Translational prediction of first-in-human pharmacokinetics and pharmacodynamics of janagliflozin, a selective SGLT2 inhibitor, using allometric scaling, dedrick and PK/PD modeling methods.

AIM: Janagliflozin is an orally selective SGLT2 inhibitor. To predict human pharmacokinetics/pharmacodynamics (PK/PD) characteristics of janagliflozin. To design optimal starting dose and effective dose for janagliflozin first-in-human (FIH) study. METHODS: Animal PK/PD properties of janagliflozin were obtained from preclinical in vivo and in vitro study. Pharmacologically effective level of same class SGLT2 inhibitors were assessed through preclinical and clinical efficacy data of dapagliflozin, empagliflozin and canagliflozin. Human PK parameters and profiles of janagliflozin were predicted by various methods such as allometric scaling (AS), dedrick and PK/PD modeling analysis. Mechanistic PK/PD model was developed to describe janagliflozin-mediated impact on urinary glucose excretion (UGE). Human IC50 was scaled from rat model-estimated IC50 by correcting interspecies difference of in vitro IC50 and plasma fu of rat and human. The quantitative PK/PD prediction of janagliflozin was evaluated via observed PK/PD profiles of healthy subjects. Predicted PK/PD characteristics of janagliflozin were applied in FIH dose design. Optimal starting dose was suggested by considering preclinical PD and toxicity data of janagliflozin. Effective dose was suggested by considering pharmacologically effective level of same class drugs. RESULTS: PK/PD characteristics of janagliflozin in preclinical species were summarized. Pharmacologically effective level for SGLT2 inhibitors was defined as 25~30% ΔUGE (ΔUGE=--(PG*GFR)within24h) based on efficacy data of three same class drugs. Human predicted CL, Vss and F were 1.04 L/h, 77.5 L and 0.80. Predicted AUC and Cmax of janagliflozin of 10 and 50 mg were within 0.47~2.08 fold of observed values. Predicted human UGE0-24 h and UGE0-144 h of 10 and 50 mg dose range were within 0.66~1.41 fold of observed values. Optimal starting dose and pharmacologically active dose (PAD) were suggested as 10 mg and 50 mg. Dose range for FIH study was designed as 10-450 mg. CONCLUSIONS: This study predicted human PK/PD characteristics of janagliflozin based on preclinical data and provide optimal dose design for janagliflozin FIH study based on pharmacologically effective level of same class drugs.

A high-performance liquid chromatography-tandem mass spectrometry method for simultaneous determination of imigliptin, its five metabolites and alogliptin in human plasma and urine and its application to a multiple-dose pharmacokinetic study.

Imigliptin is a novel DPP-4 inhibitor, designed to treat type 2 diabetes mellitus (T2DM). A selective and sensitive method was developed using high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) to simultaneously quantify imigliptin, its five metabolites, and alogliptin in human plasma and urine. Solid-phase extraction (SPE) and direct dilution were used to extract imigliptin, its five metabolites, alogliptin from plasma and urine, respectively. The extracts were injected onto a SymmetryShield RP8 column with a gradient elution of methanol and water containing 10 mM ammonium formate (pH = 7). Ionization of all analytes was performed using an electrospray ionization (ESI) source in positive mode and detection was carried out with multiple reaction monitoring (MRM) mode. The results revealed that the method had excellent selectivity and linearity. Inter- and intra-batch precisions of all analytes were less than 15% and the accuracies were within 85%-115% for both plasma and urine. The sensitivity, matrix effect, extraction recovery, linearity, and stabilities were validated for all analytes in human plasma and urine. In conclusion, the validation results showed that this method was robust, specific, and sensitive and it can successfully applied to a pharmacokinetic study of Chinese T2DM subjects after oral dose of imigliptin and alogliptin.

Metabolites characterization of a novel DPP-4 inhibitor, imigliptin in humans and rats using ultra-high performance liquid chromatography coupled with synapt high-resolution mass spectrometry.

Imigliptin has been reported as a novel dipeptidyl-peptidase-IV (DPP-4) inhibitor to treat type 2 Diabetes Mellitus (T2DM), and is currently being tested in clinical trials. In the first human clinical study, imigliptin was well tolerated and proved to be a potent DPP-4 inhibitor. Considering its potential therapeutic benefits and promising future, it is of great importance to study the metabolite profiles in the early stage of drug development. In the present study, a robust and reliable analytical method based on the ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF MS) method combined with MassLynx software was established to investigate the characterization of metabolites of imigliptin in human and rat plasma, urine and feces after oral administration. As a result, a total of 9 metabolites were identified in humans, including 6, 9 and 8 metabolites in human plasma, urine, and feces, respectively. A total of 11 metabolites were identified in rats, including 7, 10 and 8 metabolites in rat plasma, urine, and feces, respectively. In addition, 6 of the metabolites detected in humans and rats were phase I metabolites, including demethylation, carboxylation, hydroxylation and dehydrogenation metabolites, and 5 of the metabolites were phase II metabolites, including acetylation and glucuronidation. There was no human metabolite detected compared to those in rats. The major metabolites detected in human plasma (M1 and M2) were products resulting from acetylation, and hydroxylation followed by dehydrogenation. M1 was the major metabolite in rat plasma. M2 and the parent drug were the major drug-related substances in human urine. The parent drug was the major drug-related substances in rat urine. M2, M5 (hydroxylation product) and M6 (2 × hydroxylation and acetylation product) were the predominant metabolites in human feces. M2 and M5 were the major metabolites in rat feces. In addition, renal clearance was the major route of excretion for imigliptin.

Developing a novel dual PI3K-mTOR inhibitor from the prodrug of a metabolite.

This study presents a process of developing a novel PI3K-mTOR inhibitor through the prodrug of a metabolite. The lead compound (compound 1) was identified with similar efficacy as that of NVP-BEZ235 in a tumor xenograft model, but the exposure of compound 1 was much lower than that of NVP-BEZ235. After reanalysis of the blood sample, a major metabolite (compound 2) was identified. Compound 2 exerted similar in vitro activity as compound 1, which indicated that compound 2 was an active metabolite and that the in vivo efficacy in the animal model came from compound 2 instead of compound 1. However, compound 1 was metabolized into compound 2 predominantly in the liver microsomes of mouse, but not in the liver microsomes of rat, dog, or human. In order to translate the efficacy in the animal model into clinical development or predict the pharmacokinetic/pharmacodynamic parameters in the clinical study using a preclinical model, we developed the metabolite (compound 2) instead of compound 1. Due to the low bioavailability of compound 2, its prodrug (compound 3) was designed and synthesized to improve the solubility. The prodrug was quickly converted to compound 2 through both intravenous and oral administrations. Because the prodrug (compound 3) did not improve the oral exposure of compound 2, developing compound 3 as an intravenous drug was considered by our team, and the latest results will be reported in the future.

Quantitative prediction of human pharmacokinetics and pharmacodynamics of imigliptin, a novel DPP-4 inhibitor, using allometric scaling, IVIVE and PK/PD modeling methods.

PURPOSE: To predict the pharmacokinetic/pharmacodynamic (PK/PD) profiles of imigliptin, a novel DPP-4 inhibitor, in first-in-human (FIH) study based on the data from preclinical species. METHODS: Imigliptin was intravenously and orally administered to rats, dogs, and monkeys to assess their PK/PD properties. DPP-4 activity was the PD biomarker. PK/PD profiles of sitagliptin and alogliptin in rats and humans were obtained and digitized from literatures. PK/PD profiles of all dose levels for each drug in each species were analyzed using modeling approach. Human CL, Vss and PK profiles of imigliptin were then predicted using Allometric Scaling (AS), in vitro in vivo extrapolation (IVIVE), and the steady-state plasma drug concentration - mean residence time (Css-MRT) methods. In vitro EC50 corrected by fu and in vivo EC50 in rats corrected by interspecies difference of sitagliptin and alogliptin were utilized separately to predict imigliptin human EC50. The prediction by integrating all above methods was evaluated by comparing observed and simulated PK/PD profiles in healthy subjects. RESULTS: Full PK/PD profiles in animal were summarized for imigliptin, sitagliptin and alogliptin. Imigliptin CL, Vss, and Fa were predicted to be 19.1L/h, 247L, and 0.81 in humans, respectively. Predicted imigliptin AUCs, AUECs, and Emax in humans were within 0.8-1.2 times of observed values whereas other predicted PK/PD parameters were within 0.5-1.5 times of observed values. CONCLUSIONS: By integrating available preclinical and clinical data, FIH PK/PD profiles of imigliptin could be accurately predicted.

[Determination of anaprazole in human plasma by LC-MS/MS in pharmacokinetic study].

Anaprazole is a proton pump inhibitor clinically used for curing peptic ulcer. A rapid, sensitive and convenient LC-MS/MS method was first established for the determination of anaprazole in human plasma. d(3), (13)C-anaprazole was used as internal standard (IS). After extraction from human plasma by protein precipitation with acetonitrile, all components were separated on an Extend C(18) column (100 mm × 4.6 mm, 3.5 µm). The assay was linear over the concentration range of 5.00-3 000 ng·m L(-1) (r(2) > 0.995). The method was successfully applied to a pharmacokinetic study of 40 mg anaprazole enteric-coated tablets in 14 Chinese healthy volunteers under fasting or high fat diet conditions. C(max) was (1 020 ± 435) ng·m L(-1) and AUC(0-t) was (2 370 ±754) h·ng·m L(-1) under fasting condition. And C(max) was (538 ± 395) ng·m L(-1) and AUC(0-t) was (1 610 ± 650) h·ng·m L(-1) under high fat diet condition. The plasma results suggest that the exposure of anaprazole is reduced by the high fat diet.

Discovery of Novel Putative Inhibitors of UDP-GlcNAc 2-Epimerase as Potent Antibacterial Agents.

We present the discovery and optimization of a novel series of inhibitors of bacterial UDP-N-acetylglucosamine 2-epimerase (called 2-epimerase in this paper). Starting from virtual screening hits, the activity of various inhibitory molecules was optimized using a combination of structure-based and rational design approaches. We successfully designed and identified a 2-epimerase inhibitor (compound 12-ES-Na, that we named Epimerox) which blocked the growth of methicillin-resistant Staphylococcus aureus (MRSA) at 3.9 µM MIC (minimum inhibitory concentration) and showed potent broad-range activity against all Gram-positive bacteria that were tested. Additionally a microplate coupled assay was performed to further confirm that the 2-epimerase inhibition of Epimerox was through a target-specific mechanism. Furthermore, Epimerox demonstrated in vivo efficacy and had a pharmacokinetic profile that is consonant with it being developed into a promising new antibiotic agent for treatment of infections caused by Gram-positive bacteria.

S110, a novel decitabine dinucleotide, increases fetal hemoglobin levels in baboons (P. anubis).

BACKGROUND: S110 is a novel dinucleoside analog that could have advantages over existing DNA methyltransferase (DNMT) inhibitors such as decitabine. A potential therapeutic role for S110 is to increase fetal hemoglobin (HbF) levels to treat ß-hemoglobinopathies. In these experiments the effect of S110 on HbF levels in baboons and its ability to reduce DNA methylation of the γ-globin gene promoter in vivo were evaluated. METHODS: The effect of S110 on HbF and γ-globin promoter DNA methylation was examined in cultured human erythroid progenitors and in vivo in the baboon pre-clinical model. S110 pharmacokinetics was also examined in the baboon model. RESULTS: S110 increased HbF and reduced DNA methylation of the γ-globin promoter in human erythroid progenitors and in baboons when administered subcutaneously. Pharmacokinetic analysis was consistent with rapid conversion of S110 into the deoxycytosine analog decitabine that binds and depletes DNA. CONCLUSION: S110 is rapidly converted into decitabine, hypomethylates DNA, and induces HbF in cultured human erythroid progenitors and the baboon pre-clinical model.