Efficacy and Safety of a Combination of Mycophenolate Mofetil and Corticosteroid in Advanced IgA Nephropathy

Inclusion Criteria 1. Patient aged 19 to 65 years old 2. Diagnosed with IgA nephropathy 3. Confirmed with Proteinuria more than 1.0 g / day at least twice within 6 months from the time of screening 4. If eGFR (by MDRD) is \<50 mL / min / 1.73 m\^2, ≥ 15 mL / min / 1.73 m\^2 5. ACE inhibitor or ARB for at least 3 months 6. Willing and able to provide written informed consent. Exclusion Criteria: 1. If eGFR (by MDRD) is \<15 mL / min / 1.73 m\^2 2. Blood pressure is SBP\> 160 mmHg or DBP\> 100 mmHg 3. Systemic infection or have been diagnosed with cancer within the last 5 years (excluding treatment squamous cell or basal cell carcinoma skin cancer) 4. serious digestive disorder 5. WBC \<3000 / mm\^3 6. Acute (within 4 weeks) or chronic(need to treatments) allergic/hypersensitivity reaction in the history of Investigational drugs 7. Administration of other Investigational drugs within 28days before screening period 8. Administration of Investigator drug or other immunosuppressants within 84days before screening period 9. Women in pregnant or breast-feeding or don't using adequate contraception. 10. Patient has conversation impairment because alcohol or drugs addiction history within 6months or mental illness, etc. 11. In investigator's judgment