Sodium glucose cotransporter 2 (SGLT2) inhibitors have been reported to lower the serum uric acid (SUA) level. To elucidate the mechanism responsible for this reduction, SUA and the urinary excretion rate of uric acid (UEUA) were analysed after the oral administration of luseogliflozin, a SGLT2 inhibitor, to healthy subjects. After dosing, SUA decreased, and a negative correlation was observed between the SUA level and the UEUA, suggesting that SUA decreased as a result of the increase in the UEUA. The increase in UEUA was correlated with an increase in urinary d-glucose excretion, but not with the plasma luseogliflozin concentration. Additionally, in vitro transport experiments showed that luseogliflozin had no direct effect on the transporters involved in renal UA reabsorption. To explain that the increase in UEUA is likely due to glycosuria, the study focused on the facilitative glucose transporter 9 isoform 2 (GLUT9ΔN, SLC2A9b), which is expressed at the apical membrane of the kidney tubular cells and transports both UA and d-glucose. It was observed that the efflux of [14C]UA in Xenopus oocytes expressing the GLUT9 isoform 2 was trans-stimulated by 10 mm d-glucose, a high concentration of glucose that existed under SGLT2 inhibition. On the other hand, the uptake of [14C]UA by oocytes was cis-inhibited by 100 mm d-glucose, a concentration assumed to exist in collecting ducts. In conclusion, it was demonstrated that the UEUA could potentially be increased by luseogliflozin-induced glycosuria, with alterations of UA transport activity because of urinary glucose.

Derivatives of a novel scaffold, C-phenyl 1-thio-D-glucitol, were prepared and evaluated for sodium-dependent glucose cotransporter (SGLT) 2 and SGLT1 inhibition activities. Optimization of substituents on the aromatic rings afforded five compounds with potent and selective SGLT2 inhibition activities. The compounds were evaluated for in vitro human metabolic stability, human serum protein binding (SPB), and Caco-2 permeability. Of them, (1S)-1,5-anhydro-1-[5-(4-ethoxybenzyl)-2-methoxy-4-methylphenyl]-1-thio-D-glucitol (3p) exhibited potent SGLT2 inhibition activity (IC(50) = 2.26 nM), with 1650-fold selectivity over SGLT1. Compound 3p showed good metabolic stability toward cryo-preserved human hepatic clearance, lower SPB, and moderate Caco-2 permeability. Since 3p should have acceptable human pharmacokinetics (PK) properties, it could be a clinical candidate for treating type 2 diabetes. We observed that compound 3p exhibits a blood glucose lowering effect, excellent urinary glucose excretion properties, and promising PK profiles in animals. Phase II clinical trials of 3p (TS-071) are currently ongoing.

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1. To understand the clearance mechanism of luseogliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, we investigated its human metabolite profile and metabolic enzymes responsible for the primary metabolic pathways in human using reaction phenotyping. 2. Sixteen metabolites of luseogliflozin were found in human plasma and/or urine and their structural information indicated that the drug was metabolized via multiple metabolic pathways. The primary metabolic pathways involve (1) O-deethylation to form M2 and subsequent glucuronidation to form M12, (2) ω-hydroxylation at ethoxy group to form M3 followed by oxidation to form the corresponding carboxylic acid metabolite (M17) and (3) direct glucuronidation to form M8. 3. The reaction phenotyping studies indicated that the formation of M2 was mainly mediated by cytochrome P450 (CYP) 3A4/5, and subsequently M12 formation was catalyzed by UGT1A1, UGT1A8 and UGT1A9. The formation of M3 was mediated by CYP4A11, CYP4F2 and CYP4F3B, and the further oxidation of M3 to M17 was mediated by alcohol dehydrogenase and aldehyde dehydrogenase. The formation of M8 was catalyzed by UGT1A1. 4. These results demonstrate that luseogliflozin is metabolized through multiple pathways, including CYP-mediated oxidation and glucuronidation, in human.