Discovery of ASP5878: Synthesis and structure-activity relationships of pyrimidine derivatives as pan-FGFRs inhibitors with improved metabolic stability and suppressed hERG channel inhibitory activity.

Fibroblast growth factor receptor 3 (FGFR3) is an attractive therapeutic target for the treatment of bladder cancer patients harboring genetic alterations in FGFR3. We identified pyrimidine derivative ASP5878 (27) with improved metabolic stability and suppressed human ether-á-go-go related gene (hERG) channel inhibitory activity by the optimization of lead compound 1. Based on prediction of the metabolites of 1, an ether linker was introduced in place of the ethylene linker to improve metabolic stability. Moreover, conversion of the phenyl moiety into the pyrazole ring resulted in the suppression of hERG channel inhibitory activity, possibly due to the weaker π-π stacking interaction with Phe656 in the hERG channel by a reduction in π-electrical density of the aromatic ring. ASP5878 showed potent in vitro FGFR3 enzyme and cell growth inhibitory activity, and in vivo FGFR3 autophosphorylation inhibitory activity. Moreover, ASP5878 did not affect the hERG current up to 10 µM by in vitro patch-clamp assay, and a single oral dose of ASP5878 at 1, 10, and 100 mg/kg did not induce serious adverse effects on the central nervous, cardiovascular, and respiratory systems in dogs. Furthermore, ASP5878 exhibited lower total clearance than hepatic blood flow and high oral bioavailability in rats and dogs, and moderate brain penetration in rats.

Synthesis and structure-activity relationships of pyrimidine derivatives as potent and orally active FGFR3 inhibitors with both increased systemic exposure and enhanced in vitro potency.

Fibroblast growth factor receptor 3 (FGFR3) is an attractive therapeutic target for the treatment of patients with bladder cancer harboring genetic alterations in FGFR3. We identified pyrimidine derivative 20b, which induced tumor regression following oral administration to a bladder cancer xenograft mouse model. Compound 20b was discovered by optimizing lead compound 1, which we reported previously. Specifically, reducing the molecular size of the substituent at the 4-position and replacing the linker of the 5-position in the pyrimidine scaffold resulted in an increase in systemic exposure. Furthermore, introduction of two fluorine atoms into the 3,5-dimethoxyphenyl ring enhanced FGFR3 inhibitory activity. Molecular dynamics (MD) simulation of 20b suggested that the fluorine atom interacts with the main chain NH moiety of Asp635 via a hydrogen bond.

Structure-based drug design of 1,3,5-triazine and pyrimidine derivatives as novel FGFR3 inhibitors with high selectivity over VEGFR2.

Fibroblast growth factor receptor 3 (FGFR3) is an attractive therapeutic target for the treatment of bladder cancer. We identified 1,3,5-triazine derivative 18b and pyrimidine derivative 40a as novel structures with potent and highly selective FGFR3 inhibitory activity over vascular endothelial growth factor receptor 2 (VEGFR2) using a structure-based drug design (SBDD) approach. X-ray crystal structure analysis suggests that interactions between 18b and amino acid residues located in the solvent region (Lys476 and Met488), and between 40a and Met529 located in the back pocket of FGFR3 may underlie the potent FGFR3 inhibitory activity and high kinase selectivity over VEGFR2.

Synthesis and structure-activity relationships of pyrazine-2-carboxamide derivatives as novel echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) inhibitors.

Echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) is a valid therapeutic target for the treatment of EML4-ALK-positive non-small cell lung cancer (NSCLC). We discovered 12c as a novel and potent EML4-ALK inhibitor through structural optimization of 5a. In mice xenografted with 3T3 cells expressing EML4-ALK, oral administration of 12c demonstrated potent antitumor activity. This article describes the synthesis and biological evaluation of pyrazine-2-carboxamide derivatives along with studies of their structure-activity relationship (SAR) using computational modeling.

Discovery of N-{2-Methoxy-4-[4-(4-methylpiperazin-1-yl)piperidin-1-yl]phenyl}-N'-[2-(propane-2-sulfonyl)phenyl]-1,3,5-triazine-2,4-diamine (ASP3026), a Potent and Selective Anaplastic Lymphoma Kinase (ALK) Inhibitor.

Anaplastic lymphoma kinase (ALK) is a validated therapeutic target for treating echinoderm microtubule-associated protein-like 4 (EML4)-ALK positive non-small cell lung cancer (NSCLC). We synthesized a series of 1,3,5-triazine derivatives and identified ASP3026 (14a) as a potent and selective ALK inhibitor. In mice xenografted with NCI-H2228 cells expressing EML4-ALK, once-daily oral administration of 14a demonstrated dose-dependent antitumor activity. Here, syntheses and structure-activity relationship (SAR) studies of 1,3,5-triazine derivatives are described.

Synthesis and structure-activity relationship of fused-pyrimidine derivatives as a series of novel GPR119 agonists.

A series of fused-pyrimidine derivatives have been discovered as potent and orally active GPR119 agonists. A combination of the fused-pyrimidine structure and 4-chloro-2,5-difluorophenyl group provided the 5,7-dihydrothieno[3,4-d]pyrimidine 6,6-dioxide derivative 14a as a highly potent GPR119 agonist. Further optimization of the amino group at the 4-position in the pyrimidine ring led to the identification of 2-{1-[2-(4-chloro-2,5-difluorophenyl)-6,6-dioxido-5,7-dihydrothieno[3,4-d]pyrimidin-4-yl]piperidin-4-yl}acetamide (16b) as an advanced analog. Compound 16b was found to have extremely potent agonistic activity and improved glucose tolerance at 0.1 mg/kg po in mice. We consider compound 16b and its analogs to have clear utility in exploring the practicality of GPR119 agonists as potential therapeutic agents for the treatment of type 2 diabetes mellitus.

Biological activities of alpha-mangostin derivatives against acidic sphingomyelinase.

Deprenyl and benzofenone-type congeners of alpha-mangostin 1 have been synthesized to understand their role for the inhibitory activity against sphingomyelinase (SMase). While removal of the prenyl group of the right side (11 and 12) caused loss of the selectivity between ASMase (acidic sphingomyelinase) and NSMase (neutral sphingomyelinase), the prenyl group of the left side appeared to increase the inhibitory activities (16 and 17).