DOP19 High dimensional profiling of IL-23-responsive cells revealed molecular signatures that predict response to anti-IL-23 therapy in patients with Crohn’s Disease

Abstract

Abstract Background The interleukin (IL)-23 signaling plays a crucial role in the pathogenesis of Crohn’s disease (CD). IL-23 activates T-helper (Th) 17 cells, IL-17-secreting CD8 T (Tc)17 cells, gd T cells, nature killer (NK) T cells, and group 3 innate lymphoid cells (ILC3) to secrete proinflammatory cytokines including IL-17, IFN-g, and TNF-a. Risankizumab is the first selective IL-23 antagonist approved for moderate-severe CD. However, there is currently no biomarker to predict response to anti-IL-23 antibodies in IBD. Here, we characterized the cell type- and cytokine-specific pathways in IL-23-responsive cells that predict response to risankizumab in CD patients. Methods Adult patients with a history of ileal, colonic, or ileocolonic CD were included. Active CD in terminal ileum and/or colon were confirmed by colonoscopy and/or MRI. Blood samples were collected within 3 months before and 4, 8, 12, and 52 weeks after the initiation of risankizumab. Peripheral blood mononuclear cells (PBMC) were isolated and cryopreserved for batch analysis using mass cytometry (CyTOF). Pre-treatment PBMCs were stimulated ex vivo with IL-23, and stained for lineage markers to identify Th17, Tc17, gd T, NKT cells, and ILC3, as well as intracellular cytokines including IL-17, IFN-g, TNF-a, IL-22, IL-6, and GM-CSF, using a pre-optimized and validated antibody panel. The CyTOF data were analyzed using the viSNE tool in Cytobank and FlowJo. Patients’ responses were evaluated 12-40 weeks after the initiation of risankizumab based on clinical symptoms and endoscopic/radiographic assessment. Results Among IL-23-responsive cells, increased frequency of NKT cells was identified in the peripheral blood of non-responders before initiation of risankizumab (Figure 1A). In non-responders, Tc17 cells, gd T cells, and ILC3 demonstrated significant elevations in TNF-a, a key pathogenic mediator in CD. gd T cells from non-responders also showed increased IL-17F before treatment. In contrast, NKT cells from non-responders expressed significantly lower GM-CSF, which was previously shown to alleviate intestinal inflammation in patients and mouse models (Figure 1B). Ongoing study is investigating the cytokine production in IL-23-responsive cells after the initiation of risankizumab, as well as before and after starting ustekinumab, an anti-IL-12/IL-23 antibody. Conclusion High dimensional profiling of pre-treatment PBMCs revealed molecular signatures, e.g., elevated TNF-a in multiple IL-23-responsive cells, which are associated with resistance to risankizumab in CD patients. Those findings may help identify response biomarkers for IL-23 antagonists and provide a rationale for using anti-IL-23/anti-TNF combination therapy in some patients with refractory CD.