Lanthanum carbonate Vs Calcium Carbonate for Hyperphosphatemia: JAMA

Among patients with hyperphosphatemia undergoing dialysis, it is unclear whether non–calcium-based phosphate binders are more effective than calcium-based binders for reducing cardiovascular events. Therefore, Dr Hiroaki Ogata and his team conducted a study to determine whether lanthanum carbonate reduces cardiovascular events compared with calcium carbonate in patients with hyperphosphatemia at risk of vascular calcification undergoing hemodialysis.

The LANDMARK Trial was a pen-label, randomized, parallel-group clinical trial of 2374 patients with chronic kidney disease from 273 hemodialysis facilities in Japan and 1851 patients completed the trial. The researchers randomized the patients to receive either lanthanum carbonate (n = 1154) or calcium carbonate (n = 1155) and titrated to achieve serum phosphate levels of between 3.5 mg/dL and 6.0 mg/dL. The major outcome assessed was a composite cardiovascular event (cardiovascular death, nonfatal myocardial infarction or stroke, unstable angina, transient ischemic attack, or hospitalization for heart failure or ventricular arrhythmia). They also assessed overall survival, secondary hyperparathyroidism-free survival, hip fracture–free survival, and adverse events.

Key findings of the study were:

• After a median follow-up of 3.16 years, the researchers noted that the cardiovascular events occurred in 147 of 1063 patients in the lanthanum calcium group and 134 of 1072 patients in the calcium carbonate group (incidence rate, 4.80 vs 4.30 per 100 person-years; difference 0.50 per 100 person-years; hazard ratio [HR], 1.11).
• However, they found no significant differences in all-cause death (difference, 0.43 per 100 person-years; HR, 1.10) or hip fracture (difference, 0.10 per 100 person-years; HR, 1.21).
• They noted that the lanthanum carbonate group had an increased risk of cardiovascular death (difference, 0.61 per 100 person-years; HR, 1.51 ) and secondary hyperparathyroidism (difference, 1.34; HR, 1.62).
• They reported 282 (25.7%) adverse events in the lanthanum carbonate group and 259 (23.4%) in the calcium carbonate groups.

The authors concluded, "Among patients undergoing hemodialysis with hyperphosphatemia and at least 1 vascular calcification risk factor, treatment of hyperphosphatemia with lanthanum carbonate compared with calcium carbonate did not result in a significant difference in composite cardiovascular events. However, the event rate was low, and the findings may not apply to patients at higher risk."

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DOi: 10.1001/jama.2021.4807