CHOP-mediated IL-23 overexpression does not drive colitis in experimental spondyloarthritis.

HLA-B27 is a major risk factor for spondyloarthritis (SpA), yet the underlying mechanisms remain unclear. HLA-B27 misfolding-induced IL-23, which is mediated by endoplasmic reticulum (ER) stress has been hypothesized to drive SpA pathogenesis. Expression of HLA-B27 and human ß2m (hß2m) in rats (HLA-B27-Tg) recapitulates key SpA features including gut inflammation. Here we determined whether deleting the transcription factor CHOP (Ddit3-/-), which mediates ER-stress induced IL-23, affects gut inflammation in HLA-B27-Tg animals. ER stress-mediated Il23a overexpression was abolished in CHOP-deficient macrophages. Although CHOP-deficiency also reduced Il23a expression in immune cells isolated from the colon of B27+ rats, Il17a levels were not affected, and gut inflammation was not reduced. Rather, transcriptome analysis revealed increased expression of pro-inflammatory genes, including Il1a, Ifng and Tnf in HLA-B27-Tg colon tissue in the absence of CHOP, which was accompanied by higher histological Z-scores. RNAScope localized Il17a mRNA to the lamina propria of the HLA-B27-Tg rats and revealed similar co-localization with Cd3e (CD3) in the presence and absence of CHOP. This demonstrates that CHOP-deficiency does not improve, but rather exacerbates gut inflammation in HLA-B27-Tg rats, indicating that HLA-B27 is not promoting gut disease through ER stress-induced IL-23. Hence, CHOP may protect rats from more severe HLA-B27-induced gut inflammation.

Insights into Therapeutic Response Prediction for Ustekinumab in Ulcerative Colitis Using an Ensemble Bioinformatics Approach.

INTRODUCTION: Optimizing treatment with biological agents is an ideal goal for patients with ulcerative colitis (UC). Recent data suggest that mucosal inflammation patterns and serum cytokine profiles differ between patients who respond and those who do not. Ustekinumab, a monoclonal antibody targeting the p40 subunit of interleukin (IL)-12 and IL-23, has shown promise, but predicting treatment response remains a challenge. We aimed to identify prognostic markers of response to ustekinumab in patients with active UC, utilizing information from their mucosal transcriptome. METHODS: We performed a prospective observational study of 36 UC patients initiating treatment with ustekinumab. Colonic mucosal biopsies were obtained before treatment initiation for a gene expression analysis using a microarray panel of 84 inflammatory genes. A differential gene expression analysis (DGEA), correlation analysis, and network centrality analysis on co-expression networks were performed to identify potential biomarkers. Additionally, machine learning (ML) models were employed to predict treatment response based on gene expression data. RESULTS: Seven genes, including BCL6, CXCL5, and FASLG, were significantly upregulated, while IL23A and IL23R were downregulated in non-responders compared to responders. The co-expression analysis revealed distinct patterns between responders and non-responders, with key genes like BCL6 and CRP highlighted in responders and CCL11 and CCL22 in non-responders. The ML algorithms demonstrated a high predictive power, emphasizing the significance of the IL23R, IL23A, and BCL6 genes. CONCLUSIONS: Our study identifies potential biomarkers associated with ustekinumab response in UC patients, shedding light on its underlying mechanisms and variability in treatment outcomes. Integrating transcriptomic approaches, including gene expression analyses and ML, offers valuable insights for personalized treatment strategies and highlights avenues for further research to enhance therapeutic outcomes for patients with UC.

Molecular characterization, expression analysis and function identification of Pf_IL-12p35, Pf_IL-23p19 and Pf_IL-12p40 genes in yellow catfish (Pelteobagrus fulvidraco).

The interleukin-12 (IL-12) family is a class of heterodimeric cytokines that play crucial roles in pro-inflammatory and pro-stimulatory responses. Although some IL-12 and IL-23 paralogues have been found in fish, their functional activity in fish remains poorly understood. In this study, Pf_IL-12p35a/b, Pf_IL-23p19 and Pf_IL-12p40a/b/c genes were cloned from yellow catfish (Pelteobagrus fulvidraco), four α-helices were found in Pf_IL-12p35a/b and Pf_IL-23p19. The transcripts of these six genes were relatively high in mucus and immune tissues of healthy individuals, and in gill leukocytes. Following Edwardsiella ictaluri infection, Pf_IL-12p35a/b and Pf_IL-23p19 mRNAs were induced in brain and kidney (or head kidney), Pf_IL-12p40a mRNA was induced in gill, and Pf_IL-12p40b/c mRNAs were induced in brain and liver (or skin). The mRNA expression of these genes in PBLs was induced by phytohaemagglutinin (PHA) and polyinosinic-polycytidylic acid (poly I:C), while lipopolysaccharides (LPS) induced the mRNA expression of Pf_IL-12p35a and Pf_IL-12p40b/c in PBLs. After stimulation with recombinant (r) Pf_IL-12 and rPf_IL-23 subunit proteins, either alone or in combination, mRNA expression patterns of genes related to T helper cell development exhibited distinct differences. The results suggest that Pf_IL-12 and Pf_IL-23 subunits may play important roles in regulating immune responses to pathogens and T helper cell development.

Safety and effectiveness of guselkumab in Japanese patients with psoriasis: 20-week interim analysis of a postmarketing surveillance study.

A 52-week postmarketing surveillance study was initiated to evaluate the safety and effectiveness of guselkumab, a human anti-interleukin 23 subunit p19 monoclonal antibody, in Japanese patients with psoriasis vulgaris, psoriatic arthritis, generalized pustular psoriasis, and erythrodermic psoriasis in real-world practice. Here, we report results of the 20-week interim analysis of the ongoing postmarketing surveillance study. Patients who received guselkumab between May 2018 (the date of commercial launch in Japan) and October 2020 were registered in this study. In total, 411 and 245 patients were included in the safety and effectiveness analysis sets, respectively. Adverse drug reactions (ADRs) occurred in 6.6% (27 of 411) and serious ADRs in 2.2% (nine of 411) of patients. The most frequent ADRs by System Organ Class were "Infections and infestations" (2.4%), with nasopharyngitis being the most frequently observed ADR (0.7%). The mean Psoriasis Area Severity Index score decreased from 11.6 at baseline to 6.5 at week 4 and 2.2 at week 20, with improvements achieving statistical significance at each time point. Clinical Global Impression, Dermatology Life Quality Index, and Nail Psoriasis Severity Index outcomesalso showed substantial improvements. Our findings demonstrate that guselkumab is well tolerated and effective in Japanese patients with psoriasis through 20 weeks of treatment in real-world clinical practice, showing significant effectiveness observed as early as 4 weeks. The study was officially registered with the University Hospital Medical Information Network Clinical Trials Registry with the identifier UMIN000032969.

IL-23 regulation of myeloid cell biology during inflammation.

Interleukin (IL)-23 is implicated in the pathogenesis of several inflammatory diseases and is usually linked with helper T cell (Th17) biology. However, there is some data linking IL-23 with innate immune biology in such diseases. We therefore examined the effects of IL-23p19 genetic deletion and/or neutralization on in vitro macrophage activation and in an innate immune-driven peritonitis model. We report that endogenous IL-23 was required for maximal macrophage activation by zymosan as determined by pro-inflammatory cytokine production, including a dramatic upregulation of granulocyte-colony stimulating factor (G-CSF). Furthermore, both IL-23p19 genetic deletion and neutralization in zymosan-induced peritonitis (ZIP) led to a specific reduction in the neutrophil numbers, as well as a reduction in the G-CSF levels in exudate fluids. We conclude that endogenous IL-23 can contribute significantly to macrophage activation during an inflammatory response, mostly likely via an autocrine/paracrine mechanism; of note, endogenous IL-23 can directly up-regulate macrophage G-CSF expression, which in turn is likely to contribute to the regulation of IL-23-dependent neutrophil number and function during an inflammatory response, with potential significance for IL-23 targeting particularly in neutrophil-associated inflammatory diseases.

Novel bispecific nanobody mitigates experimental intestinal inflammation in mice by targeting TNF-α and IL-23p19 bioactivities.

BACKGROUND: Inflammatory bowel diseases (IBDs) pose significant challenges in terms of treatment non-response, necessitating the development of novel therapeutic approaches. Although biological medicines that target TNF-α (tumour necrosis factor-α) have shown clinical success in some IBD patients, a substantial proportion still fails to respond. METHODS: We designed bispecific nanobodies (BsNbs) with the ability to simultaneously target human macrophage-expressed membrane TNF-α (hmTNF-α) and IL-23. Additionally, we fused the constant region of human IgG1 Fc (hIgG1 Fc) to BsNb to create BsNb-Fc.  Our study encompassed in vitro and in vivo characterization of BsNb and BsNb-Fc. RESULTS: BsNb-Fc exhibited an improved serum half-life, targeting capability and effector function than BsNb. It's demonstrated that BsNb-Fc exhibited superior anti-inflammatory effects compared to the anti-TNF-α mAb (infliximab, IFX) combined with anti-IL-12/IL-23p40 mAb (ustekinumab, UST) by Transwell co-culture assays. Notably, in murine models of acute colitis brought on by 2,4,6-trinitrobenzene sulfonic acid（TNBS) and dextran sulphate sodium (DSS), BsNb-Fc effectively alleviated colitis severity. Additionally, BsNb-Fc outperformed the IFX&UST combination in TNBS-induced colitis, significantly reducing colon inflammation in mice with colitis produced by TNBS and DSS. CONCLUSION: These findings highlight an enhanced efficacy and improved biostability of BsNb-Fc, suggesting its potential as a promising therapeutic option for IBD patients with insufficient response to TNF-α inhibition. KEY POINTS: A bispecific nanobody (BsNb) was created to target TNF-α and IL-23p19, exhibiting high affinity and remarkable stability. BsNb-Fc inhibited the release of cytokines in CD4+T cells during co-culture experiments. BsNb-Fc effectively alleviated colitis severity in mouse model with acute colitis induced by DSS or TNBS, outperforming the IFX&UST combination.

IL-23p19 deficiency reduces M1 macrophage polarization and improves stress-induced cardiac remodeling by alleviating macrophage ferroptosis in mice.

BACKGROUND: Interleukin-23p19 (IL-23p19) has been demonstrated to be involved in the occurrence and development of cardiovascular diseases such as myocardial infarction and atherosclerosis. This study aimed to examine whether IL-23p19 regulates cardiac remodeling processes and explore its possible mechanisms. METHODS AND RESULTS: Transverse aortic constriction was performed to construct a mouse cardiac remodeling model, and sham surgery was used as a control. The results showed that IL-23p19 expression was increased in the heart after surgery and may be mainly produced by cardiac macrophages. Knockout of IL-23p19 attenuated M1 macrophage polarization, reduced ferroptosis, improved the process of cardiac remodeling and alleviated cardiac dysfunction in TAC mice. Cell culture experiments found that macrophages were the main cause of ferroptosis when phenylephrine (PE) was added, and blocking ferroptosis with ferrostatin-1 (Fer-1), a ferroptosis inhibitor, significantly inhibited M1 macrophage polarization. Treatment with Fer-1 also improved cardiac remodeling and alleviated cardiac dysfunction in IL-23p19-/- mice subjected to TAC surgery. Finally, TAC IL-23p19-/- mice that were administered macrophages isolated from WT mice exhibited an increased proportion of M1 macrophages and aggravated cardiac remodeling, and these effects were reversed when Fer-1 was administered. CONCLUSION: Knockout of IL-23p19 may attenuate M1 macrophage polarization to improve the cardiac remodeling process by reducing macrophage ferroptosis, and IL-23p19 may be a potential target for the prevention and treatment of cardiac remodeling.

Understanding the impact of risankizumab on keratinocyte-derived IL-23A in a novel organotypic 3D skin model containing IL-23A responsive and IL-17A producing γδ-T-cells.

PURPOSE: To study the effects of the anti-IL-23A antibody risankizumab on the IL-36γ/IL-23A/IL-17A signalling cascade we used a newly developed 3D skin model consisting of primary human keratinocytes, fibroblasts and γδ-T-cells. METHODS: In this in vitro study we developed new full-thickness 3D skin models containing normal human epidermal keratinocytes (NHEK), normal human dermal fibroblasts (NHDF) and IL-23A responsive and IL-17A producing γδ-T-cells. The effects of IL-36γ stimulation with and without risankizumab treatment on IL-23A and IL-17A expression were examined at the RNA and protein levels. RESULTS: In preliminary monolayer experiments stimulation of γδ-T-cells with IL-23A promoted the IL-17A expression that was inhibited after risankizumab treatment. Using 3D skin models containing γδ-T-cells, we found that stimulation with IL-36γ significantly increased not only IL-23A but also IL-17A expression. These effects were inhibited by concomitant treatment with risankizumab. CONCLUSIONS: Our results showed that blockade of IL-23A has inhibitory effects on the IL-36γ/IL-23A feedforward loop. Our newly developed 3D skin model containing IL-23A responsive and IL-17A producing γδ-T-cells enables molecular analysis of targeted therapies aimed at the IL-36γ/IL-23A/IL-17A signalling cascade in psoriasis.

Modulation of Interleukin-23 Signaling With Guselkumab in Biologic-Naive Patients Versus Tumor Necrosis Factor Inhibitor-Inadequate Responders With Active Psoriatic Arthritis.

OBJECTIVE: We assessed and compared immunologic differences and associations with clinical response to guselkumab, a fully human interleukin (IL)-23p19 subunit inhibitor, in participants with active psoriatic arthritis (PsA) who were biologic-naive or had inadequate response to tumor necrosis factor inhibitors (TNFi-IR). METHODS: Serum biomarker levels at baseline and after treatment with guselkumab 100 mg every 8 weeks were compared between biologic-naive (n = 251) and TNFi-IR (n = 93) subgroups identified in the pooled DISCOVER-1/DISCOVER-2/COSMOS data set. Baseline biomarker levels determined by achievement of week 24 clinical responses (≥75%/90% improvement in Psoriasis Area and Severity Index [PASI 75/90], Investigator's Global Assessment [IGA] of psoriasis score 0/1 and ≥2-point improvement], ≥20% improvement in American College of Rheumatology criteria [ACR20]) were compared between prior treatment subgroups. RESULTS: Baseline IL-22, TNFα, and beta defensin-2 (BD-2) levels were significantly lower in biologic-naive than in TNFi-IR participants. With guselkumab, week 24 IL-17A, IL-17F, IL-22, serum amyloid A, C-reactive protein, IL-6, and BD-2 levels were significantly reduced from baseline in biologic-naive and TNFi-IR participants (≥1.4-fold difference, nominal P < 0.05). Clinical responders to guselkumab exhibited significantly higher baseline levels of several biomarkers than nonresponders (IL-17A, IL-17F, BD-2 in biologic-naive PASI 90 responders; IL-17A, BD-2 in TNFi-IR IGA 0/1 responders; IL-22, BD-2 in TNFi-IR PASI 90 responders [nominal P < 0.05]) and trended higher in TNFi-IR ACR20 responders. CONCLUSION: Guselkumab modulates IL-23 signaling and provides consistent pharmacodynamic effects in both biologic-naive and TNFi-IR PsA patients. Significantly elevated baseline IL-22, TNFα, and BD-2 levels and associations between baseline IL-22, IL-17A, and BD-2 levels and skin responses to guselkumab suggest greater dysregulation of IL-23/Th17 signaling in patients with TNFi-IR.

D-alanine Inhibits Murine Intestinal Inflammation by Suppressing IL-12 and IL-23 Production in Macrophages.

BACKGROUND AND AIMS: Free D-amino acids, which have different functions from L-amino acids, have recently been discovered in various tissues. However, studies on the potential interactions between intestinal inflammation and D-amino acids are limited. We examined the inhibitory effects of D-alanine on the pathogenesis of intestinal inflammation. METHODS: We investigated serum D-amino acid levels in 40 patients with ulcerative colitis and 34 healthy volunteers. For 7 days [d], acute colitis was induced using dextran sulphate sodium in C57BL/6J mice. Plasma D-amino acid levels were quantified in mice with dextran sulphate sodium-induced colitis, and these animals were administered D-alanine via intraperitoneal injection. IFN-γ, IL-12p35, IL-17A, and IL-23p19 mRNA expression in the colonic mucosa was measured using real-time polymerase chain reaction [PCR]. In vitro proliferation assays were performed to assess naïve CD4+ T cell activation under Th-skewing conditions. Bone marrow cells were stimulated with mouse macrophage-colony stimulating factor to generate mouse bone marrow-derived macrophages. RESULTS: Serum D-alanine levels were significantly lower in patients with ulcerative colitis than in healthy volunteers. Dextran sulphate sodium-treated mice had significantly lower plasma D-alanine levels than control mice. D-alanine-treated mice had significantly lower disease activity index than control mice. IFN-γ, IL-12p35, IL-17A, and IL-23p19 mRNA expression levels were significantly lower in D-alanine-administered mice than in control mice. D-alanine suppressed naïve T cell differentiation into Th1 cells in vitro, and inhibited the production of IL-12p35 and IL-23p19 in bone marrow-derived macrophages. CONCLUSIONS: Our results suggest that D-alanine prevents dextran sulphate sodium-induced colitis in mice and suppresses IL-12p35 and IL-23p19 production in macrophages.

Targeting IL-23 for the interception of obesity-associated colorectal cancer.

Inflammation and obesity are two major factors that promote Colorectal cancer (CRC). Our recent data suggests that interleukin (IL)-23, is significantly elevated in CRC tumors and correlates with patient obesity, tumor grade and survival. Thus, we hypothesize that obesity and CRC may be linked via inflammation and IL-23 may be a potential target for intervention in high-risk patients. TCGA dataset and patient sera were evaluated for IL-23A levels. IL-23A [IL-23 p19-/-] knockout (KO) mice were crossed to Apcmin/+ mice and progeny were fed low-fat or high-fat diets. At termination intestines were evaluated for tumorigenesis. Tumors, serum, and fecal contents were analyzed for protein biomarkers, cytokines, and microbiome profile respectively. IL-23A levels are elevated in the sera of patients with obesity and colon tumors. Genetic ablation of IL-23A significantly suppressed colonic tumor multiplicity (76-96 %) and incidence (72-95 %) in male and female mice. Similarly, small-intestinal tumor multiplicity and size were also significantly reduced in IL-23A KO mice. IL-23A knockdown in Apcmin/+ mice fed high-fat diet, also resulted in significant suppression of colonic (50-58 %) and SI (41-48 %) tumor multiplicity. Cytokine profiling showed reduction in several circulating pro-inflammatory cytokines including loss of IL-23A. Biomarker analysis suggested reduced tumor cell proliferation and immune modulation with an increase in tumor-infiltrating CD4+ and CD8+ T-lymphocytes in the IL-23A KO mice compared to controls. Fecal microbiome analysis revealed potentially beneficial changes in the bacterial population profile. In summary, our data indicates a tumor promoting role for IL-23 in CRC including diet-induced obesity. With several IL-23 targeted therapies in clinical trials, there is a great potential for targeting this cytokine for CRC prevention and therapy.

Generation and Characterization of Mirikizumab, a Humanized Monoclonal Antibody Targeting the p19 Subunit of IL-23.

Interleukin (IL)-23 exists as a heterodimer consisting of p19 and p40 and is a key cytokine for promoting inflammatory responses in a variety of target organs. IL-23 plays a key role in the differentiation and maintenance of T helper 17 cells, and deregulation of IL-23 can result in autoimmune pathologies of the skin, lungs, and gut. This study describes the generation and characterization of mirikizumab (miri), a humanized IgG4 monoclonal antibody directed against the p19 subunit of IL-23. Miri binds human and cynomolgus monkey IL-23 with high affinity and binds rabbit IL-23 weakly but does not bind to rodent IL-23 or the other IL-23 family members IL-12, IL-27, or IL-35. Miri effectively inhibits the interaction of IL-23 with its receptor, and potently blocks IL-23-induced IL-17 production in cell-based assays while preserving the function of IL-12. In both local and systemic in vivo mouse models, miri blocked IL-23-induced keratin mRNA or IL-17 production, respectively. These data provide a comprehensive preclinical characterization of miri, for which efficacy and safety have been demonstrated in human clinical trials for psoriasis, ulcerative colitis, and Crohn's disease. SIGNIFICANCE STATEMENT: This article describes the generation and characterization of mirikizumab, a high affinity, neutralizing IgG4 variant monoclonal antibody that is under development for the treatment of ulcerative colitis and Crohn's disease. Neutralization of interleukin (IL)-23 is achieved by preventing the binding of IL-23 p19 subunit to the IL-23 receptor and does not affect the IL-12 pathway.

Mirikizumab: First Approval.

Mirikizumab (Omvoh®), a humanized IgG4 anti-human IL-23p19 monoclonal antibody, is being developed by Eli Lilly and Company Ltd for the treatment of ulcerative colitis and Crohn's disease. Mirikizumab was approved in March 2023 in Japan for use as induction and maintenance therapy in patients with moderate to severe ulcerative colitis who have an inadequate response to conventional therapy or therapies and is the first IL-23p19 inhibitor to be approved for this indication. Mirikizumab was granted a positive opinion in the EU in March 2023 for the treatment of adult patients with moderately to severely active UC who have had an inadequate response with, lost response to, or were intolerant to either conventional therapy or a biologic treatment. This article summarizes the milestones in the development of mirikizumab leading to this first approval for use in ulcerative colitis.

Efficacy and Safety of IL-12/23 and IL-23 Inhibitors for Crohn's Disease: Systematic Review and Meta-Analysis.

BACKGROUND: Targeting interleukin-23 (IL-23) is an important therapeutic strategy for Crohn's disease (CD). AIMS: This systematic review and meta-analysis assessed the efficacy and safety of selective IL-23p19 and IL-12/23p40 inhibitors in patients with moderate-to-severe CD. METHODS: MEDLINE, Embase, and the Cochrane library (CENTRAL) were searched from inception to May 24, 2023, for randomized, placebo- or active comparator-controlled induction and/or maintenance trials of selective IL-23p19 and IL-12/23p40 inhibitors in pediatric and adult patients with CD. The primary outcome was the proportion of patients in clinical remission. Secondary outcomes were clinical response, endoscopic remission, endoscopic response, and safety. Data were pooled using a random-effects model. Risk of bias and certainty of evidence were assessed using the Cochrane risk of bias tool and the GRADE criteria, respectively. RESULTS: Eighteen trials (n = 5561) were included. Most studies were rated as low risk of bias. Targeting IL-23 was significantly superior to placebo for inducing clinical (risk ratio [RR] = 1.87, 95% confidence interval [CI] 1.58-2.21) and endoscopic (RR = 3.20, 95%CI 2.17-4.70) remission and maintaining clinical remission (RR = 1.39, 95%CI 1.10-1.77) (GRADE high certainty evidence for all outcomes). Subgroup analysis showed that targeting IL-23 was superior to placebo for inducing clinical remission in biologic-naïve (RR = 2.20, 95%CI 1.46-3.32, I2 = 0%, p = 0.39) and biologic-experienced patients (RR = 1.82, 95%CI 1.27-2.60, I2 = 56.5%, p = 0.01). Targeting IL-23 was associated with a decreased risk of serious adverse events in induction (RR = 0.55, 95%CI 0.44-0.73) and maintenance (RR = 0.72, 95%CI 0.53-0.98) trials compared to placebo (high certainty evidence). CONCLUSION: Targeting IL-23 is effective and safe for inducing and maintaining clinical and endoscopic remission in patients with moderate-to-severe CD.

Safety of IL-23 p19 Inhibitors for the Treatment of Patients With Moderate-to-Severe Plaque Psoriasis: A Narrative Review.

The approved biologics targeting interleukin (IL)-23 p19 for the treatment of moderate-to-severe plaque psoriasis, including guselkumab, tildrakizumab, and risankizumab, have generally favorable safety profiles. The aim of the current review is to describe in detail the safety of these selective inhibitors. A literature search was performed using PubMed from inception to 1 November 2022, to identify clinical trials and real-world evidence publications using the keywords "guselkumab," "tildrakizumab," and "risankizumab." Overall, the most common adverse events (AEs) associated with IL-23 p19 inhibitors in clinical trials were nasopharyngitis, headache, and upper respiratory tract infections. Rates of serious AEs and AEs of interest, including serious infections, nonmelanoma skin cancer (NMSC), malignancies excluding NMSC, major adverse cardiovascular events, and serious hypersensitivity reactions, were not increased with long-term use in clinical trials. Selectively targeting IL-23 p19 was also not associated with elevated risk of opportunistic infections, tuberculosis reactivation, oral candidiasis, or inflammatory bowel disease. Results from real-world studies were similar, supporting the safe long-term use of these biologics in a wider population of patients with psoriasis, including older patients, patients for whom multiple biologics failed, and those with comorbidities such as obesity, metabolic syndrome, cardiovascular disease, dyslipidemia, diabetes, hypertension, and psoriatic arthritis. This review is limited by the lack of direct comparisons among therapeutic agents due to differences among study designs and safety data reporting methods. In conclusion, the favorable safety profiles of IL-23 p19 inhibitors support their long-term use in the management of patients with moderate-to-severe psoriasis.

Targeting IL-23 for IBD: Rationale and Progress to Date.

Inflammatory bowel disease, including Crohn's disease and ulcerative colitis, comprises multiple complex immune-mediated disorders. Early diagnosis and prompt disease control may prevent long-term complications and hospitalization. The therapeutic options have expanded in the last two decades, with the development of biologics and small molecules targeting specific pathways implicated in inflammatory bowel disease pathogenesis. The interleukin (IL)-23/Th-17 axis is one such example. Targeting IL-12/23 is effective for the treatment of both moderate-to-severe Crohn's disease and ulcerative colitis, and ustekinumab (an IL-12/23p40 antagonist) is approved for both indications. In patients with psoriasis, improved clinical outcomes were observed with agents that more selectively targeted IL-23 (IL-23p19 antagonists) compared with those that target both IL-12 and IL-23. Many specific IL-23p19 antagonists are currently being investigated in Crohn's disease and ulcerative colitis, and risankizumab has been recently approved for moderate-to-severely active Crohn's disease. In this review, we summarize the mechanisms of action and the evidence from clinical trials supporting the efficacy and safety of IL-23p19 antagonists for the treatment of inflammatory bowel disease.

Safety and pharmacokinetics of IBI112, an IL-23 monoclonal antibody, in Chinese healthy volunteers: a first-in-human phase 1 study.

BACKGROUND: Interleukin (IL) 23p19 monoclonal antibodies were efficacious and safe in the treatment of psoriasis. A first-in-human (FIH) study was conducted to evaluate the safety, tolerability, pharmacokinetics (PK) and immunogenicity of IBI112, a novel IL-23p19 monoclonal antibody. METHODS: In this FIH, randomized, double-blind, placebo-controlled, single-ascending-dose study, a subcutaneous (SC, 5-600 mg) or intravenous (IV, 100 and 600 mg) or placebo was administered to eligible healthy subjects. Safety was assessed by physical examinations, vital signs, laboratory tests, and electrocardiograms. Furthermore, non-compartment analysis and population PK modeling were conducted to characterize PK, and model-based simulation was applied to justify dose selection for psoriasis patients. RESULTS: A total of 46 subjects were enrolled, with 35 receiving IBI112 and 11 receiving placebo. No serious adverse events (SAEs) and no clinically significant adverse events were identified. After a single SC of IBI112, the median Tmax was 4-10.5 days, and the half-life (t1/2) ranged from 21.8 to 35.8 days. IBI112 exposures (Cmax and AUCinf) approached dose proportionality across 5-300 mg range. CONCLUSION: IBI112 was well tolerated and safe at SC or IV dose up to 600 mg and showed a linear PK characteristics at SC dose from 5 to 300 mg. CLINICAL TRIAL REGISTRATION: ClinicalTrial.gov NCT04511624.

IL-23/IL-17 immune axis mediates the imiquimod-induced psoriatic inflammation by activating ACT1/TRAF6/TAK1/NF-κB pathway in macrophages and keratinocytes.

The interleukin-23 (IL-23)/IL-17 immune axis has been linked to the pathology of psoriasis, but how this axis contributes to skin inflammation in this disease remains unclear. We measured inflammatory cytokines associated with the IL-23/IL-17 immune axis in the serum of patients with psoriasis using enzyme-linked immunosorbent assays. Psoriasis was induced in male C57BL/6J mice using imiquimod (IMQ) cream, and animals received intraperitoneal injections of recombinant mouse anti-IL-23A or anti-IL-17A antibodies for 7 days. The potential effects of the IL-23/IL-17 immune axis on skin inflammation were assessed based on pathology scoring, hematoxylin-eosin staining of skin samples, and quantitation of inflammatory cytokines. Western blotting was used to evaluate levels of the following factors in skin: ACT1, TRAF6, TAK1, NF-κB, and pNF-κB. The serum of psoriasis patients showed elevated levels of several cytokines involved in the IL-23/IL-17 immune axis: IL-2, IL-4, IL-8, IL-12, IL-17, IL-22, IL-23, and interferon-γ. Levels of IL-23p19 and IL-17 were increased in serum and skin of IMQ-treated mice, while ACT1, TRAF6, TAK1, NF-κB, and pNF-κB were upregulated in the skin. A large proportion of NF-κB p65 localized in nucleus of involucrin+ cells in the epidermis and in F4/80+ cells of the dermis of psoriatic lesional skin. Treating these animals with anti-IL-23 or anti-IL-17 antibodies improved pathological score and immune imbalance, mitigated skin inflammation and downregulated ACT1, TRAF6, TAK1, NF-κB, and pNF-κB in skin. Our results suggest that skin inflammation mediated by the IL-23/IL-17 immune axis in psoriasis involves activation of the ACT1/TRAF6/TAK1/NF-κB pathway in keratinocytes and macrophage.

Blocking interleukin-23 ameliorates neuromuscular and thymic defects in myasthenia gravis.

Acetylcholine receptor (AChR) myasthenia gravis (MG) is a chronic autoimmune disease characterized by muscle weakness. The AChR+ autoantibodies are produced by B-cells located in thymic ectopic germinal centers (eGC). No therapeutic approach is curative. The inflammatory IL-23/Th17 pathway is activated in the thymus as well as in the blood and the muscle, contributing to the MG pathogenic events. We aimed to study a potential new therapeutic approach that targets IL-23p19 (IL-23) in the two complementary preclinical MG models: the classical experimental MG mouse model (EAMG) based on active immunization and the humanized mouse model featuring human MG thymuses engrafted in NSG mice (NSG-MG). In both preclinical models, the anti-IL-23 treatment ameliorated MG clinical symptoms. In the EAMG, the treatment reduced IL-17 related inflammation, anti-AChR IgG2b antibody production, activated transduction pathway involved in muscle regeneration and ameliorated the signal transduction at the neuromuscular junction. In the NSG-MG model, the treatment reduced pathogenic Th17 cell population and expression of genes involved in eGC stabilization and B-cell development in human MG thymus biopsies. Altogether, these data suggest that a therapy targeting IL-23p19 may promote significant clinical ameliorations in AChR+ MG disease due to concomitant beneficial effects on the thymus and skeletal muscle defects.