Pos1117 downstream effects on cytokine expression profile of six different jak inhibitors in an in vitro model of immune mediated inflammatory arthritis

Background Janus kinase inhibitors (JAKis) are a group of disease modifying antirheumatic drugs (DMARDs) used for the treatment of several immune mediated inflammatory arthritides (IMIAs) including rheumatoid arthritis (RA), psoriatic arthritis (PsA) and spondyloarthritis (SpA). There are several JAK inhibitors (JAKis) with different selectivity already approved or in clinical and preclinical development [1] . Thus, tofacitinib is a JAK1/3 inhibitor, baricitinib is an JAK2/3 inhibitor, filgotinib and upadacitinib are selective JAK1 inhibitors, decernotinib is a selective JAK3 inhibitor [2] and deucravacitinib is a selective tyrosine kinase 2 (TYK2) inhibitor [3] . The downstream effects on cytokine expression profile of JAKis with different selectivity is not fully understood. Objectives Here we investigate whether JAKis with different selectivity show differences in downstream cytokine expression in an in vitro model of IMIA. Methods Synovial fluid mononuclear cells (SFMCs) from patients with peripheral SpA (n=3), PsA (n=3), juvenile idiopathic arthritis (n=4), and unspecified inflammatory arthritis (n=1). Synovial fluid was collected after therapeutic arthrocentesis. SFMCs from each patient were cultured for 48 hours with the JAKis priorly listed. Culture medium and DMSO were used as negative controls. In vitro drug response was assessed by MesoScale V-PLEX Proinflammatory Panel 1 Human Kit measuring interferon γ (IFN- γ), interleukin 1β (IL-1β), IL-2, IL-4, IL-6, IL-10, IL-12p70, IL-13 and TNFα. Results First, we tested whether JAKis with a similar selectivity had comparable effects on the secretion of cytokines. Indeed, JAKis with selectivity towards JAK1 and JAK3 clustered together in the hierarchical analysis. Then, we examined whether there was a difference between the six JAKis on mean cytokine expression merging all cytokines (mean merged cytokine expression). All JAKis with a JAK1 selectivity decreased the cytokine secretion more than the JAK2/3 inhibitor baricitinib (filgotinib vs. baricitinib, p<0.005; upadacitinib vs. baricitinib, p<0.05; tofacitinib vs. baricitinib, p<0.05). There was no difference between the JAKis with JAK1 selectivity and decernotinib (JAK3) or deucravacitinib (TYK2). After correcting for multiple comparisons using Tukey’s test, there was also no difference in mean merged cytokine expression between JAKis with JAK1 selectivity and baricitinib. Finally, we studied differences between individual patients. Interestingly, JAKis with different selectivity were better at decreasing certain cytokine secretions compared to other JAKis on an individual level. E.g., SFMCs from patient H had a generally higher decrease in cytokine secretion after filgotinib treatment. Figure 1. Cytokine secretion for each JAKi treatment relative to DMSO control for each patient (n=14). Data are z-normalized for each patient relative to each cytokine’s level of secretion. Conclusion Similarities in mode of action for the six JAKis were reflected in drug response measured by multiple cytokine secretions. Generally, JAKis with JAK1 and JAK3 selectivity decreased total cytokine secretion the most. In selected patients, specific JAKis decreased total cytokine secretion considerably more than the remaining JAKis, while most patients had an equal response to all six JAKis. References [1]Ho Lee Y, et al. Comparative efficacy and safety of tofacitinib, baricitinib, upadacitinib, filgotinib and peficitinib as monotherapy for active rheumatoid arthritis. Journal of Clinical Pharmacy and Therapeutics. 2020;45(4):674-681. doi:10.1111/jcpt.13142 [2]Genovese MC, et al, VX-509 (Decernotinib), an Oral Selective JAK-3 Inhibitor, in Combination With Methotrexate in Patients With Rheumatoid Arthritis. Arthritis & Rheum. 2016;68(1):46-55. doi:10.1002/art.39473 [3]U.S. Food and Drug Administration. Sotyktu, Reference ID: 5043643. Accessed 11/01/2023, https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/214958s000lbl.pdf Acknowledgements: NIL. Disclosure of Interests Mads Brüner Kristensen: None declared, Tue Wenzel Kragstrup Shareholder of: Co-founder and clinical developer in Aptol Pharma, Speakers bureau: Speaking fees from Pfizer, Bristol-Myers Squibb, Eli Lilly, Novartis, UCB, and Abbvie, Consultant of: Consultancy fees from Bristol-Myers Squibb, UCB, Gilead, and Eli-Lilly, Grant/research support from: Research grants from Gilead.