Phosphate Binders Derived from Natural Ores Contain Many Kinds of Metallic Elements Besides Their Active Ingredient Metals

Population pharmacokinetics of roxadustat in Japanese dialysis-dependent chronic kidney disease patients with anaemia

Aims

Our objective was to develop a population pharmacokinetic (PK) model to describe roxadustat plasma concentrations in Japanese dialysis‐dependent chronic kidney disease (DD‐CKD) patients with renal anaemia and to identify the covariate factors that affect exposure of roxadustat.

Methods

In total, 367 patients (male, 256; female, 111) contributing 1285 concentration values from 4 clinical studies were analysed using a nonlinear mixed‐effects modelling approach. Candidate covariates included clinical characteristics hypothesized to affect roxadustat clearance and bioavailability, such as demographics, hepatic parameters and concomitant drugs.

Results

The roxadustat PK data in Japanese DD‐CKD patients with renal anaemia were well described by a 2‐compartment disposition model with first‐order absorption and interindividual variability on clearance, central volume of distribution and absorption rate constant. Age was identified as a significant covariate on clearance. PK profiles of haemodialysis and peritoneal dialysis patients were comparable. Eighty‐two percent of patients were administered at least 1 phosphate binder (PB). The effect of PBs on roxadustat concentration was modelled as a decrease in bioavailability. Staggered administration of PBs reduced the effect on roxadustat bioavailability. The clinical impact of all covariates on roxadustat PK was mild and manageable as the roxadustat dose was titrated based on haemoglobin level and administered starting from a low dose.

Conclusion

Roxadustat PK in Japanese DD‐CKD patients were successfully described by a population PK model. The identified key covariates included coadministration of PBs on the roxadustat bioavailability and age on clearance of roxadustat.

Phosphate binders in chronic kidney disease: an updated narrative review of recent data

Chronic kidney disease (CKD) is frequently accompanied by hyperphosphatemia. High serum phosphate usually requires dietary measures, adequate dialysis prescription and/or phosphate binders. For this narrative review a PubMed searched was undertaken to identify new publications on phosphate binders that had been published between January 2015 and July 2019. The present review summarizes this most recent information on dietary measures and their problems in treating hyperphosphatemia in CKD patients, overall effects of phosphate binders on cardiovascular mortality and morbidity, adherence to phosphate binder therapy as well as new data on specific aspects of the various phosphate binders on the market: calcium-containing phosphate binders, polymeric phosphate binders (sevelamer, bixalomer, colestilan), magnesium-containing phosphate binders, lanthanum carbonate, ferric citrate, sucroferric oxyhydroxide, and new compounds in development, in particular drugs targeting intestinal phosphate transporters.