Background Dialyzers shall be designed to efficiently eliminate uremic toxins during a dialysis treatment, given that the accumulation of small and middle molecular weight uremic solutes is associated with increased mortality risk of patients with end-stage renal disease. In the present study we investigated the novel FX CorAL dialyzer with a modified membrane surface for the performance during online-hemodiafiltration in a clinical setting. Methods comPERFORM was a prospective, open, controlled, multi-centric, interventional, cross-over study with randomized treatment sequences. It randomized stable patients receiving regular post-dilution online hemodiafiltration (HDF) to FX CorAL 600 (Fresenius Medical Care Deutschland GmbH), xevonta Hi 15 (B. Braun), and ELISIO 150H (Nipro), each for one week. The primary outcome was β2-microglobulin removal rate (ß2-m RR) during online-HDF. Secondary endpoints were RR and/or clearance of ß2-m and other molecules. Albumin removal over time was an exploratory endpoint. Non-inferiority and superiority of FX CorAL 600 vs. competitors were tested. Results 52 patients were included and analyzed. FX CorAL 600 showed the highest ß2-m RR (75.47%), followed by xevonta Hi 15 (74.01%) and ELISIO 150H (72.70%). Superiority to its competitors was statistically significant (P = 0.0216 and P < 0.0001, respectively). Secondary endpoints related to middle molecules affirmed these results. FX CorAL 600 demonstrated the lowest albumin removal up to 60 min, and its sieving properties changed less over time than with competitors. Conclusions FX CorAL 600 efficiently removed middle and small molecules and was superior to the two comparators in ß2-m RR. Albumin sieving kinetics point to a reduced formation of a secondary membrane.

Background: High-flux dialyzers shall effectively remove uremic toxins and be hemocompatible to minimize intradialytic humoral and cellular stimulation and long-term impact on patient outcomes. A new dialyzer with a modified membrane surface has been tested for performance and hemocompatibility. Methods: This multicenter, prospective, randomized, cross-over study applied for one week each the new polysulfone-based FX CorAL 600 (Fresenius Medical Care, Bad Homburg, Germany), the polyarylethersulfone-based Polyflux 170H (Baxter Healthcare Corporation, Deerfield, IL, USA) and the cellulose-triacetate-based SureFluxTM 17UX (Nipro Medical Europe, Mechelen, Belgium) to assess non-inferiority of removal rate of β2-microglobulin of the FX CorAL 600. Performance was assessed by removal rate and clearance of small and middle molecules. Hemocompatibility was assessed through markers of complement, cell activation, contact activation and coagulation. Results: Of 70 patients, 58 comprised the intention-to-treat population. The removal rate of β2-microglobulin of the FX CorAL 600 was non-inferior to both comparators (P<0.0001 vs SureFluxTM 17UX; P=0.0006 vs Polyflux 170H), and superior to SureFluxTM 17UX. The activation of C3a and C5a with FX CorAL 600 was significantly lower 15 min after treatment start than with SureFluxTM 17UX. The activation of sC5b-9 with FX CorAL 600 was significantly lower over the whole treatment than with SureFluxTM 17UX, and lower after 60 min than with Polyflux 170H. The treatments with FX CorAL 600 were well tolerated. Conclusions: FX CorAL 600 efficiently removed small and middle molecules, showed a favorable hemocompatibility profile and was associated with a low frequency of adverse events in the present study with a limited patient number and follow-up time. Further studies with longer observation times are warranted to provide further evidence supporting the use of the new dialyzer in a wide range of therapeutic options and long-term treatments of hemodialysis patients to minimize the potential impact on inflammatory processes.

Background and Aims Hemodialyzers containing membranes made from a blend of polysulfone and polyvinylpyrrolidone (PVP) are widely used. PVP makes the membrane material more hydrophilic to reduce interactions with plasma proteins and platelets. A modified spinning technique has been established to stabilize the PVP on the blood-side surface in the polysulfone dialysis membrane in the new dialyzer FX CorAL 600. The objective of the present study was to prove for this new dialyzer non-inferiority of performance in comparison to established dialyzers. Further, hemocompatibility and safety of the dialyzers were explored. Method In a multicenter, prospective, randomized, crossover study adult patients on online hemodiafiltration (HDF) were enrolled. They were treated for one week each with on-line HDF in post-dilution mode, and in randomized order with the dialyzers FX CorAL 600, FX 600, and FX CorDiax 600 (all Fresenius Medical Care, Bad Homburg, Germany). Blood samples were taken on the midweek session before start, at the end to analyze removal rate and at 60 min to determine clearance of ß2-microglobulin, myoglobin, urea, creatinine and phosphate. Further a pattern of hemocompatibility parameters and safety was evaluated. Assuming no carry over effect, linear mixed models were used for statistical analysis. Results The mean age of the 49 enrolled patients was 66.3±13.6 years, 76% were male. Treatments were performed in post-dilution mode with a mean blood flow &gt; 300 mL/min and a substitution volume &gt;19 L. The removal rate of ß2-microglobulin was 74.4, 70.4, and 73.1% for the FX CorAL 600, FX 600, and FX CorDiax 600 dialyzer, respectively. FX CorAL 600 proved to be statistically significantly non-inferior to FX 600 (p=0.0006) and to FX CorDiax 600 (p=0.036). The removal rate of FX CorAL 600 was by 4.0% (confidence interval 0.4 – 7.5%) significantly higher than with FX 600. The difference to FX CorDiax 600 was not significant. The clearance of ß2-microglobulin and myoglobin and the removal rate of myoglobin were significantly higher with the new dialyzer FX CorAL 600 than with the FX 600, and comparable to the FX CorDiax 600. Performance for small molecules was similar for all dialyzers. The complement factors C3a and C5a increased early in the treatment with a peak at 15 min, without differences between the three dialyzers for C3a, and for C5a with significantly lower increase at 15 min with FX CorAL 600 than for FX 600 (p=0.007); the difference of increase between FX CorAL 600 and FX CorDiax 600 was not significant (p=0.515). The course of sC5b9 was similar for all three dialyzers, with significantly lower increase at 15 min for both FX CorAL 600 (p=0.009) and FX CorDiax 600 (p=0.026) as compared to FX 600 and similar increase at 60 min for both FX CorAL 600 (p=0.573) and FX CorDiax 600 (p=0.386) as compared to FX 600. The area-under-the-curve for the course of sC5b-9 with FX CorAL 600 was significantly lower than with FX 600 (p=0.044) and comparable to FX CorDiax 600 (p=0.092). The leukocyte count showed a decrease in the first 15 min of the treatment, which recovered afterwards, similarly for all treatment phases with the different dialyzers. Further, the dialyzers did not differ with respect to adverse events. Conclusion All three dialyzers showed good performance, with higher removal rates for middle molecules with the new dialyzer FX CorAL 600 compared to the FX 600. Hemocompatibility profiles were mostly similar, with lower activation of C5a and of sC5b9 with FX CorAL 600 compared to FX 600. The new dialyzer provides comparable performance levels capable of delivering adequate treatment and good tolerability for the patient.