Clinical Nephrology – Epidemiology – Clinical Trials
Kidney International (1999) 55, 299–307; doi:10.1046/j.1523-1755.1999.00240.x
RenaGel®, a nonabsorbed calcium- and aluminum-free phosphate binder, lowers serum phosphorus and parathyroid hormone
EDUARDO A SLATOPOLSKY, STEVEN K BURKE and MAUREEN A DILLON THE RENAGEL® STUDY GROUP1
Renal Division, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, and GelTex Pharmaceuticals, Inc., Waltham, Massachusetts, USA
Correspondence: Eduardo Slatopolsky , M.D., Washington University School of Medicine, 660 South Euclid Avenue, Box 8129, St. Louis, MO 63110, USA. E-mail: eslatopo@imgate.wustl.edu
1Members of the RenaGel® Study Group include the following: PAUL BOLIN (Greenville, NC); KENNETH BOREN (Mesa, AZ); K. BURKE and MAUREEN AL DILLON (GelTex Pharmaceuticals, Inc., Waltham, MA); DOUGLASS T. DOMOTO (St. Louis, MO); THOMAS A. GOLPER (Little Rock, AR); FRED JONES (Raleigh, NC); C.J. KAUPKE (Orange, CA); ROBERT LEVINSON (Hollywood, FL); MICHAEL A. MARX (Little Rock, AR); WILLIAM MATTERN (Chapel Hill, NC); MARK S. PALLER (Minneapolis, MN); MARYELLA D. SIRMON (Mobile, AL); EDUARDO SLATOPOLSKY (St. Louis, MO); RANDALL STOLTZ, (Evansville, IN); JOHN WAGNER (New Hyde Park, NY); MARC WEINBERG (Providence, RI); BARRY WILKES (Manhasset, NY); DUANE WOMBOLT (Norfolk, VA); and JAMES VAN GELDER (Hollywood, FL, USA).
Received 1 April 1998; Revised 30 July 1998; Accepted 5 August 1998.
Abstract
RenaGel®, 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®, a nonabsorbed calcium- and aluminum-free phosphate binder, in lowering serum phosphorus. Secondary outcomes were its effects on serum intact parathyroid hormone (iPTH) and serum lipids.
Methods.
Phosphate binders were discontinued during a two-week washout period. Patients whose serum phosphorus was more than 6.0 mg/dl during washout were eligible for treatment. RenaGel®, at starting doses of two, three, or four 440 mg capsules three times per day with meals, was administered to 172 hemodialysis patients for eight weeks. RenaGel® could be increased by one capsule per meal every two weeks as necessary to achieve serum phosphorus 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® treatment period (P < 0.0001). Serum phosphorus increased to 8.0 2.2 mg/dl at the end of the second washout period. The mean dose at the end of RenaGel® treatment was 5.4 g per day. Eighty-four percent of the patients previously used calcium-based phosphate binders. As expected, calcium declined during the initial washout period when calcium-based phosphate binders were discontinued. Mean 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® treatment. Median serum iPTH increased during the two-week washout 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® reduced mean serum total cholesterol from 171.0 43.1 mg/dl to 145.0 38.7 mg/dl (P < 0.0001) and mean 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, triglycerides, and serum albumin did not change.
Conclusions.
RenaGel®, 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 osteodystrophy in uremic patients.
Keywords:
dialysate, renal failure, osteodystrophy, uremia, hyperphosphatemia, bone disease
