Inflammatory bowel disease (IBD) consists of chronic conditions that severely impact a patient's health and quality of life. Interleukin-10 (IL-10), a potent anti-inflammatory cytokine has strong genetic links to IBD susceptibility and has shown strong efficacy in IBD rodent models, suggesting it has great therapeutic potential. However, when tested in clinical trials for IBD, recombinant human IL-10 (rhIL-10) showed weak and inconsistent efficacy due to its short half-life and pro-inflammatory properties that counteract the anti-inflammatory efficacy. Here we present an engineered, IL-10, antibody-graft therapeutic (GFT-IL10M) designed to rectify these issues. GFT-IL10M combines the half-life extension properties of a monoclonal IgG antibody with altered IL-10 cell-type selective signaling, retaining desirable signaling on monocytes while reducing unwanted signaling on T, natural killer (NK), and B cells. Our structural and biochemical results indicate that the altered IL-10 topology in GFT-IL10M leads to a predominantly anti-inflammatory profile, potentially altering cell-type specific signaling patterns and extending half-life.
Toll-like receptors (TLR) 7 and 8 are innate sensors of single stranded RNA (ssRNA). Genetic and in vivo evidence suggests that aberrant recognition of RNA-containing autoantigens by TLR7/8 drives autoimmune diseases (Junt and Barchet, 2015). More validation for a pathogenic effect of TLR7 in chronic inflammation comes from recent data showing that a TLR7 gain-of-function mutation is sufficient to drive lupus-like disease (Brown et al., 2022).
Objectives
Here we report on the preclinical characterization of MHV370, a highly selective, orally active TLR7/8 inhibitor for treatment of chronic inflammatory diseases.
Methods
We used a suite of in vitro profiling assays to investigate the effect of MHV370 on TLR responses. This included the stimulation of PBMCs by immune complexes from systemic lupus erythematosus patient sera. Furthermore we characterized MHV370 in different mouse models of acute and chronic TLR7-driven inflammation.
Results
In vitro, MHV370 interfered with TLR7/8-dependent production of cytokines in humans and mice, most notably of interferon alpha, a clinically validated driver of autoimmune diseases. MHV370 abrogates B cell, monocyte, and neutrophil responses downstream of TLR7/8. In vivo, prophylactic or therapeutic administration of MHV370 suppressed TLR7-dependent cytokines and interferon stimulated genes. In the NZB/W F1 mouse model of lupus, MHV370 prevented halted disease progression and glomerulonephritis. Unlike hydroxychloroquine, MHV370 interfered with cytokine production triggered by immune complexes between systemic lupus erythematosus patient sera and necrotic cell extract, suggesting differentiation from clinical standard of care.
Conclusion
The pharmacological data presented here support further development of MHV370 towards clinical proof of concept trials in man.
References
[1]Brown, G.J., Canete, P.F., Wang, H., Medhavy, A., Bones, J., Roco, J.A., He, Y., Qin, Y., Cappello, J., Ellyard, J.I., et al. (2022). TLR7 gain-of-function genetic variation causes human lupus. Nature 605, 349-356. [2]Junt, T., and Barchet, W. (2015). Translating nucleic acid-sensing pathways into therapies. Nature reviews Immunology 15, 529-544.
Acknowledgements:
NIL.
Disclosure of Interests
Stuart Hawtin Shareholder of: Novartis, Employee of: Novartis, Cédric André Shareholder of: Novartis, Employee of: Novartis, Géraldine Collignon Zipfel Shareholder of: Novartis, Employee of: Novartis, Simone Appenzeller: None declared, Bettina Bannert: None declared, Lea Baumgartner Shareholder of: Novartis, Employee of: Novartis, Damian Beck Shareholder of: Novartis, Employee of: Novartis, Claudia Betschart Shareholder of: Novartis, Employee of: Novartis, Thomas Boulay Shareholder of: Novartis, Employee of: Novartis, Hermine Brunner Speakers bureau: Novartis, Pfizer, Roche, Grant/research support from: From Pfizer. The Cincinnati Children's Hospital where Dr. Brunner works as a full-time employee, has received contributions from the following industries in the past 2 years: AbbVie, Astra Zeneca-Medimmune, Biogen, Boehringer, Bristol-Myers Squibb, Celgene, Cerocor, horizon, Janssen, Eli Lilly, Idorsia, Cerocor, F. Hoffmann-La Roche, Merck, Novartis, and Sanofi. This funding has been reinvested for the research activities of the hospital in a fully independent manner, without any commitment to third parties, Melanie Ceci Shareholder of: Novartis, Employee of: Novartis, Jonathan Deane Shareholder of: Novartis, Employee of: Novartis, Kumquat Biosciences, Roland Feifel Shareholder of: Novartis, Employee of: Novartis, Enrico Ferrero Shareholder of: Novartis, Employee of: Novartis, GSK, Diego Kyburz Consultant of: AbbVie, Eli Lilly, Janssen, Novartis, Pfizer, Roche, Grant/research support from: Abbvie, Frederique Lafossas Shareholder of: Novartis, Employee of: Novartis, Pius Loetscher Shareholder of: Novartis, Employee of: Novartis, Christina Merz-Stoeckle Shareholder of: Novartis, Employee of: Novartis, Pierre Michellys Shareholder of: Novartis, Employee of: Novartis, Odyssey Therapeutics, Barbara Nuesslein-Hildesheim Shareholder of: Novartis, Employee of: Novartis, Friedrich Raulf Shareholder of: Novartis, Employee of: Novartis, James Rush Shareholder of: Novartis, Employee of: Novartis, Kling Bio, Giulia Ruzzante Shareholder of: Novartis, Employee of: Novartis, Thomas Stein Shareholder of: Novartis, Employee of: Novartis, Samantha Zaharevitz Shareholder of: Novartis, Employee of: Novartis, Grazyna Wieczorek Shareholder of: Novartis, Employee of: Novartis, Richard Siegel Shareholder of: Novartis, Employee of: Novartis, Peter Gergely Shareholder of: Novartis, Employee of: Novartis, Tamas Shisha Shareholder of: Novartis, Employee of: Novartis, Tobias Junt Shareholder of: Novartis, Employee of: Novartis.
Genetic and in vivo evidence suggests that aberrant recognition of RNA-containing autoantigens by Toll-like receptors (TLRs) 7 and 8 drives autoimmune diseases. Here we report on the preclinical characterization of MHV370, a selective oral TLR7/8 inhibitor. In vitro, MHV370 inhibits TLR7/8-dependent production of cytokines in human and mouse cells, notably interferon-α, a clinically validated driver of autoimmune diseases. Moreover, MHV370 abrogates B cell, plasmacytoid dendritic cell, monocyte, and neutrophil responses downstream of TLR7/8. In vivo, prophylactic or therapeutic administration of MHV370 blocks secretion of TLR7 responses, including cytokine secretion, B cell activation, and gene expression of, e.g., interferon-stimulated genes. In the NZB/W F1 mouse model of lupus, MHV370 halts disease. Unlike hydroxychloroquine, MHV370 potently blocks interferon responses triggered by specific immune complexes from systemic lupus erythematosus patient sera, suggesting differentiation from clinical standard of care. These data support advancement of MHV370 to an ongoing phase 2 clinical trial.
Millions of platelets are produced each hour by bone marrow (BM) megakaryocytes (MKs). MKs extend transendothelial proplatelet (PP) extensions into BM sinusoids and shed new platelets into the blood. The mechanisms that control platelet generation remain incompletely understood. Using conditional mutants and intravital multiphoton microscopy, we show here that the lipid mediator sphingosine 1-phosphate (S1P) serves as a critical directional cue guiding the elongation of megakaryocytic PP extensions from the interstitium into BM sinusoids and triggering the subsequent shedding of PPs into the blood. Correspondingly, mice lacking the S1P receptor S1pr1 develop severe thrombocytopenia caused by both formation of aberrant extravascular PPs and defective intravascular PP shedding. In contrast, activation of S1pr1 signaling leads to the prompt release of new platelets into the circulating blood. Collectively, our findings uncover a novel function of the S1P–S1pr1 axis as master regulator of efficient thrombopoiesis and might raise new therapeutic options for patients with thrombocytopenia.
