Gene Signature-Based Approach Identified MEK1/2 as a Potential Target Associated With Relapse After Anti-TNFα Treatment for Crohn's Disease.

Background: Anti-tumor necrosis factor alpha (anti-TNFα) therapy has become the mainstay of therapy for Crohn's disease (CD). However, post-therapy, the recurrence rate is still high. The aim of this study was to dissect the molecular mechanism for recurrence of CD treated with anti-TNFα therapy and investigate novel therapeutic options that could induce complete remission.

Discovery and pharmacological characterization of a new class of prolyl-tRNA synthetase inhibitor for anti-fibrosis therapy.

Scleroderma has clinical characteristics including skin and other tissue fibrosis, but there is an unmet need for anti-fibrotic therapy. Halofuginone (HF) is a well-known anti-fibrosis agent in preclinical and clinical studies which exerts its effect via inhibition of TGF-β/Smad3 signaling pathway. Recently, prolyl-tRNA synthetase (PRS) was elucidated as a target protein for HF that binds to the proline binding site of the catalytic domain of PRS.

A Novel LSD1 Inhibitor T-3775440 Disrupts GFI1B-Containing Complex Leading to Transdifferentiation and Impaired Growth of AML Cells.

Dysregulation of lysine (K)-specific demethylase 1A (LSD1), also known as KDM1A, has been implicated in the development of various cancers, including leukemia. Here, we describe the antileukemic activity and mechanism of action of T-3775440, a novel irreversible LSD1 inhibitor. Cell growth analysis of leukemia cell lines revealed that acute erythroid leukemia (AEL) and acute megakaryoblastic leukemia cells (AMKL) were highly sensitive to this compound.

An inhibitor of apoptosis protein antagonist T-3256336 potentiates the antitumor efficacy of the Nedd8-activating enzyme inhibitor pevonedistat (TAK-924/MLN4924).

Inhibitors of apoptosis proteins (IAPs) are antiapoptotic regulators that block cell death, and are frequently overexpressed in several human cancers, where they facilitate evasion of apoptosis and promote cell survival. IAP antagonists are also known as second mitochondria-derived activator of caspase (SMAC)-mimetics, and have recently been considered as novel therapeutic agents for inducing apoptosis, alone and in combination with other anticancer drugs. In this study, we showed that T-3256336, the orally available IAP antagonist has synergistically enhances the antiproliferative effects of the NEDD8-activating enzyme (NAE) inhibitor pevonedistat (TAK-924/MLN4924), and these effects were attenuated by a TNFα-neutralizing antibody.

T-3256336, a novel and orally available small molecule IAP antagonist, induced tumor cell death via induction of systemic TNF alpha production.

Inhibitors of apoptosis proteins (IAPs) are a family of antiapoptotic regulators that have attracted attention as potential targets for cancer therapeutics. Although recent studies have revealed that small-molecule IAP antagonists induce tumor selective cell death in an autocrine tumor necrosis factor (TNF)α-dependent manner, the single-agent efficacy of IAP antagonists is restricted to a small subset of cancer cells. In this study, we showed that the single-agent activity of T-3256336 was limited to a few cancer cell lines in vitro, and these cell lines were defined by relatively high levels of TNFα mRNA expression.

Design, synthesis, and biological activities of novel hexahydropyrazino[1,2-a]indole derivatives as potent inhibitors of apoptosis (IAP) proteins antagonists with improved membrane permeability across MDR1 expressing cells.

We previously reported octahydropyrrolo[1,2-a]pyrazine derivative 2 (T-3256336) as a potent antagonist for inhibitors of apoptosis (IAP) proteins. Because compound 2 was susceptible to MDR1 mediated efflux, we developed another scaffold, hexahydropyrazino[1,2-a]indole, using structure-based drug design. The fused benzene ring of this scaffold was aimed at increasing the lipophilicity and decreasing the basicity of the scaffold to improve the membrane permeability across MDR1 expressing cells.

Design, stereoselective synthesis, and biological evaluation of novel tri-cyclic compounds as inhibitor of apoptosis proteins (IAP) antagonists.

We recently reported the discovery of octahydropyrrolo[1,2-a]pyrazine A as a lead compound for an inhibitor of apoptosis proteins (IAP) antagonist. To develop IAP antagonists with favorable PK profiles, we designed novel tri-cyclic compounds, octahydro-1H-cyclopropa[4,5]pyrrolo[1,2-a]pyrazines 1 and 2 based on co-crystal structural analysis of A with cellular IAP-1 (cIAP-1). The additional cyclopropane moiety was used to block the predicted metabolic site of compound A without detriment to the binding affinity for cIAP.

Discovery of a selective kinase inhibitor (TAK-632) targeting pan-RAF inhibition: design, synthesis, and biological evaluation of C-7-substituted 1,3-benzothiazole derivatives.

With the aim of discovering a selective kinase inhibitor targeting pan-RAF kinase inhibition, we designed novel 1,3-benzothiazole derivatives based on our thiazolo[5,4-b]pyridine class RAF/VEGFR2 inhibitor 1 and developed a regioselective cyclization methodology for the C-7-substituted 1,3-benzothiazole scaffold utilizing meta-substituted anilines. Eventually, we selected 7-cyano derivative 8B (TAK-632) as a development candidate and confirmed its binding mode by cocrystal structure with BRAF. Accommodation of the 7-cyano group into the BRAF-selectivity pocket and the 3-(trifluoromethyl)phenyl acetamide moiety into the hydrophobic back pocket of BRAF in the DFG-out conformation contributed to enhanced RAF potency and selectivity vs VEGFR2.

Design and synthesis of potent inhibitor of apoptosis (IAP) proteins antagonists bearing an octahydropyrrolo[1,2-a]pyrazine scaffold as a novel proline mimetic.

To develop novel inhibitor of apoptosis (IAP) proteins antagonists, we designed a bicyclic octahydropyrrolo[1,2-a]pyrazine scaffold as a novel proline bioisostere. This design was based on the X-ray co-crystal structure of four N-terminal amino acid residues (AVPI) of the second mitochondria-derived activator of caspase (Smac) with the X-chromosome-linked IAP (XIAP) protein. Lead optimization of this scaffold to improve oral absorption yielded compound 45, which showed potent cellular IAP1 (cIAP1 IC(50): 1.

Antitumor activity and pharmacodynamic biomarkers of a novel and orally available small-molecule antagonist of inhibitor of apoptosis proteins.

Inhibitor of apoptosis proteins (IAP), which are key regulators of apoptosis, are inhibited by second mitochondria-derived activator of caspase (SMAC). Small-molecule IAP antagonists have recently been reported as novel therapeutic treatments for cancer. In this study, we showed that the octahydro-pyrrolo[1,2-a]pyrazine derivative, T-3256336, is a novel and orally available small-molecule IAP antagonist.

Design and synthesis of novel DFG-out RAF/vascular endothelial growth factor receptor 2 (VEGFR2) inhibitors: 3. Evaluation of 5-amino-linked thiazolo[5,4-d]pyrimidine and thiazolo[5,4-b]pyridine derivatives.

Our aim was to discover RAF/vascular endothelial growth factor receptor 2 (VEGFR2) inhibitors that possess strong activity and sufficient oral absorption, and thus, we selected a 5-amino-linked thiazolo[5,4-d]pyrimidine derivative as the lead compound because of its potential kinase inhibitory activities and its desired solubility. The novel tertiary 1-cyano-1-methylethoxy substituent was designed to occupy the hydrophobic region of 'back pocket' of BRAF on the basis of the X-ray co-crystal structure data of BRAF. In addition, we found that N-methylation of the amine linker could control the twisted molecular conformation leading to improved solubility.

Design and synthesis of novel DFG-out RAF/vascular endothelial growth factor receptor 2 (VEGFR2) inhibitors: 2. Synthesis and characterization of a novel imide-type prodrug for improving oral absorption.

As an alternative to the previously reported solid dispersion formulation for enhancing the oral absorption of thiazolo[5,4-b]pyridine 1, we investigated novel N-acyl imide prodrugs of 1 as RAF/vascular endothelial growth factor receptor 2 (VEGFR2) inhibitors. Introducing N-acyl promoieties at the benzanilide position gave chemically stable imides. N-tert-Butoxycarbonyl (Boc) introduced imide 6 was a promising prodrug, which was converted to the active compound 1 after its oral administration in mice.

Design and synthesis of novel DFG-out RAF/vascular endothelial growth factor receptor 2 (VEGFR2) inhibitors. 1. Exploration of [5,6]-fused bicyclic scaffolds.

To develop RAF/VEGFR2 inhibitors that bind to the inactive DFG-out conformation, we conducted structure-based drug design using the X-ray cocrystal structures of BRAF, starting from an imidazo[1,2-b]pyridazine derivative. We designed various [5,6]-fused bicyclic scaffolds (ring A, 1-6) possessing an anilide group that forms two hydrogen bond interactions with Cys532. Stabilizing the planarity of this anilide and the nitrogen atom on the six-membered ring of the scaffold was critical for enhancing BRAF inhibition.

Ser46 phosphorylation of p53 is not always sufficient to induce apoptosis: multiple mechanisms of regulation of p53-dependent apoptosis.

The tumor suppressor gene p53 plays a central role in determining cell fate in response to DNA damage; cells may undergo either senescence or apoptosis, depending on cell type. Phosphorylation of Serine 46 (Ser(46)) of p53 is considered to be a primary determinant for the induction of apoptosis, by selectively inducing transactivation of p53 target genes that have proapoptotic function. However, the generality of this mechanism of regulation of p53 remains a matter of debate.