Effect of food on the pharmacokinetics of darexaban, an oral direct factor Xa inhibitor, in healthy Japanese subjects.

BACKGROUND: Darexaban is a potent direct factor Xa (FXa) inhibitor developed for prophylaxis of venous and arterial thromboembolic disease. This drug is rapidly and extensively metabolized to darexaban glucuronide (YM-222714), which is a pharmacologically active metabolite. The potential effects of food on the harmacokinetics of darexaban glucuronide after darexaban administration were assessed in two studies. METHODS: Both studies were conducted as open-label, two-way crossover studies. Healthy non-elderly Japanese male subjects received darexaban as a single 15 mg tablet (Study 1, n = 24) or a single 30 mg tablet (Study 2, n = 24). The geometric mean ratio (GMR) (fed/fasted) for AUClast and Cmax were evaluated as primary parameters. RESULTS: GMR(fed/fasted) for AUClast emonstrated slight decreases as 0.797 (90% CI: 0.758 - 0.838) in Study 1 and 0.821 (90% CI: 0.752 - 0.896) in Study 2. For Cmax, the GMR was 0.908 (90%CI: 0.835 - 0.988) in Study 1 and 1.039 (90% CI: 0.953 - 1.131) in Study 2. There were no serious adverse events during the two studies. None was considered to be drug-related. CONCLUSION: These studies demonstrated that there was no clinically significant effect of food on the pharmacokinetics after administration of darexaban. We therefore conclude that darexaban can be administered without regard to food intake.

Single- and Multiple-dose Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of ASP1128, a Novel Peroxisome Proliferator-activated Receptor δ Modulator, in Healthy Participants.

Peroxisome proliferator-activated receptor δ (PPARδ) plays a central role in modulating mitochondrial function in ischemia-reperfusion injury. ASP1128, a potent and selective modulator of PPARδ, is currently under investigation for treating acute kidney injury. This randomized, first-in-human study assessed the safety, tolerability, pharmacokinetics, and pharmacodynamics of ASP1128 administered intravenously in healthy participants. Forty-nine participants received a single dose of ASP1128 0.3-10 mg (n = 37) or placebo (n = 12) and 53 received daily (7 days) doses of ASP1128 3-100 mg (n = 39) or placebo (n = 14), including a cohort aged ≥65 years (ASP1128 100 mg, n = 3; placebo, n = 2). Treatment-emergent adverse events occurred in 37.8%, 59.0%, and 33.3%-35.7% of participants in the single ASP1128, multiple ASP1128, and placebo groups, respectively. All were mild in severity, and the frequency of adverse events did not appear to be dose-related. One participant (multiple ASP1128 3 mg group) withdrew with an infusion site erythema, possibly related to study drug. Exposure was roughly dose-proportional, and elimination was generally consistent across doses (mean t½ 14.6-17.4 hours in the 10, 30, and 100 mg groups on day 7). There was little accumulation in plasma following multiple dosing; steady state was reached after ∼4 days. ASP1128 treatment led to rapid and dose-related upregulation of six fatty acid oxidation-related PPARδ target genes at ≥10 mg, which lasted >24 hours postdose. In conclusion, single and multiple intravenous doses of ASP1128 were generally well tolerated, with dose-dependent pharmacokinetics and target gene engagement in healthy participants.

A phase I, open-label, single-dose micro tracer mass balance study of 14C-labeled ASP7991 in healthy Japanese male subjects using accelerator mass spectrometry.

ASP7991 is a calcimimetic that acts on the calcium-sensing receptor on parathyroid cell membranes and suppresses parathyroid hormone (PTH) secretion in the treatment of secondary hyperparathyroidism. The mass balance and metabolite profile of [14C]ASP7991 were investigated in six healthy male subjects after a single oral dose of [14C]ASP7991 [1 mg, 18.5 kBq (500 nCi)] in solution. [14C] radioactivity in plasma, urine and feces was analyzed using Accelerator mass spectrometry. ASP7991 was rapidly absorbed, metabolized and excreted. Mean recovery of [14C] radioactivity in urine and feces was 30.08% and 49.31%, respectively, and mean total recovery of [14C] radioactivity was 79.39%. The majority of [14C] radioactivity in urine and feces was excreted within the first 72 h following administration. Seven metabolites were detected in plasma, urine and feces samples, and their structures were determined by mass spectrometry. The main metabolic pathways of ASP7991 in humans were predicted to be N-dealkylation, followed by N-acetylation and taurine conjugation to a carboxylic acid moiety. Our findings show that a mass balance study using micro radioactivity doses is suitable for elucidating the pharmacokinetics of the absorption, metabolism and excretion of administered drugs.

NPT-IIb Inhibition Does Not Improve Hyperphosphatemia in CKD.

INTRODUCTION: Serum phosphate levels are insufficiently controlled in many patients with end-stage renal disease (ESRD), and novel therapeutic strategies are needed. Blocking intestinal phosphate absorption mediated by sodium-dependent phosphate co-transporter type 2b (NPT-IIb) holds promise; thus, we evaluated the efficacy, safety, tolerability, and pharmacokinetics of the novel and specific small molecule NPT-IIb inhibitor ASP3325 for the first time in humans. METHODS: We conducted a randomized, double-blind, placebo-controlled, phase 1a single (n = 88) and multiple (n = 36) ascending dose study in healthy subjects, and a randomized, open-label, uncontrolled, phase 1b study in hyperphosphatemic ESRD patients on hemodialysis (single oral dose, n = 5; multiple oral doses, n = 17). Primary efficacy measures were urinary phosphate and fecal phosphorous excretion (healthy subjects) and serum phosphate level (ESRD patients). RESULTS: No time- or dose-dependent changes in urinary phosphate or fecal phosphorous excretion were observed following single/multiple ASP3325 doses for 7 days in healthy subjects. In ESRD patients, ASP3325 administered 3 times daily for 2 weeks before or after a meal did not reduce serum phosphate levels. ASP3325 was safe and well tolerated in both populations. CONCLUSION: NPT-IIb inhibition with ASP3325 was not effective in reducing serum phosphate levels in ESRD patients. The relevance of NPT-IIb in humans and feasibility of oral NPT-IIb inhibitors for treatment of hyperphosphatemia in ESRD remain uncertain.

Clinical pharmacokinetics and pharmacodynamics of the novel SGLT2 inhibitor ipragliflozin.

Ipragliflozin (Suglat(®)) is a potent and selective inhibitor of sodium-glucose cotransporter-2 that was recently launched in Japan. Its mechanism of action involves the suppression of glucose re-absorption in the kidney proximal tubules, causing excretion of glucose in the urine. The aim of this review is to provide a comprehensive overview of currently available pharmacokinetic and pharmacodynamic data on ipragliflozin, including studies in healthy subjects, patients with type 2 diabetes mellitus and special populations. In single- and multiple-dose studies, the maximum plasma concentration and area under the plasma concentration-time curve (AUC) for ipragliflozin increased in a dose-dependent manner. Although urinary excretion of ipragliflozin is low (approximately 1 %), tubular concentration of free ipragliflozin is adequate to provide pharmacological activities. No clinically relevant effects of age, gender or food on the exposure of ipragliflozin were observed. The AUC for ipragliflozin was 20-30 % greater in patients with moderate renal or hepatic impairment than in patients with normal renal or hepatic function. In drug-drug interaction studies, the pharmacokinetics of ipragliflozin and other oral antidiabetic drugs (metformin, sitagliptin, pioglitazone, glimepiride, miglitol and mitiglinide) were not significantly affected by their co-administration. Urinary glucose excretion (UGE) also increased in a dose-dependent manner, approaching a maximum effect at 50-100 mg dosages in Japanese healthy volunteers and patients with type 2 diabetes. The change in UGE from baseline (ΔUGE) tended to be lower in older subjects and female subjects, compared with younger subjects and male subjects, respectively. ΔUGE tended to decrease with decreasing renal function, especially in patients with type 2 diabetes with moderate or severe renal impairment.

Prodrug-based design, synthesis, and biological evaluation of N-benzenesulfonylpiperidine derivatives as novel, orally active factor Xa inhibitors.

We describe here our investigation of a new series of orally active fXa inhibitors based on a prodrug strategy. Solid-phase parallel synthesis identified a unique series of fXa inhibitors with a substituted benzenesulfonyl group as a novel S4 binding element. This series resulted in compound 39, which exhibited potent inhibitory activity against fXa (IC50 = 13 nM) and excellent selectivity over thrombin (>7000-fold). The masking of its highly hydrophilic groups led to the creation of related prodrug 28, which demonstrated an anticoagulant effect after oral dosing.

Synthesis and biological activity of novel 1,2-disubstituted benzene derivatives as factor Xa inhibitors.

Factor Xa (fXa) is a serine protease that plays a pivotal role in the coagulation cascade. High-throughput screening of the Yamanouchi compound library yielded lead compound 1 with the ability to inhibit fXa at micromolar concentrations. To improve its fXa inhibitory activity and its oral anticoagulant activity, the linker between benzamidine and the central benzene ring was modified and a carboxyl group was introduced at the central benzene ring. The resulting compounds 40b (YM-203552), 41a (YM-202054), and 41c (YM-203558) exhibited potent fXa inhibitory activity and oral anticoagulant activity. In particular, YM-203558 exhibited the most potent oral anticoagulant activity, prolonging PT more than 3-fold at 0.5 and 2.0 h. Additionally, these compounds showed a high degree of selectivity for other serine proteases.

Synthesis and biological activity of novel 1,4-diazepane derivatives as factor Xa inhibitor with potent anticoagulant and antithrombotic activity.

Factor Xa (fXa) is a serine protease involved in the coagulation cascade, which has received great interest as a potential target for the development of new antithrombotic drugs. Herein we report a novel series of fXa inhibitors in which the 1,4-diazepane moiety was designed to interact with the S4 aryl-binding domain of the fXa active site. Compound 13 (YM-96765) showed potent fXa inhibitory activity (IC(50) = 6.8 nM) and effective antithrombotic activity without prolonging bleeding time.

The discovery of YM-60828: a potent, selective and orally-bioavailable factor Xa inhibitor.

Since Factor Xa (FXa) is well known to play a central role in thrombosis and hemostasis, inhibition of FXa is an attractive target for antithrombotic strategies. As a part of our investigation of a non-peptide, orally available FXa inhibitor, we found that a series of N-[(7-amidino-2-naphthyl)methyl]aniline derivatives possessed potent and selective inhibitory activities. Structure--activity relationship (SAR) of the substituent (R(1)) on the central aniline moiety suggested that increasing lipophilicity caused a detrimental effect on anticoagulant activity (prothrombin time assay) in plasma. Several compounds bearing a hydrophilic substituent in R(1) showed not only potent FXa inhibitory activities but also high anticoagulant activities. The best compound in this series was sulfamoylacetic acid derivative (YM-60828) which was a potent, selective and orally bioavailable FXa inhibitor and was chosen for clinical development.

Design, synthesis and biological activity of YM-60828 derivatives: potent and orally-bioavailable factor Xa inhibitors based on naphthoanilide and naphthalensulfonanilide templates.

Factor Xa (FXa) is a serine protease which plays a pivotal role in the coagulation cascade. The inhibition of FXa has received great interest as a potential target for the development of new antithrombotic drug. Herein we describe a series of novel 7-amidino-2-naphthoanilide and 7-amidino-2-naphthalensulfonanilide derivatives which are potent FXa inhibitors. These scaffolds are rigid and are allowed to adopt an L-shape conformation which was estimated as the active conformation based on a docking study of YM-60828 with FXa. Optimization of the side chain at the central aniline nitrogen of 7-amidino-2-naphthoanilide has led to several potent and orally active FXa inhibitors. 5h (YM-169964), the best compound of these series, showed potent FXa inhibitory activity (IC(50)=3.9nM) and effectively prolonged prothrombin time by 9.6-fold ex vivo at an oral dose of 3mg/kg in squirrel monkeys.

Design, synthesis and biological activity of YM-60828 derivatives. Part 2: potent and orally-bioavailable factor Xa inhibitors based on benzothiadiazine-4-one template.

Compound YM-60828 was previously characterized in our laboratory as a potent, selective and orally-bioavailable Factor Xa (FXa) inhibitor. The L-shape conformation of this compound in the active site of FXa was recognized as an important factor in displaying its FXa inhibitory activity. This led to the exploration of conformationally restricted cyclic scaffolds bearing a similar active conformation. The current study investigated a novel series of benzothiadiazine-4-one based compounds as FXa inhibitors. Structure-activity relationship (SAR) investigations revealed some potent FXa inhibitors that were selected for further in vitro and ex vivo anticoagulant studies. Among them, compound 6j (YM-169920) was proved to be most effective anticoagulant in this series. The synthesis and SAR in addition to docking studies of this class of inhibitors are described.

Orally active factor Xa inhibitor: synthesis and biological activity of masked amidines as prodrugs of novel 1,4-diazepane derivatives.

Factor Xa (fXa) is a serine protease, which plays a pivotal role in the coagulation cascade. To improve the oral anticoagulant activity of fXa inhibitors containing a 1,4-diazepane moiety as the P4 part, a prodrug strategy was examined. Among the compounds evaluated in this study, amidoxime prodrugs bearing an ester moiety, such as compounds 21 and 30, showed effective oral anticoagulant activity in mice.