Clinical Study of Rituximab for the Treatment for Idiopathic Membranous Nephropathy with Nephrotic Syndrome

Inclusion Criteria:

1. Patients who undergo kidney biopsy and are diagnosed as having idiopathic membranousnephropathy prior to the obtainment of informed consent

2. Patients who are diagnosed as having nephrotic syndrome prior to the obtainment ofinformed consent and receive no steroids or immunosuppressants within 12 weeks priorto the obtainment of informed consent

3. Patients with urine protein-creatinine ratio ≥ 3.5 g/gCr at the screening

4. Patients with hypoalbuminemia (serum albumin ≤ 3.0 g/dL) at the screening

5. Patients aged 15 years or older at informed consent

6. Patients who give voluntary written consent after having received adequateinformation on this study (legally acceptable representatives should also giveconsent for underage patients, and informed assent should be obtained from children)

Exclusion Criteria:

1. Patients with primary nephrotic syndrome other than membranous nephropathy (IgAnephropathy, minimal change disease, focal segmental glomerulosclerosis and soforth), and patients with secondary nephrotic syndrome (autoimmune disease,metabolic disease, infection, allergic/hypersensitive disease, tumor, anddrug-induced disease)

2. Patients with the renal function lowered (eGFR <30 mL/min/1.73 m2 based on CKD-EPIcrformula) at the screening

3. Patients who have used anti-CD20 antibody including rituximab (geneticalrecombination) prior to the informed consent for idiopathic membranous nephropathy

4. Patients who have participated in another clinical study within 12 weeks prior tothe informed consent (enrollment is allowed for those participating in a clinicalstudy in the range of 'Indications' or 'Dosage and Administration' in Japan) orpatients who are participating in another study

5. Patients with history of renal transplant

6. Patients with poorly controlled diabetes (HbA1c of 8.0% or higher)

7. Patients who have or are suspected to have active infection (infection requiringtreatment with systemic antimicrobial, antifungal, or antiviral agents) at the timeof informed consent

8. Patients tested positive for HBs antigen, HBs antibody, HBc antibody, and/or HCVantibody (patients with positive HBs antibody and/or HBc antibody can be enrolledonly when HBV-DNA test is negative [less than the detection limit]), or patientswith positive HIV antibody or HTLV-1 antibody at the time of the screening

9. Patients with leukopenia (less than 2,000 /mm3), neutropenia (less than 1,000 /mm3),or lymphopenia (less than 500 /mm3) at the time of the screening

10. Patients with history of serious hypersensitivity or anaphylactic reaction to one ofthe ingredients in the investigational drug or murine protein-containing products

11. Patients who are judged to be life-threatening nephrotic syndrome by theinvestigator or a subinvestigator

12. Patients with serious comorbidity (e.g., hepatic, renal (excluding idiopathicmembranous nephropathy with nephrotic syndrome), cardiac, lung, hematologic, orbrain disease)

13. Female patients who are pregnant, lactating, or potentially pregnant, patients whoare not willing to use contraceptive measures during the study period, or femalepatients not willing to use contraceptive measures until 12 months after the lastdose of study drug (except for female patients who are unale to pregnant)

14. Patients who are judged to be unsuitable by the investigator or a subinvestigator