P0151Anti-inflammatory effect of RIPK1 inhibitor eclitasertib in inflamed human gut tissue

Background Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) is a critical mediator of inflammation and cell death. Eclitasertib, a selective RIPK1 inhibitor, was tested for its anti-inflammatory efficacy in ex vivo models of inflammatory bowel disease (IBD). Methods Colonic biopsies from patients with active ulcerative colitis (UC), n = 15, or Crohn’s disease (CD), n = 20, and from healthy controls, were cultured with increasing concentrations of eclitasertib. Cytokine release in tissue supernatants was measured using Luminex and MSD multiplex assays. Transcriptomic profiling and cell type deconvolution were performed to assess broader molecular effects and tissue composition. Results In ex vivo cultured UC-derived biopsies eclitasertib reduced the production of pro-inflammatory cytokines TNF-α, MIP1α, Granzyme B, IL1b and IFNγ to levels less than 50% compared to unexposed biopsies in 7 UC donors that responded to eclitasertib incubation with 1000 nM concentration. In CD-derived biopsies, in addition to TNF-α, MIP1α, Granzyme B, IL1b and IFNγ, IL6, and, Eotaxin and IL13 were also found to be reduced by more than 50% in the biopsy supernatant from 7 CD donors that responded to eclitasertib incubation with 1000 nM concentration. A Th2-effect (IL-13, Eotaxin) was observed in CD but not UC tissues. Transcriptomic analyses confirmed trends for reduced inflammatory gene expression in biopsies from UC patients exposed to eclitasertib, with greater modulation by tofacitinib as control. Cell-type composition remained stable across conditions. Conclusion Eclitasertib exhibits selective anti-inflammatory effects in ex vivo human gut tissues in UC and CD by modulation of cytokines involved in the pathogenesis of IBD. Transcriptional analysis supported the anti-inflammatory effect of eclitasertib, in particular in UC. The difficulty of reaching statistically relevant thresholds for observed effects might be based on limited sample size, high inter-donor variation but also by intra-donor variation of the biopsies linked to the experimental model. The findings support further investigation of eclitasertib in populations with IBD. Conflict of interest: Errico, Carmela: no conflict of interest Massimino, Luca: No conflict of interest Cagliani, Stefania: I have no relevant financial relationships to disclose. Parigi, Tommaso: No conflict of interest Spano, Salvatore: No conflict of interest Bhattacharya, Mahasweta: MB is an employee of Sanofi and may hold stock in the company Iyyanki, Tejaswi: TJ is an employee of Sanofi and may hold stock in the company Chatelain, Clement: CC is an employee of Sanofi and may hold stock/stock options in the company. Khader, Shameer: SK is an employee of Sanofi and may hold stock/stock options in the company. Badalamenti, Salvatore: SB is an employee of Sanofi and may hold stock/stock options in the company. Ungaro, Federica: No conflict of interest Saas, Joachim: JS is an employee of Sanofi and may hold stock/stock options in the company.