Effect of lanthanum carbonate treatment on bone in Japanese dialysis patients with hyperphosphatemia

Lanthanum carbonate (LC), a newly developed non-calcium-containing phosphate binder, has been shown to possess high phosphate-binding capacity and safety when used for hyperphosphatemia in patients with chronic kidney disease undergoing dialysis. The effects of LC on bone metabolism in Japanese dialysis patients have not been investigated; therefore, we performed histomorphometric analysis on bone from dialysis patients with hyperphosphatemia. This was a prospective, open-label study in Japanese chronic kidney disease patients on dialysis, with a flexible daily dosage of 750-4500 mg to achieve target phosphorus levels of 3.5-5.5 mg/dL (1.10-1.78 mmol/L). Bone biopsy samples for histomorphometric analysis were obtained at baseline and after treatment with LC. The median bone lanthanum level increased during the LC treatment from 54.1 µg/kg at baseline to 4270.9 µg/kg at three years. After one year of treatment with LC, two cases with an initial classification of osteitis fibrosa improved toward normal bone turnover. The diagnosis of normal remained the same for up to three years. We also noted that two cases with a baseline classification of adynamic bone disease improved after one year, and was maintained for three years. Our data suggest that LC is effective not only for treating hyperphosphatemia, but also for improving renal osteodystrophy in Japanese dialysis patients.