A randomized, controlled trial of oral intestinal sorbent AST-120 on renal function deterioration in patients with advanced renal dysfunction

Background and objectives The notion that oral intestinal sorbent AST-120 slows renal disease progression has not been evaluated thoroughly. In this study, we investigated the long-term effect of AST-120 on renal disease progression (doubling of serum creatinine, eGFR decrease >50%, or initiation of RRT) in patients with advanced CKD. Design, setting, participants, & measurements We prospectively recruited 579 patients (CKD stage 3 or 4) from 11 medical centers in Korea from March 4, 2009 to August 31, 2010 and randomized them into an AST-120 arm and a control arm. Patients in the AST-120 arm were given 6 g AST-120 in three divided doses per day, and those in the control arm received only standard conventional treatment (open-label design) for 36 months or until the occurrence of primary outcomes. Results Levels of serum and urine indoxyl sulfate and β2-microglobulin decreased throughout the study period in both treatment arms; however, there was not a significant difference in change in uremic toxins in the AST-120 and control arms. The two arms were not different in the occurrence of composite primary outcomes (100 events in 272 individuals in the AST-120 arm and 100 events in 266 individuals in the control arm; hazard ratio, 1.12; 95% confidence interval, 0.85 to 1.48; log-rank P=0.45). The decline in eGFR and change in proteinuria were similar in the two treatment arms over time (P_{randomization–time} =0.64 and P_{randomization–time} =0.16, respectively). There was no difference in mortality (nine deaths in the AST-120 arm and 11 deaths in the control arm; log-rank P=0.73) or unplanned hospitalizations (102 in the AST-120 arm and 109 in the control arm; log-rank P=0.76) in the two treatment arms. There was no significant difference of the health–related quality of life score between the two arms. Conclusions Long-term use of AST-120 added to standard treatment did not change renal disease progression, proteinuria, mortality, and health–related quality of life in patients with advanced renal dysfunction.