Selective RORγt Inverse Agonist Research Articles

Azatricyclic Inverse Agonists of RORγt That Demonstrate Efficacy in Models of Rheumatoid Arthritis and Psoriasis.

Structure-activity relationship studies directed toward the replacement of the fused phenyl ring of the lead hexahydrobenzoindole RORγt inverse agonist series represented by 1 with heterocyclic moieties led to the identification of three novel aza analogs 5-7. The hexahydropyrrolo[3,2-f]quinoline series 5 (X = N, Y = Z=CH) showed potency and metabolic stability comparable to series 1 but with improved in vitro membrane permeability and serum free fraction. This structural modification was applied to the hexahydrocyclopentanaphthalene series 3, culminating in the discovery of 8e as a potent and selective RORγt inverse agonist with an excellent in vitro profile, good pharmacokinetic properties, and biologic-like in vivo efficacy in preclinical models of rheumatoid arthritis and psoriasis.

Novel Tricyclic Pyroglutamide Derivatives as Potent RORγt Inverse Agonists Identified using a Virtual Screening Approach.

Employing a virtual screening approach, we identified the pyroglutamide moiety as a nonacid replacement for the cyclohexanecarboxylic acid group which, when coupled to our previously reported conformationally locked tricyclic core, provided potent and selective RORγt inverse agonists. Structure-activity relationship optimization of the pyroglutamide moiety led to the identification of compound 18 as a potent and selective RORγt inverse agonist, albeit with poor aqueous solubility. We took advantage of the tertiary carbinol group in 18 to synthesize a phosphate prodrug, which provided good solubility, excellent exposures in mouse PK studies, and significant efficacy in a mouse model of psoriasis.

Tricyclic sulfones as potent, selective and efficacious RORγt inverse agonists – Exploring C6 and C8 SAR using late-stage functionalization

In order to rapidly develop C6 and C8 SAR of our reported tricyclic sulfone series of RORγt inverse agonists, a late-stage bromination was employed. Although not regioselective, the bromination protocol allowed us to explore new substitution patterns/vectors that otherwise would have to be incorporated at the very beginning of the synthesis. Based on the SAR obtained from this exercise, compound 15 bearing a C8 fluorine was developed as a very potent and selective RORγt inverse agonist. This analog’s in vitro profile, pharmacokinetic (PK) data and efficacy in an IL-23 induced mouse acanthosis model will be discussed.

Optimization and biological evaluation of thiazole-bis-amide inverse agonists of RORγt

The nuclear receptor retinoic acid receptor-related orphan receptor gamma t (RORγt) is a transcription factor that drives Th17 cell differentiation and IL-17 production in both innate and adaptive immune cells. The IL-23/IL-17 pathway is implicated in major autoimmune and inflammatory diseases. RORγt lies at the core of this pathway and represents an attractive opportunity for intervention with small molecule therapeutics. Despite diverse chemical series having been reported, combining high potency and nuclear receptor selectivity with good physicochemical properties remains a challenging endeavor in the field of RORγt drug discovery. We recently described the discovery and evaluation of a new class of potent and selective RORγt inverse agonists based on a thiazole scaffold. Herein we describe the successful optimization of this class by incorporation of an additional amide moiety at the 4-position of the thiazole core. In several optimization cycles, we have reduced human PXR activation, improved solubility, and increased potency while maintaining nuclear receptor selectivity. X-ray crystallographic analysis of compound 1g bound in the sterol binding site of the ligand binding domain of RORγt was largely consistent with an earlier structure, guiding further insight into the molecular mechanism for RORγt inhibition with this series. Compound 1g is orally bioavailable, potent in a human whole blood assay and proved to be efficacious in an ex-vivo IL-17A assay, and was selected for preclinical evaluation.

Discovery of BMS-986251: A Clinically Viable, Potent, and Selective RORγt Inverse Agonist

Novel tricyclic analogues were designed, synthesized, and evaluated as RORγt inverse agonists. Several of these compounds were potent in an IL-17 human whole blood assay and exhibited excellent oral bioavailability in mouse pharmacokinetic studies. This led to the identification of compound 5, which displayed dose-dependent inhibition of IL-17F production in a mouse IL-2/IL-23 stimulated pharmacodynamic model. In addition, compound 5 was studied in mouse acanthosis and imiquimod-induced models of skin inflammation, where it demonstrated robust efficacy comparable to a positive control. As a result of this excellent overall profile, compound 5 (BMS-986251) was selected as a clinically viable developmental candidate.

Rationally Designed, Conformationally Constrained Inverse Agonists of RORγt-Identification of a Potent, Selective Series with Biologic-Like in Vivo Efficacy.

RORγt is an important nuclear receptor that regulates the production of several pro-inflammatory cytokines such as IL-17 and IL-22. As a result, RORγt has been identified as a potential target for the treatment of various immunological disorders such as psoriasis, psoriatic arthritis, and inflammatory bowel diseases. Structure and computer-assisted drug design led to the identification of a novel series of tricyclic RORγt inverse agonists with significantly improved in vitro activity in the reporter (Gal4) and human whole blood assays compared to our previous chemotype. Through careful structure activity relationship, several potent and selective RORγt inverse agonists have been identified. Pharmacokinetic studies allowed the identification of the lead molecule 32 with a low peak-to-trough ratio. This molecule showed excellent activity in an IL-2/IL-23-induced mouse pharmacodynamic study and demonstrated biologic-like efficacy in an IL-23-induced preclinical model of psoriasis.

Biochemical Properties of TAK-828F, a Potent and Selective Retinoid-Related Orphan Receptor Gamma t Inverse Agonist

Background/Aims: Retinoid-related orphan receptor gamma t (RORγt) is a master regulator of T helper 17 cells that plays a pivotal role in the production of inflammatory cytokines including interleukin (IL)-17. Therefore, RORγt has attracted much attention as a target receptor for the treatment of inflammatory diseases including rheumatoid arthritis, multiple sclerosis, inflammatory bowel diseases, and psoriasis. This study aims to characterize TAK-828F, a potent and selective RORγt inverse agonist. Methods: The biochemical properties of TAK-828F were evaluated using Time-Resolved Fluorescence Resonance Energy Transfer (TR-FRET) binding assay, surface plasmon resonance (SPR) biosensor assay, cofactor recruitment assay, reporter assay, and IL-17 expression assay. Results: TR-FRET binding assay and SPR biosensor assay revealed rapid, reversible, and high affinity binding of TAK-828F to RORγt. The cofactor recruitment assay showed that TAK-828F inhibited the recruitment of steroid receptor coactivator-1 to RORγt. Furthermore, TAK-828F inhibited the transcriptional activity of human and mouse RORγt with selectivity against human RORα and RORβ. TAK-828F also suppressed IL-17 production in Jurkat cells, overexpressing human RORγt. Conclusion: These favorable properties will be of advantage in the evaluation of TAK-828F in clinical studies for inflammatory diseases. Furthermore, these findings demonstrate that TAK-828F could serve as a pharmacological tool for further studies of RORγt and inflammatory diseases.

Pharmacological Evaluation of TAK-828F, a Novel Orally Available RORγt Inverse Agonist, on Murine Colitis Model.

IL-17-producing Th17 cells and IFN-γ and IL-17 double-producing Th1/17 cells have been identified as the pathogenic cells in inflammatory bowel disease (IBD). Retinoic acid-related orphan receptor γt (RORγt) is a master regulator for the differentiation and activation of Th17 and Th1/17 cells. We discovered a novel orally available TAK-828F, a strong and selective RORγt inverse agonist. To assess the potential of RORγt blockade in the therapy for IBD, the efficacy of TAK-828F in activated T cell transfer mouse colitis model was investigated. This model was highly sensitive to the prophylactic treatment of anti-TNF-α monoclonal antibody but partially susceptible to sulfasalazine, tacrolimus, and prednisolone. Oral administration of TAK-828F, at doses of 1 and 3mg/kg, b.i.d, strongly protected the progression of colitis. TAK-828F decreased the population of Th17 and Th1/17 cells in a dose-dependent manner in the mesenteric lymph node. Moreover, expression of mRNA that are characteristic of the Th17 signature, such as IL-17A and IL-17F in the colon, were inhibited by TAK-828F, while the expression of IL-10, an anti-inflammatory cytokine, was increased. In the therapeutic treatment, TAK-828F lessened disease severity compared to the vehicle control mice. Interestingly, gene expression of zonula occludens-1 (ZO-1) and mucin 2 (Muc2), which play an important role in barrier function of the intestinal mucosa, was recovered by TAK-828F. These results indicate that blocking RORγt has promising pharmacological profile in the colitis model. RORγt blockade may provide a novel therapeutic paradigm for treatment of IBD with unique mechanism by which improves imbalance of the immune system.

Identification and biological evaluation of thiazole-based inverse agonists of RORγt

The nuclear receptor retinoic acid receptor-related orphan receptor gamma t (RORγt) is a transcription factor that drives Th17 cell differentiation and IL-17 production in both innate and adaptive immune cells. The IL-23/IL-17 pathway is implicated in major autoimmune and inflammatory diseases. RORγt lies at the core of this pathway and represents an attractive opportunity for intervention with a small molecule. Despite diverse chemical series having been reported, combining high potency and nuclear receptor selectivity with good physicochemical properties remains a challenging endeavor in the field of RORγt drug discovery. We describe the discovery and evaluation of a new class of potent and selective RORγt inverse agonists based on a thiazole core. Acid analog 1j demonstrated oral bioavailability in rats and was potent in a human whole blood assay, suggesting potential utility in treating autoimmune and inflammatory diseases such as psoriasis. X-ray crystallographic data helped to elucidate the molecular mechanism for RORγt inhibition with this series.

Pharmacological inhibitory profile of TAK-828F, a potent and selective orally available RORγt inverse agonist

Retinoic acid-related orphan receptor γt (RORγt) is a key master regulator of the differentiation and activation of IL-17 producing CD4+ Th17, CD8+ Tc17 and IL-17/IFN-γ co-producing cells (Th1/17 cells). These cells play critical roles in the pathogenesis of autoimmune diseases such as inflammatory bowel disease and multiple sclerosis. Thus, RORγt is an attractive target for the treatment of these diseases. We discovered TAK-828F, an orally available potent and selective RORγt inverse agonist. The inhibitory effect on the activation and differentiation of Th17 cells by TAK-828F was evaluated in mouse and human primary cells. TAK-828F inhibited IL-17 production from mouse splenocytes and human peripheral blood mononuclear cells dose-dependently at concentrations of 0.01–10 μM without affecting the production of IFN-γ. Additionally, TAK-828F strongly inhibited Th17, Tc17 and Th1/17 cells’ differentiation from naive T cells and memory CD4+ T cells at 100 nM without affecting Th1 cells’ differentiation. In addition, TAK-828F improved Th17/Treg cells’ population ratio by inhibiting Th17 cells’ differentiation and up-regulating Treg cells. Furthermore, TAK-828F, at 100 nM, reduced the production of Th17-related cytokines (IL-17, IL-17F and IL-22) without affecting IFN-γ production in whole blood. These results demonstrate that TAK-828F has the potent and selective inhibitory activity against RORγt both in mouse and human cells. Additionally, oral administration of TAK-828F showed promising efficacy in naive T cell transfer mouse colitis model. TAK-828F may provide a novel therapeutic option to treat immune diseases by inhibiting Th17 and Th1/17 cells’ differentiation and improving imbalance between Th17 and Treg cells.

Pharmacologic inhibition of RORγt regulates Th17 signature gene expression and suppresses cutaneous inflammation in vivo (THER6P.855)

Abstract IL-17-producing Th17 cells, Tc17 cells and γδ T cells play critical roles in the pathogenesis of autoimmune psoriasis. RORγt is required for the differentiation of Th17 cells and expression of IL-17. Here we describe a novel, potent, and selective RORγt inverse agonist (TMP778), and its inactive diastereomer (TMP776). This chemistry, for the first time, provides a unique and powerful set of tools to probe RORγt-dependent functions. TMP778, but not TMP776, blocked human Th17 and Tc17 cell differentiation and also acutely modulated Th17-signature gene expression. In addition, TMP778 but not TMP776 inhibited IL-17 production in both human and mouse γδ T cells. IL-23-induced IL-17 production was also blocked by TMP778 treatment. In vivo targeting of RORγt in mice via TMP778 administration reduced imiquimod-induced psoriasis-like cutaneous inflammation. Further, TMP778 selectively regulated Th17-signature gene expression in mononuclear cells isolated from both the blood and affected skin of psoriasis patients. In summary, we are the first to demonstrate that RORγt inverse agonists (1) inhibit Tc17 cell differentiation, as well as IL-17 production by γδ T cells and CD8+ Tc17 cells; (2) block imiquimod-induced cutaneous inflammation; (3) inhibit Th17 signature gene expression by cells isolated from psoriatic patient samples; and (4) block IL-23-induced IL-17A expression. Thus, RORγt is a tractable drug target for the treatment of cutaneous inflammatory disorders.

Pharmacologic Inhibition of RORγt Regulates Th17 Signature Gene Expression and Suppresses Cutaneous Inflammation In Vivo

IL-17-producing CD4(+)Th17 cells, CD8(+)Tc17 cells, and γδ T cells play critical roles in the pathogenesis of autoimmune psoriasis. RORγt is required for the differentiation of Th17 cells and expression of IL-17. In this article, we describe a novel, potent, and selective RORγt inverse agonist (TMP778), and its inactive diastereomer (TMP776). This chemistry, for the first time to our knowledge, provides a unique and powerful set of tools to probe RORγt-dependent functions. TMP778, but not TMP776, blocked human Th17 and Tc17 cell differentiation and also acutely modulated IL-17A production and inflammatory Th17-signature gene expression (Il17a, Il17f, Il22, Il26, Ccr6, and Il23) in mature human Th17 effector/memory T cells. In addition, TMP778, but not TMP776, inhibited IL-17A production in both human and mouse γδ T cells. IL-23-induced IL-17A production was also blocked by TMP778 treatment. In vivo targeting of RORγt in mice via TMP778 administration reduced imiquimod-induced psoriasis-like cutaneous inflammation. Further, TMP778 selectively regulated Th17-signature gene expression in mononuclear cells isolated from both the blood and affected skin of psoriasis patients. In summary, to our knowledge, we are the first to demonstrate that RORγt inverse agonists: 1) inhibit Tc17 cell differentiation, as well as IL-17 production by γδ T cells and CD8(+) Tc17 cells; 2) block imiquimod-induced cutaneous inflammation; 3) inhibit Th17 signature gene expression by cells isolated from psoriatic patient samples; and 4) block IL-23-induced IL-17A expression. Thus, RORγt is a tractable drug target for the treatment of cutaneous inflammatory disorders, which may afford additional therapeutic benefit over existing modalities that target only IL-17A.