JTT-751 (ferric citrate hydrate) is a novel oral, iron-based phosphate binder being developed for the treatment of hyperphosphatemia among chronic kidney disease patients who are on dialysis. This study investigated the dose-response and safety of JTT-751 among Japanese hemodialysis patients. This was a multicenter, randomized, placebo-controlled, double-blind, parallel-group, comparative study. A total of 192 subjects with serum phosphorus (P) levels between 6.1 and 10.0 mg/dl were randomized to JTT-751 (1.5, 3 or 6 g/day) or to placebo treatment for 28 days. Changes in serum P level from baseline were examined. In the full analysis set, the mean change in serum P level at week 4 was 0.04, -1.28, -2.16 and -4.10 mg/dl in the placebo, 1.5-grams, 3-grams and 6-grams/day groups, respectively, demonstrating a dose-response relationship up to 6 g/day. Overall, a reduction in serum P levels to ≤5.5 mg/dl was achieved in 2.5, 16.7, 50.0 and 92.6% of subjects, in the placebo, 1.5-grams, 3-grams and 6-grams/day groups, respectively. The most common adverse events (AEs) were gastrointestinal disorders. Most AEs were mild. In 25 patients, treatment was discontinued due to increased transferrin saturation ≥50%; however, this was not considered to be a safety issue. When hemodialysis subjects received JTT-751 at doses between 1.5 and 6 g/day for 28 days, serum P levels were significantly reduced in a dose-dependent manner (p < 0.001). JTT-751 was found to be efficacious and safe, with the majority of subjects in the 6-grams/day group achieving a serum P level of ≤5.5 mg/dl.