Purpose

The primary objectives of this trial are as follows: * to compare the achievement of a partial remission (PR) or complete remission (CR) in urinary protein: creatinine ratio (Up/c ratio) in patients treated with fresolimumab versus placebo * to compare the safety profile of patients treated with fresolimumab versus placebo The secondary objectives are as follows: * To compare the reduction in proteinuria in patients treated with fresolimumab versus placebo * To evaluate fresolimumab dose-dependent reduction in proteinuria * To compare the change in renal function (estimated glomerular filtration rate \[eGFR\]) in patients treated with fresolimumab versus placebo * To evaluate the multiple-dose pharmacokinetics of fresolimumab