Safety Study of Soluble Ferric Pyrophosphate (SFP) in Dialysate in CKD Patients Receiving Chronic Hemodialysis

The purpose of the parent study is to assess the short-term safety and tolerability of soluble ferric pyrophosphate (SFP) in dialysate administered to a large number of representative adult chronic kidney disease patients on hemodialysis (CKD-HD).

The purpose of the extension study is to assess the long-term safety and tolerability of SFP.

Parent Study: randomized, double-blinded, crossover, up to 6 weeks, 700 patients. Patients were randomized to receive SFP 2 µmoles (110 µg) iron/L of dialysate in liquid bicarbonate concentrate or placebo (standard liquid bicarbonate concentrate) x 2 weeks, then a 1 week washout, then crossed over to the alternate treatment x 2 weeks.

Extension Study: open-label, single active arm, uncontrolled study, up to 53 weeks, 300 patients. Following completion of the RMTI-SFP-6 parent study, patients could enter the extension study, where they received SFP 2 µmoles (110 µg) iron/L of dialysate in liquid bicarbonate concentrate for up to 52 weeks.

Eligibility Criteria:
Parent Study, Double Blinded, Crossover:

Key Inclusion Criteria:

1. Adult ≥ 18 years of age.
2. Has chronic kidney disease (CKD) receiving maintenance hemodialysis (HD) (CKD-HD subjects) and regularly undergoing 2 or more dialysis sessions per week.
3. Stable pre-dialysis Hgb ≥ 9.0 to ≤ 12.5 g/dL.
4. Stable pre-dialysis TSAT ≥ 15% to ≤ 45%.
5. Stable pre-dialysis ferritin ≥ 100 to ≤ 1200 µg/L (1200 ng/mL).

Key Exclusion Criteria:

1. Any previous exposure to SFP.
2. Therapy with intravenous, intramuscular or oral iron at any time between the first/screening visit and the randomization visit, or anticipated requirement for iron supplementation during the study period.
3. Non-tunneled vascular catheter for dialysis.
4. Scheduled for kidney transplant within the next 8 weeks.
5. Active infection requiring systemic antimicrobial or antifungal therapy within 2 weeks prior to screening, or during screening period prior to randomization.
6. Hospitalization within 1 month prior to screening (except for vascular access surgery).

Extension Study, Open Label, Single Active Arm:

Key Inclusion Criteria:

1. Participated in Parent Study RMTI-SFP-6 and completed the follow-up/early term visit.
2. Hemoglobin ≤12.0 g/dL at screening.
3. TSAT ≤45% at screening. (Excursion of TSAT by ≤10% outside this range permitted only if all other inclusion/exclusion criteria are met).
4. Serum ferritin ≤1000 µg/L at screening. (Excursion of ferritin by ≤10% outside this range permitted only if all other inclusion/exclusion criteria are met).

Key Exclusion Criteria:

1. Had a serious adverse event attributable (i.e., probably, possibly, or definitely related) to study drug or had an adverse event attributable to study drug that necessitated premature withdrawal from the double-blind, placebo-controlled crossover phase of the parent study RMTI-SFP-6.
2. Non-tunneled vascular catheter for dialysis.
3. Scheduled for kidney transplant within 12 weeks after entry into extension phase.
4. Active infection requiring systemic antimicrobial or antifungal therapy within 2 weeks prior to dosing.
5. Pregnancy or intention to become pregnant during the study.