Takamitsu Kobayashi

CH5424802, a Selective ALK Inhibitor Capable of Blocking the Resistant Gatekeeper Mutant

Anaplastic lymphoma kinase (ALK) is a tyrosine kinase that is constitutively activated in certain cancers, following gene alterations such as chromosomal translocation, amplification, or point mutation. Here, we identified CH5424802, a potent, selective, and orally available ALK inhibitor with a unique chemical scaffold, showing preferential antitumor activity against cancers with gene alterations of ALK, such as nonsmall cell lung cancer (NSCLC) cells expressing EML4-ALK fusion and anaplastic large-cell lymphoma (ALCL) cells expressing NPM-ALK fusion in vitro and in vivo. CH5424802 inhibited ALK L1196M, which corresponds to the gatekeeper mutation conferring common resistance to kinase inhibitors, and blocked EML4-ALK L1196M-driven cell growth. Our results support the potential for clinical evaluation of CH5424802 for the treatment of patients with ALK-driven tumors.

Design and synthesis of a highly selective, orally active and potent anaplastic lymphoma kinase inhibitor (CH5424802).

Anaplastic lymphoma kinase (ALK) receptor tyrosine kinase is considered an attractive therapeutic target for human cancers, especially non-small cell lung cancer (NSCLC). Our previous study revealed that 8,9-side-chains of 6,6-dimethyl-11-oxo-6,11-dihydro-5H-benzo[b]carbazole scaffold crucially affected kinase selectivity, cellular activity, and metabolic stability. In this work, we optimized the side-chains and identified highly selective, orally active and potent ALK inhibitor CH5424802 (18a) as the clinical candidate.

Discovery of Tofogliflozin, a Novel C-Arylglucoside with an O-Spiroketal Ring System, as a Highly Selective Sodium Glucose Cotransporter 2 (SGLT2) Inhibitor for the Treatment of Type 2 Diabetes

Inhibition of sodium glucose cotransporter 2 (SGLT2) has been proposed as a novel therapeutic approach to treat type 2 diabetes. In our efforts to discover novel inhibitors of SGLT2, we first generated a 3D pharmacophore model based on the superposition of known inhibitors. A search of the Cambridge Structural Database using a series of pharmacophore queries led to the discovery of an O-spiroketal C-arylglucoside scaffold. Subsequent chemical examination combined with computational modeling resulted in the identification of the clinical candidate 16d (CSG452, tofogliflozin), which is currently under phase III clinical trials.

Tofogliflozin, a potent and highly specific sodium/glucose cotransporter 2 inhibitor, improves glycemic control in diabetic rats and mice

Sodium/glucose cotransporter 2 (SGLT2) is the predominant mediator of renal glucose reabsorption and is an emerging molecular target for the treatment of diabetes. We identified a novel potent and selective SGLT2 inhibitor, tofogliflozin (CSG452), and examined its efficacy and pharmacological properties as an antidiabetic drug. Tofogliflozin competitively inhibited SGLT2 in cells overexpressing SGLT2, and Ki values for human, rat, and mouse SGLT2 inhibition were 2.9, 14.9, and 6.4 nM, respectively. The selectivity of tofogliflozin toward human SGLT2 versus human SGLT1, SGLT6, and sodium/myo-inositol transporter 1 was the highest among the tested SGLT2 inhibitors under clinical development. Furthermore, no interaction with tofogliflozin was observed in any of a battery of tests examining glucose-related physiological processes, such as glucose uptake, glucose oxidation, glycogen synthesis, hepatic glucose production, glucose-stimulated insulin secretion, and glucosidase reactions. A single oral gavage of tofogliflozin increased renal glucose clearance and lowered the blood glucose level in Zucker diabetic fatty rats. Tofogliflozin also improved postprandial glucose excursion in a meal tolerance test with GK rats. In db/db mice, 4-week tofogliflozin treatment reduced glycated hemoglobin and improved glucose tolerance in the oral glucose tolerance test 4 days after the final administration. No blood glucose reduction was observed in normoglycemic SD rats treated with tofogliflozin. These findings demonstrate that tofogliflozin inhibits SGLT2 in a specific manner, lowers blood glucose levels by increasing renal glucose clearance, and improves pathological conditions of type 2 diabetes with a low hypoglycemic potential.

9-Substituted 6,6-Dimethyl-11-oxo-6,11-dihydro-5H-benzo[b]carbazoles as Highly Selective and Potent Anaplastic Lymphoma Kinase Inhibitors

9-Substituted 6,6-dimethyl-11-oxo-6,11-dihydro-5H-benzo[b]carbazoles were discovered as highly selective and potent anaplastic lymphoma kinase (ALK) inhibitors by structure-based drug design. The high target selectivity was achieved by introducing a substituent close to the E(0) region of the ATP binding site, which has a unique amino acid sequence. Among the identified inhibitors, compound 13d showed highly selective and potent inhibitory activity against ALK with an IC(50) value of 2.9 nM and strong antiproliferative activity against KARPAS-299 with an IC(50) value of 12.8 nM. The compound also displayed significant antitumor efficacy in an established ALK fusion gene-positive anaplastic large-cell lymphoma (ALCL) xenograft model in mice without body weight loss.

5a-Carba-β-D-glucopyranose derivatives as novel sodium-dependent glucose cotransporter 2 (SGLT2) inhibitors for the treatment of type 2 diabetes.

5a-Carba-β-D-glucopyranose derivatives were synthesized and identified as novel SGLT2-selective inhibitors. These inhibitors exhibited potent SGLT2 inhibition with high selectivity over SGLT1. Among the tested compounds, 6f indicated the most potent hSGLT2 inhibition and the highest selectivity over hSGLT1. Moreover, the pharmacokinetics data also showed that 6h, which had the same aglycon structure as sergliflozin-active (3-active), had a threefold longer half-life time (T(1/2)) than sergliflozin (3) with a high distribution volume in db/db mice. Subsequently, 6h lowered blood glucose levels as much as 3 and showed longer hypoglycemic action than 3 in db/db mice.

Novel nonsecosteroidal vitamin D3 carboxylic acid analogs for osteoporosis, and SAR analysis.

Novel vitamin D(3) analogs with carboxylic acid were explored, focusing on a nonsecosteroidal analog, LG190178, with a bisphenyl skeleton. From X-ray analysis of these analogs with vitamin D receptor (VDR), the carboxyl groups had very unique hydrogen bonding interactions in VDR and mimicked 1α-hydroxy group and/or 3β-hydroxy group of 1α,25-dihydroxyvitamin D(3). A highly potent analog, 6a, with good in vitro activity and pharmacokinetic profiles was identified from an SAR study. Compound 6a showed significant prevention of bone loss in a rat osteoporosis model by oral administration.

C-Aryl 5a-carba-β-d-glucopyranosides as novel sodium glucose cotransporter 2 (SGLT2) inhibitors for the treatment of type 2 diabetes.

C-Aryl 5a-carba-β-d-glucopyranose derivatives were synthesized and evaluated for inhibition activity against hSGLT1 and hSGLT2. Modifications to the substituents on the two benzene rings resulted in enhanced hSGLT2 inhibition activity and extremely high hSGLT2 selectivity versus SGLT1. Using the created superimposed model, the reason for the high hSGLT2 selectivity was speculated to be that additional substituents occupied a new space, in a different way than known inhibitors. Among the tested compounds, the ethoxy compound 5h with high hSGLT2 selectivity exhibited more potent and longer hypoglycemic action in db/db mice than our O-carbasugar compound (1) and sergliflozin (2), which could be explained by its improved PK profiles relative to those of the two compounds. These results indicated that 5h might be a promising drug candidate for the treatment of type 2 diabetes.

Design and evaluation of azaindole-substituted N-hydroxypyridones as glyoxalase I inhibitors

We conducted a high throughput screening for glyoxalase I (GLO1) inhibitors and identified 4,6-diphenyl-N-hydroxypyridone as a lead compound. Using a binding model of the lead and public X-ray coordinates of GLO1 enzymes complexed with glutathione analogues, we designed 4-(7-azaindole)-substituted 6-phenyl-N-hydroxypyridones. 7-Azaindoles 7-nitrogen was expected to interact with a water network, resulting in an interaction with the protein. We validated this inhibitor design by comparing its structure-activity relationship (SAR) with that of corresponding indole derivatives, by analyzing the binding mode with X-ray crystallography and by evaluating its thermodynamic binding parameters.

Abstract 3559: A new selective ALK inhibitor CH5424802 shows potent efficacy against ALK-positive cancers including the gatekeeper mutant-driven tumors

The recent development of targeted protein kinase inhibitors has provided new opportunity in cancer treatment. However, certain factors limit the efficacy of cancer therapies, such as a narrow therapeutic index caused by inhibition of multiple kinases, and the emergence of resistant mutants. Thus, kinase inhibitors with more potent and selective properties and effectiveness against resistant mutants need to be developed. Anaplastic lymphoma kinase (ALK) is a tyrosine kinase that is constitutively activated in certain cancers following gene alterations such as chromosomal translocation, amplification, or point mutation. Here, we identified CH5424802, a potent, selective, and orally available ALK inhibitor with a new chemical scaffold, showing preferential antitumor activity against cancers with gene alterations of ALK, such as non-small cell lung cancer (NSCLC) cells expressing EML4-ALK fusion and anaplastic large-cell lymphoma (ALCL) cells expressing NPM-ALK fusion in vitro and in vivo. CH5424802 inhibited ALK L1196M, which corresponds to the gatekeeper mutation conferring common resistance to kinase inhibitors, and blocked EML4-ALK L1196M-driven tumors. Our results support the potential for the clinical evaluation of CH54242802 for long-term treatment of patients with ALK-driven tumors. CH5424802 is currently being investigated in Phase I/II clinical trials for patients with ALK-positive NSCLC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3559. doi:10.1158/1538-7445.AM2011-3559