Randomized, Double-Blind, Placebo-Controlled, Withdrawal Study of Colestilan after Dose Titration in Chronic Kidney Disease Dialysis Patients with Hyperphosphatemia.

BACKGROUND/AIMS: Colestilan is a new non-calcium-based phosphate binder licensed in Europe for the treatment of hyperphosphatemia in chronic kidney disease patients on dialysis (CKD 5D). This study was conducted to evaluate efficacy in a North American patient population and also to examine secondary actions of colestilan on lipid profile and glycated hemoglobin (HbA1c).

METHODS: This was a multicenter, randomized, double-blind, placebo-controlled withdrawal study, after an initial open-label titration period. Patients (n = 245) with stable phosphate control received 6-15 g/day colestilan during a 12-week, flexible titration period after which 169 were randomized to continue the same dose (n = 85) or switch to placebo (n = 84) for 4 weeks. The primary endpoint was the change in serum phosphorus level during the placebo-controlled withdrawal period.

RESULTS: A significant difference of -1.01 mg/dl (-0.33 mmol/l) in mean change in serum phosphorus, favoring colestilan, was seen during the placebo-controlled withdrawal period (p < 0.001). Colestilan reduced serum phosphorus significantly from baseline to week 12 (-1.54 mg/dl (-0.50 mmol/l); p < 0.001). Serum calcium levels were not affected. Colestilan significantly reduced and maintained reductions in calcium × phosphorus ion product (Ca × P), parathyroid hormone, total cholesterol, low-density lipoprotein cholesterol, uric acid and also HbA1c in patients with elevated baseline HbA1c. Colestilan was generally well tolerated; most adverse events were gastrointestinal.

CONCLUSION: In this first clinical trial with colestilan in a North American patient population, colestilan demonstrated significant efficacy in controlling serum phosphorus levels in CKD 5D patients with hyperphosphatemia, without increasing calcium levels.