A Study to Evaluate the Efficacy and Safety of Obinutuzumab Versus MMF in Participants With Childhood Onset Idiopathic Nephrotic Syndrome

Inclusion Criteria:

• Diagnosis of frequently relapsing nephrotic syndrome (FRNS) or steroid dependentnephrotic syndrome (SDNS) before the age of 18 years

• Must be in complete remission defined by the absence of edema, UPCR <= 0.2 g/g atscreening and have three consecutive daily urine dipstick readings of trace ornegative for protein within the week prior to randomization

• Must have had at least one relapse in the 6 months prior to screening, afterdiscontinuation of or while receiving oral corticosteroids and/or immunosuppressivetherapy to prevent relapses

• Participants having received cyclophosphamide in the 6 months prior to randomizationmust have experienced at least 1 relapse subsequent to cyclophosphamidediscontinuation

• Estimated glomerular filtration rate (eGFR) within normal range for age

• For females of childbearing potential: participants who agree to remain abstinent (refrain from heterosexual intercourse) or use highly effective contraception,during the treatment period and for 18 months after the final dose of obinutuzumaband for 6 weeks after the final dose of MMF

• For males: participants who agree to remain abstinent (refrain from heterosexualintercourse) or use contraceptive methods, and agree to refrain from donating spermduring the treatment period and for 90 days after the final dose of MMF

Exclusion Criteria:

• Secondary nephrotic syndrome

• History of steroid resistant nephrotic syndrome

• History of genetic defects known to directly cause nephrotic syndrome

• Treatment with other immunosuppressive medications to prevent relapse, other thanMMF or oral corticosteroids within 2 months prior to randomization

• Pregnancy or breastfeeding or intending to become pregnant during the study orwithin 18 months after the final dose of obinutuzumab, or within 6 weeks after thefinal dose of MMF

• Females of childbearing potential, including those who have had a tubal ligation,must have a negative serum pregnancy test result within 28 days prior to initiationof study treatment and a negative urine pregnancy test at Day 1, prior torandomization

• History of organ or bone marrow transplant

• Participation in another therapeutic trial within 30 days of enrollment or 5half-lives of the investigational drug

• Intolerance or contraindication to study therapies

• Participants demonstrating prior treatment failure to MMF as defined by two or morerelapses in any 6-month period of time while receiving MMF for at least a 6-monthduration

• Participants in the judgment of the investigator likely to require systemiccorticosteroids for reasons other than idiopathic nephrotic syndrome during thestudy

• Active infection of any kind or any major episode of infection requiringhospitalization or treatment with IV anti-infective medications within 4 weeks priorto screening, or completion of oral anti-infectives within 2 weeks prior torandomization

• History of or currently active primary or secondary immunodeficiency, includingknown history of human immunodeficiency virus (HIV) infection and other severeImmunodeficiency blood disorders

• History of progressive multifocal leukoencephalopathy

• History of or current cancer, including solid tumors, hematological malignancies,and carcinoma in situ within the past 5 years

• Major surgery requiring hospitalization during the 4 weeks prior to screening orduring screening

• High risk for clinically significant bleeding or any condition requiringplasmapheresis, intravenous immunoglobulin, or acute blood product transfusions

• Evidence of any significant or uncontrolled concomitant disease that, in theinvestigator's judgment, would preclude participant's participation, including butnot limited to nervous system, respiratory, cardiac, hepatic, endocrine, malignant,or gastrointestinal disorders

• Currently active alcohol or drug abuse or history of alcohol or drug abuse