Effect of anti-claudin 18.2 monoclonal antibody zolbetuximab alone or combined with chemotherapy or programmed cell death-1 blockade in syngeneic and xenograft gastric cancer models.

The development of targeted cancer therapies based on monoclonal antibodies against tumor-associated antigens has progressed markedly over recent decades. This approach is dependent on the identification of tumor-specific, normal tissue-sparing antigenic targets. The transmembrane protein claudin-18 splice variant 2 (CLDN18.2) is frequently and preferentially displayed on the surface of primary gastric adenocarcinomas, making it a promising monoclonal antibody target. Phase 3 studies of zolbetuximab, a chimeric immunoglobulin G1 monoclonal antibody targeting CLDN18.2, combined with 5-fluorouracil/leucovorin plus oxaliplatin (modified FOLFOX6) or capecitabine plus oxaliplatin (CAPOX) in advanced or metastatic first-line gastric or gastroesophageal junction (G/GEJ) adenocarcinoma have demonstrated favorable clinical results with zolbetuximab. In studies using xenograft or syngeneic models with gastric cancer cell lines, zolbetuximab mediated death of CLDN18.2-positive human cancer cell lines via antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity in vitro and demonstrated anti-tumor efficacy as monotherapy and combined with chemotherapy in vivo. Mice treated with zolbetuximab plus chemotherapy displayed a significantly higher frequency of tumor-infiltrating CD8+ T cells versus vehicle/isotype control-treated mice. Furthermore, zolbetuximab combined with an anti-mouse programmed cell death-1 antibody more potently inhibited tumor growth compared with either agent alone. These results support the potential of zolbetuximab as a novel treatment option for G/GEJ adenocarcinoma.

Comparison of Pharmacokinetic Profiles of Beraprost Sustained Release in Japanese, Chinese, and Korean Healthy Adult Males.

BACKGROUND AND OBJECTIVES: Beraprost sodium (BPS), an orally administrable prostaglandin I2 derivative, is used for the treatment of chronic arterial occlusion and pulmonary arterial hypertension and has potential efficacy in nephropathy. Beraprost sustained release (beraprost SR) is an oral sustained-release formulation of BPS. To confirm the dose rationale reported in a multi-regional study of nephropathy patients in Asia, this open-label study evaluated ethnic differences in the pharmacokinetic profiles of BPS and its active diastereomer (BPS-314d) after beraprost SR administration among healthy Japanese, Chinese, and Korean adult males. METHODS: Twelve healthy subjects in each ethnic group were enrolled. Subjects received a single oral dose of 120 µg beraprost SR under fasting conditions. RESULTS: The geometric mean ratio (90% confidence interval) of the maximum plasma concentration (Cmax) and area under the plasma concentration-time curve from time 0 to time of the last quantifiable concentration (AUClast) of BPS was 1.12 (0.85-1.48) and 1.40 (1.05-1.86) in Chinese, and 1.18 (0.90-1.55) and 1.18 (0.89-1.58) in Korean compared to Japanese subjects. These differences were not clinically relevant. Similarly, differences in the Cmax and AUClast of BPS-314d were also small among the ethnic groups. Urinary excretion of BPS and BPS-314d was limited in all ethnic groups. Together, these findings indicate that the pharmacokinetics of beraprost SR are not affected by ethnic background. CONCLUSIONS: There were no clinically meaningful ethnic differences in the pharmacokinetics of BPS and BPS-314d following beraprost SR administration among Japanese, Chinese and Korean populations.

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.

The Pharmacokinetics of Beraprost Sodium Following Single Oral Administration to Subjects With Impaired Kidney Function.

The purpose of the present study was to evaluate the pharmacokinetics of beraprost sodium (BPS) and its active enantiomer, BPS-314d, in Japanese subjects with impaired kidney function. The plasma and urine concentrations of BPS and BPS-314d were measured following the single oral administration of 120 µg of BPS as the sustained-release tablet, TRK-100STP, under fasting conditions to 18 subjects with impaired kidney function (stage 2, 3, and 4 chronic kidney disease [CKD] as categorized by the estimated glomerular filtration rate) and to 6 age-, body weight-, and gender-matched subjects with normal kidney function (stage 1 CKD). The Cmax values (mean ± SD) of BPS in stage 1, 2, 3, and 4 CKD, respectively, were 84.9 ± 22.9, 119.8 ± 36.4, 190.6 ± 137.3, and 240.2 ± 110.5 pg/mL; its AUC0-48h were 978 ± 226, 1252 ± 427, 1862 ± 964, and 1766 ± 806 pg·h/mL, respectively, and its cumulative urinary excretion rates were 0.704 ± 0.351%, 0.638 ± 0.292%, 0.485 ± 0.294%, and 0.159 ± 0.136%. The Cmax values of BPS-314d were 22.4 ± 6.4, 30.8 ± 8.5, 46.7 ± 30.6, and 54.4 ± 25.2 pg/mL, its AUC0-48h were 155 ± 56, 226 ± 67, 341 ± 176, and 329 ± 143 pg·h/mL, and its cumulative urinary excretion rates were 0.428 ± 0.242%, 0.349 ± 0.179%, 0.356 ± 0.270%, and 0.096 ± 0.099%, respectively. Adverse events were reported in 2 subjects with stage 2 CKD and 1 subject with stage 4 CKD. The Cmax and AUC0-48h of BPS and BPS-314d were higher based on the severity of impaired kidney function. No relationship was observed between the incidence of adverse events and the severity, and tolerability was confirmed. We consider that dose adjustment is not necessary, but BPS is more carefully treated in patients with impaired kidney function.

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.

Identification of HMG-CoA reductase inhibitors as activators for human, mouse and rat constitutive androstane receptor.

Constitutive active (or androstane) receptor (CAR, NR1I3), a member of the nuclear receptor family, is a major regulator for induction of cytochrome P450 2B (CYP2B) genes by phenobarbital. Phenobarbital-like inducer, 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene is a potent mouse CAR ligand that has been used to study CAR target genes in mice but does not activate human CAR (hCAR) or rat CAR (rCAR). Although 6-(4-chlorophenyl) imidazo[2,1-b][1,3]thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime (CITCO) was reported to be an hCAR agonistic ligand, activation of hCAR by CITCO in cell-based reporter assay was weak. Therefore, we performed a screening of 50 drugs and chemicals using cell-based reporter assays to identify activators of hCAR. Among them, HMG-CoA reductase inhibitors (cerivastatin, simvastatin, fluvastatin, and atorvastatin) enhanced the hCAR-mediated transcriptional activation of phenobarbital-responsive enhancer module reporter gene by up to 3-fold. Similar activation by HMG-CoA reductase inhibitors was also observed with mouse and rat CARs. On the other hand, pravastatin did not activate hCAR at the concentrations tested (up to 30 microM). The extent of activation by the HMG-CoA reductase inhibitors was stronger than that by CITCO. Cerivastatin, simvastatin, fluvastatin, and atorvastatin induced CYP2B6 mRNA in stable hCAR-expressed FLC7 cells but not in original FLC7 cells. Therefore, we concluded that CAR mediates the effects of HMG-CoA reductase inhibitors on the induction of CYP2B genes, although HMG-CoA reductase inhibitors also activate pregnane X receptor. HMG-CoA reductase inhibitors such as cerivastatin would be useful to study for elucidating molecular and cellular mechanisms of hCAR.