The clinical Investigation will be performed to compare the safety and clinical performance profile of different hemodialyzers, all applied in on-line postdilution hemodiafiltration

The primary objective of this study is to test whether the new FX P600 (applied during post-dilution online HDF) is non-inferior to two comparator dialyzers (Sureflux-17UX (Nipro) and Polyflux 170 H (Baxter/Gambro) in removing β2-microglobulin. The secondary objective is to exploratively compare the efficacy in removing other uremic solutes between the new FX P600 and the Sureflux-17UX as well as the Polyflux 170 H membranes. Additionally, the safety of the FX P600 dialyzer with a modified polysulfone membrane will be investigated.

Inclusion Criteria:

• Minimum age of 18 years
• Existing informed consent form signed and dated by study patient as well as investigator/authorized physician
• The patient is legally competent and able to understand the nature, risks, meaning, and consequences of the clinical trial and can subsequently declare his consent for participation in the clinical trial
• Patients with a chronic kidney disease stage 5D (end stage renal disease with a glomerular filtration rate of 15 ml/min or less) on hemodiafiltration as extracorporeal renal replacement therapy

Exclusion Criteria:

• Any condition which could interfere with the patient's ability to comply with the study. This decision is at the discretion of the treating physician and relates to the general stable condition of the patient (e.g. absence of any acute condition, e.g. infection or mental problem which might give reason for concern etc.).
• Ongoing participation in an interventional clinical study during the preceding 30 days
• Previous participation in this study
• Pregnancy (pregnancy test will be conducted with female patients aged ≤ 55 years) or lactation period
• Patient is not able to give informed consent