Effect of a Carbonaceous Oral Adsorbent on the Progression of CKD: A Multicenter, Randomized, Controlled Trial

Background

The carbonaceous oral adsorbent AST-120 slows the deterioration of kidney function in patients with advanced chronic kidney disease (CKD). However, information about AST-120 in patients with less severe stages of CKD is lacking.

Study Design

Randomized controlled trial.

Setting & Participants

75 medical facilities, 460 patients with CKD with serum creatinine (sCr) concentrations less than 5.0 mg/dL (not undergoing dialysis).

Intervention

Random assignment to either a low-protein diet and antihypertensive medication in the control group or that treatment combined with AST-120 (6 g/d).

Outcomes & Measurements

Composite primary end point: doubling of sCr level, increase in sCr level to 6.0 mg/dL or more, need for dialysis or transplantation, or death. Secondary outcomes: adverse events and changes in estimated creatinine clearance (CCr) rate, proteinuria (protein in milligrams per day), and quality of life.

Results

Mean sCr level was 2.66 mg/dL and estimated CCr was 22.4 mL/min in both groups. During 56 weeks, numbers of primary end-point events (43 for control versus 42 for AST-120) and event-free survival (P = 0.9) did not differ between groups. Gastrointestinal adverse events were less common in the control group than the AST-120 group (2 versus 32 events). Estimated CCr decreased more in the control group than in the AST-120 group (−0.15 versus −0.12 mL/min/y; P = 0.001). Median proteinuria changed from protein of 1,162 to 1,167 mg/d in the control group versus 1,102 to 906 mg/d in the AST-120 group (P = 0.2).

Limitation

Infrequent primary end-point events.

Conclusion

AST-120 did not substantially slow the progression of kidney disease in patients with moderate to severe CKD during 1 year.

Index Words: Randomized controlled trial, carbonaceous oral adsorbent, chronic kidney disease (CKD)