Discovery and SAR of JTE-151: A Novel RORγ Inhibitor for Clinical Development.

A number of RORγ inhibitors have been reported over the past decade. There were also several examples advancing to human clinical trials, however, none of them has reached the market yet, suggesting that there could be common obstacles for their future development. As was expected from the general homology of nuclear receptor ligands, insufficient selectivity as well as poor physicochemical properties were identified as potential risks for a RORγ program. Based on such considerations, we conducted a SAR investigation by prioritizing drug-like properties to mitigate such potential drawbacks. After an intensive SAR exploration with strong emphasis on "drug-likeness" indices, an orally available RORγ inhibitor, JTE-151, was finally generated and was advanced to a human clinical trial. The compound was confirmed to possess highly selective profiles along with good metabolic stability, and most beneficially, no serious adverse events (SAE) and good PK profiles were observed in the human clinical trial.

Discovery of Novel NLRP3 Inflammasome Inhibitors Composed of an Oxazole Scaffold Bearing an Acylsulfamide.

The NLRP3 inflammasome plays an important role in the defense mechanism of the innate immune system and has recently attracted much attention as a drug target for various inflammatory disorders. Among the strategies for generating the novel chemotype in current drug discovery, scaffold hopping and bioisosteric replacement are known to be attractive approaches. As the results of our medicinal chemistry campaign, which involved exploration of core motifs using a ring closing approach, a five-membered oxazole-based scaffold was identified, and subsequent implementation of bioisosteric replacement led to discovery of a novel chemical class of NLRP3 inflammasome inhibitor bearing the acylsulfamide group. Further optimization of aniline and sulfamide moieties to improve potency in human whole blood assay led to the identification of the orally bioactive compound 32 in the LPS challenge model. Furthermore, compound 32 attenuated kidney injury in adriamycin-induced glomerulonephritis in mice. These investigations indicated that the NLRP3 inhibitor could be a potential therapeutic agent for glomerulonephritis.

Discovery of a Janus Kinase Inhibitor Bearing a Highly Three-Dimensional Spiro Scaffold: JTE-052 (Delgocitinib) as a New Dermatological Agent to Treat Inflammatory Skin Disorders.

Dermatologic disorders such as atopic dermatitis arise from genetic and environmental causes and are complex and multifactorial in nature. Among possible risk factors, aberrant immunological reactions are one of the leading etiologies. Immunosuppressive agents including topical steroids are common treatments for these disorders. Despite their reliability in clinical settings, topical steroids display side effects, typified by skin thinning. Accordingly, there is a need for alternate effective and well-tolerated therapies. As part of our efforts to investigate new immunomodulators, we have developed a series of JAK inhibitors, which incorporate novel three-dimensional spiro motifs and unexpectedly possess both excellent physicochemical properties and antidermatitis efficacy in the animal models. One of these compounds, JTE-052 (ent-60), also known as delgocitinib, has been shown to be effective and well-tolerated in human clinical trials and has recently been approved in Japan for the treatment of atopic dermatitis as the first drug among Janus kinase inhibitors.

Concise SAR Exploration Based on the "Head-to-Tail" Approach: Discovery of PI4KIIIα Inhibitors Bearing Diverse Scaffolds.

In typical kinase inhibitor programs, a hinge binder showing best potency with preferential specificity is initially selected, followed by fine-tuning of the accompanying substituents on its core module. A shortcoming of this approach is that the exclusive focus on a single chemotype can endanger all the analogues in the series if a critical shortcoming is revealed. Thus, an early evaluation of structure-activity relationships (SARs) can mitigate unforeseen outcomes within a series of multiple compounds, although there have been very few examples to follow such a policy. PI4KIIIα is one of four mammalian phosphatidylinositol-4 kinases and has recently drawn significant attention as an emerging target for hepatitis C virus (HCV) treatment. In this letter, a novel "head-to-tail" approach to discover a diverse set of PI4KIIIα inhibitors is reported. We believe this method will generate distinct core scaffolds, a rational strategy to circumvent potential risks in general kinase programs.

Pharmacological properties of JTE-052: a novel potent JAK inhibitor that suppresses various inflammatory responses in vitro and in vivo.

OBJECTIVE: To evaluate the pharmacological properties of JTE-052, a novel Janus kinase (JAK) inhibitor. METHODS: The JAK inhibitory activity of JTE-052 was evaluated using recombinant human enzymes. The inhibitory effects on cytokine signaling pathways were evaluated using primary human inflammatory cells. The in vivo efficacy and potency of JTE-052 were examined in a mouse interleukin (IL)-2-induced interferon (IFN)-γ production model and a rat collagen-induced arthritis model. RESULTS: JTE-052 inhibited the JAK1, JAK2, JAK3, and tyrosine kinase (Tyk)2 enzymes in an adenosine triphosphate (ATP)-competitive manner and inhibited cytokine signaling evoked by IL-2, IL-6, IL-23, granulocyte/macrophage colony-stimulating factor, and IFN-α. JTE-052 inhibited the activation of inflammatory cells, such as T cells, B cells, monocytes, and mast cells, in vitro. Oral dosing of JTE-052 resulted in potent suppression of the IL-2-induced IFN-γ production in mice with an ED50 value of 0.24 mg/kg, which was more potent than that of tofacitinib (ED50 = 1.1 mg/kg). In the collagen-induced arthritis model, JTE-052 ameliorated articular inflammation and joint destruction even in therapeutic treatments where methotrexate was ineffective. CONCLUSIONS: The present results indicate that JTE-052 is a highly potent JAK inhibitor, and represents a candidate anti-inflammatory agent for suppressing various types of inflammation.

A case of laughter therapy that helped improve advanced gastric cancer.

We have reported the case of a patient diagnosed as having advanced gastric cancer at the age of 88 years old. An endoscopy revealed a type-2 gastric cancer of 25 x 30 mm in the lesser curvature of the middle stomach body and an IIa gastric cancer with T2 SS and cardiac accessory lesions. Both the type-2 and IIa lesions were defined as tub1 with surrounding atrophic gastritis and entero-epithelium metaplastic carcinoma. Considering the patient's age and her desire not to receive cancer treatment, we prescribed laughter therapy as recommended by the Society for Healing Environment. The program was implemented in a laughter-inducing environment and consisted of five stages: (1) Making the patient feel safe, (2) Relaxing the patient, (3) Increasing the effectiveness, (4) Improving her condition and (5) Increasing her joy of living. One year and seven months later, an endoscopy of the lesser curvature of the middle stomach body indicated that the lesions clearly improved with a morphological reduction into IIa + IIc masses. A tissue biopsy revealed that nucleus abnormality clearly improved from the initial diagnosis, with no irregularity in size. The suspected lesion was localized to a limited area near the stomach wall. Although partial gastric adenocarcinoma was suspected, the cancers turned into gastric adenoma, atrophic gastritis, and enteroepithelium metaplastic carcinoma. Now, five years after the initial diagnosis, she maintains a good condition. Laughter, one of our casual behaviors, has the effect of reducing the stress experienced by the human body. Laughter is expected to become alternative medicine in the future, and we hope to see more reports and evidence on soothing therapies using laughter.

Further studies on hepatitis C virus NS5B RNA-dependent RNA polymerase inhibitors toward improved replicon cell activities: benzimidazole and structurally related compounds bearing the 2-morpholinophenyl moiety.

Following the discovery of JTK-109 (1) as a potent inhibitor of hepatitis C virus NS5B RNA-dependent RNA polymerase, [(a) Hirashima, S.; Suzuki, T.; Ishida, T.; Noji, S.; Yata, S.; Ando, I.; Komatsu, M.; Ikeda, S.; Hashimoto, H. J. Med. Chem.2006, 49, 4721. (b) Hashimoto, H.; Mizutani, K.; Yoshida, A. Int. Patent Appl. WO 01/47883, 2001.] further studies toward the improvement of the cellular potency have been performed. A greater than 40-fold improvement was achieved through replacing the biphenyl moiety with a 2-morpholinophenyl group and the benzimidazole ring with the tetracyclic scaffold to afford compound 7 with an excellent replicon potency (EC(50)=7.6 nM).

Discovery of conformationally constrained tetracyclic compounds as potent hepatitis C virus NS5B RNA polymerase inhibitors.

We report a new series of hepatitis C virus NS5B RNA polymerase inhibitors containing a conformationally constrained tetracyclic scaffold. SAR studies led to the identification of 6,7-dihydro-5H-benzo[5,6][1,4]diazepino[7,1-a]indoles (19 and 20) bearing a basic pendent group with high biochemical and cellular potencies. These compounds displayed a very small shift in cellular potency when the replicon assay was performed in the presence of human serum albumin.

Benzimidazole derivatives bearing substituted biphenyls as hepatitis C virus NS5B RNA-dependent RNA polymerase inhibitors: structure-activity relationship studies and identification of a potent and highly selective inhibitor JTK-109.

Following the discovery of a new series of benzimidazole derivatives bearing a diarylmethyl group as inhibitors of hepatitis C virus NS5B RNA-dependent RNA polymerase (HCV NS5B RdRp),1,2 we extended the structure-activity relationship (SAR) study to analogues bearing a substituted biphenyl group and succeeded in a significant advancement of activity. Starting from compound 1, optimization of the A, B, and C rings afforded potent inhibitors with low nanomolar potency against genotype 1b NS5B. The compounds, which have a substituent with a carbonyl function at the 4-position of the B-ring, efficiently blocked subgenomic viral RNA replication in the replicon cell assay at low submicromolar concentrations. Among the new compounds, compound 10n (JTK-109) exhibited favorable pharmacokinetic profiles, high selectivity for NS5B, and good safety profiles, suggesting the potential for a clinical candidate in the treatment of hepatitis C.