 The primary objective of this study is to characterize the safety and tolerability of multiple doses of chronic SPL therapy compared with placebo in maintenance hemodialysis patients and to assess the feasibility of conducting a full-scale, mortality-powered trial of SPL. The effects of SPL compared with placebo on multiple cardiovascular efficacy parameters will also be analyzed. The primary efficacy parameter will be the change in the E measurement on tissue Doppler echocardiography TDI as an index of diastolic function and a surrogate for myocardial fibrosis. Secondary cardiac parameters of interest that will be studied in the overall population or in sub-studies include heart rate variability, circulating markers of fibrosis, and coronary flow reserve CFR as an index of microvascular function. These parameters are designed to broaden insight into the potential effects of SPL on cardiac structure and function in individuals with dialysis-dependent ESRD and to assess the feasibility of conducting a full-scale, mortality-powered trial. 