Long-term safety and efficacy of a novel iron-containing phosphate binder, JTT-751, in patients receiving hemodialysis.

Objective: JTT-751 is a novel phosphate binder containing ferric citrate as the active ingredient. This study investigated long-term safety and efficacy of JTT-751 for hyperphosphatemia in patients receiving hemodialysis.

Design And Methods: This was 52-week, phase 3, multicenter, open-label, dose titration, long-term study. All patients were receiving thrice-weekly hemodialysis for ≥3 months before the initiation of the study. JTT-751 was given at titrated doses between 1.5 and 6.0 g/day.

Main Outcome Measures: Safety endpoints were adverse events and adverse drug reactions. Efficacy outcomes were the change in serum phosphate, corrected serum calcium, and intact parathyroid hormone. Changes in ferritin, transferrin saturation, and doses of erythropoiesis-stimulating agents (ESAs) and intravenous iron formulations were additional outcomes.

Results: One hundred and eighty patients were included in the trial. Dose-titrated JTT-751 decreased mean serum phosphate after administration and satisfactorily maintained serum phosphate concentrations throughout the entire duration of the 52-week trial. Mean serum phosphate concentrations were kept lower than 5.5 mg/dL from weeks 5 to 52. The most common adverse events were gastrointestinal disorders, which were mild to moderate in intensity. Serum ferritin concentrations rose to a peak around week 28 and stabilized thereafter. The mean intravenous iron dose decreased from 57.3 mg/4 weeks (weeks 0-12) to 3.6 mg/4 weeks (weeks 28-52); weekly ESA dose declined by 25% over the same time frame, while mean hemoglobin concentrations remained stable.

Conclusion: JTT-751 1.5-6.0 g/day controls serum phosphorus concentrations and reduces the need for ESAs and intravenous iron in patients receiving hemodialysis.