Modulation of blood inflammatory markers by benralizumab in patients with eosinophilic airway diseases

Abstract

Background: Benralizumab, a humanized, afucosylated, monoclonal antibody that targets interleukin-5 receptor α, depletes eosinophils and basophils by enhanced antibody-dependent cell-mediated cytotoxicity. It demonstrated efficacy for patients with moderate to severe asthma and, in a Phase IIa trial, for chronic obstructive pulmonary disease (COPD) with eosinophilic inflammation. We investigated effects of benralizumab 100 mg every 8 weeks (first three doses every 4 weeks) subcutaneous on blood inflammatory markers through proteomic and gene-expression analyses collected during two Phase II studies of patients with eosinophilic asthma and eosinophilic COPD.

Methods: Serum samples for proteomic analysis and whole blood for gene expression analysis were collected at baseline and 52 weeks (asthma study) or 32 weeks (COPD study) post-treatment. Proteomic analyses were conducted on a custom set of 90 and 147 Rules-Based Medicine analytes for asthma and COPD, respectively. Gene expression was profiled by Affymetrix Human Genome U133 plus 2 arrays (~ 54 K probes). Gene set variation analysis (GSVA) was used to determine transcriptomic activity of immune signatures. Treatment-related differences between analytes, genes, and gene signatures were analyzed for the overall population and for patient subgroups stratified by baseline blood eosinophil count (eosinophil-high [≥300 cells/μL] and eosinophil-low [< 300 cells/μL]) via t-test and repeated measures analysis of variance.

Results: Eosinophil chemokines eotaxin-1 and eotaxin-2 were significantly upregulated (false discovery rate [FDR] < 0.05) by approximately 2.1- and 1.4-fold in the asthma study and by 2.3- and 1.7-fold in the COPD study following benralizumab treatment. Magnitude of upregulation of these two chemokines was greater for eosinophil-high patients than eosinophil-low patients in both studies. Benralizumab was associated with significant reductions (FDR < 0.05) in expression of genes associated with eosinophils and basophils, such as CLC, IL-5Rα, and PRSS33; immune-signaling complex genes (FCER1A); G-protein-coupled receptor genes (HRH4, ADORA3, P2RY14); and further immune-related genes (ALOX15 and OLIG2). The magnitude of downregulation of gene expression was greater for eosinophil-high than eosinophil-low patients. GSVA on immune signatures indicated significant treatment reductions (FDR < 0.05) in eosinophil-associated signatures.

Conclusions: Benralizumab is highly selective, modulating blood proteins or genes associated with eosinophils or basophils. Modulated protein and gene expression patterns are most prominently altered in eosinophil-high vs. eosinophil-low patients.

Trial registration: NCT01227278 and NCT01238861 .

Keywords: Asthma; Basophils; Benralizumab; Blood; Chronic obstructive pulmonary disease; Eosinophils; Gene expression; Gene set variation analysis; Inflammatory markers; Proteomics.

Conflict of interest statement

Ethics approval and consent to participate

Protocols of both studies included in this analysis were developed by the chief investigators and MedImmune and were approved by the institutional review board at each study site. Participants provided written informed consent, and the studies were performed in accordance with the Declaration of Helsinki.

Consent for publication

Not applicable.

Competing interests

All authors are employees of AstraZeneca/MedImmune LLC, the manufacturer of benralizumab.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1

Protein analyte concentrations of eotaxin-1 and eotaxin-2 in patients with asthma and COPD. Concentrations of eotaxin-1 and eotaxin-2 at baseline and after 52 weeks of treatment with benralizumab vs. placebo in the overall population of the asthma cohort (a and c). Concentrations of eotaxin-1 and eotaxin-2 at baseline and after 32 weeks of treatment with benralizumab vs. placebo in the overall population of the COPD cohort (b and d). Boxplots display the 25th–75th percentile values, with bars denoting median values. Boxes are labeled with the mean concentration per treatment arm. The dotted line denotes the analyte LLOQ. COPD, chronic obstructive pulmonary disease; FDR, false discovery rate; LLOQ, lower limit of quantification

Fig. 2

GSVA scores for eosinophil signatures in patients with asthma and COPD over time. GSVA signature scores of the four eosinophil-related gene signatures for the overall population in the asthma cohort treated with benralizumab vs. placebo (a, c, e, and g). GSVA signature scores of the four eosinophil-related gene signatures for the overall population in the COPD cohort treated with benralizumab vs. placebo (b, d, f, and h). Signature scores ranged from − 1 to 1, with negative scores indicating relative decreases in signature expression and positive scores indicating relative elevations in signature expression. Mean GSVA scores per signature are given for each treatment arm at each timepoint with standard error bars shown. COPD chronic obstructive pulmonary disease, GSVA gene set variation analysis