Continuous Soluble Ferric Pyrophosphate (SFP) Iron Delivery Via Dialysate in Hemodialysis Patients

The purpose of this study is to confirm the safety and efficacy of Soluble Ferric Pyrophosphate (SFP) dialysate solution in maintaining iron delivery for erythropoiesis in anemic adult patients with chronic kidney disease (CKD) receiving hemodialysis. Efficacy will be measured primarily by the change from baseline in hemoglobin (Hgb).

Screening: 2-3 weeks prior to enrollment in Stage 1.

Stage 1 (Run-In): 1-4 weeks depending on qualification for Stage 2.

Stage 2 (Randomized Blinded Treatment): 12 months unless withdrawn prematurely.

Stage 3 (Open-Label Treatment): The duration of Stage 2 plus Stage 3 is intended to be 18 months regardless of treatment assignment in Stage 2.

Eligibility Criteria:
Stage 1:

Main Inclusion Criteria:

* Adult subject ≥ 18 years of age undergoing chronic hemodialysis three or four times per week for chronic kidney disease (CKD) for at least 4 months, and expected to remain on hemodialysis three to four times weekly and be able to complete the duration of the study.
* Received IV iron therapy between 6 months and 2 weeks prior to enrollment in order to replace iron losses resulting from hemodialysis procedure.
* Mean Screening Hgb ≥ 9.5 to ≤ 11.5 grams per deciliter (g/dL).
* Mean Screening Transferrin Saturation (TSAT) ≥ 15% to ≤ 40%.
* Mean Screening serum ferritin ≥ 200 to ≤ 800 micrograms per liter (µg/L).
* If being administered epoetin, darbepoetin, or CERA, epoetin dose ≤ 45,000 Units (U)/week, darbepoetin dose ≤ 200 micrograms (µg)/week, or CERA dose ≤ 400 micrograms (µg)/month during the four weeks prior to enrollment.

Main Exclusion Criteria:

* Patient has living kidney donor identified or living-donor kidney transplant scheduled. (Note: Patients awaiting deceased-donor transplant need not be excluded.)
* Vascular access for dialysis with femoral catheter or non-tunneled catheter.
* Received a total of \> 800 milligrams (mg) IV iron during the 8 weeks prior to enrollment
* If being administered an ESA, route of administration change or ESA dose change \> 35% (i.e., \[max - min dose\]/max dose \> 0.35) over the 2 weeks prior to screening.
* Serum albumin \< 3.0 grams per deciliter (g/dL) any time over the 8 weeks prior to enrollment.
* Red Blood Cell (RBC) or whole blood transfusion within 12 weeks prior to enrollment.

Stage 2:

Main Inclusion Criteria:

* Patient currently enrolled in the Stage 1 run-in period of study.
* Undergoing chronic hemodialysis three or four times per week for chronic kidney disease (CKD), and expected to remain on hemodialysis three to four times weekly and be able to complete duration of the study.
* Mean Hgb ≥ 9.5 to ≤ 11.5 g/dL over the three most recent consecutive every-week measurements prior to randomization.
* Stable Hgb defined as ≤ 1.0 g/dL difference between the maximum and minimum Hgb values over the 3 weeks immediately prior to randomization.
* Mean TSAT ≥ 15% to ≤ 40% over the two most recent consecutive every-other-week measurements prior to randomization.
* Mean serum ferritin ≥ 200 to ≤ 800 µg/L over the two most recent consecutive every-other-week measurements prior to randomization.
* If being administered epoetin, darbepoetin, or CERA, epoetin dose ≤ 45,000 U/week, darbepoetin dose ≤ 200 µg/week, or CERA dose ≤ 400 µg/month during the four weeks prior to randomization.

Main Exclusion Criteria:

* Patient has living kidney donor identified or living-donor kidney transplant scheduled. (Note: Patients awaiting deceased-donor transplant need not be excluded.)
* Vascular access for dialysis with femoral catheter or non-tunneled catheter.
* Received any amount of IV iron during the 4 weeks prior to randomization.
* If being administered an (Erythropoietin Stimulating Agent) ESA, change in dose over the 6 weeks immediately prior to randomization.
* Serum albumin \< 3.0 g/dL any time over the 8 weeks prior to randomization.
* RBC or whole blood transfusion during Stage 1.

Stage 3:

Main Inclusion Criteria:

* Patient randomized in Stage 2 who has completed the full duration of Stage 2 and less than 4 weeks have elapsed since completion of Stage 2, OR
* Patient in Stage 2 who has been prematurely withdrawn from Stage 2 for protocol-defined Protocol-Mandated Change in Anemia Management and less than 4 weeks have elapsed since withdrawal from Stage 2, OR
* Patient in Stage 2 who has been prematurely withdrawn from Stage 2 for Hgb \>11.5 g/dL over ≥ 1 week confirmed by ≥ 2 consecutive measurements AND an associated increase in Hgb by ≥ 1 g/dL over 4 weeks.

Main Exclusion Criteria:

* Patient in Stage 2 who has been prematurely withdrawn from Stage 2 for any reason other than as noted in inclusion criteria above.