Long-Residence Time Peptide Antagonist for the Vasopressin V2 Receptor to Treat Autosomal Dominant Polycystic Kidney Disease.

The dysregulated intracellular cAMP in the kidneys drives cystogenesis and progression in autosomal dominant polycystic kidney disease (ADPKD). Mounting evidence supports that vasopressin V2 receptor (V2R) antagonism effectively reduces cAMP levels, validating this receptor as a therapeutic target. Tolvaptan, an FDA-approved V2R antagonist, shows limitations in its clinical efficacy for ADPKD treatment. Therefore, the pursuit of better-in-class V2R antagonists with an improved efficacy remains pressing. Herein, we synthesized a set of peptide V2R antagonists. Peptide 33 exhibited a high binding affinity for the V2R (Ki = 6.1 ± 1.5 nM) and an extended residence time of 20 ± 1 min, 2-fold that of tolvaptan. This prolonged interaction translated into sustained suppression of cAMP production in washout experiments. Furthermore, peptide 33 exhibited improved efficacies over tolvaptan in both ex vivo and in vivo models of ADPKD, underscoring its potential as a promising lead compound for the treatment of ADPKD.

Vasopressin V2 receptor, tolvaptan, and ERK1/2 phosphorylation in the renal collecting duct.

Tolvaptan, a vasopressin antagonist selective for the V2-subtype vasopressin receptor (V2R), is widely used in the treatment of hyponatremia and autosomal-dominant polycystic kidney disease (ADPKD). Its effects on signaling in collecting duct cells have not been fully characterized. Here, we perform RNA-seq in a collecting duct cell line (mpkCCD). The data show that tolvaptan inhibits the expression of mRNAs that were previously shown to be increased in response to vasopressin including aquaporin-2, but also reveals mRNA changes that were not readily predictable and suggest off-target actions of tolvaptan. One such action is activation of the MAPK kinase (ERK1/ERK2) pathway. Prior studies have shown that ERK1/ERK2 activation is essential in the regulation of a variety of cellular and physiological processes and can be associated with cell proliferation. In immunoblotting experiments, we demonstrated that ERK1/ERK2 phosphorylation in mpkCCD cells was significantly reduced by vasopressin, in contrast to the increases seen in non-collecting-duct cells overexpressing V2R in prior studies. We also found that tolvaptan has a strong effect to increase ERK1/ERK2 phosphorylation in the presence of vasopressin and that tolvaptan's effect to increase ERK1/ERK2 phosphorylation is absent in mpkCCD cells in which both protein kinase A (PKA)-catalytic subunits have been deleted. Thus, it appears that the tolvaptan effect to increase ERK activation is PKA-dependent and is not due to an off-target effect of tolvaptan. We conclude that in cells expressing V2R at endogenous levels: 1) vasopressin decreases ERK1/ERK2 activation; 2) in the presence of vasopressin, tolvaptan increases ERK1/ERK2 activation; and 3) these effects are PKA-dependent.NEW & NOTEWORTHY Vasopressin is a key hormone that regulates the function of the collecting duct of the kidney. ERK1 and ERK2 are enzymes that play key roles in physiological regulation in all cells. The authors used collecting duct cell cultures to investigate the effects of vasopressin and the vasopressin receptor antagonist tolvaptan on ERK1 and ERK2 phosphorylation and activation.

Tolvaptan reduces angiotensin II-induced experimental abdominal aortic aneurysm and dissection.

Tolvaptan has been approved for the treatment of autosomal dominant polycystic kidney disease and heart failure. However, the role of tolvaptan in patients with abdominal aortic aneurysm (AAA) has not been examined. Human aortic smooth muscle cells (HASMCs) were used as the in vitro model. Via Ang II infusion, experimental AAAs were induced in Apo-E knockout mice. In vitro study showed that tolvaptan suppressed matrix metalloproteinase (MMP) expressions (MMP-2 and MMP-9) and apoptosis in Ang II-stimulated HASMCs. In the Apo-E knockout mice with Ang II-induced AAA, the animals exhibited AAA formation with elastic lamina degradation, dilatation of the suprarenal aorta, increased macrophage infiltration and higher expressions of MMPs. Treatment with a high dose of tolvaptan prevented experimental AAA formation while preserving the elastic lamina structure, reducing inflammatory macrophages, and inhibiting gelatinolytic activity, MMP expressions and apoptosis of SMCs in aorta tissue. Specifically, tolvaptan reduced the expression of receptor-interacting protein kinase 3 (RIP3) and decreased apoptosis of SMCs. Our data demonstrated that tolvaptan reduces experimental AAA formation and dissection by inhibiting destruction of the aortic structure integrity and reducing inflammatory macrophage infiltration, MMP-2 and MMP-9 expressions, and apoptosis of vascular SMCs, indicating tolvaptan may have therapeutic potential for AAA and dissection.

Regulatory guidelines do not accurately predict tolvaptan and metabolite interactions at BCRP, OATP1B1, and OAT3 transporters.

Tolvaptan (TLV) was US Food and Drug Administration (FDA)-approved for the indication to slow kidney function decline in adults at risk of rapidly progressing autosomal dominant polycystic kidney disease in 2018. In vitro, TLV was a breast cancer resistance protein (BCRP) inhibitor, whereas the oxobutyric acid metabolite of TLV (DM-4013) was an inhibitor of organic anion transport polypeptide (OATP)1B1 and organic anion transporter (OAT)3. Based on the 2017 FDA guidance, potential for clinically relevant inhibition at these transporters was indicated for the highest TLV regimen. Consequently, two postmarketing clinical trials in healthy subjects were required. In trial 1, 5 mg rosuvastatin calcium (BCRP and OATP1B1 substrate) was administered alone, with 90 mg TLV or 48 h following 7 days of once daily 300 mg TLV (i.e., in the presence of DM-4103). In trial 2, 40 mg furosemide (OAT3 substrate) was administered alone and in presence of DM-4103. For BCRP, rosuvastatin geometric mean ratios (90% confidence intervals [CIs]) for maximum plasma concentration (Cmax ) were 1.54 (90% CI 1.26-1.88) and for area under the concentration-time curve from time 0 to the time of the last measurable concentration (AUCt ) were 1.69 (90% CI 1.34-2.14), indicating no clinically significant interaction. DM-4103 produced no clinically meaningful changes in rosuvastatin or furosemide concentrations, indicating no inhibition at OATP1B1 or OAT3. The BCRP prediction assumed the drug dose is completely soluble in 250 ml; TLV has solubility of ~0.01 g/250 ml. For OATP1B1/OAT3, if fraction unbound for plasma protein binding (PPB) is less than 1%, then 1% is assumed. DM-4103 has PPB greater than 99.8%. Use of actual drug substance solubility and unbound fraction in plasma would have produced predictions consistent with the clinical results.

Tolvaptan- and Tolvaptan-Metabolite-Responsive T Cells in Patients with Drug-Induced Liver Injury.

Tolvaptan is an effective drug for the treatment of autosomal dominant polycystic kidney disease, but its use is associated with a significant risk of liver injury in a small number of patients. Herein we describe the presence of tolvaptan- and tolvaptan-metabolite-responsive T cell clones within the peripheral circulation of patients with liver injury. Drug treatment of the clones resulted in a proliferative response and secretion of IFN-γ, IL-13, and the cytolytic molecule granzyme B. Future work should explore pathways of tolvaptan driven T cell activation and the role of T cells in the disease pathogenesis.

Experiencia clínica con distintas dosis iniciales de tolvaptán en SIADH / Clinical experience with different initial doses of tolvaptan in SIADH

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Validated liquid chromatography coupled to tandem mass spectrometry method for simultaneous quantitation of tolvaptan and its five major metabolites in human plasma.

BACKGROUND: Tolvaptan is converted to major metabolites including three monohydroxylates (DM-4110, DM-4111 and DM-4119), an oxidate (MOP-21826) and a carboxylate (DM-4103) in humans. This study developed a simultaneous quantitative method for tolvaptan and its five major metabolites in human plasma using liquid chromatography coupled to tandem mass spectrometry. METHODS: Deproteinized plasma specimens using acetonitrile were separated using a 3- µm particle size octadecylsilyl column with 250 mm length and a simple linear gradient program at a flow rate of 0.3 mL/min with a total run time of 15 min. This method was applied to the determination of plasma samples collected from 20 heart failure patients treated with 3.75-15 mg tolvaptan. RESULTS: No interfering peak was found in drug-free plasma specimens. The calibration curves of tolvaptan, DM-4110, DM-4111, DM-4119, MOP-21826 and DM-4103 were linear over the concentration ranges of 3.125-1000, 0.3125-100, 1.25-400, 0.625-200, 0.125-40 and 31.25-10,000 ng/mL, respectively. Their pretreatment recovery rates and matrix factors were 94.1-113.9% and 86.9-108.0%, respectively. The intra- and inter-day accuracies and imprecisions were 91.6-106.5% and 0.9-10.9%, respectively, for all analytes. The plasma concentration ranges of tolvaptan, DM-4110, DM-4111, DM-4119, MOP-21826 and DM-4103 were 9.37-280, 1.91-16.3, 3.43-88.9, 1.43-10.4, 0.160-1.01 and 40.2-1471 ng/mL, respectively, in heart failure patients. CONCLUSIONS: This validated method with acceptable analytical performance can be utilized for evaluating the pharmacokinetics of oral tolvaptan, including the determination of its major metabolites, in heart failure patients.

Altered Hepatobiliary Disposition of Tolvaptan and Selected Tolvaptan Metabolites in a Rodent Model of Polycystic Kidney Disease.

Tolvaptan, a vasopressin V2-receptor antagonist, has demonstrated efficacy in slowing kidney function decline in patients with autosomal dominant polycystic kidney disease (ADPKD). In the pivotal clinical trial, the incidence of elevated liver enzymes was higher in patients receiving tolvaptan compared with placebo. Adjudication by a panel of expert hepatologists concluded a causal link of tolvaptan to liver injury in patients with ADPKD. An ex situ isolated perfused liver (IPL) study of tolvaptan disposition was undertaken in a rodent model of ADPKD, the polycystic kidney (PCK) rat (n = 5), and compared with wild-type (WT) Sprague-Dawley rats (n = 6). Livers were perfused with tolvaptan, followed by a tolvaptan-free washout phase. Total recovery (mean ± S.D. percentage of dose; PCK vs. WT) of tolvaptan and two metabolites, DM-4103 and DM-4107, quantified by liquid chromatography-tandem mass spectroscopy, was 58.14% ± 24.72% vs. 43.40% ± 18.11% in liver, 20.10% ± 9.15% vs. 21.17% ± 12.51% in outflow perfusate, and 0.08% ± 0.01% vs. 0.39% ± 0.32% in bile. DM-4103 recovery (mean ± S.D. percentage of dose) was decreased in PCK vs. WT bile (<0.01% ± <0.01% vs. 0.02% ± 0.01%; P = 0.0037), and DM-4107 recovery was increased in PCK vs. WT outflow perfusate (1.60% ± 0.57% vs. 0.43% ± 0.29%; P = 0.0017). A pharmacokinetic compartmental model assuming first-order processes was developed to describe the rate vs. time profiles of tolvaptan and DM-4103 + DM-4107 in rat IPLs. The model-derived estimate of tolvaptan's biliary clearance was significantly decreased in PCK compared with WT IPLs. The model predicted greater hepatocellular concentrations of tolvaptan and DM-4103 + DM-4107 in PCK compared with WT IPLs. Increased hepatocellular exposure to tolvaptan and metabolites may contribute to the hepatotoxicity in patients with ADPKD treated with tolvaptan.