Henderson omalizumab study

A considerable proportion of patients with H1-antihistamine-resistant chronic spontaneous urticaria (CSU) fails to respond to omalizumab. However, there is yet no available biomarker that accurately predicts such a response outcome. The utility of blood basophil and eosinophil levels and exosomal and basophil micro(mi)RNAs as biomarkers of response to omalizumab in CSU was explored. In this prospective cohort study of twenty patients with antihistamine-resistant CSU, subjects were treated with 3-monthly doses of omalizumab, and their response assessed using the weekly urticaria activity score (UAS7) for a period of 12-weeks. Basophil and eosinophil levels in the blood and differentially expressed exosomal and basophil miRNAs of complete responders compared to non-responders were identified at baseline. Canonical pathways, altered by differentially expressed miRNAs, were identified using Ingenuity Pathway Analysis (IPA). Complete responders had higher baseline basophil levels (≥21 cells/L) in the peripheral blood compared to non-responders (P = 0.005). Baseline levels of eosinophils did not differ between the study groups. Complete responders in comparison to non-responders had an expression profile characterized by a significantly higher expression of six exosomal miRNAs (miR-6499-5p, miR-7848, miR-4494-3p, miR-450a-2-3p, miR-6877-3p, and miR-3976) and lower expression of miR-141-3p. Complete responders also had higher expression of three basophil miRNAs (miR-1200, miR-1236-3p, and miR-4496). The exosomal miRNA expression profile was predicted by IPA to alter Tec Kinase Signaling pathway activity (P = 0.003). This was a single center, prospective cohort study, to investigate biomarkers of response to omalizumab in 22 adult patients (≥18 years) with CSU who had remained symptomatic despite the use of high dose H1-antihistamines (ClinicalTrials.gov ID: NCT02814630). The study protocol was approved by the Western Institutional Review Board. The clinical part of the study was conducted at ASTHMA Inc. Clinical Research Center, Seattle, WA (now named Seattle Allergy & Asthma Research Institute; https://seattleallergy.org). Before inclusion in the study, all patients provided written informed consent. Inclusion criteria were: 1) at least 6 weeks of CSU with itching despite current use of up to x4 H1-antihistamines49 and 2) an urticaria activity score (UAS) during a 7-day period (UAS7) of ≥16 (on a scale ranging from 0 to 42, with higher scores indicating greater activity)50 during the 7 days before the first treatment with omalizumab. Exclusion criteria were: 1) a clearly defined underlying cause for chronic urticaria, 2) routine administration (i.e., daily or every other day for ≥5 consecutive days) of systemic glucocorticoids, hydroxychloroquine, methotrexate, cyclosporine, cyclophosphamide, or intravenous immune globulin within the previous 30 days, 3) the use of any H2-antihistamine or leukotriene-receptor antagonist within 7 days preceding the screening visit, 4) treatment with omalizumab within the previous year, or a known hypersensitivity to omalizumab, 5) a history of cancer, or 6) women who were pregnant or nursing or unable to use an effective method of contraception during dosing with omalizumab. After initial screening within two weeks of study start, patients received one subcutaneous injection of omalizumab (Xolair®; Genentech, South San Francisco, CA) at a dose of 300 mg on Days 0, 30, and 60 (Figure 1A). This dose was based on results of two international, multicenter, randomized, double-blind, placebo-controlled Phase 3 studies, ASTERIA I25 and ASTERIA II17 that demonstrated that omalizumab significantly decreased clinical symptoms and signs of chronic urticaria in patients who had remained symptomatic despite the use of H1-antihistamines.25 Patients were closely monitored for 2 hours after each dose of omalizumab with epinephrine administered if evidence of anaphylaxis per the joint task force guidelines of the American Academy of Allergy, Asthma & Immunology and the American College of Allergy, Asthma & Immunology. Patients were provided with an epinephrine injector for self-administration of epinephrine if development of anaphylaxis after discharge from the CRC. Plasma samples were collected at baseline (Day 0, prior to omalizumab injection) for isolation of basophils and exosomes (Figure 1A). Patients completed a twice-daily diary that was used to determine UAS7. Patients were classified as complete responder, partial responder or non-responder based on their UAS7 score.

相当比例的H1抗组胺药耐药慢性自发性荨麻疹（chronic spontaneous urticaria, CSU）患者对奥马珠单抗（omalizumab）治疗无应答，但目前尚无能够准确预测此类治疗结局的生物标志物。本研究探讨了外周血嗜碱性粒细胞、嗜酸性粒细胞水平，以及外泌体和嗜碱性粒细胞微小RNA（micro(mi)RNAs）作为CSU患者奥马珠单抗治疗反应生物标志物的应用价值。本前瞻性队列研究纳入20例抗组胺药耐药CSU患者，予每3个月一次的奥马珠单抗治疗，并通过每周荨麻疹活动度评分（weekly urticaria activity score, UAS7）持续12周评估治疗反应。基线时，比较完全应答者与无应答者的外周血嗜碱性粒细胞、嗜酸性粒细胞水平，以及差异表达的外泌体和嗜碱性粒细胞miRNA，并通过Ingenuity Pathway Analysis (IPA) 分析差异表达miRNA所调控的经典通路。结果显示，完全应答者外周血基线嗜碱性粒细胞水平更高（≥21个/μL），显著高于无应答者（P=0.005）；而两组患者的基线嗜酸性粒细胞水平无显著差异。与无应答者相比，完全应答者的表达谱特征为：6种外泌体miRNA（miR-6499-5p、miR-7848、miR-4494-3p、miR-450a-2-3p、miR-6877-3p及miR-3976）表达显著升高，miR-141-3p表达降低；同时3种嗜碱性粒细胞miRNA（miR-1200、miR-1236-3p及miR-4496）表达升高。IPA预测显示，该外泌体miRNA表达谱可改变Tec激酶信号通路活性（P=0.003）。本研究为单中心前瞻性队列研究，旨在探究22例成人（≥18岁）H1抗组胺药耐药CSU患者的奥马珠单抗治疗反应生物标志物，这些患者在使用高剂量H1抗组胺药后仍有症状（ClinicalTrials.gov编号：NCT02814630）。研究方案经西部伦理审查委员会（Western Institutional Review Board）批准。研究的临床部分在华盛顿州西雅图的ASTHMA Inc.临床研究中心（现更名为西雅图过敏与哮喘研究所，https://seattleallergy.org）开展。入组前所有患者均签署书面知情同意书。纳入标准如下：1）在当前使用最多4倍剂量H1抗组胺药的情况下，CSU症状持续至少6周；2）首次奥马珠单抗治疗前7天内的7天荨麻疹活动度评分（UAS7）≥16分（评分范围0~42分，分值越高代表疾病活动度越强）。排除标准如下：1）存在明确的慢性荨麻疹潜在病因；2）近30天内常规系统使用糖皮质激素、羟氯喹、甲氨蝶呤、环孢素、环磷酰胺或静脉注射免疫球蛋白（即每日或隔日连续使用≥5天）；3）筛选访视前7天内使用过任何H2抗组胺药或白三烯受体拮抗剂；4）近1年内接受过奥马珠单抗治疗，或已知对奥马珠单抗过敏；5）有恶性肿瘤病史；6）妊娠或哺乳期女性，或在奥马珠单抗治疗期间无法采取有效避孕措施的女性。研究开始前两周完成初步筛查后，患者分别于第0、30、60天皮下注射300mg奥马珠单抗（Xolair®；Genentech，加利福尼亚州南旧金山）（见图1A）。该给药剂量基于两项国际多中心随机双盲安慰剂对照Ⅲ期临床试验ASTERIA I25和ASTERIA II17的研究结果，这两项研究证实，奥马珠单抗可显著改善H1抗组胺药治疗无效的CSU患者的临床症状与体征。每次注射奥马珠单抗后，患者需接受2小时的密切监测，若出现过敏性休克征象，则按照美国过敏、哮喘与免疫学会和美国过敏、哮喘与免疫学院联合工作组指南给予肾上腺素治疗。患者可获得肾上腺素自动注射器，以便在离开临床研究中心后若发生过敏性休克可自行给药。基线时（第0天，奥马珠单抗注射前）采集血浆样本，用于分离嗜碱性粒细胞和外泌体（见图1A）。患者每日完成两次日记记录，用于计算UAS7评分。研究人员根据UAS7评分将患者分为完全应答者、部分应答者或无应答者。