Discovery of Novel 5-(Piperazine-1-carbonyl)pyridin-2(1H)-one Derivatives as Orally eIF4A3-Selective Inhibitors.

Starting from our previous eIF4A3-selective inhibitor 1a, a novel series of (piperazine-1-carbonyl)pyridin-2(1H)-one derivatives was designed, synthesized, and evaluated for identification of orally bioavailable probe molecules. Compounds 1o and 1q showed improved physicochemical and ADMET profiles, while maintaining potent and subtype-selective eIF4A3 inhibitory potency. In accord with their promising PK profiles and results from initial in vivo PD studies, compounds 1o and 1q showed antitumor efficacy with T/C values of 54% and 29%, respectively, without severe body weight loss. Thus, our novel series of compounds represents promising probe molecules for the in vivo pharmacological study of selective eIF4A3 inhibition.

Optimization of (2,3-dihydro-1-benzofuran-3-yl)acetic acids: discovery of a non-free fatty acid-like, highly bioavailable G protein-coupled receptor 40/free fatty acid receptor 1 agonist as a glucose-dependent insulinotropic agent.

G protein-coupled receptor 40 (GPR40)/free fatty acid receptor 1 (FFA1) is a free fatty acid (FFA) receptor that mediates FFA-amplified glucose-stimulated insulin secretion in pancreatic ß-cells. We previously identified (2,3-dihydro-1-benzofuran-3-yl)acetic acid derivative 2 as a candidate, but it had relatively high lipophilicity. Adding a polar functional group on 2 yielded several compounds with lower lipophilicity and little effect on caspase-3/7 activity at 30 µM (a marker of toxicity in human HepG2 hepatocytes). Three optimized compounds showed promising pharmacokinetic profiles with good in vivo effects. Of these, compound 16 had the lowest lipophilicity. Metabolic analysis of 16 showed a long-acting PK profile due to high resistance to ß-oxidation. Oral administration of 16 significantly reduced plasma glucose excursion and increased insulin secretion during an OGTT in type 2 diabetic rats. Compound 16 (TAK-875) is being evaluated in human clinical trials for the treatment of type 2 diabetes.

Discovery of phenylpropanoic acid derivatives containing polar functionalities as potent and orally bioavailable G protein-coupled receptor 40 agonists for the treatment of type 2 diabetes.

As part of a program to identify potent GPR40 agonists with drug-like properties suitable for clinical development, the incorporation of polar substituents was explored with the intention of decreasing the lipophilicity of our recently disclosed phenylpropanoic acid derivative 1. This incorporation would allow us to mitigate the cytotoxicity issues observed with compound 1 and enable us to move away from the multifunctional free fatty acid-like structure. Substitutions on the 2',6'-dimethylbiphenyl ring were initially undertaken, which revealed the feasibility of introducing polar functionalities at the biphenyl 4'-position. Further optimization of this position and the linker led to the discovery of several 4'-alkoxybiphenyl derivatives, which showed potent GPR40 agonist activities with the best balance in terms of improved cytotoxicity profiles and favorable pharmacokinetic properties. Among them, 3-{2-fluoro-4-[({4'-[(4-hydroxy-1,1-dioxidotetrahydro-2H-thiopyran-4-yl)methoxy]-2',6'-dimethylbiphenyl-3-yl}methyl)amino]phenyl}propanoic acid (35) exhibited a robust plasma glucose-lowering effect and insulinotropic action during an oral glucose tolerance test in rats with impaired glucose tolerance.