Phase III Clinical Trial Data for Subcutaneous C1 Inhibitor and Relevance for Patient Management.

PURPOSE: Hereditary angioedema (HAE), most often caused by a genetically mediated deficiency in the activity of C1 inhibitor (C1INH) protein, is characterized clinically by recurrent episodes of localized swelling without wheals. HAE attacks can be painful, debilitating, and even fatal, resulting in physical discomfort, emotional stress, and interruptions of work, school, and/or social activities, all of which can affect health-related quality of life (HRQoL). Subcutaneous C1INH (C1INH[SC]) is recommended as a first-line option for long-term prophylaxis (LTP) in HAE. This narrative review provides a concise but comprehensive overview of all published data generated from the pivotal Phase III Clinical Study for Optimal Management of Preventing Angioedema With Low-Volume Subcutaneous C1-Inhibitor Replacement Therapy (COMPACT) study program, which evaluated the use of C1INH(SC) as LTP. METHODS: A PubMed search was performed using the search terms subcutaneous C1 inhibitor plus COMPACT with no filters, and another search was performed using the term subcutaneous C1 inhibitor, with output limited to clinical trial data only. All publications that reported data generated during the Phase III COMPACT study were included. Data presentation focused on the US Food and Drug Administration-approved dose of 60 IU/kg. FINDINGS: The search strategy identified a total of 11 publications that reported data and analyses from the Phase III COMPACT study. Publications reported overall findings from the double-blind, placebo-controlled, crossover COMPACT study and a subsequent long-term open-label extension (OLE) study. Other published analyses included pharmacokinetic/pharmacodynamic data, HRQoL assessments, and findings in patient subgroups including women, pediatric patients, and patients ≥65 years of age. Subgroup analyses reported good safety and efficacy profiles among age-based subgroups from the COMPACT OLE, including pediatric patients, patients ≥65 years of age with comorbidities, and among female patients, despite a tendency for HAE to be more severe in women. A number of significant HRQoL improvements were noted with C1INH(SC) use, including better overall health status, less anxiety, and less work- and activity-related impairment versus placebo (double-blind study), and compared with baseline (OLE). IMPLICATIONS: This review provides a concise overview of all published COMPACT study data with C1INH(SC). The data reviewed here portray a high level of efficacy and tolerability with C1INH(SC), even during periods of treatment that exceed 2 years, which does not appear to vary based on patient age or sex. Clinically relevant improvements in multiple facets of HRQoL were also reported, including better overall HRQoL, less anxiety and depression, and less disruptions in work attendance and productivity. These data should be useful for assessing the appropriateness of C1INH(SC) therapy for individual patients.

Effects of Omalizumab on Rhinovirus Infections, Illnesses, and Exacerbations of Asthma.

RATIONALE: Allergic inflammation has been linked to increased susceptibility to viral illnesses, but it is unclear whether this association is causal. OBJECTIVES: To test whether omalizumab treatment to reduce IgE would shorten the frequency and duration of rhinovirus (RV) illnesses in children with allergic asthma. METHODS: In the PROSE (Preventative Omalizumab or Step-up Therapy for Severe Fall Exacerbations) study, we examined children with allergic asthma (aged 6-17 yr; n = 478) from low-income census tracts in eight U.S. cities, and we analyzed virology for the groups randomized to treatment with guidelines-based asthma care (n = 89) or add-on omalizumab (n = 259). Weekly nasal mucus samples were analyzed for RVs, and respiratory symptoms and asthma exacerbations were recorded over a 90-day period during the fall seasons of 2012 or 2013. Adjusted illness rates (illnesses per sample) by treatment arm were calculated using Poisson regression. MEASUREMENTS AND MAIN RESULTS: RVs were detected in 97 (57%) of 171 exacerbation samples and 2,150 (36%) of 5,959 nonexacerbation samples (OR, 2.32; P < 0.001). Exacerbations were significantly associated with detection of rhinovirus C (OR, 2.85; P < 0.001) and rhinovirus A (OR, 2.92; P < 0.001), as well as, to a lesser extent, rhinovirus B (OR, 1.98; P = 0.019). Omalizumab decreased the duration of RV infection (11.2 d vs. 12.4 d; P = 0.03) and reduced peak RV shedding by 0.4 log units (95% confidence interval, -0.77 to -0.02; P = 0.04). Finally, omalizumab decreased the frequency of RV illnesses (risk ratio, 0.64; 95% confidence interval, 0.49-0.84). CONCLUSIONS: In children with allergic asthma, treatment with omalizumab decreased the duration of RV infections, viral shedding, and the risk of RV illnesses. These findings provide direct evidence that blocking IgE decreases susceptibility to RV infections and illness. Clinical trial registered with www.clinicaltrials.gov (NCT01430403).

Can we predict fall asthma exacerbations? Validation of the seasonal asthma exacerbation index.

BACKGROUND: A Seasonal Asthma Exacerbation Predictive Index (saEPI) was previously reported based on 2 prior National Institute of Allergy and Infectious Diseases Inner City Asthma Consortium trials. OBJECTIVE: This study sought to validate the saEPI in a separate trial designed to prevent fall exacerbations with omalizumab therapy. METHODS: The saEPI and its components were analyzed to characterize those who had an asthma exacerbation during the Preventative Omalizumab or Step-Up Therapy for Fall Exacerbations (PROSE) study. We characterized those inner-city children with and without asthma exacerbations in the fall period treated with guidelines-based therapy (GBT) in the absence and presence of omalizumab. RESULTS: A higher saEPI was associated with an exacerbation in both the GBT alone (P < .001; area under the curve, 0.76) and the GBT + omalizumab group (P < .01; area under the curve, 0.65). In the GBT group, younger age at recruitment, higher total IgE, higher blood eosinophil percentage and number, and higher treatment step were associated with those who had an exacerbation compared with those who did not. In the GBT + omalizumab group, younger age at recruitment, increased eosinophil number, recent exacerbation, and higher treatment step were also associated with those who had an exacerbation. The saEPI was associated with a high negative predictive value in both groups. CONCLUSIONS: An exacerbation in children treated with GBT with or without omalizumab was associated with a higher saEPI along with higher markers of allergic inflammation, treatment step, and a recent exacerbation. Those that exacerbated on omalizumab had similar features with the exception of some markers of allergic sensitization, indicating a need to develop better markers to predict poor response to omalizumab therapy and alternative treatment strategies for children with these risk factors. The saEPI was able to reliably predict those children unlikely to have an asthma exacerbation in both groups.