title: Phosphate Binding Therapy to Lower Serum Fibroblast-Growth-Factor-23 Concentrations in Chronic Kidney Disease: Rationale and Study Design of the Sevelamer on FGF23 Trial (SoFT).
abstract: BACKGROUND
  Increased levels of phosphate and fibroblast growth factor-23 (FGF23) are strong predictors of cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD). Preliminary data suggest that interventions lowering gastro-intestinal phosphate uptake lowers serum FGF23 concentrations and improves cardiovascular risk and subsequently survival. However, data are lacking about the magnitude of effects, the effect in different stages of CKD and whether there is a dose-effect relationship.
  
  
  METHODS
  Therefore, the Sevelamer on FGF23 Trial (SoFT) is designed as an open-label, single-arm, clinical pilot study aiming to demonstrate the feasibility of a phosphate-restricted diet in combination with the phosphate binder sevelamer to induce an effective, predictable and sustained decrease in FGF23 level in patients with an estimated glomerular filtration rate (eGFR) of 15-90 or >90 ml/min/1.73 m2 with proteinuria >1.0 g in 24 h urine collection, despite optimally dosed RAAS blockade, without inducing hypophosphatemia using a forced uptitration treatment regimen aimed at restricting phosphate uptake.
authors.forename: Aaltje Y
authors.initials: AY
authors.lastname: Adema
authors.forename: Maarten A
authors.initials: MA
authors.lastname: de Jong
authors.forename: Martin H
authors.initials: MH
authors.lastname: de Borst
authors.forename: Pieter M
authors.initials: PM
authors.lastname: Ter Wee
authors.forename: Marc G
authors.initials: MG
authors.lastname: Vervloet
mesh_terms: D000328:Adult; D000368:Aged; D002614:Chelating Agents / Q000627:therapeutic use*; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010710:Phosphates / Q000008:administration & dosage / Q000097:blood*; D010865:Pilot Projects; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000188:drug therapy*; D000069603:Sevelamer / Q000627:therapeutic use*
chemical_list: D002614:Chelating Agents; C000717427:FGF23 protein, human; D010710:Phosphates; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; D000069603:Sevelamer