Abstract Background GLPG3970 targeted inhibition of salt-inducible kinases (SIK) 2/3 combines anti-inflammatory and immunoregulatory activity.1,2 GLPG3970 showed positive effects on histology, endoscopy and faecal calprotectin in a 6-week phase 2a signal-detection study, consistent with preclinical findings of pro-inflammatory cytokines suppression and goblet cell protection, although without differentiation from placebo for total Mayo Clinic Score.2-5 Building on our previous ex vivo comparison of GLPG3970 with approved UC therapy tofacitinib,6 this study aimed to elucidate the mechanistic effects of GLPG3970 and delineate response patterns in bio-naive and bio-experienced patients. Methods Inflamed UC biopsies (bio-naive n = 5, bio-experienced n = 5; eMayo ≥ 2) were treated ex vivo for 24h with GLPG3970 (60 µM), vehicle, or tofacitinib (10 µM), followed by supernatant profiling (MSD 54 V-PLEX) and bulk transcriptomics by Illumina NovaSeq 6000 (Salmon + DESeq2; FoldChange 1.5, FDR 0.05). Weighted gene co-expression analysis (WGCNA) was run on DMSO and GLPG3970 samples only along Gene ontology (GO) pathways, with multiple testing correction (FDR0.05) (Fig1A). RNA–protein correlation was assessed in matched samples (Log2FC, Spearman R, p-values). Results GLPG3970 exposure significantly reduced pro-inflammatory cytokine (TNFα, GM-CSF, IFN-γ) and chemokine (MCP-1, MIP1α, MIP1β) release in supernatant, as well as transcriptomic activity of NF-κB driven inflammatory mediators (e.g. CSF2, MMP9, CCL4), antigen presentation, collagen formation and inflammasome signalling (Fig1B-D). Transcriptomic and proteomic responses were strongly correlated (R = 0.70, p = 1.3 × 10−7), while GLPG3970 exposure could partially reverse a UC transcriptomic disease signature7 (ρ:−0.25) (Fig1E-F). WGCNA identified 18 gene expression modules, 7 of which were significantly associated with bio-experienced status turquoise module (extracellular structure and remodelling; r = 0.58, FDR 3.6x10−5; green module (r = 0.34, FDR 0.031) Fig2A-B. Upon GLPG3970 exposure, the green module correlation was reversed (r=-0.41, FDR 0.028) encompassing angiogenesis, cell motility and connective tissue pathways with TGFB1 identified as central hub gene (Fig2B). Modulation of this and the purple module – linked to RNA and mRNA processing - was driven by bio-experienced patients, and absent in bio-naive patients (Fig2C). Conclusion GLPG3970 effectively suppressed inflammatory signalling in UC ex vivo biopsies. Network analysis showed enhanced extracellular remodelling in bio-experienced patients, with GLPG3970 reversing connective tissue-related processes in this group. These findings emphasize the importance of considering prior treatment exposure in patient stratification and preclinical study design. References: 1. Peixoto C et al. J Med Chem 2024;67:5233–58. 2. Pereira-Fernandes A et al. abstract United European Gastroenterol J 2021;9:S8. 3. https://clinicaltrials.gov/study/NCT04577794. 4. https://www.glpg.com/press-releases/galapagos-demonstrates-early-clinical-activity-with-sik2-3-inhibition-in-inflammation 5. Lavazais S et al. abstract United European Gastroenterol J 2021;9:S8. 6. Giorio, Arnauts et al., abstract United European Gastroenterol J 2024 MP564 7. Massimino L et al. Nat Comput Sci 2021;1:511–15. KA and LG are joint first authors. Conflict of interest: Dr. Arnauts, Kaline: Research support by Galapagos NV Giorio, Lorenzo: Research support from Galapagos NV Colli, Maikel: No conflicts of interest Kolb, Fabrice: No conflict of interest De Vos, Steve: I declare no conflict of interest Guedelha Sabino, João: Speaker’s fees: Lilly, Pfizer, Abbvie, Ferring, Falk, Takeda, Janssen, Fresenius, and Galapagos. Consultancy fees: Takeda, Pfizer, Janssen, Ferring, Fresenius, Abbvie, Galapagos, Celltrion, Pharmacosmos, and Pharmanovia. Research support: Galapagos, Viatris, and Eurogenerics. JS is supported by a Senior Clinical researcher grant from the Research foundation – Flanders. Ferrante, Marc: Research grants from AbbVie, EG Pharma, Celltrion, Janssen, Pfizer, Takeda and Viatris Consultancy fees from AbbVie, AgomAb Therapeutics, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Janssen-Cilag, MRM Health, Merck Sharp and Dohme, Pfizer, Takeda and ThermoFisher Speakers’ fees from AbbVie, Biogen, Boehringer Ingelheim, Dr Falk Pharma, Ferring, Janssen-Cilag, Merck Sharp and Dohme, Pfizer, Takeda, Truvion Healthcare and Viatris Vermeire, Séverine: Grant: AbbVie, Pfizer, Takeda, J&J, Galapagos Personal Fees: AbbVie - AbolerIS Pharma - AgomAb - Alimentiv - Arena Pharmaceuticals - AstraZeneca - Avaxia- BMS - Boehringer Ingelheim - Celgene - CVasThera - Dr Falk Pharma - Ferring - Galapagos - Genentech-Roche - Gilead - GSK - Hospira - Imidomics - Janssen - J&J - Lilly - Materia Prima - MiroBio - Morphic - MrMHealth - Mundipharma - MSD - Pfizer - Prodigest - Progenity - Promakhos Therapeutics - Prometheus - Robarts Clinical Trials - Second Genome - Shire - Surrozen - Takeda - Theravance - Tillots Pharma AG - Zealand Pharma - Other: AbbVie, MSD, Takeda, Ferring, Genentech/Roche, Shire, Pfizer Inc, Galapagos, Mundipharma, Verstockt, Bram: - Research support from AbbVie, Biora Therapeutics, Celltrion, Landos, Pfizer, Sanofi, Sossei Heptares/Nxera and Takeda. - Speaker’s fees from Abbvie, Agomab, Alfasigma, Biogen, Bristol Myers Squibb, Celltrion, Eli Lily, Falk, Ferring, Galapagos, Materia Prima, Johnson and Johnson, Pfizer, Sandoz, Takeda, Tillots Pharma, Truvion and Viatris. - Consultancy fees from Abbvie, Alfasigma, Alimentiv, Anaptys Bio, Applied Strategic, Astrazeneca, Atheneum, BenevolentAI, Biora Therapeutics, Boxer Capital, Bristol Myers Squibb, Domain Therapeutics, Eli Lily, Galapagos, Guidepont, Landos, Merck, Mirador Therapeutics, Mylan, Nxera, Inotrem, Ipsos, Johnson and Johnson, Pfizer, Sandoz, Sanofi, Santa Ana Bio, Sapphire Therapeutics, Sosei Heptares, Takeda, Tillots Pharma and Viatris. - Stock options Vagustim and Thethis Pharma.
Durbec et al. (2026) studied this question.