Role of AST120 for Sarcopenia Prevention in Pre-dialysis Chronic Kidney Disease

Inclusion Criteria: * Adult older than 19 years * Pre-dialysis chronic kidney disease * Serum creatinine level 2.0-5.0 mg/dL or MDRD or CKD-EPI eGFR 15-60 mL/min/1.73 m² * Serum albumin ≥ 3.0 g/dL * No previous use of oral absorbant during 4 weeks prior to screening * No change of treatment for chronic kidney disease during 4 weeks prior to screening * Written informed consent to participate in this clinical study * Capable of independent physical activity, an assisted device use is acceptable Exclusion Criteria: * Impaired GI peristalsis * Uncontrolled constipation * Prior renal transplant * On immunosuppressant (small dose users may be accepted according to the PI's decision) * GI ulcer or esophageal varix * Uncontrolled hypertension (systolic BP ≥180 mmHg or diastolic BP ≥110 mmHg) * History of admission for an acute cardiovascular incident within 3 months prior to screening * Current acute infection state * Liver function failure (ALT, AST over 2.5 times of normal reference range) * Uncontrolled diabetes patient (HbA1c \>10 % or fasting glucose \>250 mg/dL) * Malignancy (patients of post-remission 5 years without any recurrence can be enrolled, except for squamous cell carcinoma in situ) * Pregnancy, on breastfeeding * Not agreed to medical contraceptive use during participating in the study * Concurrent participation in another clinical trial * Drug or alcohol-dependent * Other clinical trial medication administration more than once within 30 days prior to enrollment * Expected dialysis or kidney transplantation within 3 months prior to enrollment * Dependent physical activity * Musculoskeletal disease that may debilitate functional independence * Lower limb amputee not using a prosthesis * Severe retinal disease (e.g., proliferative diabetic retinopathy, vitreous hemorrhage) * Claudication * Other patients inappropriate to participate by the PI's decision