Abstract
BACKGROUND: Researchers have yet to determine the optimal care of patients with advanced CKD. Evidence suggests that anemia and CKD-related disordered mineral metabolism (including abnormalities in phosphate and fibroblast growth factor 23 [FGF23]) contribute to adverse outcomes in this population. METHODS: To investigate whether fixed-dose ferric citrate coordination complex favorably affects multiple biochemical parameters in patients with advanced CKD, we randomly assigned 203 patients with eGFR≤20 ml/min per 1.73 m(2) 2:1 to receive a fixed dose of ferric citrate coordination complex (two tablets per meal, 210 mg ferric iron per tablet) or usual care for 9 months or until 3 months after starting dialysis. No single biochemical end point was designated as primary; sample size was determined empirically. RESULTS: The two groups had generally similar baseline characteristics, although diabetes and peripheral vascular disease were more common in the usual-care group. Ferric citrate coordination complex significantly increased hemoglobin, transferrin saturation, and serum ferritin, and it significantly reduced serum phosphate and intact FGF23 (P<0.001 for all). Of the 133 patients randomized to ferric citrate coordination complex, 31 (23%) initiated dialysis during the study period, as did 32 of 66 (48%) patients randomized to usual care (P=0.001). Compared with usual care, ferric citrate coordination complex treatment resulted in significantly fewer annualized hospital admissions, fewer days in hospital, and a lower incidence of the composite end point of death, provision of dialysis, or transplantation (P=0.002). CONCLUSIONS: The beneficial effects of fixed-dose ferric citrate coordination complex on biochemical parameters, as well as the exploratory results regarding the composite end point and hospitalization, suggest that fixed-dose ferric citrate coordination complex has an excellent safety profile in an unselected population with advanced CKD and merits further study.