Terminated by the DSMB based on low chance of finding differences in mGFR slopes, but higher risk of serious adverse events in the IV iron group (aIRR = 1.60)

The long-term goal is to assess the fall in kidney function measured by glomerular filtration rate (GFR) when patients with chronic kidney disease (CKD) are exposed to intravenous iron (IVIR). We hypothesize that in subjects with mild to moderate CKD, infusion of intravenous iron (IVIR), will generate oxidative stress and cause an inflammatory response that will be associated with a more rapid decline in glomerular filtration rate (GFR) compared to oral iron.

Intravenous iron is commonly utilized and is likely a mechanism of renal injury in patients with CKD. This proposal will provide translational data on the role of intravenous iron to progression of kidney disease in patients with CKD. Comparison of IV iron with oral iron will allow testing the hypothesis that IVIR will generate an inflammatory response and albuminuria in the short-term, that will directly lead to a greater rate of fall in GFR, in the long-term, compared to oral iron. We hypothesize that after administration of one gram of IV iron over a course of 8 weeks, renal injury as documented by albuminuria (and fall in GFR) will be increased with IV iron sucrose therapy compared to those randomized to oral iron therapy. A randomized, parallel group, controlled trial will be performed. GFR will be measures every 6 months for two years in 200 participants by iothalamate clearances.

Inclusion Criteria:

• Age greater than 18 years
• Calculated GFR by MDRD formula < or = 60ml/min/1.73m2. We will use the MDRD formula that incorporates serum creatinine, age, race and sex, but not albumin, and blood urea nitrogen.
• Presence of anemia and iron deficiency. Anemia will be defined as blood hemoglobin concentration <12g/dL and iron deficiency will be defined using National Kidney Foundation/Kidney Disease Outcome Quality Initiative (NFK-K/DOQI) Guidelines as serum ferritin concentration of <100ng/mL or serum transferrin saturation of <25%.

Exclusion Criteria:

• Pregnant or breastfeeding women or women who are planning to become pregnant or those not using a reliable form of contraception (oral contraceptives, condoms, and diaphragms will be considered reliable).
• Known hypersensitivity to iron sucrose (Venofer), iothalamate meglumine (Conray 60, Mallinckrodt) or iodine.
• Anemia that requires RBD transfusion (Hgb <8g/dL) or may potentially need transfusion (active gastrointestinal bleeding). It would be unsafe to withdraw 150 mL blood over the study in such anemic patients.
• Presence of acute renal failure defined as an increase in the baseline serum creatinine concentration of 0.5 mg/dl over 48 hours. This would produce oxidative stress by itself, may give unreliable rate of decline in renal function and may confound results.
• History of IVIR use within 1 month of the study (may confound results of the study if the baseline oxidative stress is increased).
• Evidence of iron overload (serum ferritin >800ng/nl or transferrin saturation >50%)
• Anemia not caused by iron deficiency eg. sickle cell anemia.
• Surgery or systemic or urinary tract infection within 1 month.
• Organ transplant recipient or therapy with immunosuppressive agents. Nasal or inhaled corticosteroids will be permitted.

Adverse event data were routinely collected at 2, 4, 6, and 8 weeks after randomization during the treatment phase and again at 3, 6, 12, 18, and 24 months after randomization during the follow-up phase.