Citations

Abstract Rationale: The 1-year double-blind period of the MANDARA trial (NCT04157348) demonstrated non-inferiority of benralizumab to mepolizumab for achieving remission, in adults with relapsing/refractory eosinophilic granulomatosis with polyangiitis (EGPA). Here, we report the 2-year combined double-blind and ongoing open-label extension (OLE) data. Methods: On completion of the double-blind period (n=136/140) comparing benralizumab 1x30mg versus mepolizumab 3x100mg subcutaneously every 4 weeks, patients were invited to enter the OLE where they continued benralizumab (benra/benra) or switched from mepolizumab to benralizumab (mepo/benra). Endpoints included remission (Birmingham Vasculitis Activity Score=0 and oral glucocorticoid [OGC[ dose ≤4 mg/day), OGC use, relapse, blood eosinophil count (bEOS), Asthma Control Questionnaire (ACQ-6), pre-bronchodilator forced expiratory volume in 1 second (pre-BD FEV1), and safety. Results: In total, 128 patients entered the OLE (n=66 benra/benra, n=62 mepo/benra; mean age 52.8 years; 60.2% female), and 119 completed OLE Year 1. Baseline characteristics of those entering the OLE were similar to the double-blind period. At Week 104, over 60% in both groups (41 [62.1%] benra/benra and 42 [67.7%] mepo/benra patients) achieved remission. During the OLE, 51 (77.3%) benra/benra and 42 (67.7%) mepo/benra patients had no relapses. The percentage of benra/benra patients who discontinued OGCs was similar at Weeks 49-52 (27 [40.9%]) and Weeks 101-104 (29 [43.9%]), while the percentage increased for mepo/benra patients between Weeks 49-52 (16 [25.8%]) and Weeks 101-104 (27 [43.5%]; Figure). The median (IQR) OGC dose at Weeks 101-104 was 0.5 (0,5) in benra/benra and 1.36 (0,5) mg/day in mepo/benra patients. The median (IQR) bEOS in benra/benra patients was 20 (10,40) cells/µL at both Weeks 52 and 100; bEOS were depleted in mepo/benra patients from 70 (40,90) cells/µL to 20 (10,50) cells/µL by 4 weeks after switching. Mean (SD) ACQ-6 scores were 0.64 (0.78) in benra/benra patients and 0.60 (0.76) in mepo/benra patients at Week 104 compared with 1.39 (1.18) and 1.11 (0.95) at baseline. Mean (SD) pre-BD FEV1 was 2.59 (0.90) L versus 2.62 (0.84) L in benra/benra versus mepo/benra patients at Week 52, and 2.61 (0.90) versus 2.63 (0.81) L, at Week 100. Safety of mepolizumab and benralizumab was consistent with their known profiles. Conclusions: In patients with EGPA receiving benralizumab, remission rates, OGC discontinuation, and bEOS depletion were durable over 104 weeks with low relapse rates, and without loss of asthma control or lung function decline. Additional bEOS depletion and OGC sparing was observed in patients switching from mepolizumab to benralizumab.

Abstract Eosinophils comprise only 1-3% of circulating leukocytes but are often a diagnostic feature associated with a variety of inflammatory and disease states, including parasitic and fungal infections, allergic diseases (e.g., asthma, rhinitis and sensitivities to specific foods), cancer, and transplant rejection. The accurate evaluations of eosinophilia as well as the release of stored eosinophil granule proteins are important for the monitoring disease progression and/or assessing the effectiveness of a given treatment strategy(ies). Despite the availability of detection methods for each of the eosinophil granule proteins logistical difficulties limiting either the assays specificity and/or sensitivity have prevented their extensive use. We have generated unique eosinophil peroxidase specific monoclonal antibodies (EPX-mAb) and a high throughput sandwich ELISA assay as a means of overcoming these difficulties. Our EPX-mAb based ELISA is ~10 times more sensitive than traditional OPD based activity assays and allows detection of EPX in mouse BAL fluid after an acute OVA protocol as well as EPX release from mouse eosinophils stimulated ex vivo. The assay is highly specific and gives no signal in samples from EPX deficient mice even with massive eosinophilia (e.g., EPX deficient IL-5 transgenic mice). More significantly, this assay detects EPX in human tissue extracts and biological fluids and thus represents novel diagnostic assay previously unavailable in clinical settings.

AbstractBackgroundSputum eosinophilia has been shown to be a predictor of response to anti‐eosinophil therapies in patients with airway diseases. However, quantitative cell counts and differentials of sputum are labor intensive. The objective of this study was to validate a novel ELISA‐based assay of eosinophil peroxidase (EPX) in sputum as a rapid and reliable marker of airway eosinophils.MethodsThe utility of EPX‐based ELISA as an eosinophil‐specific assay was achieved through comparisons with sputum eosinophil differential counts in freshly prepared and archived patient samples from a variety of clinical settings.ResultsEPX levels in sputum correlated with eosinophil percentage (rs = 0.84) in asthma patients with varying degrees of airway eosinophilia. Significantly, unlike assays of other eosinophil granule proteins (e.g., ECP and EDN), which often detect the presence of these proteins even in asthma patients with neutrophilic bronchitis, EPX‐based ELISA levels are not increased in this subset of asthma patients or in COPD patients lacking evidence of an airway eosinophilia. Moreover, sputum EPX was a surrogate marker of airway eosinophilia in other patient studies (e.g., allergen inhalation and treatment trials the anti‐(IL‐5) therapeutic Mepolizumab™). Finally, EPX levels in cytocentrifuged prepared sputum supernatants correlated with those from rapidly prepared noncentrifuged filtrates of sputum (rs = 0.94).Conclusion and clinical implicationEPX‐based ELISA is a valid, reliable, repeatable, and specific surrogate marker of eosinophils and/or eosinophil degranulation in the sputum of respiratory patients. The novel EPX assay is a valid and reproducible eosinophil‐specific assay that can potentially be developed into a point‐of‐care assessment of eosinophil activity in airway secretions.