PARIS—Raising the dose of the calcium-free phosphate binder lanthanum carbonate from a lower conventionally used dose of 2,250 or less to 3,000 mg/day may reduce phosphorus levels in patients with chronic kidney disease (CKD) and hyperphosphatemia, investigators announced at the 49^th Congress of the European Renal Association-European Dialysis and Transplant Association.  

The higher dose may also increase the percentage of patients who are able to achieve target phosphorus levels.

Rosamund Wilson, PhD, pharmaceutical consultant at Spica Consultants, Marlborough, U.K., and colleagues presented data in patients who entered the maintenance phase of a phase 3 trial on a dose of less than 3,000 mg/day of lanthanum and then increased their dose to 3,000 mg/day. 

Hyperphosphatemia occurs in more than 60% of patients with CKD undergoing hemodialysis (HD), Dr. Wilson said. Phosphorus is known to be actively involved in the pathogenesis of vascular calcification, which, in turn, may contribute to cardiovascular disease. Cardiovascular disease is the leading cause of death in CKD patients. 

CKD patients experiencing hyperphosphatemia need to manage their intake of dietary phosphate while maintaining adequate levels of protein intake, which may be problematic, she added. A protein intake of at least 1.2 g/kg/day is recommended, but this may lead to high phosphorus levels.

The investigators hypothesized that increasing the dose of phosphate binders may offset increases in dietary phosphate associated with increased protein intake and therefore may help control phosphorus levels.

The study included adult patients who had stage 5 CKD and required treatment for hyperphosphatemia, defined as a serum phosphorus level greater than 5.5 mg/dL and were on a stable HD regimen three times per week for at least two months before screening.

Of 289 patients who entered the maintenance period, 35 patients who entered on 1,500 or 2,250 mg/day lanthanum carbonate had their dose increased to 3,000 mg/day.

Of the 35 patients, 23 (66%) had better serum phosphorus control on 3,000 mg/day than on lower doses.

On average, these patients had phosphorus levels approximately 0.6 mg/dL lower on 3,000 mg/day of lanthanum compared with doses of 2,250 mg/day or less. “If we can control hyperphosphatemia with a higher dose of lanthanum, we may be better able to achieve the dual goals of phosphorus control and adequate nutritional intake,” Dr. Wilson said.

Side effects with the higher dose were consistent with previous studies of lanthanum and were primarily gastrointestinal. 

Future research should aim to examine nutritional markers and phosphorus control concomitantly in CKD patients. 

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