MP365SUCROFERRIC OXYHYDROXIDE DOES NOT IMPACT THE IPTH-LOWERING EFFECTS OF ORAL VDRAS OR CINACALCET: A POST HOC ANALYSIS OF A PHASE 3 STUDY

Abstract

Introduction and Aims: A post hoc analysis of a randomized, open‐label, Phase 3 study was performed to evaluate the effects of concomitant oral vitamin D receptor agonist (VDRA) or cinacalcet use on CKD‐MBD parameters in dialysis patients treated with the iron‐based phosphate binder sucroferric oxyhydroxide (SFOH; VELPHORO®) or sevelamer carbonate (SEV). Methods: 1059 patients were randomized 2:1 to SFOH (1.0‐3.0 g/day; n=710) or SEV (2.4‐14.4 g/day; n=349) for 12 weeks' dose titration plus 12 weeks' maintenance. Eligible patients enrolled in a 28‐week extension. Two patient groups from the full analysis set population (N=1041) were analysed: those who received at least one dose of oral VDRA and/or cinacalcet during the 52‐week study (Group 1; n=372) and those who did not receive these treatments (Group 2; n=669). Results: Changes in mean serum phosphorus and iPTH for SFOH and SEV groups stratified by concomitant oral VDRA/cinacalcet use are shown (Table). Decreases in serum phosphorus were maintained over 52 weeks with SFOH and SEV irrespective of concomitant VDRA/cinacalcet usage, with similar reductions observed in Groups 1 and 2. In Group 1 (oral VDRA/cinacalcet group), mean serum iPTH levels decreased from baseline to Weeks 24 and 52 in the SFOH group, whereas iPTH levels increased over 52 weeks in SEV‐treated patients; these differences between the treatment groups atWeek 52 were statistically significant ( p=0.02). In Group 2 (no oral VDRA/ cinacalcet group), iPTH decreased to a similar degree with SFOH and SEV treatment up toWeek 24, increasing to greater than baseline values byWeek 52 in both groups. Conclusions: The results of this analysis demonstrated that SFOH and SEV maintained serum phosphorus control over 1 year irrespective of oral VDRA or cinacalcet use. SEV treatment appeared to slightly inhibit the iPTH‐lowering effects of oral VDRAs or cinacalcet, whereas this effect was not observed in SFOH‐treated patients. (Table Presented).