Assessing Pharmacokinetics and Safety of Therapeutic Alpha-1-Microglobulin in First-in-Human Kidney Transplantation: A Noncomparative Open-Label Multiple-Dose Phase 1b Study.

Background: RMC-035 is a modified version of alpha-1-microglobulin, an endogenous protein developed as a renoprotective agent. Its intended use is to reduce the risk of irreversible loss of kidney function in cardiac surgery patients and to reduce delayed graft function in kidney transplant recipients. This first-in-human study aimed to evaluate the pharmacokinetics and safety of RMC-035 in kidney transplant recipients.

Efficacy and safety of therapeutic alpha-1-microglobulin RMC-035 in reducing kidney injury after cardiac surgery: a multicentre, randomised, double-blind, parallel group, phase 2a trial.

Background: Cardiac surgery invariably triggers acute kidney stress causing adverse renal outcomes. The AKITA study evaluated the efficacy and safety of RMC-035, a novel analogue of alpha-1-microglobulin, for reducing cardiac surgery-associated kidney injury.

Methods: In this randomised double-blind placebo-controlled phase 2a study, we randomly assigned (1:1) adult hospitalised patients undergoing open-chest cardiac surgery at high risk for acute kidney injury (AKI) at 21 sites in North America and Europe to receive either RMC-035 (1.

Therapeutic α-1-microglobulin ameliorates kidney ischemia-reperfusion injury.

α-1-Microglobulin (A1M) is a circulating glycoprotein with antioxidant, heme-binding, and mitochondrial protection properties. The investigational drug RMC-035, a modified therapeutic A1M protein, was assessed for biodistribution and pharmacological activity in a broad set of in vitro and in vivo experiments, supporting its clinical development. Efficacy and treatment posology were assessed in various models of kidney ischemia and reperfusion injury (IRI).

Study protocol of a phase 2, randomised, placebo-controlled, double-blind, adaptive, parallel group clinical study to evaluate the efficacy and safety of recombinant alpha-1-microglobulin in subjects at high risk for acute kidney injury following open-chest cardiac surgery (AKITA trial).

Introduction: Acute kidney injury (AKI) is a common complication after cardiac surgery (CS) and is associated with adverse short-term and long-term outcomes. Alpha-1-microglobulin (A1M) is a circulating glycoprotein with antioxidant, heme binding and mitochondrial-protective mechanisms. RMC-035 is a modified, more soluble, variant of A1M and has been proposed as a novel targeted therapeutic protein to prevent CS-associated AKI (CS-AKI).

A Transgenic Model Reveals the Role of Klotho in Pancreatic Cancer Development and Paves the Way for New Klotho-Based Therapy.

Klotho is an anti-aging transmembrane protein, which can be shed and can function as a hormone. Accumulating data indicate that klotho is a tumor suppressor in a wide array of malignancies, and designate the subdomain KL1 as the active region of the protein towards this activity. We aimed to study the role of klotho as a tumor suppressor in pancreatic ductal adenocarcinoma (PDAC).

Longitudinal change in c-terminal fibroblast growth factor 23 and outcomes in patients with advanced chronic kidney disease.

Background: Fibroblast growth factor23 (FGF23) is elevated in CKD and has been associated with outcomes such as death, cardiovascular (CV) events and progression to Renal Replacement therapy (RRT). The majority of studies have been unable to account for change in FGF23 over time and those which have demonstrate conflicting results. We performed a survival analysis looking at change in c-terminal FGF23 (cFGF23) over time to assess the relative contribution of cFGF23 to these outcomes.

Population pharmacokinetics and pharmacodynamics of a novel vascular adhesion protein-1 inhibitor using a multiple-target mediated drug disposition model.

ASP8232 is a novel inhibitor of vascular adhesion protein-1 that was under evaluation for reducing residual albuminuria in patients with diabetic kidney disease. To characterize the pharmacokinetics (PK) of ASP8232 and its effect on vascular adhesion protein 1 (VAP-1) plasma activity and VAP-1 concentrations (pharmacodynamics, PD) in an integrated and quantitative manner, a target mediated drug disposition model was developed based on pooled data from four completed clinical trials with ASP8232 in healthy volunteers, and in patients with diabetic kidney disease and diabetic macular edema, respectively. In this model, the binding of ASP8232 to its soluble and membrane-bound target in the central and peripheral compartments were included.

Mechanism-based modeling of the effect of a novel inhibitor of vascular adhesion protein-1 on albuminuria and renal function markers in patients with diabetic kidney disease.

The vascular adhesion protein-1 (VAP-1) inhibitor ASP8232 reduces albuminuria in patients with type 2 diabetes and chronic kidney disease. A mechanism-based model was developed to quantify the effects of ASP8232 on renal markers from a placebo-controlled Phase 2 study in diabetic kidney disease with 12 weeks of ASP8232 treatment. The model incorporated the available pharmacokinetic, pharmacodynamic (plasma VAP-1 concentration and activity), serum and urine creatinine, serum cystatin C, albumin excretion rate, urinary albumin-to-creatinine ratio, and urine volume information in an integrated manner.

Carbazate modified dextrans as scavengers for carbonylated proteins.

A series of biocompatible and non- toxic polysaccharide molecules have been successfully fabricated and explored their potential application for scavenging the carbonyl species in vitro. These macromolecules were dextrans with different hydrazide substitution ratios determined by TNBS assay, NMR and FTIR characterization. The colorimetric assay had demonstrated that these macromolecules could effectively scavenge acrolein, oxidized bovine serum albumin (BSA) in buffer solutions as well as carbonyl proteins from serum.

Weak acidic stable carbazate modified cellulose membranes target for scavenging carbonylated proteins in hemodialysis.

Carbazate groups were grafted on the commercial cellulose membrane (CM) to specifically scavenge the carbonylated proteins for hemodialysis. It confirmed that carbazate groups were successfully covalently attached on the CMs by XPS and EDS, and the modified CMs still saved their original morphology and crystalline structures by SEM and XRD. Furthermore, the modified CMs presented favorable physicochemical stability at wide pH range from 2.

Klotho controls the brain-immune system interface in the choroid plexus.

Located within the brain's ventricles, the choroid plexus produces cerebrospinal fluid and forms an important barrier between the central nervous system and the blood. For unknown reasons, the choroid plexus produces high levels of the protein klotho. Here, we show that these levels naturally decline with aging.

Efficacy of a novel inhibitor of vascular adhesion protein-1 in reducing albuminuria in patients with diabetic kidney disease (ALBUM): a randomised, placebo-controlled, phase 2 trial.

Background: Many patients with diabetic kidney disease have residual albuminuria and are at risk of disease progression. The ALBUM trial investigated the efficacy of a novel, orally active inhibitor of vascular adhesion protein-1, ASP8232, compared with placebo for reducing albuminuria in individuals with type 2 diabetes and chronic kidney disease.

Methods: In this randomised, double-blind, placebo-controlled phase 2 trial, we randomly assigned individuals (aged 18-85 years) from 64 clinical sites in nine European countries to receive ASP8232 40 mg or placebo orally once daily for 12 weeks using a web-based randomisation schedule (block size 4), stratified by country.

In vivo evidence for an interplay of FGF23/Klotho/PTH axis on the phosphate handling in renal proximal tubules.

Phosphate homeostasis is primarily maintained in the renal proximal tubules, where the expression of sodium/phosphate cotransporters (Npt2a and Npt2c) is modified by the endocrine actions of both fibroblast growth factor 23 (FGF23) and parathyroid hormone (PTH). However, the specific contribution of each regulatory pathway in the proximal tubules has not been fully elucidated in vivo. We have previously demonstrated that proximal tubule-specific deletion of the FGF23 coreceptor Klotho results in mild hyperphosphatemia with little to no change in serum levels of FGF23, 1,25(OH)D, and PTH.

Interrelated role of Klotho and calcium-sensing receptor in parathyroid hormone synthesis and parathyroid hyperplasia.

The pathogenesis of parathyroid gland hyperplasia is poorly understood, and a better understanding is essential if there is to be improvement over the current strategies for prevention and treatment of secondary hyperparathyroidism. Here we investigate the specific role of Klotho expressed in the parathyroid glands (PTGs) in mediating parathyroid hormone (PTH) and serum calcium homeostasis, as well as the potential interaction between calcium-sensing receptor (CaSR) and Klotho. We generated mouse strains with PTG-specific deletion of Klotho and CaSR and dual deletion of both genes.

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).

Associations of Fibroblast Growth Factor 23 with Markers of Inflammation and Leukocyte Transmigration in Chronic Kidney Disease.

Background: Patients with chronic kidney disease (CKD) show elevated levels of inflammatory markers and have an increased risk of infections as well as cardiovascular morbidity. Recent studies have implied effects of fibroblast growth factor 23 (FGF23) on inflammation in CKD. We analyzed potential correlations between levels of FGF23 with pro-inflammatory chemokines and markers of leukocyte transmigration in CKD patients.

Klotho expression in osteocytes regulates bone metabolism and controls bone formation.

Osteocytes within the mineralized bone matrix control bone remodeling by regulating osteoblast and osteoclast activity. Osteocytes express the aging suppressor Klotho, but the functional role of this protein in skeletal homeostasis is unknown. Here we identify Klotho expression in osteocytes as a potent regulator of bone formation and bone mass.

Tissue expression and source of circulating αKlotho.

αKlotho (Klotho), a type I transmembrane protein and a coreceptor for Fibroblast Growth Factor-23, was initially thought to be expressed only in a limited number of tissues, most importantly the kidney, parathyroid gland and choroid plexus. Emerging data may suggest a more ubiquitous Klotho expression pattern which has prompted reevaluation of the restricted Klotho paradigm. Herein we systematically review the evidence for Klotho expression in various tissues and cell types in humans and other mammals, and discuss potential reasons behind existing conflicting data.

Klotho expression in long bones regulates FGF23 production during renal failure.

Circulating levels of bone-derived fibroblast growth factor 23 (FGF23) increase early during acute and chronic kidney disease and are associated with adverse outcomes. Membrane-bound Klotho acts as a permissive coreceptor for FGF23, and its expression was recently found in osteoblasts/osteocytes. We hypothesized that Klotho in bone cells is part of an autocrine feedback loop that regulates FGF23 expression during renal failure.

FGF-23 and Osteoprotegerin but not Fetuin-A are associated with death and enhance risk prediction in non-dialysis chronic kidney disease stages 3-5.

Aim: Numerous biomarkers have been shown to associate with clinical endpoints in chronic kidney disease (CKD). There is limited evidence whether biomarkers improve risk prediction in relation to clinical outcomes. Our study investigates whether a small suite of key chronic kidney disease-mineral and bone disorder biomarkers could be used to enhance risk assessment in CKD.

In vivo evidence for a limited role of proximal tubular Klotho in renal phosphate handling.

Klotho is a transmembrane protein expressed in the renal tubules where it acts as a permissive coreceptor for fibroblast growth factor 23 (FGF23). FGF23 signaling reduces the abundance of CYP27b1 and phosphate cotransporters NPT2a and NPT2c, leading to a decrease in 1,25(OH)2D3 synthesis and a rise in urinary phosphate excretion, respectively. Systemic or whole-nephron deletion of Klotho in mice results in renal FGF23 resistance characterized by high 1,25(OH)2D3 and phosphate levels and premature aging.

Bone histomorphometry and indicators of bone and mineral metabolism in wait-listed dialysis patients.

Aims: The aim of this study was to evaluate the associations between bone histomorphometry and bone volume measured by dual-energy X-ray absorptiometry (DXA) in wait-listed dialysis patients. Further, the circulating markers of mineral metabolism and bone turnover were compared.

Material And Methods: Bone biopsies were performed on 61 wait-listed dialysis patients.

Soluble Tumor Necrosis Factor Receptor 1 Is Associated with Glomerular Filtration Rate Progression and Incidence of Chronic Kidney Disease in Two Community-Based Cohorts of Elderly Individuals.

Objective: We aimed to explore and validate the longitudinal associations between soluble tumor necrosis factor receptor 1 (sTNFR1), glomerular filtration rate (GFR) progression, and chronic kidney disease (CKD) incidence in two independent community-based cohorts of elderly individuals with prespecified subgroup analyses in individuals without prevalent diabetes.

Research Design And Methods: Two community-based cohorts of elderly individuals were used with 5-year follow-up data on estimated GFR: the Uppsala Longitudinal Study of Adult Men (ULSAM; n = 437 men; mean age: 78 years) and the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS; n = 703; mean age: 70 years; 51% women). GFR categories were defined as ≥60, 30-60, and <30 ml/min/1.

FGF23, metabolic risk factors, and blood pressure in patients with primary hyperparathyroidism undergoing parathyroid adenomectomy.

Background: Fibroblast growth factor-23 (FGF23), a regulator of secretion of parathyroid hormone (PTH), is implicated in the development of cardiovascular disease. The role of FGF23 in primary hyperparathyroidism (pHPT) is unclear.

Methods: A total of 150 consecutive patients with pHPT were examined with ambulatory blood pressure monitoring ((24h)ABP) before parathyroid adenomectomy (PTX).

Soluble klotho and mortality: the Ludwigshafen Risk and Cardiovascular Health Study.

Background: Experimental evidence suggests that soluble klotho (s-klotho), a co-receptor for fibroblast growth factor 23 (FGF23), may modulate cardiovascular risk through multiple mechanisms. However, the predictive value of s-klotho in patients remains unclear. Therefore, the present study examined in a large cohort of patients referred for coronary angiography whether s-klotho is associated with cardiovascular and total mortality.