RenaGel (R), a nonabsorbed calcium- and aluminum-free phosphate binder, lowers serum phosphorus and parathyroid hormone

Background. This multicenter, open-label, dose-titration study assessed the safety and efficacy of RenaGel(R), a nonabsorbed calcium- and aluminum-fre e phosphate binder, in lowering serum phosphorus. Secondary outcomes were i ts effects on serum intact parathyroid hormone (iPTH) and serum lipids. Methods. Phosphate binders were discontinued during a two-week washout peri od. Patients whose serum phosphorus was more than 6.0 mg/dl during washout were eligible for treatment. RenaGel(R), at starting doses of two, three, o r four 440 mg capsules three times per day with meals, was administered to 172 hemodialysis patients for eight weeks. RenaGel(R) could be increased by one capsule per meal every two weeks as necessary to achieve serum phospho rus control. A second two-week washout period followed. Results. Mean serum phosphorus rose from 6.8 +/- 2.0 mg/dl at prewashout to 9.1 +/- 2.4 mg/dl at the end of the washout period. It then declined to 6. 6 +/- 1.9 mg/dl by the end of the eight-week RenaGel(R) treatment period (P < 0.0001). Serum phosphorus increased to 8.0 +/- 2.2 mg/dl at the end of t he second washout period. The mean dose at the end of RenaGel(R) treatment was 5.4 g per day. Eighty-four percent of the patients previously used calc ium-based phosphate binders. As expected, calcium declined during the initi al washout period when calcium-based phosphate binders were discontinued. M ean serum calcium declined from 9.6 +/- 1.0 mg/dl at prewashout to 9.1 +/- 0.8 mg/dl after washout. It then increased to 9.4 +/- 0.9 mg/dl by the end of RenaGel(R) treatment. Median serum iPTH increased during the two-week wa shout from 208 pg/ml to 316 pg/ml and then declined to 224 pg/ml at the end of the eight-week treatment period (P < 0.0001 vs. end of initial washout) . After eight weeks of treatment, RenaGel(R) reduced mean serum total chole sterol from 171.0 +/- 43.1 mg/dl to 145.0 +/- 38.7 mg/dl (P < 0.0001) and m ean serum low-density lipoprotein cholesterol from 102.0 +/- 34.9 mg/dl to 75.6 +/- 29.4 mg/dl (P < 0.0001). High-density lipoprotein cholesterol, tri glycerides, and serum albumin did not change. Conclusions. RenaGel(R), a novel and calcium- plus aluminum-free effective phosphate binder, can control serum phosphorus and reduce the levels of PTH and cholesterol without inducing hypercalcemia or other side effects. Thus , this new phosphate binder may be effective in the treatment of renal oste odystrophy in uremic patients.