Omalizumab facilitates rapid oral desensitization for peanut allergy.

BACKGROUND: Peanut oral immunotherapy is a promising approach to peanut allergy, but reactions are frequent, and some patients cannot be desensitized. The anti-IgE medication omalizumab (Xolair; Genentech, South San Francisco, Calif) might allow more rapid peanut updosing and decrease reactions. OBJECTIVE: We sought to evaluate whether omalizumab facilitated rapid peanut desensitization in highly allergic patients. METHODS: Thirty-seven subjects were randomized to omalizumab (n = 29) or placebo (n = 8). After 12 weeks of treatment, subjects underwent a rapid 1-day desensitization of up to 250 mg of peanut protein, followed by weekly increases up to 2000 mg. Omalizumab was then discontinued, and subjects continued on 2000 mg of peanut protein. Subjects underwent an open challenge to 4000 mg of peanut protein 12 weeks after stopping study drug. If tolerated, subjects continued on 4000 mg of peanut protein daily. RESULTS: The median peanut dose tolerated on the initial desensitization day was 250 mg for omalizumab-treated subjects versus 22.5 mg for placebo-treated subject. Subsequently, 23 (79%) of 29 subjects randomized to omalizumab tolerated 2000 mg of peanut protein 6 weeks after stopping omalizumab versus 1 (12%) of 8 receiving placebo (P < .01). Twenty-three subjects receiving omalizumab versus 1 subject receiving placebo passed the 4000-mg food challenge. Overall reaction rates were not significantly lower in omalizumab-treated versus placebo-treated subjects (odds ratio, 0.57; P = .15), although omalizumab-treated subjects were exposed to much higher peanut doses. CONCLUSION: Omalizumab allows subjects with peanut allergy to be rapidly desensitized over as little as 8 weeks of peanut oral immunotherapy. In the majority of subjects, this desensitization is sustained after omalizumab is discontinued. Additional studies will help clarify which patients would benefit most from this approach.

Multicenter prevalence of anaphylaxis in clinic-based oral food challenges.

BACKGROUND: Although previous single-center studies report the rate of anaphylaxis for oral food challenges (OFCs) as 9% to 11%, little is known regarding the epidemiology of clinical OFCs across multiple centers in the United States. OBJECTIVE: To examine the epidemiology, symptoms, and treatment of clinical low-risk OFCs in the nonresearch setting. METHODS: Data were obtained from 2008 to 2013 through a physician survey in 5 food allergy centers geographically distributed across the United States. Allergic reaction rates and the association of reaction rates with year, hospital, and demographics were determined using a linear mixed model. Meta-analysis was used to pool the proportion of reactions and anaphylaxis with inverse-variance weights using a random-effects model with exact confidence intervals (CIs). RESULTS: A total of 6,377 OFCs were performed, and the pooled estimate of anaphylaxis was 2% (95% CI, 1%-3%). The rate of allergic reactions was 14% (95% CI, 13%-16%) and was consistent during the study period (P = .40). Reaction rates ranged from 13% to 33%. Males reacted 16% more frequently than females (95% CI, 4%-37.5%; P = .04). Foods challenged in 2013 varied geographically, with peanut as the most challenged food in the Northeast, Midwest, and West and egg as the most challenged in the South. CONCLUSION: As the largest national survey of allergic reactions of clinical open OFCs in a nonresearch setting in the United States, this study found that performing clinical nonresearch open low-risk OFCs results in few allergic reactions, with 86% of challenges resulting in no reactions and 98% without anaphylaxis.

Plasma-derived C1-INH for managing hereditary angioedema in pediatric patients: A systematic review.

Presently, medications approved for children with Hereditary Angioedema (HAE) are extremely limited. This is especially the case for children under 12 years of age. For this reason we reviewed and summarized the data on treatment of children with HAE. Available data indicate that plasma derived C1-inhibitor is a safe, effective treatment option for HAE in pediatric patients, including those below 12 years of age. Other therapies are also appear safe for the under 12 year of age, but less data are available. Importantly, home-based treatment of HAE in this age group appears to be safe and effective and can improve quality of life. These findings support current HAE consensus guidelines which strongly recommend the use of plasma derived C1-inhibitor as a first-line treatment in children and encourage home and self-treatment.

Pediatric hereditary angioedema.

Hereditary angioedema (HAE) is a lifelong illness characterized by recurrent swelling of the skin, intestinal tract, and, ominously, the upper airway. It is caused by inadequate activity of the protein C1-inhibitor, with dysfunction in the kallikrein/bradykinin pathway underlying the clinical symptoms. In addition to the physical symptoms, patients experience significant decrements in vocational and school achievement as well as in overall quality of life. Symptoms often begin in childhood and occur by age 20 in most patients, but life-threatening attacks are uncommon in the pediatric population. The availability of new therapies has transformed the management of HAE.

Outcomes after ecallantide treatment of laryngeal hereditary angioedema attacks.

BACKGROUND: Hereditary angioedema (HAE) is a rare disorder associated with episodic attacks of well-demarcated angioedema. Attacks that affect the larynx can result in life-threatening airway obstruction. OBJECTIVES: To examine efficacy and safety of ecallantide treatment for laryngeal HAE attacks. METHODS: Data were combined from 4 clinical studies (EDEMA2, EDEMA3, EDEMA4, and DX-88/19) evaluating 30 mg of subcutaneous ecallantide for treatment of acute HAE attacks. Efficacy was assessed using 2 validated, HAE-specific, patient-reported outcome measures. The change in Mean Symptom Complex Severity (MSCS) score indicates change in symptom severity; a negative score indicates improvement. The calculated minimally important difference (MID) for change in severity is -0.30. The Treatment Outcome Score (TOS) measures treatment response. A positive score indicates improvement; the calculated MID is 30. RESULTS: Overall, 98 patients received ecallantide for 220 laryngeal attacks. The mean ± SD change in MSCS score was -1.1 ± 0.73 and -1.6 ± 0.68 at 4 and 24 hours, respectively. The mean ± SD TOS was 73.5 ± 35.8 and 85.5 ± 27.8 at 4 and 24 hours, respectively. Median time to significant improvement was 185 minutes (95% confidence interval, 167-226). One attack required intubation. Four treatment-emergent serious adverse events were reported, including 2 HAE attacks that resulted in hospitalization and 2 anaphylactic reactions. One of these reactions required treatment with epinephrine, but both patients recovered fully. There were no deaths. CONCLUSION: In this large attack series, ecallantide was effective for treatment of laryngeal HAE attacks. There is a risk of hypersensitivity, including anaphylaxis, consistent with product labeling. As such, ecallantide should be administered under the supervision of a health care professional. TRIAL REGISTRATION: clinicaltrials.gov Identifiers: not applicable for EDEMA2 (trial was conducted before implementation of registration requirements); NCT00262080 for EDEMA3, NCT00457015 for EDEMA4, and NCT00456508 for DX-88/19.

Analysis of hereditary angioedema attacks requiring a second dose of ecallantide.

BACKGROUND: Effective treatment of acute attacks is critical in managing hereditary angioedema (HAE). Ecallantide, a plasma kallikrein inhibitor, is approved for the treatment of HAE attacks. Occasionally, a second dose is needed when treating attacks of HAE. OBJECTIVE: To evaluate the characteristics of HAE attacks requiring a second dose (dose B) of ecallantide. METHODS: Data from all ecallantide clinical trials (EDEMA2, EDEMA4, and DX-88/19) that allowed an open-label dose B were included in this analysis. Patient and attack characteristics potentially predictive of dose B after ecallantide were analyzed by logistic regression. A multivariate model was built using a backward selection process, incorporating variables from the univariate model with P < .20 and removing factors with the highest P value until only significant (P < .05) factors remained. RESULTS: The analysis included 732 ecallantide-treated HAE attacks in 179 patients. Dose B was required in 88 attacks (12.0%), most (80.5%) for incomplete response. By attack location, 31 of 325 abdominal attacks (9.5%), 17 of 158 laryngeal attacks (10.8%), and 40 of 242 peripheral attacks (16.5%) required dose B. On the basis of the univariate analysis, baseline severity (odds ratio = 1.33, P = .15) and peripheral attack (odds ratio = 1.80, P = .01) were identified as potential predictive factors; abdominal attacks had an inverse correlation (odds ratio = 0.64, P = .055). However, the multivariate analysis identified only peripheral attacks as statistically significantly correlated (P < .05) with dose B requirement. CONCLUSION: A single, 30-mg dose of ecallantide was effective for most HAE attacks (88.0%). Patients with peripheral attacks of HAE were more likely to require a second dose of ecallantide after 4 hours. TRIAL REGISTRATION: clinicaltrials.gov Identifiers: not applicable for EDEMA2 (trial was conducted before registration requirements were implemented), NCT00457015 for EDEMA4, and NCT00456508 for DX-88/19.

Efficacy and safety of ecallantide in treatment of recurrent attacks of hereditary angioedema: open-label continuation study.

Hereditary angioedema (HAE) is a rare disorder characterized by recurrent attacks of potentially life-threatening edema. The plasma kallikrein inhibitor ecallantide is approved for treatment of acute HAE attacks. This study evaluates the efficacy and safety of ecallantide for treatment of multiple HAE episodes in the DX-88/19 (continuation) study. Patients received 30 mg of subcutaneous ecallantide for acute HAE attack symptoms, with no limit on number of episodes treated. Primary end point was change in patient-reported mean symptom complex severity (MSCS) score at 4 hours. Additional end points included change in MSCS score at 24 hours, treatment outcome score (TOS) at 4 and 24 hours, and time to response. Safety parameters included adverse events. Statistical analyses were conducted on qualifying treatment episodes (those with ≥12 patients). One hundred forty-seven patients received treatment for 625 episodes; analyses were conducted through 13 treatment episodes. Across 13 episodes at 4 hours, mean change in MSCS score ranged from -1.04 to -1.36, and mean TOSs ranged from 56.2 to 79.8. Median time to onset of sustained improvement ranged from 59 to 113 minutes. There was no indication of reduced efficacy with repeated ecallantide use. No new safety signals were detected. Eight patients (5.4%) reported potential hypersensitivity reactions, six of whom met the definition of anaphylaxis based on National Institute of Allergy and Infectious Diseases criteria. Ecallantide is effective for acute recurrent HAE attacks and maintains its efficacy and safety during multiple treatment episodes in patients with HAE. Potential hypersensitivity reactions were consistent with prior reports.

Long-acting beta-agonists and the risk of intensive care unit admission in children.

OBJECTIVE: A possible association between long-acting beta-agonists (LABA) and severe asthma exacerbations including death remains controversial. We examined whether LABA in the setting of combination therapy with inhaled corticosteroids (ICS) increase the risk of near-fatal asthma in children using a case-control study design. METHODS: Medical records from admissions for asthma exacerbations in children 4-18 years of age during the 2005 calendar year at Children's Hospital of Pittsburgh of UPMC were reviewed. Cases and controls were determined by pediatric intensive care unit (PICU) and floor admission, respectively. Exposure was defined by LABA use in combination with ICS versus ICS alone. RESULTS: Records from 85 PICU and 96 pediatric floor admissions were reviewed. LABA use in combination with ICS did not increase the risk of PICU admission (odds ratio 1.07, 95% CI 0.46-2.52) compared to ICS only without LABA. After adjusting for demographics, asthma severity, history of PICU admissions, and concurrent infection, LABA/ICS use still did not increase the risk of PICU admission (adjusted odds ratio 0.84, 95% CI 0.26-2.76) compared to ICS alone. There were no deaths and five intubations within the study period. CONCLUSIONS: The combination of LABA and ICS did not appear to increase the risk of near-fatal asthma in children.

Ecallantide for treatment of acute hereditary angioedema attacks: analysis of efficacy by patient characteristics.

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.

Development and Validation of the Asthma Exacerbation Risk Score Using Claims Data.

OBJECTIVE: Pediatric asthma is a costly and complex disease with proven interventions to prevent exacerbations. Finding the patients at highest risk of exacerbations is paramount given limited resources. Insurance claims identify all outpatient, inpatient, emergency, pharmacy, and diagnostic services. The objective was to develop a risk score indicating the likelihood of asthma exacerbation within the next year based on prior utilization. METHODS: A retrospective analysis of insurance claims for patients 2 to 18 years in a network in Massachusetts with 3 years of continuous enrollment in a commercial plan. Thirty-six potential predictors of exacerbation in the third year were assessed with a stepwise regression. Retained predictors were weighted relative to their contribution to asthma exacerbation risk and summed to create the Asthma Exacerbation Risk (AER) score. RESULTS: In a cohort of 28,196 patients, there were 10 predictors associated with the outcome of having an asthma exacerbation in the next year that depend on age, meeting the Healthcare Effectiveness Data and Information Set persistent asthma criteria, fill patterns of asthma medications and oral steroids, counts of nonexacerbation outpatient visits, an exacerbation in the last 6 months, and whether spirometry was performed. The AER score is calculated monthly from a claims database to identify potential patients for an asthma home-visiting program. CONCLUSIONS: The AER score assigns a risk of exacerbation within the next 12 months using claims data to identify patients in need of preventive services.

Indoor allergen sensitization and the risk of asthma and eczema in children in Pittsburgh.

Several studies have shown that sensitization to cockroach and mouse allergens is correlated with presence and severity of asthma, especially among children living in inner cities. This study evaluated the prevalence of positive skin testing to indoor allergens in the Pittsburgh area and the association with asthma and eczema. A retrospective analysis was performed of 540 children from the Pittsburgh area who underwent skin testing to indoor allergens. Presence of asthma and eczema were determined by parent and/or physician report. Asthma and eczema are not significantly more frequent among children who had positive skin testing to cockroaches or mice. However, asthma was more common among children who had positive skin testing to dogs (odds ratio [OR], 1.4; 95% CI, 1.23-1.65), cats (OR, 1.4; 95% CI, 1.21-1.58), and dust mites (OR, 1.2; 95% CI, 1.03-1.37). Eczema was more common in children who had positive skin testing to cats (OR, 1.5; 95% CI, 1.14-2.02). Both asthma (OR, 1.4; 95% CI, 1.18-1.58) and eczema (OR, 1.4; 95% CI, 1.07-1.92) were more prevalent among children with any positive skin test. We did not find that sensitization to cockroaches or mice was correlated with the diagnosis or asthma or eczema in the Pittsburgh area. However, sensitization to any allergen, and to cats and/or dogs specifically, was associated with diagnosis of both asthma and eczema. Our result suggests that allergic sensitization is associated with these diseases, but the implicated allergens may vary.

High-resolution epitope mapping by AllerScan reveals relationships between IgE and IgG repertoires during peanut oral immunotherapy.

Peanut allergy can result in life-threatening reactions and is a major public health concern. Oral immunotherapy (OIT) induces desensitization to food allergens through administration of increasing amounts of allergen. To dissect peanut-specific immunoglobulin E (IgE) and IgG responses in subjects undergoing OIT, we have developed AllerScan, a method that leverages phage-display and next-generation sequencing to identify the epitope targets of peanut-specific antibodies. We observe a striking diversification and boosting of the peanut-specific IgG repertoire after OIT and a reduction in pre-existing IgE levels against individual epitopes. High-resolution epitope mapping reveals shared recognition of public epitopes in Ara h 1, 2, 3, and 7. In individual subjects, OIT-induced IgG specificities overlap extensively with IgE and exhibit strikingly similar antibody footprints, suggesting related clonal lineages or convergent evolution of peanut-specific IgE and IgG B cells. Individual differences in epitope recognition identified via AllerScan could inform safer and more effective personalized immunotherapy.

Chronic granulomatous disease in an adolescent with recurrent impetigo and cholecystectomy.

Chronic granulomatous disease is a rare primary immunodeficiency disorder resulting from a defect in the microbicidal activity of phagocytes. Patients are susceptible to certain bacterial and fungal infections, as well as other inflammatory complications. We report the case of a 12-year-old girl with recurrent impetigo whose history of cholecystitis triggered an evaluation that revealed chronic granulomatous disease.

The Role of Food Challenges in Clinical Practice.

Food challenges are the criterion standard for establishing the presence or absence of food allergy. However, they remain underused because of their resource-intensive nature, inadequate reimbursement, and concern for the risk of anaphylaxis. Here, we review indications for performing food challenges, including scenarios of uncertain diagnosis, quality-of-life effects following food challenges, and the impact on office practice including coding and reimbursement issues. Demand for food challenges is likely to increase and allergists should be capable of providing this service to their patients when indicated.

Efficacy and Safety of AR101 in Oral Immunotherapy for Peanut Allergy: Results of ARC001, a Randomized, Double-Blind, Placebo-Controlled Phase 2 Clinical Trial.

BACKGROUND: Peanut oral immunotherapy, using a variety of approaches, has been previously shown to induce desensitization in peanut-allergic subjects, but no products have been approved for clinical use by regulatory agencies. OBJECTIVE: We performed the first phase 2 multicentered study to assess the safety and efficacy of AR101, a novel oral biologic drug product. METHODS: A randomized, double-blind, placebo-controlled trial was conducted at 8 US centers. Eligible subjects were 4 to 26 years old, sensitized to peanut, and had dose-limiting symptoms to ≤143 mg of peanut protein in a screening double-blind, placebo-controlled food challenge (DBPCFC). Subjects were randomized 1:1 to daily AR101 or placebo and gradually up-dosed from 0.5 to 300 mg/day. The primary endpoint was the proportion of subjects in each arm able to tolerate ≥443 mg (cumulative peanut protein) at exit DBPCFC with no or mild symptoms. RESULTS: Fifty-five subjects (29 AR101, 26 placebo) were enrolled. In the intention-to-treat analysis, 23 of 29 (79%) and 18 of 29 (62%) AR101 subjects tolerated ≥443 mg and 1043 mg at exit DBPCFC, respectively, versus 5 of 26 (19%) and 0 of 26 (0%) placebo subjects (both P < .0001). Compared with placebo, AR101 significantly reduced symptom severity during exit DBPCFCs and modulated peanut-specific cellular and humoral immune responses. Gastrointestinal (GI) symptoms were the most common treatment-related adverse events (AEs) in both groups, with 6 AR101 subjects (21%) withdrawing, 4 of those due primarily to recurrent GI AEs. CONCLUSIONS: In this study, AR101 demonstrated an acceptable safety profile and demonstrated clinical activity as a potential immunomodulatory treatment option in peanut-allergic children over the age of 4, adolescents, and young adults.

Implementation of a Standardized Clinical Assessment and Management Plan (SCAMP) for Food Challenges.

BACKGROUND: Oral food challenges (OFCs) are routinely used to confirm ongoing food allergy. Serum-specific IgE (sIgE) and skin prick testing (SPT) are imperfect predictors of which patients will pass OFCs. OBJECTIVE: The objective of this study was to describe the design and implementation of a Standardized Clinical Assessment and Management Plan (SCAMP) to study and iteratively improve sIgE and SPT thresholds to determine when and where to conduct OFCs for patients. METHODS: Allergists consulted recommended sIgE and SPT thresholds when ordering challenges although diversions were permitted. Criteria were iteratively improved after periodic analyses of challenge outcome and diversions. RESULTS: Over 3 years, allergists ordered 2368 food challenges for 1580 patients with histories of IgE-mediated reactions to food: 1386 in an outpatient clinic and 945 in a higher resource infusion center. Reactions to challenge were observed in 13% of clinic and 23% of infusion center challenges. Six patients challenged in clinic required treatment with epinephrine compared with 22 in the infusion center. The need for epinephrine was more common in patients with asthma-5% of asthmatic patients required epinephrine compared with 1% of nonasthmatic patients (P < .01). Recommended sIgE and SPT thresholds were incrementally changed and, using the control chart methodology, a significant decrease was noted in the proportion of challenges ordered in the higher resource location. CONCLUSIONS: By setting and continually refining sIgE and SPT recommendations using the SCAMP method, allergists can better determine the risk of severe reaction and triage patients to the appropriate setting for an OFC.