Division of Clinical Immunology and Allergy, David Geffen School of Medicine at University of California, Los Angeles, Calif.
Teva Branded Pharmaceutical Products R&D Inc., West Chester, Pa.
J Allergy Clin Immunol Pract. 2021 Mar;9(3):1224-1231.e9. doi: 10.1016/j.jaip.2020.10.033. Epub 2020 Oct 28.
Blood eosinophil (EOS) counts are critical to the accurate identification of asthma phenotypes. However, there are few long-term data on intraindividual EOS count variability among patients with eosinophilic asthma.
This post hoc analysis of 2 phase III clinical trials from the reslizumab BREATH program explored the variability of blood EOS counts in patients with eosinophilic asthma receiving placebo.
Pooled data from study participants receiving placebo (previously randomized 1:1 to receive reslizumab or placebo) were analyzed for blood EOS count variability over 52 weeks. EOS counts were measured up to twice during screening, every 4 weeks from randomization to the end of treatment and at the 90-day follow-up visit.
Of 476 included patients, 31 (6.5%), 38 (8.0%), 55 (11.6%), and 352 (73.9%) patients had baseline blood EOS counts of <150, ≥150 to <300, ≥300 to <400, and ≥400 cells/μL, respectively. Patients frequently shifted between EOS count categories during the 52-week treatment period, most often moving to the highest EOS category. Among patients in each of the lower 3 EOS categories, 27% to 56% of patients shifted to the ≥400 cells/μL category at some point during the treatment period.
Intraindividual variability in blood EOS count was high among patients with eosinophilic asthma receiving placebo, with shifts to ≥400 cells/μL from lower categories frequently observed. Repeat determinations of blood EOS count may be important to ensure appropriate selection of therapy in patients with severe asthma.
血液嗜酸性粒细胞（EOS）计数对于准确识别哮喘表型至关重要。然而，关于嗜酸性粒细胞性哮喘患者个体内 EOS 计数变异性的长期数据很少。
这项来自 reslizumab BREATH 计划的 2 项 3 期临床试验的事后分析探讨了接受安慰剂的嗜酸性粒细胞性哮喘患者血液 EOS 计数的变异性。
对接受安慰剂的研究参与者（先前随机分配 1:1 接受 reslizumab 或安慰剂）的汇总数据进行了分析，以了解 52 周内血液 EOS 计数的变异性。EOS 计数在筛选期间最多测量两次，从随机分组到治疗结束时每 4 周一次，以及 90 天随访时。
在纳入的 476 例患者中，分别有 31 例（6.5%）、38 例（8.0%）、55 例（11.6%）和 352 例（73.9%）患者的基线血液 EOS 计数<150、≥150 至<300、≥300 至<400 和≥400 细胞/μL。在 52 周治疗期间，患者经常在 EOS 计数类别之间转换，最常见的是向最高 EOS 类别转换。在每个较低的 3 个 EOS 类别中的患者中，有 27%至 56%的患者在治疗期间的某个时间点转移到≥400 细胞/μL 类别。
接受安慰剂的嗜酸性粒细胞性哮喘患者血液 EOS 计数的个体内变异性很高，经常从较低类别转移到≥400 细胞/μL。重复测定血液 EOS 计数可能对确保严重哮喘患者的治疗选择适当很重要。
