Study hypotheses are: (1) in patients not requiring dialysis, based on renal response after 3 cycles as the main endpoint, to show a benefit of 30% in absolute rate from an expected 30% response rate in the control arm; and (2) in patients requiring hemodialysis, using the prevalence of patients free of dialysis after 3 cycles as the main endpoint, to show a benefit of at least 20% from an assumed rate of 50% in the control arm. A total sample size of 284 patients was computed to be enrolled (type I and II error rates at 5 and 20%, respectively).