Intravenous anti-IL-13 mAb QAX576 for the treatment of eosinophilic esophagitis.

BACKGROUND: Eosinophilic esophagitis (EoE) is a chronic allergic disease with limited treatment options. OBJECTIVE: We evaluated QAX576, an mAb against IL-13, in the treatment of patients with EoE. METHODS: Patients (18-50 years) with proton pump inhibitor-resistant esophageal eosinophilia received intravenous QAX576 (6 mg/kg) or placebo (2:1) at weeks 0, 4, and 8 and were followed for 6 months. The primary end point was the responder rate for a greater than 75% decrease in peak eosinophil counts at week 12. Efficacy was to be declared if the lower 90% confidence limit for the proportion of responders on QAX576 was 35% or greater. Secondary end points included changes in esophageal eosinophil counts, symptoms assessed by questionnaire scores, and quantification of a series of biomarkers. RESULTS: Twenty-three patients completed the study up to week 12, and 18 continued to the end of the study. For the proximal and distal esophageal biopsies combined, the responder rate was 12.5% (90% confidence limit, 1% to 43%) with placebo, compared to 40.0% (90% confidence limit, 22% to 61%) with QAX576. Although the primary end point was not met, the mean esophageal eosinophil count decreased by 60% with QAX576 versus an increase of 23% with placebo (P = .004), and the decrease was sustained up to 6 months. There was a trend for improved symptoms, particularly dysphagia. QAX576 improved expression of EoE-relevant esophageal transcripts, including eotaxin-3, periostin, and markers of mast cells and barrier function, for up to 6 months after treatment. QAX576 was well tolerated. CONCLUSIONS: QAX576 significantly improved intraepithelial esophageal eosinophil counts and dysregulated esophageal disease-related transcripts in adults with EoE in a sustained manner.

PedsQL eosinophilic esophagitis module: feasibility, reliability, and validity.

OBJECTIVE: Eosinophilic esophagitis (EoE) is a chronic esophageal inflammatory condition with a paucity of information on health-related quality of life (HRQOL). The objective of the study was to report on the measurement properties of the PedsQL EoE Module. METHODS: The PedsQL EoE Module was completed in a multisite study by 196 pediatric patients with EoE and 262 parents of patients with EoE. RESULTS: The PedsQL EoE Module scales evidenced excellent feasibility (0.6%-3.1% missing), excellent group comparison reliability across total scale scores (patient α 0.93; parent proxy α 0.94), good reliability for the 7 individual scales (patient α 0.75-0.87; parent proxy α 0.81-0.92), excellent test-retest reliability (patient intraclass correlation coefficient 0.88; parent intraclass correlation coefficient 0.82), demonstrated no floor effects and low ceiling effects, and demonstrated a high percentage of scaling success for most scales. Intercorrelations with the PedsQL Generic Core Scales were in the medium (0.30) to large (0.50) range. PedsQL EoE Module scores were worse among patients with active histologic disease (≥ 5 eos/hpf) compared with those in remission (patient self-report: 63.3 vs 69.9 [P < 0.05]; parent proxy report: 65.1 vs 72.3 [P < 0.01]), and those treated with dietary restrictions compared with those with no restrictions (patient self-report: 61.6 vs 74.3 [P < 0.01]; parent proxy report: 65.5 vs 74.7 [P < 0.01]). CONCLUSIONS: The results demonstrate excellent measurement properties of the PedsQL EoE Module. Patients with active histologic disease and those treated with dietary restrictions demonstrated worse PedsQL scores. The PedsQL EoE Module may be used in the evaluation of pediatric EoE disease-specific HRQOL in clinical research and practice.

Development of the Pediatric Quality of Life Inventory™ Eosinophilic Esophagitis module items: qualitative methods.

BACKGROUND: Currently there is no disease-specific outcome measure to assess the health-related quality of life (HRQOL) of pediatric patients with Eosinophilic Esophagitis (EoE). Therefore, the objective of this qualitative study was to further develop and finalize the items and support the content validity for the new Pediatric Quality of Life Inventory™ (PedsQL™) Eosinophilic Esophagitis Module. METHODS: Multiphase qualitative methodology was utilized in the development of the PedsQL™ EoE Module conceptual model. Focus interview transcripts of pediatric patients with EoE and their parents and expert review were previously used to develop the initial items and domains for the PedsQL™ EoE Module. In the current investigation, utilizing the respondent debriefing methodology, cognitive interviewing was conducted individually with pediatric patients with EoE and their parents on each newly developed item. RESULTS: Information from a total of 86 participants was obtained in combination from the previous investigation and the current study. From the previous 42 focus interviews, items were developed around the domain themes of symptoms, difficulties with eating food, treatment adherence, worry about symptoms and illness, feelings of being different than family and peers, and problems discussing EoE with others. In the current study's cognitive interviewing phase, a separate cohort of 44 participants systematically reviewed and provided feedback on each item. Items were added, modified or deleted based on this feedback. Items were finalized after this feedback from patients and parents. CONCLUSIONS: Using well-established qualitative methods, the content validity of the new PedsQL™ Eosinophilic Esophagitis Module items was supported in the current investigation. In the next iterative instrument development phase, the PedsQL™ Eosinophilic Esophagitis Module is now undergoing multisite national field testing.

Development of a validated patient-reported symptom metric for pediatric eosinophilic esophagitis: qualitative methods.

BACKGROUND: Previous attempts to measure symptoms in pediatric Eosinophilic Esophagitis (EoE) have not fully included patients and parents in the item development process. We sought to identify and validate key patient self-reported and parent proxy-reported outcomes (PROs) specific to EoE. METHODS: We developed methodology for focus and cognitive interviews based on the Food and Drug Administration (FDA) guidelines for PROs, the validated generic PedsQL™ guidelines, and the consolidated criteria for reporting qualitative research (COREQ). Both child (ages 8-12 and 13-18) and parent-proxy (ages 2-4, 5-7, 8-12, and 13-18) interviews were conducted. RESULTS: We conducted 75 interviews to construct the new instrument. Items were identified and developed from individual focus interviews, followed by cognitive interviews for face and content validation. Initial domains of symptom frequency and severity were developed, and open-ended questions were used to generate specific items during the focus interviews. Once developed, the instrument construct, instructions, timeframe, scoring, and specific items were systematically reviewed with a separate group of patients and their parents during the cognitive interviews. CONCLUSIONS: To capture the full impact of pediatric EoE, both histologic findings and PROs need to be included as equally important outcome measures. We have developed the face and content validated Pediatric Eosinophilic Esophagitis Symptom Score (PEESS™ v2.0). The PEESS™ v2.0 metric is now undergoing multisite national field testing as the next iterative instrument development phase.

Long-term outcomes in pediatric-onset esophageal eosinophilia.

BACKGROUND: Pediatric eosinophilic esophagitis (EoE) is a newly recognized antigen-induced form of chronic esophagitis (CE). OBJECTIVE: Characterization of long-term clinical outcomes in patients with pediatric EoE is needed. METHODS: From histologic review of 3817 pediatric esophageal biopsy specimens from 1982-1999, we conducted a nested case-control study of patients with retrospectively identified histologic eosinophilic esophagitis (rEoE) and CE, as well as an age-matched control cohort. Participants were asked to complete validated health-related outcome questionnaires. RESULTS: At an average of 15 years after initial endoscopy, both cohorts (42/198 patients with rEoE and 67/468 patients with CE, as well as 100 age-matched control subjects) completed questionnaires. Compared with control subjects, quality of life was significantly decreased among patients with rEoE (P < .001) and patients with CE (P < .001). Rates of dysphagia (patients with rEoE, 49%; patients with CE, 37%; control subjects, 6%) and food impaction (patients with rEoE, 40%; patients with CE, 14%; control subjects, 3%) were significantly increased in the rEoE cohort compared with those seen in control subjects (P < .001 and P < .001, respectively). Increased esophageal eosinophil counts (odds ratio [OR], 1.6; 95% CI, 1.1-2.5; P < .05) during childhood were predictive of dysphagia during early adulthood. Food allergy (OR, 2.7; 95% CI, 1.2-6.0; P < .01), allergic rhinitis (OR, 3.5; 95% CI, 1.8-6.8; P < .001), and asthma (OR, 2.1; 95% CI, 1.04-4.3; P = .04) were associated with dysphagia. Food impaction was more common among patients with reported food allergy than among those without (OR, 3.1; 95% CI, 1.2-7.8; P = .02). CONCLUSIONS: Esophageal eosinophilia is associated with reduced quality of life and persistent symptoms 15 years after presentation. Increased esophageal eosinophil counts and the occurrence of food allergy and atopy in childhood increase the rate of dysphagia in young adulthood.

Coordinate interaction between IL-13 and epithelial differentiation cluster genes in eosinophilic esophagitis.

We have previously proposed that the pathogenesis of eosinophilic esophagitis (EE) is mediated by an IL-13-driven epithelial cell response associated with marked gene dysregulation including eotaxin-3 overproduction. In this study, we compared epithelial responses between healthy patients and those with EE, aiming to uncover molecular explanations for EE pathogenesis. Esophageal epithelial cells could be maintained for up to five passages, with 67% and 62% of cell lines reaching confluence in healthy controls and EE cases, respectively. Both sets of epithelial cells avidly responded to IL-13 at similar levels as assessed by eotaxin-3 production. Acidic pH increased cellular release of eotaxin-3 (4.6 +/- 1.98 ng/ml versus 12.46 +/- 2.90 ng/ml at pH 7.4 and 4, respectively; p < 0.05). Numerous epidermal differentiation complex (EDC) genes, such as filaggrin and SPRR3, were downregulated both in IL-13-stimulated esophageal epithelial cells and in EE biopsies specimens compared with healthy controls. Whereas the filaggrin loss of function mutation 2282del4 was overrepresented in EE compared with control individuals (6.1% versus 1.3% respectively; p = 0.0172), the decreased filaggrin expression was uniformly seen in all EE cases in vivo. Indeed, expression of the EDC genes filaggrin and involucrin was strongly decreased directly by IL-13. These results establish that the epithelial response in EE involves a cooperative interaction between IL-13 and expression of EDC genes.