#3944 COMPARISON OF CLINICAL PERFORMANCE AND HEMOCOMPATIBILITY OF DIALYZERS APPLIED DURING POST-DILUTION ONLINE HEMODIAFILTRATION (HDF) – EMPORA III STUDY
Authors: Ehlerding Götz , Ronova Petra , Krizsán Mária , Griesshaber Bettina , Erlenkötter Ansgar , Nitschel Robert , Zawada Adam , Ottillinger Bertram , Braun Jennifer , Stauss-Grabo Manuela 
Published: June 2023

Abstract

Background and Aims
Performance and hemocompatibility are the two main functions of a hemodialyzer. Synthetic dialysis membranes made from polysulfone (PSU) or polyethersulfone (PES) are mainly used for dialysis treatments and are blended with the hydrophilic agent polyvinylpyrrolidone (PVP), to improve hemocompatibility during dialysis treatments. A novel PSU-based dialyzer (FX CorAL) with an increased and stabilized PVP content has been developed and has shown strong performance and a favourable hemocompatibility profile within previous short term clinical studies. In the present clinical study, we now investigated the performance and hemocompatibility of the FX CorAL vs. two comparators over a longer follow-up time and applied an extended panel of hemocompatibility biomarkers. This allowed us to analyse treatment-specific performance as well as an extensive intra- and interdialytic hemocompatibility profile.

Method
eMPORA III was a prospective, open, controlled, multicentre crossover trial with randomized treatment sequences conducted in DE, CZ and HU. It randomized stable patients receiving regular post-dilution online HDF to FX CorAL 600, FX CorDiax 600 (both Fresenius Medical Care) and xevonta Hi 15 (B. Braun), each for 4 weeks. The primary outcome was β2-m removal rate (RR) during 4 hrs HDF. Non-inferiority (margin: 5%) and superiority of FX CorAL 600 versus comparators were tested at α = 2.5% (one-sided), with adjustment for multiple tests. Secondary endpoints were RR and/or clearance of β2-m and other molecules, as well as intra- and interdialytic changes of markers of complement activation (C3a, sC5b-9), cell activation / inflammation (white blood cells (WBC), PMN elastase, IL-6, IL-8, LTB-4, sICAM-1, hsCRP), platelet activation (platelet count, β-TG, TxB-2), and oxidative stress (MDA, GSH-Px). Intradialytic hemocompatibility markers were analysed descriptively as differences vs. the values determined at the start of the HDF session (LS means).

Results
Eighty-two patients were included and analysed in the safety population, with n = 76 presenting data for the primary outcome (ITT population). FX CorAL 600 showed the highest β2-m RR (LS mean: 76.31%), followed by FX CorDiax 600 (75.71%) and xevonta Hi 15 (74.49%). Non-inferiority to its comparators was statistically significant (p&lt;0.0001 each). Superiority was shown vs. xevonta Hi 15 (p&lt;0.0001), but not vs. FX CorDiax 600 (p = 0.0606). The secondary endpoints β2-m clearance as well as myoglobin clearance and RR affirmed these results; small molecule clearances and/or RR were similar between dialyzers.
Analyses of hemocompatibility markers within one HDF session, found the following significant differences:
Complement activation
• C3a 15 min: FX CorAL: 31%; FX CorDiax: 59% (p = 0.003 vs. FX CorAL); xevonta: 41% (p = 0.029 vs. FX CorAL)
• sC5b-9 60 min: FX CorAL: 24%; FX CorDiax: 25% (p = 0.337); xevonta: 41% (p&lt;0.0001)
Cell activation/ Inflammation
• WBC 15 min: FX CorAL: -7.7%; FX CorDiax: -11.1% (p = 0.015); xevonta: -10.1% (p = 0.246)
• Monocytes 15 min: FX CorAL: -30.9%; FX CorDiax: -30.3% (p = 0.533); xevonta: -38.2% (p = 0.012)
• Neutrophils 15 min: FX CorAL: -3.0%; FX CorDiax: -7.5% (p = 0.019); xevonta: -6.1% (p = 0.258)
• PMN elastase 60 min: FX CorAL: 18%; FX CorDiax: 42% (p = 0.003); xevonta: 52% (p = 0.0003)
• LTB-4 15 min: FX CorAL: 170%; FX CorDiax: 217% (p = 0.047); xevonta: 186% (p = 0.539)
Platelet activation
• β-TG 60 min: FX CorAL: -15%; FX CorDiax: 4% (p&lt;0.0001); xevonta: 18% (p&lt;0.0001)
Hemocompatibility markers showed no interdialytic changes, i.e., no significant changes within treatment periods. Nine serious adverse events occurred in this study, none of which was dialyser related.

Conclusion
FX CorAL 600 efficiently removed middle and small molecules and was non-inferior to both comparators and significantly superior to xevonta Hi 15 in β2-m RR. The typical drop in WBC, monocyte, and neutrophil count during dialysis as well as the rise of complement (C3a, sC5b-9) and cell / platelet activation markers (PMN elastase, LTB-4 and β-TG) were lower or comparable during treatment with FX CorAL vs. both comparators, indicating superior hemocompatibility properties.