Design and baseline characteristics of the LANDMARK study

Background Calcium (Ca)-based phosphate (P) binders, compared to non-Ca-based P binders, contribute to vascular calcification, which is associated with cardiovascular events. Methods The LANDMARK study is a multicenter, randomized, open-label, parallel comparative study of lanthanum carbonate (LC) and calcium carbonate (CC) in hemodialysis patients. Stable hemodialysis patients with intact parathyroid hormone ≤240 pg/mL meeting ≥1 of the following criteria (age >65 years, postmenopause, diabetes mellitus) were randomized into the LC and CC groups. LC group patients initially received LC 750 mg/day or the previously used dose and were titrated up to a maximum 2250 mg/day to achieve serum P levels of 3.5–6.0 mg/dL. CC group patients received CC 3 g/day or the previously used dose and were titrated to achieve the same P range. If the target serum P level was not achieved, non-Ca-based P binders (other than LC) could also be added. The primary endpoint is survival time free of cardiovascular events, including cardiovascular death, non-fatal myocardial infarction or stroke, and unstable angina. Results Overall, 2309 patients were allocated to the LC ( N = 1154) or CC group ( N = 1155). At baseline, the mean age was 68.4 years, 40.4 % were women, 55.9 % had diabetes, 18.3 % had a history of ischemic heart disease, and 13.9 % had cerebrovascular disease. A total of 184 patients (8.4 %) had undergone coronary intervention procedures. Baseline characteristics were well balanced between groups. Conclusions The LANDMARK study will determine whether LC, a non-Ca-based P binder, reduces cardiovascular mortality and morbidity in chronic hemodialysis patients.